physicsworld.com Volume 25 No 3 March 2012
PHYSICS AND THE EARTH
Our planet in perspective
© 2012 COMSOL. COMSOL and COMSOL Multiphysics are registered trademarks of COMSOL AB. Capture the Concept is a trademark of COMSOL AB. Other product or brand names are trademarks or registered trademarks of their respective holders.
Contact us at 01223 451580
SOLAR ENERGY: These type of collectors utilize solar energy by heating a fl uid fl ow that is then used to generate electricity. Heat is transferred by surface-to-surface radiation from the outside shell to the pipe walls. Shown is the heat fl ux vector and temperature on both surfaces.
Capture the Concept.With COMSOL Multiphysics ® you are empowered to build simulations that accurately replicate the important characteris-tics of your designs. The key is the ability to include all physical effects that exist in the real world. This multiphysics approach delivers results —tangible results that save precious develop-ment time and spark innovation.
comsol.com /bookletcomsol.co
Capture the Concept.Capture the Concept.Capture the Concept.Capture the Concept.Capture the Concept.Capture the Concept.Capture the Concept.Capture the Concept.
Quanta 3
Frontiers 4New supercontinents model ● Distilling water using nanofilters ● Arachnid designs
News & Analysis 7US pulls out of ExoMars ● Russia announces Phobos-Grunt 2 ● Brazil opens theoretical-physics centre ● First Kavli centre for Japan ● Robert Hazen: carbon pioneer ● Fracking comes under the microscope
Comment 17Our planet in perspective
Forum 19Lessons from Fukushima Mike Weightman
Critical Point 23Measuring the Earth Robert P Crease
Feedback 25Your views on presidential science pledges, plus comments from physicsworld.com
Physics and the EarthIn perspective 30A feast of spectacular images of our planet from afar
A pressing matter 37Deep inside the Earth, our planet’s core is one of the most unusual and extremeplaces in the entire solar system. And as David Appell finds out, it could even containgiant crystals up to 10 km long
Eyeing the Earth with neutrinos 44Fleeting and elusive they may be, but “geoneutrinos” generated through the radioactive decay of nuclei inside the Earth could revolutionize our understanding of what lies beneath, as Gianpaolo Bellini and Livia Ludhova explain
When north heads south 51The Earth’s magnetic field has flipped many times, but is the reversal spontaneous or caused by some external trigger? François Pétrélis, Jean-Pierre Valet and Jean Bessethink the answer may lie with the distribution of the Earth’s continents
How to forecast an earthquake 58While it seems unlikely that we will ever be able to predict precisely when, where and with what strength an earthquake will occur, progress is being made in the idea of “probabilistic” forecasting, as Edwin Cartlidge explains
Reviews 64The time of our lives ● Physics not for poets ● Web life: Earth Exploration Toolbook
Graduate Careers 71Finding jobs in hard times Simon Perks ● All the latest graduate vacancies and courses
Recruitment 76
Lateral Thoughts 88Baking, speed limits and circuits John Swanson
Spot on – creating the “ideal foam” 5
Physics World is published monthly as 12 issues per annualvolume by IOP Publishing Ltd, Temple Circus, Temple Way, Bristol BS1 6BE, UK
United States Postal Identification Statement
Physics World (ISSN 0953-8585) is published monthly by IOP Publishing Ltd, Temple Circus, Temple Way, Bristol BS1 6BE,UK. Air freight and mailing in the USA by Publications Expediting,Inc., 200 Meacham Ave, Elmont NY 11003. Periodicals postageat Jamaica NY 11431.US Postmaster: send address changes to Physics World,American Institute of Physics, Suite 1NO1, 2 Huntington Quadrangle, Melville, NY 11747-4502
On the cover
Physics and the Earth: our planet inperspective 30–63 (ESA)
Potato-shaped – Earth’s gravity map 30–35
ESA/
HPF
/DLR
physicsworld.com Contents: March 2012
1Physics World March 2012
Rugg
ero
Gab
brie
lli
Untitled-2 1 17/01/2012 11:21
By the end of my second term, we will have the first permanent base on the MoonUS Republican presidential candidateNewt Gingrich speaking at a campaign rally in FloridaGingrich says he wants Americans to “think boldlyabout the future” and for the country to have thecapacity in space that the “Chinese and Russianswill never come anywhere close to matching”.
We already have a word for those whoclamour to send Americans back tothe Moon: lunaticsRobert Park from the University of Maryland in hisWhat’s New bulletinPark says that Gingrich’s plans are not only veryexpensive, but also “insane”.
We live in a world where it’s quite allright to be proudly ignorant of Faradayor EinsteinCERN director-general Rolf-Dieter Heuer speakingat the World Economic Forum in Davos, SwitzerlandHeuer says science faces a challenge to reverse “a trend in society towards scientific apathy, andeven antagonism”.
I would hate it to come down to a shootoutThomas Ludlam, chair of the physics departmentat the Brookhaven National Laboratory, New York,quoted in ScienceLudlam was commenting on budget difficulties atthe US Department of Energy, which may have tochoose between continuing to run the RelativisticHeavy Ion Collider at Brookhaven or building the$615m Facility for Rare Isotope Beams atMichigan State University.
Particle physics? I don’t think so. The whole place was a front for snowboardersComedian Ben Miller writing in Eureka!Miller says that the Large Hadron Collider at CERNis really just a smokescreen for physicists wantingto get some time on Alpine slopes.
Nobody had cut the weeds. It lookedso sadJill Tarter, an astronomer at the SETI Institute in Mountain View, California, quoted in the New York TimesTarter was commenting after astronomers returnedto the Hat Creek Observatory in California, whichreopened thanks to private donations pluggingbudget cuts at the University of California, Berkeley.
For the record
Quanta
Nuclear gnashersCleaning up a redundant nuclear plant isusually a very serious business. But workersdecommissioning the Dounreay site innorthern Scotland could be in for a surpriseafter news emerged that deep inside theplant’s iconic sphere lies half a set of falseteeth. According to the February issue ofDounreay News, the dentures belonged to acolleague of retired engineer Don Ryan,who worked on the site from 1961 until1994. Speaking as part of an oral-historyproject recording the memories of workersat the site, Ryan revealed that the colleague“just happened to be leaning on rails besidethe instrument panels, facing outwardstowards the spherical steel ‘wall’ ” when hesneezed “quite energetically”. Half a set offalse teeth then disappeared from view“under the influence of gravity and theinternal sphere slope” before the choppers“rattled down to the never-visited bottom-sphere skirt”. Ryan adds that the colleagueeven tried claiming for his gnashers, but theUK Atomic Energy Authority, which thenran the site, “rebuffed [this] in firm administrative terms”.
Bet you can’t win?Are you looking to make a cool $100 000? Ifso, Scott Aaronson has a challenge for you.The mathematical physicist at theMassachusetts Institute of Technology isoffering this princely sum to anyone whocan convince him that scalable quantumcomputers are impossible. This might seemlike easy money – after all, physicists havestruggled for years to build even the mostprimitive quantum processors, and scalingthese up to make a working quantumcomputer seems a tall order. But Aaronsonis not talking about hardware – instead, hewants you to disprove the underlying quantum physics that would make aquantum computer tick. “This is a bet onthe validity of quantum mechanics as it’scurrently understood,” he explains.Aaronson is confident he can raise themoney and he even thinks it would be wellspent, because disproving some or all or
quantum mechanics would lead to a revolution in physics. As Physics World wentto press, Aaronson had not yet received anyserious entries but, with no time limit on thechallenge, it’s time to start thinking.
Meteoric wine“Earthy”, “floral”, “oaky”. Wine tasters areknown for their rich vocabulary whendescribing different wines but now they canadd “hints of meteorite” to theirrepertoire. That is because UK astronomerIan Hutcheon has released a wine that isaged with a lump of 4.5-billion-year-oldmeteorite. Dubbed Meteorito, the extraterrestrial wine was created atHutcheon’s Tremonte Vineyard in Chileusing Cabernet Sauvignon grapes picked inApril 2010. These underwent “malolacticfermentation” for 12 months in a woodenbarrel containing the meteorite, beforebeing blended with other batches. Thethree-inch meteorite apparently belongs toa US collector and is believed to havecrashed into the Atacama Desert in northern Chile around 6000 years ago.About 10 000 litres of the meteor-agedwine have been made but if you want to getyour hands on a splash, then you will needto make a trip to the Centro AstronomicoTagua in Chile – an observatory Hutcheonestablished in 2007.
Fringe sciencePhysicists in the UK havetaken the whole concept of“fringe science” to a newlevel by studying that
hairstyle of choice for men and women of acertain disposition – the ponytail. RaymondGoldstein of the University of Cambridge,Robin Ball of the University of Warwickand Patrick Warren from shampoo-makerUnilever claim that the shape of a ponytailis defined by a competition between gravity,the elasticity of individual hairs and theirmutual interactions (Phys. Rev. Lett. 108078101). And because a ponytail cancontain as many as 100 000 hairs, theproblem is best addressed using statisticalphysics. The researchers derived an “equation of state” for a ponytail thatincludes what they dub a “Rapunzelnumber” – a dimensionless measure ofponytail length. The equation was thenused to predict how the shape of a ponytailvaries with length, with a real ponytailrequiring an additional term that reflectshair getting frizzier as it grows longer. Whyanyone would want a ponytail in the firstplace, however, remains unanswered.
Seen and heard
physicsworld.com
3Physics World March 2012
iSto
ckph
oto/
Dar
renM
ower
Nuc
lear
Dec
omm
issi
onin
g Au
thor
ity
Geophysicists in the US have developed amodel that may have finally solved the riddleof how supercontinents form. The modelsuggests that each new supercontinentassembles a quarter of the way around theglobe from the centre of the previous super-continent. Projecting their model into thefuture, it indicates that the next supercon-tinent – “Amasia” – will form as a merger ofthe Americas and Asia via the Arctic Ocean.
The collision of continents into one hugelandmass – and their subsequent driftingapart – is thought to have occurred severaltimes during the Earth’s history, in a cycle of300–500 million years. Rifting and driftingoccurs at subduction zones – areas on theplanet where two tectonic plates movetowards one another and one slides under theother. The last supercontinent, Pangaea,began to disintegrate about 200 million yearsago and two competing hypotheses have pre-viously tried to explain how a new supercon-tinent would form.
The first says that the continents will con-
tinue to drift apart as they do today, with theAtlantic Ocean continuing to widen – even-tually bringing together North America andAsia. In this “extroversion model”, the newsupercontinent would be situated on theopposite side of the globe to its predecessor.The second idea is that the continents atsome point do a U-turn and drift backtowards their starting position. This “intro-version model” relies on new subductionzones opening up that would allow theAtlantic oceanic crust to sink back beneaththe continents, closing off the Atlantic Oceanand forming a new supercontinent in thesame location as Pangaea.
However, as neither of these models suc-cessfully explains all of the features of previ-ous supercontinent transitions, geophysicistsat Yale University, led by Ross Mitchell, havenow developed a different model that theysay provides a better fit for past data. In their“orthoversion model”, after a supercon-tinent breaks up, the continents initially driftapart but become trapped within a north–south band of subduction – a relic of the pre-vious supercontinent. The new supercon-tinent forms in this band, one-quarter of theway around the Earth or at 90° from the cen-tre of its predecessor.
To test their model, the researchers usedpaleomagnetic data – records of the Earth’smagnetic field preserved in rocks – to studyvariations in the rotation of the planet withrespect to its spin axis. Their analysis revealsan angle of 87° between Pangaea and its pre-decessor Rodinia, and an angle of 88° be-tween Rodinia and its predecessor Nuna.From this, the researchers inferred that thenew model best describes supercontinenttransitions (Nature 482 208).
Researchers at Manchester University in theUK, led by Nobel-prize-winner Andre Geim,have made an ultrathin membrane fromgraphene oxide that appears to be highlypermeable to water while being imperme-able to all other liquids and gases. Grapheneoxide is like ordinary graphene, which wasco-discovered by Geim in 2004, but is cov-ered with molecules, such as hydroxylgroups. Each membrane consists of millionsof small flakes of graphene oxide stacked ontop of each other, with nanometre-sized cap-illaries between the flakes.
Geim and colleagues found that waterpasses through the graphene-oxide mem-brane extremely fast, while all other gases
and liquids are completely blocked by it.According to the team, water is able to flowthrough the capillaries with minimal friction.Indeed, the water diffuses though thegraphene-oxide sheets so quickly that it is asif it were passing through air.
The researchers say the membranes areimpermeable to other substances becausethe graphene-oxide sheets are arranged suchthat there is only room for one layer of watermolecules. So when water passes through thecapillaries, it blocks them and does not allowany other substance to go through. And ifthere is no water, the capillaries shrink anddo not let any other substances through. Thenew property could lead to much more effi-cient water filters or a way of removing waterfrom a mixture or container while retainingall the other ingredients (Science 334 422).
Cool sun could host habitable planetAn international team of scientists has discovereda potentially habitable super-Earth orbiting withinthe habitable zone of a cool star that is a memberof a triple-star system located about 22 light-yearsaway. This is the fourth exoplanet found within thehabitable zone of a star – the first was found lastMay – and its discovery demonstrates thathabitable planets could form in more variedenvironments than previously thought. The newplanet receives 90% of the light that the Earthreceives but because the light is infrared, a higherpercentage of this energy must be absorbed by theplanet. The researchers believe that the planetabsorbs about the same amount of energy from itsstar as the Earth absorbs from the Sun, meaningthat the surface temperature is similar to that onEarth, which in turn suggests that liquid watercould exist on the planet’s surface. However,further information about the planet will be neededto confirm this hypothesis.
Frequency comb reaches extreme ultravioletPhysicists in the US have created an opticalfrequency comb that, for the first time, operates inthe extreme ultraviolet (XUV). The comb, whichcould be used to look for tiny variations in the fine-structure constant, consists of a train of laserpulses with peaks that are evenly paced infrequency, like the teeth on a comb. It was createdusing a high-power laser to make an intenseinfrared comb within an optical cavity. The cavitywas then filled with xenon gas, which gets ionizedby the laser, liberating electrons that areaccelerated and emit pulses of XUV light. Thesepulses bounce back and forth in the cavity tocreate XUV combs in the 40–120 nm wavelengthrange. The team used the comb to study specificatomic transitions in argon and neon atwavelengths of 82 and 63 nm, respectively.
Heating cools a semiconductorLaser cooling has been used on a solid film ofsemiconductor for the first time, reducing its temperature to a chilly 4 K. In the study,researchers from Denmark reduced the vibrationsof a thin-film semiconductor membrane placed inan optical cavity so that it captures light betweentwo reflectors. The semiconductor absorbs thephotons, exciting them to electrons that then fallback to a lower energy before releasing that energyas heat. This changes the length of the cavity,which in turn cools the semiconductor. The teamsuggests that with future developments, the semiconductor’s temperature could be chilled further so that its vibrations are reduced almost tothe quantum ground state in at least one direction.
How supercontinents are born
Filters of the future
In brief
Read these articles in full and sign up for freee-mail news alerts at physicsworld.com
Merged Amasia: the next supercontinent.
R M
itche
ll et
al.,
Nat
ure
Frontiersphysicsworld.com
4 Physics World March 2012
Every seasoned flyer knows better than to carry alarge bottle of shampoo, perfume or evenchampagne in their hand luggage. But all thatmight change, thanks to researchers in the UK whohave developed a scanner that can be used at airports to screen liquids in opaque or translucentbottles. The device could allow the ban on liquidsof more than 100 ml in hand luggage to be lifted asearly as 2013.
The scanner uses a technology known asspatially offset Raman spectroscopy (SORS),which was invented and developed byPavel Matousek and collaborators at theRutherford Appleton Laboratory in the UK in 2004.A variation on conventional Raman technology, itprovides a chemical analysis deep within a sampleand can be used to scan everything from bonebeneath skin and drugs in plastic packages to liquids in opaque bottles. The new scanner isknown as the INSIGHT100 and was developed byCobalt Light Systems – a company founded byMatousek in 2006 to exploit the SORS technique.
Conventional Raman spectroscopy relies on theinelastic backscattering of photons as lightinteracts with matter. Normally, the scattered photons are detected from the same spot on thesample that has been illuminated. The problem isthat Raman signals from surface layers tend todominate those signals from within the sample.
To get around this issue, the researchers collectphotons from a spot a few millimetres away fromthe illuminated area – a “spatially offset” spot. Thisworks because photons migrate from theilluminated spot and travel through the body of thesample. Thus, SORS delivers a smaller surface signal and a sharper signal from deeper within thesample, while always being non-invasive.
The current ban on liquids of more than 100 mlin hand luggage can only be lifted when airportsare able to screen liquids quickly and without opening containers. While X-ray scanners currently do that job, they produce high false-alarm rates, which slow the screening process.Cobalt claims that the false-alarm rate with theINSIGHT100 is considerably lower, at 1% or less,and that the scanner can screen individual bottlesin less than 5 s and also provide a high chemicalspecificity with all types of containers in a varietyof sizes. The scanner has already passed the stringent testing procedure necessary to allow it tobe trialled and is now being used at anundisclosed number of major European airports.Matousek points out that the scanner is to be usedin parallel with X-ray scanners as it “complementsthe existing technology”.
Raman technique peersinto cabin baggage
The foam in this image might have been made using everyday Fairy Liquid detergent, but it is also the firstever example of a “Weaire–Phelan foam”, which physicists believe is the lowest energy structure for a foamformed of equal-volume bubbles. The first theoretical concept for an “ideal foam” of equal-sized bubbles wasdeveloped by Lord Kelvin back in 1887 and was considered to be the ideal until 1994, when Trinity CollegeDublin physicist Denis Weaire and his student Robert Phelan identified from computer simulations that afoam at an even lower energy should exist. The Weaire–Phelan foam is a complex 3D structure of two kinds of equal-volume polyhedral bubbles, and is 0.3% lower in energy than the Kelvin foam. Making one provedtricky, however, until Ruggero Gabbrielli from the University of Trento in Italy realized that the problem lay withthe shape of the containers used, and so designed a receptacle with walls of an intricate form that encourageand accommodate the Weaire–Phelan bubbles. The foam is created by placing the special template in a simple solution of water and Fairy Liquid, with bubbles introduced by releasing nitrogen gas from a glass capillary. The resulting foam was backlit and photographed using a digital SLR camera. The samples thatwere produced comprised up to 1500 bubbles (Phil. Mag. Lett. 10.1080/09500839.2011.645898).
Innovation
The incredible robustness of spider webs,which lets them survive even the fiercest ofstorms, is down to a feature of the silk thatlocalizes damage to small sections of the web.That is the finding of researchers based in theUS and Italy, who claim that this property ofspider silk could help civil engineers to devisemore robust structures.
Spider silk is known to have a greater ten-sile strength than high-grade steel. But pre-vious studies have not explained how spiderwebs can remain relatively intact after beingsubjected to extreme loading such as hurri-cane-strength winds. A team led by MarkusBuehler from the Massachusetts Institute ofTechnology now says it has an answer aftercombining modelling with experiment torelate the nanoscale properties of spider silkto the large-scale integrity of spider webs.
A spider’s silk is made from basic proteins,
including some that form thin, planar crys-tals called beta sheets. When stress is appliedto a strand of this silk, the sheets slide acrosseach other, until the silk eventually ruptures.To examine this process of structural failure,Buehler’s team developed an atomic-scalesimulation of silk from the Nephila clavipes –a species of golden orb-web spider native tothe warmer regions of the Americas. Itrevealed that when the spider silk is sub-jected to an applied load, its stiffness variesin a nonlinear fashion. Under light stresses,the silk responds fairly uniformly by soften-ing and spreading the load across the entireweb. But at high stresses, the materialbecomes stiffer near the applied load butremains soft elsewhere in the web.
When the failure point is eventuallyreached, the stiff silk ruptures, but only in theregion where the load was applied. In thisway, the web is effectively sacrificing only asmall section, which can then be repaired bythe spider (Nature 482 72).
Why spider webs endure
Getting to the froth of the matter
Rugg
ero
Gab
brie
lliphysicsworld.com Frontiers
5Physics World March 2012
*Conditions apply. See tda.gov.uk/conditions for full details.
The future of a joint US and Euro-pean mission to Mars is uncertainafter NASA told the European SpaceAgency (ESA) that it is pulling out ofthe 7850m ExoMars venture. The USwithdrawal comes following the USpresident’s budget request, releasedlast month, which sees NASA’s $1.5bnplanetary-science budget slashed by21%, with Mars exploration receiving$360m – a 39% cut from 2012 levels.ESA is now in discussion with theRussian space agency Roscosmosabout ExoMars’s future.
ExoMars, which is supposed tolaunch in 2018, consists of two parts.The idea is to launch a Trace GasOrbiter in 2016 to orbit Mars and mapthe red planet for sources of methaneand other gases. Two years later, anExoMars rover, weighing almost300 kg, would be launched to searchfor possible signs of life on Mars, char-acterize the water and geochemicaldistribution of the surface, and iden-tify any hazards for future mannedmissions to the planet.
While NASA’s overall 2013 budgetis similar to 2012 – roughly $17.7bn –the agency still needs to pay for itsflagship James Webb Space Telescope(JWST) mission, the costs of whichare expected to balloon from $476.8m
in 2011 to $659m in 2014. It is this hikethat has resulted in the need for cutselsewhere in the programme and thecancelling of NASA’s involvement in ExoMars. NASA administratorCharles Bolden said in a statementthat the agency would instead“develop an integrated strategy toensure that the next steps for Marsexploration will support science aswell as human-exploration goals, andpotentially take advantage of the2018–2020 exploration window”.
The president’s budget request still
has to pass through Congress, whichis unlikely to be easy in an electionyear. However, regardless of whatbudget emerges, severe cutbacks willhave to be made. “Having just beeninvolved in a near-death experiencefor the JWST, I am very sympatheticto the feelings of my scientist col-leagues who are dealing with the can-cellation of a key Mars mission,” saysastronomer Garth Illingworth, who ischair of the JSWT advisory commit-tee. “I am particularly concerned thatthese cuts are affecting our interna-tional partners significantly.”
Meanwhile, a report by theNational Research Council recom-mends the US makes a £20m contrib-ution to ESA’s Euclid dark-energymission. Euclid, to be launched in2019, will map the large-scale distrib-ution of dark matter and characterizethe properties of dark energy. Thecommittee says that the US shouldstill go ahead with building the Wide-Field Infrared Survey Telescope, to belaunched in 2020, which would searchfor dark energy as well as search forexoplanets. “NASA involvement inEuclid is, I hope, a start to renewedinternational collaborations,” addsIllingworth.Michael Banks
News & Analysis
Mars mission in doubt as US pulls out
Down and out
Budget constraintsmean that NASA will pull out of the7850m ExoMarsmission, which wasset to launch its firststage in 2016.
ESA
physicsworld.com
7Physics World March 2012
Russia has announced it may launch a
second mission to Mars’s moon Phobos
after its original Phobos-Grunt mission
ended in disaster in January when
scientists lost contact with the craft and
it crashed back down to Earth. Lev
Zelenyi, director of the Institute of Space
Research at the Russian Academy of
Sciences, which was behind the Phobos-
Grunt mission, told a press conference in
Moscow that a new spacecraft, named
provisionally as Phobos-Grunt 2, could be
launched in 2018.
The timing of the new mission is
designed to take advantage of a launch
window when Mars will be particularly
close to the Earth. Such windows occur
roughly every 26 months, but the next
window in 2013 does not leave enough
time to prepare for the new mission, while
the 2016 window coincides with Russia’s
planned lunar projects.
Zelenyi says the new mission will be a
pared-down version of Phobos-Grunt,
retaining the control systems from the
original design but with less
instrumentation and simpler rovers for
exploring the surface of Phobos. However,
he cautions that the plans for the new
mission are still in the very early stages.
“Nothing has been decided yet,” he told
Physics World. Indeed, Roscosmos, the
Russian federal space agency, has been
in discussions with the European Space
Agency (ESA) since late last year about
participating in the ExoMars mission –
another mission to the red planet that is
set for 2016 (see above). “If no deal is
reached [with ESA], we will repeat the
attempt [to launch a Phobos mission],”
says Roscosmos boss Vladimir Popovkin.
Meanwhile, following intense
speculation about why Phobos-Grunt
failed, an official report has concluded
that a computer malfunction, possibly
caused by a burst of cosmic radiation or
defective microchips, was to blame.
Phobos-Grunt’s failure also affected
China, which had its own Yinghuo-1
orbiter aboard the craft. Wu Ji, director-
general of the National Space Science
Centre of the Chinese Academy of
Sciences, told China Daily last month that
the country has had to rethink its plans
for Mars exploration, with a new mission
in 2016 at the earliest.
Simon Perks
Plans unveiled to reincarnate Phobos-GruntRussia
Second time lucky?
Russia may launch asuccessor to thefailed Phobos-Gruntmission to Mars’moon Phobos.
Rosc
osm
os
The Indian government has black-listed four top space scientists foralleged “procedural lapses” whennegotiating a $250m deal for the leas-ing of two communications satellitesto an Indian private company. Thefour scientists include G MadhavanNair, former head of the Indian SpaceResearch Organization (ISRO), whoguided ISRO in launching the coun-try’s first mission to the Moon in 2008.The others are K R Sridhara Murthi,former head of the Antrix Corpora-tion in Bangalore, K N Shankara, for-mer head of the ISRO Satellite Centrein Bangalore, and A Bhaskarana-rayana, former director of ISRO’ssatellite-communications program-mes. All four, who have been bannedfor life from holding any governmentpositions, deny any wrongdoing.
The controversy dates back to 2005when Antrix – ISRO’s commercialarm – signed a deal with Bangalore-based Devas Multimedia PrivateLimited to build two high-poweredcommunications satellites that woulddeliver India with multimedia andinformation services, even to those inremote areas. On 17 February 2011,however, the government cancelled
the contract citing “increased stra-tegic needs”. It then appointed twointernal investigation committees –the first led by B K Chaturvedi, a for-mer cabinet secretary, and the next byPratyush Sinha, a former CentralVigilance Commissioner – to lookinto the situation. In a statement onISRO’s website, Sinha’s report says“We conclude that there have beennot only serious administrative andprocedural lapses, but also suggestionof collusive behaviour on the part ofcertain individuals.”
Nair claims he did nothing wrong
and that no rules of government wereviolated, but the key sticking point isthat he and others apparently did notinform the government in writing thatISRO was manufacturing and leasingcommunications transponders to aprivate company and that the spec-trum was sold too cheaply. To date,neither ISRO nor Devas Multimediahas been accused by the governmentof any wrongdoing.
Nair claims that the scientists havebeen subjected to “a witch hunt”. Henow wants Indian prime ministerManmohan Singh to put a hold onimplementing the ban. “The condem-nation and tarnishing of the images ofthese scientists is beyond all compre-hension and against the principles ofnatural justice,” Nair wrote in a letterto Singh. “The four scientists havegiven their sweat and blood to thecountry…they virtually gave theMoon to the country.” Nair adds thatno formal enquiry has been conductedand the four have not been “given anychance to present or defend the case”.The matter is now being heard inIndia’s Supreme Court.Pallava Bagla
New Delhi
Blacklisted former space boss protests at ‘witch hunt’India
Lunar pioneer
G Madhavan Nair, former head of theIndian SpaceResearchOrganization, guidedthe agency in launching thecountry’s first missionto the Moon.
Palla
va B
agla
physicsworld.comNews & Analysis
8 Physics World March 2012
A new centre for theoretical physics has
opened in Brazil that aims to become one
of the leading research institutes in South
America. The centre – named after the
renowned International Centre for
Theoretical Physics (ICTP) in Trieste, Italy
– will be located at Universidade Estadual
Paulista (UNESP) in Sao Paulo. Known as
the ICTP South American Institute for
Fundamental Research (ICTP-SAIFR), the
new centre was officially opened on
6 February in a ceremony attended by the
president of the Brazilian Academy of
Science, Jacob Palis, as well as
Peter Goddard, director of Institute for
Advanced Study, Princeton, US.
The ICTP-SAIFR has been created in a
collaboration between the ICTP, UNESP
and the Sao Paulo Research Funding
Agency. Its activities are modelled on
those of the ICTP and will begin with the
centre holding international schools and
workshops. Among the first events will be
a workshop on gravity and string theory in
May and a school on astrophysics and
cosmology in July.
Initially, there will be five permanent
researchers as well as a director, who is
the Brazilian physicist Nathan Berkovits.
The centre expects to support about a
dozen postdoc positions per year as well
as playing host to a number of
international visitors and students. With a
budget of about $1m per year, the
institute will also have an active visitors’
programme. “We very much hope that this
will be only the beginning of a great new
project that will increase the scientific
level of the region and that will play a
major role in international scientific
collaboration,” Fernando Quevedo,
director of the ICTP in Trieste, told
Physics World. “I have the highest hopes
[for this institute].”
Berkovits says that the idea for the
institute emerged eight years ago but
accelerated once Quevedo became
director of the ICTP in 2009. “The ICTP
was crucial for the creation of this
institute,” says Berkovits. “It is, of
course, exciting and a great challenge to
start this new institute.” The opening of
the new centre is part of a five-year plan
to expand the ICTP into other countries,
especially in the developing world.
“Brazil, India and China are playing a
more relevant role worldwide,” says
Quevedo. “The scientific level of Brazil is
very high and a centre located there can
therefore play the same role for South
America that the ICTP has already been
playing worldwide.”
Michael Banks
South America
Theoretical-physics hub opens in BrazilA meeting of minds
Physicists includingICTP directorFernando Quevedo,fourth from right, atthe opening of theICTP South AmericanInstitute forFundamentalResearch inSao Paolo.
The future of one of Japan’s leadingcosmological-research centres ap-pears safe after it was awarded a mas-sive $7.5m cash boost from theUS-based Kavli Foundation. TheInstitute for the Physics and Math-ematics of the Universe, which isbased at the University of Tokyo,becomes the first centre in Japan to besupported by the foundation. Thereare now a total of 16 Kavli institutesaround the world, including 10 in theUS, three in Europe and two in China.
Set up in 2007, the centre will nowbe known as the Kavli Institute for thePhysics and Mathematics of theUniverse (Kavli IPMU). It seeks totackle some of the biggest questionsin physics, such as the origin, evolu-tion and fate of the universe, as wellas the nature of dark matter and darkenergy. The work is carried out on aninterdisciplinary basis by more than200 researchers, including theoreticaland experimental physicists, math-ematicians and astronomers.
The new money is a vital boost forthe institute, which was set up as partof a Japanese initiative to attract sci-entists from abroad to work in thecountry. A total of five institutes werefounded under the country’s World
Premier International (WPI) pro-gramme, each of which was promised$10m a year for a decade and told torecruit 30% of its researchers fromoverseas. However, in early 2010 theJapanese government cut the WPI’sbudget by 22%, raising questionmarks about the IPMU’s long-termfuture. Plans for two new WPI insti-tutes were then axed, leaving theIPMU with a smaller, but still prob-lematic, 3.6% budget cut.
Hitoshi Murayama, director of theIPMU, says that the support from theKavli Foundation will now help theinstitute to keep going even when theWPI funding runs out. “The return
[from the endowment] is nowhereclose to the current funding level, butit is a start,” he told Physics World.Murayama is confident that the Kavlicash will also bring “prestige andinternational visibility [that] shouldhelp the institute to attract and recruitmore scientists”. Murayama himselfwas lured back to Japan to run theIPMU after almost 15 years in the USat the University of California,Berkeley. Currently, some 56% of theIPMU’s staff are non-Japanese.
The Kavli Foundation, based inCalifornia, was set up in 2000 by theNorwegian-born physicist and phil-anthropist Fred Kavli. It sponsorsresearch in astrophysics, nanoscience,neuroscience and theoretical physics.It also awards three prestigious $1mprizes each year as well as fundingworkshops, symposia, Kavli profes-sorships and a programme for sciencejournalists. “I hope that our supportof science in Japan can demonstratethat the quest for knowledge has noboundaries, and that finding theanswers to some of science’s biggestand most fundamental questionsrequires international collaboration,”says Kavli.Matin Durrani
Cosmology centre secures long-term futureJapan
A promising future
The five-floor mainbuilding of the KavliInstitute for thePhysics andMathematics of theUniverse in Tokyo wascompleted in 2009.
physicsworld.com News & Analysis
9Physics World March 2012
Kavl
i IP
MU
The University of Manchester in theUK has been invited to be the solebidder for a new £45m GrapheneInstitute, which would be housed onthe university’s campus. Around£38m of the funding will be providedby the UK’s Engineering and PhysicalSciences Research Council, whichsays that the institute’s main aim willbe to “lead the commercialization ofgraphene through the developmentof applications, building on thestrength of UK research in this field”.The rest of the cash is expected tocome from the university and alsofrom private investment.
Manchester physicist Andre Geim,who shared the 2010 Nobel Prize forPhysics with his colleague KonstantinNovoselov for their work ongraphene, says that it is the right timefor the UK to invest in this areabecause countries such as Singapore
and South Korea are already doing so.However, Geim has mixed feelingsabout the new institute and its benttowards commercialization. “Mystrength has always been in curiosity-driven research, [and] this fundingpushes me hard in the direction of the commercialization of graphene
research,” Geim told Physics World. “Iwas not really looking forward to thisnew funding. I consider it not as afavour by [the government] but as anextra burden I was asked to carry.”
A University of Manchesterspokesperson says that even at thisearly stage various companies areshowing an interest in workingtogether with the institute’s re-searchers to commercialize graphene,including Samsung, which already hasa strong graphene-research pro-gramme. Details are scarce aboutwhat the new building will look like orwhen it will open. However, the 40 orso researchers who currently work atthe university on graphene areexpected to transfer to the new facil-ity, with more scientists then beinghired once the institute is open at adate yet to be fixed.Kulvinder Singh Chadha
Manchester set to bid for new Graphene InstituteResearch
Blessing or burden?
Nobel laureateAndre Geim hasmixed views about anew institute to commercializegraphene.
Jam
es K
ing-
Hol
mes
/Sci
ence
Pho
to L
ibra
ry
physicsworld.comNews & Analysis
10 Physics World March 2012
A bipartisan bill introduced in the USHouse of Representatives aims toreverse 2008 legislation that requiresrecipients of National Institutes ofHealth (NIH) grants to make copiesof their peer-reviewed papers freelyavailable online. Introduced inDecember and sponsored by Cali-fornia Republican Darrell Issa andNew York Democrat CarolynMaloney, the New Research WorksAct could limit public access to pri-vately published research, includingthat funded by the government.
The current legislation means thatNIH-funded scientists have to placetheir papers in the National Library ofMedicine’s repository, which is free toaccess for the public. Supporters ofthe new bill, which would scrap thatrequirement, include the Associationof American Publishers (AAP),whose members includes several pub-lishers of scholarly journals. Theyargue that the bill is necessary becausethe process of peer-reviewing andpublishing research involves signifi-cant financial outlay. “America’s pro-fessional and scholarly publishers aremaking more research available tomore people through more channelsthan ever before in our history,” the
association noted in a statement.“The Research Works Act ensures thesustainability of this industry.”
However, the bill only has a rela-tively small chance of passage this year.Indeed, some of the AAP’s academicmembers, including the University ofCalifornia Press, have come out inopposition. The American Institute ofPhysics (AIP) – an umbrella group forphysical-science societies – and theAmerican Physical Society (APS),both of which publish peer-reviewedjournals, have also stated their oppo-sition to the new act. “The proposedlegislation is counterproductive to cur-rent efforts and not needed at thistime,” said the AIP in a statement.
“We always allow authors to publishour version of their papers on theirand their institutions’ websites with-out embargo,” Gene Sprouse, theAPS’s editor-in-chief, told PhysicsWorld. “We have 500 libraries signedup to our library initiative, whichmakes the complete contents of ourjournals from 1893 to today availableto anyone who visits the libraries phys-ically. And starting last year we havemade our articles freely available inhigh schools.”
Meanwhile, as Physics World wentto press, more than 6000 researchershad signed a petition pledging not topublish in Elsevier’s journals or to actas a referee or editor for the pub-lisher. They say that peer review is car-ried out by voluntary, unpaidacademics and that the publicationsserve largely to line the pockets of thepublishing company. In response tothe boycott, initiated by University ofCambridge mathematician TimothyGowers, Elsevier declared that it was“proud of the way we have been ableto work in partnership with the re-search community to make real andsustainable contributions to science”.Peter Gwynne
Boston, MA
US bill seeks to overturn NIH research-archiving rulePublishing
Change of course
A US bill aims toreverse current legislation that NIH-funded scientistshave to place theirresearch in theNational Library ofMedicine’srepository, which isfree to access for the public.
Wik
imed
ia C
omm
ons
At first glance it may look more like afancy paint job but a new car roofdesigned by researchers at Philips andchemical giant BASF has the unusualproperty of giving drivers and passen-gers a clear view by day before turninginto an interior light at night. The roofcontains 129 glass hexagons contain-ing organic light-emitting diodes(OLEDs) that are transparent duringthe day but can generate light when itis dark. The OLEDs are shown herein the roof of a prototype electricDaimler Smart Car.
OLEDs are light-emitting diodes(LEDs) in which the luminescentlayer is a film of organic compoundsthat emits light in response to an elec-tric current. Unlike LEDs, they canemit light from their entire surfacearea – which creates “softer” lightthan LEDs. They are already used inrigid form in some display screens andalso in interior design, such as in
glass table tops.BASF remains tight-lipped about
its OLED material, except to say thatit has developed dyes and other“organo-chemical” materials that are“used in the development and manu-facturing of OLEDs by Philips”. TheOLEDs are built into glass panes that
also contain embedded solar cells,which generate electricity during theday and then store that energy in thecar’s lithium-ion batteries. Thisenergy is used to power the OLEDs toilluminate the car’s interior at night.
It is not certain when the technol-ogy might be ready for commercialproduction and neither BASF norPhilips has said how efficient theseOLEDs are. While regular LEDs turnonly about 20% of supplied electric-ity into light (the same as a conven-tional incandescent light bulb), firmsdeveloping OLEDs – especially forelectronic gadgets – are still trying toreduce power consumption. Forexample, Osram – a subsidiary ofSiemens – last month claimed to havedeveloped a bendable plastic OLEDribbon that yields 32 lumens per watt(lm/W), which compares with just 10–20 lm/W for a halogen bulb.Mark Halper
Industry
Philips and BASF put a new spin on the car roof
Clear view
Organic light-emittingdiodes make this carroof be transparentby day but light up at night.
BAS
F
The US’s failure to get to grips withthe long-term storage of nuclearwaste has been “damaging andcostly”, according to the final reportby the Blue Ribbon Commission onAmerica’s Nuclear Future. The com-mission’s report contains several rec-ommendations, including the needfor any future repository to firstobtain local consent for any wastefacilities. It also says an independentorganization should be set up solelydedicated to overseeing the US’snuclear-waste management.
The work of the commission, whichconsisted of politicians, scientists andengineers, gained particular rele-vance last year when US PresidentBarack Obama halted work on theplanned repository in YuccaMountain, Nevada. First mooted inthe 1980s, the repository was to havestored the US’s spent nuclear fuel andhigh-level radioactive waste.
While the state of Nevada has nowvetoed a repository, other statesmight accept one. “There has beenlocal support in Carlsbad, NewMexico, which already hosts theWaste Isolation Pilot Plant,” sayscommission member Ernest Moniz,
director of the MassachusettsInstitute of Technology EnergyInitiative. “There is no physical rea-son why a new repository has to cometomorrow or the day after, but whatwe need fairly urgently is to adopt theoverall strategy that the commissionhas put forward.”
US energy secretary Steven Chu,who set up the commission, welcomedthe report as “a critical step towardfinding a sustainable approach to dis-posing of used nuclear fuel andnuclear waste”. At the request ofCongress, Chu’s department will nowwithin the next six months develop astrategy for handling spent nuclearfuel and other waste.Peter Gwynne
Boston, MA
US urged to develop new strategy for nuclear wasteNuclear waste
Nobel trio back US neutrino facilityA group of 43 theoretical physicists in theUS – including the Nobel laureatesSheldon Glashow, Steven Weinberg andFrank Wilczek – have expressed support fora key component of the proposed $1.3bnLong Baseline Neutrino Experiment (LBNE).The experiment would involve sending anintense beam of neutrinos that are createdat Fermilab to a large detector deep insideSouth Dakota’s Homestake mine, lyingsome 1300 km away. In a letter sent to theUS Department of Energy (DOE), the theorists praised the “high discovery potential” of such an undergrounddetector, noting it could be used to studysymmetry violation in neutrinos, to searchfor proton decays and to perform sensitivestudies of neutrinos emitted in supernovaexplosions. The signatories say that thefacility’s flexibility means it is “urgentlyneeded” even in a time of budgetconstraints. The support is likely to boostthe LBNE’s chances of passing a fundingreview later this summer, when DOEofficials are expected to decide whether the project will go ahead.
CERN ramps up collision energyCERN has announced that it will increasethe energy of proton–proton collisions atthe Large Hadron Collider (LHC) from 7 TeVto 8 TeV per beam. The move to a higherenergy later this year should help make itclearer whether the Higgs boson has beenfound with a mass of about 125 GeV, aswas suggested in December 2011.Meanwhile, Ximo Poveda of the ATLASexperiment delivered a talk at CERN lastmonth on the latest search for supersymmetry (SUSY). Many physicistshope the LHC will confirm SUSY’s centralprediction that for each of the StandardModel particles there exists a heavier “sparticle” sibling. Poveda reported on thesearch for several supersymmetric partnersof various quarks and leptons – squarksand sleptons – called the stop, stau andsbottom. However, so far ATLAS has seen“nothing beyond the Standard Model”.
UK physics numbers jump by 8.3%Applications to study physics at UK universities have shot up by around 8.3%,according to figures from the Universitiesand Colleges Admissions Service. This year24 934 students have applied to do aphysics course in the UK – up by 2000 onlast year’s figures. The boost for physics isin stark contrast to the overall 8.7%decline in university applicants across theUK, which is thought to be caused bytuition fees rising to a maximum of £9000per year for students studying in England.
Sidebands
Waste woes
Work on developingYucca Mountain intoa long-term repositoryfor nuclear waste wasscrapped last year byUS PresidentBarack Obama.
Japan has announced it is to launch a
second asteroid sample-return mission
following the success of the Hayabusa
craft, which in 2010 returned the first
samples ever obtained from the surface
of an asteroid. The Space Activities
Commission, which governs funding for
the Japanese space programme, formally
approved the Hayabusa-2 mission in late
January. The Japanese firm NEC, which
built parts of the original Hayabusa
mission, has also announced that it has
started designing the communications
system and an infrared camera for the
Hayabusa-2 craft.
Weighing almost 600 kg and costing
around $200m, Hayabusa-2 will land on
1999 JU3 – an almost spherical asteroid
that is 920 m in diameter and is thought
to contain organic matter and hydrated
minerals. Hayabusa-2 will attempt to find
out where such organic matter and water
originated from and how they are related
to life and ocean water on Earth.
The Japanese Space Agency, JAXA,
plans to launch the craft in 2014 when
the asteroid’s path will be closest to
Earth, eventually reaching the body by the
middle of 2018. The craft will then land
on the asteroid and stay there for around
18 months to retrieve samples before
beginning its return to Earth at the end
of 2019.
While the original Hayabusa mission
only scraped the surface of the asteroid
it landed on, Hayabusa-2 will instead
release a 2 kg impactor before touching
down. The impactor will hit the asteroid’s
surface and make a small crater several
metres in diameter. Hayabusa-2 will then
land in the crater and collect samples
from within the asteroid.
Michael Banks
Space
Japan plans successor to asteroid mission
Dep
artm
ent
of E
nerg
y
physicsworld.com News & Analysis
11Physics World March 2012
New and improved
Hayabusa-2 willfollow in the footstepsof Hayabusa-1(pictured), which in2010 successfullyretrieved the firstsamples ever fromthe surface of anasteroid.
JAXA
METALS & ALLOYS for Research / Development & IndustrySmall Quantities • Competitive Prices • Fast Shipment
57-70
*
89-102
**
*Lanthanoids
**Actinoids
Periodic Table of the Elements
1
2
3 4 5 6 7 8 9 10 11 12
13 14 15 16 17
18
1.00790.090-252.87
Hydrogen
H1
6.9410.54180.5
Lithium
Li39.01221.851287
Beryllium
Be4
22.9900.9797.7
Sodium
Na1124.3051.74650
Magnesium
Mg12
39.0980.8663.4
Potassium
K1940.0781.55842
Calcium
Ca20
85.4681.5339.3
Rubidium
Rb3787.622.63777
Strontium
Sr38
132.911.8828.4
Caesium
Cs55137.333.51727
Barium
Ba56
[223]––
Francium
Fr87[226]5.0700
Radium
Ra88
138.916.146920
Lanthanum
La57140.126.689795
Cerium
Ce58140.916.64935
Praseodymium
Pr59144.246.801024
Neodymium
Nd60[145]7.2641100
Promethium
Pm61150.367.3531072
Samarium
Sm62151.965.244826
Europium
Eu63157.257.9011312
Gadolinium
Gd64158.938.2191356
Terbium
Tb65162.508.5511407
Dysprosium
Dy66164.938.7951461
Holmium
Ho67167.269.0661497
Erbium
Er68168.939.3211545
Thulium
Tm69173.046.57824
Ytterbium
Yb70
[227]10.071050
Actinium
Ac89232.0411.721842
Thorium
Th90231.0415.371568
Protactinium
Pa91238.0319.051132
Uranium
U92[237]20.45637
Neptunium
Np93[244]19.816639
Plutonium
Pu94[243]–
1176
Americium
Am95[247]13.511340
Curium
Cm96[247]14.78986
Berkelium
Bk97[251]15.1900
Californium
Cf98[252]–860
Einsteinium
Es99[257]–
1527
Fermium
Fm100[258]–827
Mendelevium
Md101[259]–827
Nobelium
No102
44.9562.991541
Scandium
Sc2147.8674.511668
Titanium
Ti2250.9426.111910
Vanadium
V2351.9967.141907
Chromium
Cr2454.9387.471246
Manganese
Mn2555.8457.871538
Iron
Fe2658.9338.901495
Cobalt
Co2758.6938.911455
Nickel
Ni2863.5468.921084.6
Copper
Cu2965.397.14419.5
Zinc
Zn3069.7235.9029.8
Gallium
Ga3172.645.32938.3
Germanium
Ge3274.9225.73816.9
Arsenic
As3378.964.82221
Selenium
Se3479.9043.12-7.3
Bromine
Br3583.803.733-153.22
Krypton
Kr36
10.8112.462076
Boron
B512.0112.273900
Carbon
C614.0071.251-195.79
Nitrogen
N715.9991.429-182.95
Oxygen
O818.9981.696-188.12
Fluorine
F920.1800.900-246.08
Neon
Ne10
26.9822.70660.3
Aluminium
Al1328.0862.331414
Silicon
Si1430.9741.8244.2
Phosphorus
P1532.0651.96115.2
Sulphur
S1635.4533.214-34.04
Chlorine
Cl1739.9481.784-185.85
Argon
Ar18
4.00260.177-268.93
Helium
He2
88.9064.471526
Yttrium
Y3991.2246.511855
Zirconium
Zr4092.9068.572477
Niobium
Nb4195.9410.282623
Molybdenum
Mo42[98]11.52157
Technetium
Tc43101.0712.372334
Ruthenium
Ru44102.9112.451964
Rhodium
Rh45106.4212.021554.9
Palladium
Pd46107.8710.49961.8
Silver
Ag47112.418.65321.1
Cadmium
Cd48114.827.31156.6
Indium
In49118.717.31231.9
Tin
Sn50121.766.70630.6
Antimony
Sb51127.606.24449.5
Tellurium
Te52126.904.94113.7
Iodine
I53131.295.887-108.05
Xenon
Xe54
174.979.841652
Lutetium
Lu71178.4913.312233
Hafnium
Hf72180.9516.653017
Tantalum
Ta73183.8419.253422
Tungsten
W74186.2121.023186
Rhenium
Re75190.2322.613033
Osmium
Os76192.2222.652466
Iridium
Ir77195.0821.091768.3
Platinum
Pt78196.9719.301064.2
Gold
Au79200.5913.55-38.83
Mercury
Hg80204.3811.85304
Thallium
Tl81207.211.34327.5
Lead
Pb82208.989.78271.3
Bismuth
Bi83[209]9.20254
Polonium
Po84[210]–302
Astatine
At85[222]9.73-61.85
Radon
Rn86
[262]–
1627
Lawrencium
Lr103[265]––
Rutherfordiu
m104
[268]––
Dubnium
Db105[271]––
Seaborgium
Sg106[272]––
Bohrium
Bh107[270]––
Hassium
Hs108[276]––
Meitnerium
Mt109[281]––
Darmstadtium
Ds110[280]––
Roentgenium
Rg111[285]––
Copernicium
Cn112[289]––
Ununquadium
Uuq114
Solids�& Liquids (g/cm3)�Gases(g/l)
€
Melting�point�(Solids�&�Liquids)�•�Boiling�point�(Gases)
€
Standard Catalogue Items
Element Name
SymbolAtomic�weight
DensityM.pt./B.pt.(˚C)
AtomicNo.
advent-rm.com� � � � � � � � �
ADVENT
[284]––
Ununtrium
Uut113[288]––
Ununpentium
Uup115[293]––
Ununhexium
Uuh116
Tel + 44 1865 884440Fax + 44 1865 [email protected]
RESEARCH MATERIALS
[–]––
Ununseptium
Uus117[294]––
Ununoctium
Uuo118
*Lanthanoids
**Actinoids
––
5.0700
138.916.146920
Lanthanum
La57140.126.689795
Cerium
Ce58140.916.64935
Praseodymium
Pr59144.246.801024
Neodymium
Nd60[145]7.2641100
Promethium
Pm61150.367.3531072
Samarium
Sm62151.965.244826
Europium
Eu63157.257.9011312
Gadolinium
Gd64158.938.2191356
Terbium
Tb65162.508.5511407
Dysprosium
Dy162.50
Dy162.50
66164.938.7951461
Holmium
Ho67167.269.0661497
Erbium
Er68168.939.3211545
Thulium
Tm69173.046.57824
Ytterbium
Yb70
[227]10.071050
Actinium
Ac89232.0411.721842
Thorium
Th90231.0415.371568
Protactinium
Pa91238.0319.051132
Uranium
U92[237]20.45637
Neptunium
Np[237]Np
[237]
93[244]19.816639
Plutonium
Pu94[243]–
1176
Americium
Am95[247]13.511340
Curium
Cm96[247]14.78986
Berkelium
Bk97[251]15.1900
Californium
Cf98[252]–860
Einsteinium
Es99[257]–
1527
Fermium
Fm100[258]–827
Mendelevium
Md101[259]–827
Nobelium
No102
–1627
––
––
––
––
––
––
––
––
––
––
––
––
––
––
85595�P�T�A5�2010��14/07/2010��14:14��Page�1
Advent�Research�Materials�Ltd�•�Oxford�•�England�OX29�4JA
METALS & ALLOYS for Research / Development & IndustrySmall Quantities • Competitive Prices • Fast Shipment
57-70
*
89-102
**
*Lanthanoids
**Actinoids
Periodic Table of the Elements
1
2
3 4 5 6 7 8 9 10 11 12
13 14 15 16 17
18
1.00790.090
-252.87
Hydrogen
H1
6.9410.54180.5
Lithium
Li39.01221.851287
Beryllium
Be4
22.9900.9797.7
Sodium
Na1124.3051.74650
Magnesium
Mg12
39.0980.8663.4
Potassium
K1940.0781.55842
Calcium
Ca20
85.4681.5339.3
Rubidium
Rb3787.622.63777
Strontium
Sr38
132.911.8828.4
Caesium
Cs55137.333.51727
Barium
Ba56
[223]––
Francium
Fr87[226]5.0700
Radium
Ra88
138.916.146920
Lanthanum
La57140.126.689795
Cerium
Ce58140.916.64935
Praseodymium
Pr59144.246.801024
Neodymium
Nd60[145]7.2641100
Promethium
Pm61150.367.3531072
Samarium
Sm62151.965.244826
Europium
Eu63157.257.9011312
Gadolinium
Gd64158.938.2191356
Terbium
Tb65162.508.5511407
Dysprosium
Dy66164.938.7951461
Holmium
Ho67167.269.0661497
Erbium
Er68168.939.3211545
Thulium
Tm69173.046.57824
Ytterbium
Yb70
[227]10.071050
Actinium
Ac89232.0411.721842
Thorium
Th90231.0415.371568
Protactinium
Pa91238.0319.051132
Uranium
U92[237]20.45637
Neptunium
Np93[244]
19.816639
Plutonium
Pu94[243]
–1176
Americium
Am95[247]13.511340
Curium
Cm96[247]14.78986
Berkelium
Bk97[251]15.1900
Californium
Cf98[252]
–860
Einsteinium
Es99[257]
–1527
Fermium
Fm100[258]
–827
Mendelevium
Md101[259]
–827
Nobelium
No102
44.9562.991541
Scandium
Sc2147.8674.511668
Titanium
Ti2250.9426.111910
Vanadium
V2351.9967.141907
Chromium
Cr2454.9387.471246
Manganese
Mn2555.8457.871538
Iron
Fe2658.9338.901495
Cobalt
Co2758.6938.911455
Nickel
Ni2863.5468.92
1084.6
Copper
Cu2965.397.14419.5
Zinc
Zn3069.7235.9029.8
Gallium
Ga3172.645.32938.3
Germanium
Ge3274.9225.73816.9
Arsenic
As3378.964.82221
Selenium
Se3479.904
3.12-7.3
Bromine
Br3583.803.733
-153.22
Krypton
Kr36
10.8112.462076
Boron
B512.0112.273900
Carbon
C614.0071.251
-195.79
Nitrogen
N715.9991.429
-182.95
Oxygen
O818.9981.696
-188.12
Fluorine
F920.1800.900
-246.08
Neon
Ne10
26.9822.70660.3
Aluminium
Al1328.0862.331414
Silicon
Si1430.9741.8244.2
Phosphorus
P1532.0651.96115.2
Sulphur
S1635.4533.214-34.04
Chlorine
Cl1739.9481.784
-185.85
Argon
Ar18
4.00260.177
-268.93
Helium
He2
88.9064.471526
Yttrium
Y3991.2246.511855
Zirconium
Zr4092.9068.572477
Niobium
Nb4195.9410.282623
Molybdenum
Mo42[98]11.52157
Technetium
Tc43101.0712.372334
Ruthenium
Ru44102.9112.451964
Rhodium
Rh45106.4212.021554.9
Palladium
Pd46107.8710.49961.8
Silver
Ag47112.418.65321.1
Cadmium
Cd48114.827.31156.6
Indium
In49118.717.31231.9
Tin
Sn50121.766.70630.6
Antimony
Sb51127.606.24449.5
Tellurium
Te52126.904.94113.7
Iodine
I53131.295.887
-108.05
Xenon
Xe54
174.979.841652
Lutetium
Lu71178.4913.312233
Hafnium
Hf72180.9516.653017
Tantalum
Ta73183.8419.253422
Tungsten
W74186.2121.023186
Rhenium
Re75190.2322.613033
Osmium
Os76192.2222.652466
Iridium
Ir77195.0821.091768.3
Platinum
Pt78196.9719.301064.2
Gold
Au79200.5913.55-38.83
Mercury
Hg80204.3811.85304
Thallium
Tl81207.211.34327.5
Lead
Pb82208.989.78271.3
Bismuth
Bi83[209]9.20254
Polonium
Po84[210]
–302
Astatine
At85[222]9.73
-61.85
Radon
Rn86
[262]–
1627
Lawrencium
Lr103[265]
––
Rutherfordium
Rf104[268]
––
Dubnium
Db105[271]
––
Seaborgium
Sg106[272]
––
Bohrium
Bh107[270]
––
Hassium
Hs108[276]
––
Meitnerium
Mt109[281]
––
Darmstadtium
Ds110[280]
––
Roentgenium
Rg111[285]
––
Copernicium
Cn112[289]
––
Ununquadium
Uuq114
Solids�& Liquids (g/cm3)�Gases(g/l)
€
Melting�point�(Solids�&�Liquids)�•�Boiling�point�(Gases)
€
Standard Catalogue Items
Element Name
SymbolAtomic�weight
DensityM.pt./B.pt.(˚C)
AtomicNo.
advent-rm.comAdvent�Research�Materials�Ltd�•�Oxford�•�England�OX29�4JA
ADVENT
[284]––
Ununtrium
Uut113[288]
––
Ununpentium
Uup115[293]
––
Ununhexium
Uuh116
2010
Dat
a�pr
ovid
ed�b
y�ki
nd�p
erm
issi
on�o
f�ww
w.w
ebel
emen
ts.c
om
Tel + 44 1865 884440Fax + 44 1865 [email protected]
RESEARCH MATERIALS
[–]––
Ununseptium
Uus117[294]
––
Ununoctium
Uuo118
�83442�P�T�A5�2010��23/04/2010��12:29��Page�1
System integration and competence in vacuum technology complement themselves with piezo technology and nanopositioning: As part of the PI group, PI miCos creates new solutions for precision positioning. In this way, an extended product portfolio and a tighter international sales network are created.
A common goal: Enthusiastic customers.
Physik Instrumente (PI) GmbH & Co. KGAuf der Römerstr. 1 · 76228 KarlsruheTel. +49 (721) 4846-0 · Fax +49 (721) [email protected] · www.pi.ws
PI miCos GmbHFreiburger Str. 30 · 79427 Eschbach Tel. +49 (7634) 5057-0 · Fax +49 (7634) [email protected] · www.pimicos.com
A big playerI N T H E W O R L D O F T H E V E R Y S M A L L
W W W. P I M I C O S . C O M
pi_120082_PI_MICOS_193x125_en.indd 1 16.02.12 09:06
News & Analysisphysicsworld.com
13Physics World March 2012
So what is the Deep Carbon Observatory?
The Deep Carbon Observatory(DCO) is a 10-year international pro-gramme, which began in 2009, with theobject of achieving a transformationalunderstanding of carbon – that is, itsbiological, chemical and physical rolein the Earth, from crust to core. TheDCO is co-ordinated from the Car-negie Institution in Washington, DC,where I am based, consisting of about1000 researchers in 40 countries.
How did you get funding from the Alfred
Sloan Foundation for this programme?
The Alfred Sloan Foundation is aphilanthropic, not-for-profit institu-tion. It had just finished the census formarine life, attempting to classify allocean life, and so was looking for anew 10-year project. One of its pro-gramme officers heard me talk aboutthe origins of life at a conference andasked me about the possibility ofSloan sponsoring a study looking intowhether life originated deep withinthe Earth rather than at its surface.
So you went ahead with that suggestion?
I thought that topic alone was too nar-row to support a large effort, althoughit is a very important question. How-ever, I thought about doing a study ofhow carbon operates within ourplanet. I wrote a proposal that wasaccepted by an external committee setup by the Alfred Sloan Foundation.
How much funding will the DCO receive
from the foundation?
Our approach is that researcherscome to us with ideas and then wehelp to set up collaborations to tacklethe issues. There is no set amount, butwe expect to fund research to the tuneof about $5m per year. We do not seeourselves as a $50m research agencybut rather as using Sloan funds toleverage much bigger things. In orderto get going fast, we initially providedseed funding for 30–40 projects withabout 200 researchers. The nextaspect is to get researchers to thinkabout setting up much bigger andlonger-term research programmes.
Why carbon?
Carbon is an astonishing element.Because it has the widest range ofbonding environments, it forms mat-erials with the most extreme range ofproperties, from the hardest – dia-mond – to the softest – graphite.Carbon forms biological materials, soit is the molecule of life. As we know,it also has tremendous implicationsfor the environment. And yet we donot even have a clear idea how muchcarbon there is in the Earth.
Why is it called the “Deep” Carbon
Observatory?
We wanted to make it clear that weare not looking at climate issues,ocean carbon or carbon sequestra-tion. We are studying carbon from afew metres under the ground to thou-sands of kilometres inside the Earth.The carbon cycle has been intenselystudied over the last few decades butthe part of the cycle that lies beneaththe surface has been largely ignored.
What are some issues you are tackling?
A fundamental part of the carboncycle is tied up with volcanoes.Subduction in the Earth’s tectonic
plates takes carbon down into themantle and it is very easy to calculatehow much is going down. It is alsoeasy to monitor the amount of carboncoming out via volcanoes. However,there is a vast imbalance between thetwo, with the carbon emitted fromvolcanoes being only around 5% ofthat being subducted. So within a fewhundred million years, all of theEarth’s surface carbon would disap-pear and there would be no carbon forlife. One very important issue thatneeds answering is whether carbondiffuses out slowly and steadilythrough the crust or whether theremay be periods when lots of carbon isreleased more rapidly.
How will you look for the origins of life?
Another question we are looking at isthe nature of deep hydrocarbons. Weknow that most petroleum comesfrom the processing of dead biologi-cal matter, but there are suggestionsof deep reserves of methane or hydro-carbons that may not be entirely bio-logical in nature but formed by otherprocesses. This idea was first pro-posed 150 years ago by Dmitri Men-deleev, creator of the first version ofthe periodic table. It may not be valid,but we need to do experiments to findout whether this is case. That thenleads to the origin of life. Where didthe first “abiological” molecules comefrom to form the first living cells? Westill do not know the mechanisms thatformed these biological molecules.
Will the DCO have a role in the climate-
change debate?
When you study this subject from afundamental viewpoint, it has prac-tical implications for bigger ques-tions such as climate change, carbonsequestration and fracking. The kindof discoveries we hope to make willinform some of those questions. Wedon’t want to get directly involved inthose debates, but rather provide theground truth that people can thenuse to form policy.
What do you hope to achieve after the
10 years are up?
We have a number of very ambitiousgoals. One is to provide real-timetracking of every active volcano onthe planet, including its emissions andseismology. We also want a carry out aglobal census of so-called deep fluids– fluids that lie hundreds of metresbelow the Earth’s surface – as well asa census of deep microbial life to discover the 3D distribution andnature of microbial life within theEarth’s crust.
Asking the big
questions
The 10-year DeepCarbon Observatoryprogramme, led byRobert Hazen, willattempt to fullyunderstand how theEarth uses carbon.
We do not evenhave a clearidea how muchcarbon there isin the Earth
A new 10-year project funded by the Alfred Sloan Foundation aims tounderstand how carbon interacts deep within the Earth, and may evenanswer how life started out. Michael Banks talks to Robert Hazen, director of the Deep Carbon Observatory
Q&A
Understanding the element of life
Evan
Can
trel
l
Physics World March 2012
News & Analysis physicsworld.com
14
Hydraulic fracturing, or “fracking”, isby any measure controversial. Theprocess – which involves pumpingsand and liquid into deep shaledeposits to liberate natural gas – hasbeen touted by its proponents as anenergy saviour. For them, frackingallows energy companies to tap intoreserves that are otherwise difficult, ifnot impossible, to get gas from. Yetthe process has been slammed byopponents as being hugely damagingto the environment.
While fracking has taken off rapidlyin the US, it has been banned inFrance and Bulgaria. Unfortunately,this polarized debate about frackingis not helped by a shortage of facts.No-one is sure to what extent frackingcan contaminate groundwater, eitherwith methane or with toxic chemicals.There is also a concern that frackingcan trigger moderate earthquakes.While there may be no hard-and-fastanswers, it seems that geophysics maybe able to prod the debate in a constructive direction.
Without geophysics, of course,fracking would not be possible at all.Shale is a fine, clay-based sedimentaryrock that has low permeability, so itwill not release its gas into a well eas-ily. To get at the gas, therefore, energycompanies have to display their engi-neering prowess by drilling wells1500–3000m deep into a shale depositand then running a perforated steelpipe horizontally. Millions of litres ofwater are pumped into the pipe,together with sand and chemicals, athigh pressure. The mixture bursts outof the holes in the pipe, creating frac-tures in the shale around it. Over time,natural gas, which is primarilymethane, can then flow from the shaleinto the pipe and back to the surface,where it can be extracted.
Fracking in this modern form –which can use hundreds of thousandsof litres of fluid per well – began inTexas in the mid-1990s, although itonly really took off in 2007 when otherUS states such as Arkansas, Louisianaand Pennsylvania also became sitesfor drilling. The reason for this strongUS interest is that some parts of thecountry appear to be sitting on mas-sive shale-gas reserves – roughly
2.4 trillion m3, according to the USGeological Survey, which is one of themore modest estimates. Colorado-based business-information companyHIS, for example, puts the figure atabout 42 trillion m3.
The US is not, though, the onlynation with large deposits. UK energyfirm Cuadrilla Resources estimatesaround 5.6 trillion m3 of shale-gasreserves in the UK. Hardly surprising,then, that a report last year from theInternational Energy Agency sug-gested the world might be en route to“a golden age of gas”.
Halting the gold rushIn his State of the Union address inJanuary, US President Barack Obamaembraced shale gas, saying that USreserves could last “nearly 100 years”.Obama called for governments todevelop a roadmap for responsibleshale-gas production and said hisadministration would move forwardwith “common sense” new rules tomake sure drillers protect the public.“America will develop this resourcewithout putting the health and safetyof our citizens at risk,” he said.
Environmental campaigners, how-ever, are not letting this route gounobstructed. One problem they high-
light is the suspected contaminationof groundwater around drilling sites.Last year, ecologist Robert Jacksonand colleagues at Duke University inNorth Carolina published evidencethat aquifers in north-east Penn-sylvania and upstate New York hadbeen contaminated with methane,which can be explosive in high con-centrations (Proc. Natl Acad. Sci. USA108 8172). That risk had already beenhighlighted the year before in the do-cumentary film Gasland, directed bythe US environmental campaignerJosh Fox, which pictured families inDimock, Pennsylvania, igniting theirtap water, allegedly thanks to methanecontamination as a result of nearbygas drilling.
A more serious potential problemis contamination with fracking chem-icals, which include “surfactants” –short-chain organic molecules thatlower the surface tension of a liquid orthe interfacial tension between twoliquids or a liquid and a solid – as wellas chemical compounds that act asfriction reducers. Most of these arethought to be relatively benign, butsome may be toxic. Indeed, the precisefracking mixture is often kept secretby the energy companies involved.
While it is unlikely that such liquidscould seep up from fracture zones toground level, there is the possibilitythat they could contaminate watersources via surface spills or poor dis-posal. There is no peer-reviewed evi-dence of this, but a 1987 report by the US Environmental ProtectionAgency, which was brought to lightonly last year by the New York Times,revealed at least one documentedinstance of fracking-fluid contami-nation of drinking water. It occurredin 1984 in Jackson County, WestVirginia, albeit at a time when therewas poorer technology and fewer environmental safeguards.
Anthony Gorody, a consultant atUniversal Geoscience Consulting inHouston, Texas, believes such reportsof contamination are based on poorscience, and that the issues havebecome less scientific and more polit-ical. “In my experience, I have neitherfound nor seen any evidence to sup-port the contention that hydraulicfracturing is responsible for contami-nating shallow groundwater,” he says.
But if the issues are mostly political,then both sides might be to blame.“It’s a cavalier and frankly idiotic atti-tude that’s causing [energy] compa-nies all these problems,” says SteveCohen, an expert in environmentalpolicy at Columbia University in NewYork. “They’re acting as if it’s the gold
Settling the fracking questionEnergy firms have not convinced sceptics that shale-gas extraction, or“fracking”, is safe for the environment. Jon Cartwright examines whether physics could help
Heading
underground
The InternationalEnergy Agencysuggests the worldmight be en route to“a golden age of gas”thanks to theemergence ofhydraulic fracturing,or “fracking” – a rigfor which is picturedhere in Colorado.
iSto
ckph
oto.
com
/jon
mul
len
Physics World March 2012
News & Analysisphysicsworld.com
15
rush – let’s just get out there and startdigging. And that sort of attitudebreeds mistrust.”
Shaky groundGeophysics, and specifically seismol-ogy – the study of earthquakes – maybe one way to help matters. In fact,seismology has long been used by oiland gas companies as a means to “see” underground. Typically, surfacesources of seismic energy, such asdynamite, are used to create minorearthquakes. Then seismologists canmeasure the subsequent seismic wavesto map underground geology and frac-tures in three dimensions, just as radaris used to map overground terrain.
New techniques in seismology aremaking this type of mapping bothmore adaptable and more precise,which may make fracking safer.Rather than using explosions to createearthquakes, seismologists can nowmonitor the tiny man-made earth-quakes, or microseisms, that occurduring the fracking process, as rocksfracture and move around. The energyreleased in these microseisms is rela-tively small – think of dropping a bagof sugar from a three storey house –but using arrays of “geophones” inadjacent wells, seismologists can justabout detect them. This could allowengineers to observe the fracking inreal time to see how it is progressingand stop if anything looks suspect.“The industry is getting close to usingsuch data to modify fracture propaga-tion rates in real time,” says Gorody.“Quite a feat, but not possible yet.”
Another nascent technique in seis-mology avoids the need for man-made earthquakes altogether. Knownas seismic interferometry, it reliesmerely on the background noise ofseismic waves that is ever present inthe Earth’s crust to map the geologyunderground. “If you go into a darkroom, you need a torch to see some-thing,” says Peter Styles, a geophysi-cist at Keele University in the UK.“But when there’s already sunlight,you don’t need the torch.”
Last year, seismologist BrianBaptie of the British GeologicalSurvey and colleagues showed thatseismic interferometry could be usedpick out major geological features inthe Scottish Highlands, such as sedi-mentary basins and centres of igneousand metamorphic rock – therebydemonstrating some potential of thetechnique (Proc. Geol. Assoc. 123 74).Styles believes studies like this showthat seismic interferometry andmicroseismic mapping could help sci-entists assess where the safest places
are to frack in the first place.Earthquakes are one of the greatest
concerns about fracking. In April andMay last year, for example, two frack-ing-related quakes of magnitude 2.3and 1.4 hit Lancashire in the UK.Those magnitudes were not especiallyhigh – magnitude-3.1 quakes resultingfrom coal mining had hit the region inthe past – but they were strong enoughfor protestors to mobilize against thedrilling and persuade the energy com-pany performing the fracking, Cuad-rilla Resources, to stop operations.
According to Styles, these earth-quakes probably occurred becausethe fracking was done on pre-existingfaults. Gaining a more precise knowl-edge of the underlying geology couldreveal these faults beforehand, hesays, encouraging energy companiesto frack elsewhere. Nonetheless, hestresses that “It’s important to realizethat without very small earthquakes,we would have no idea what was goingon underground when we are carryingout things like fracking.”
Climate concerns?The potential for any earthquakescaused by fracking may worry somepeople, but they might find solace ina recent unpublished analysis thatshows it could be possible to predictthe size of earthquakes caused byfracking (although not the timing orlikelihood of their occurring). Bystudying previous cases of quakes trig-gered by fluid injection into theground, geophysicist Arthur McGarrof the University of the Witwaters-rand in Johannesburg, South Africa,found that there is a relationshipbetween the magnitude of a quakeand the amount of water injected.Double the volume of water, he con-cludes, and the maximum magnitudequake rises by about 0.4 on theRichter scale.
So could geophysics help scientistsbetter understand the risks of con-tamination of groundwater by frack-
ing? It may be too soon to tell.However, ecologist Bob Howarth ofCornell University in New Yorkthinks it might be a good time forphysicists to begin investigating arelated issue: the amount of methaneleaked into the atmosphere fromfracking sites and gas pipes. Methaneis a more potent greenhouse gas thancarbon dioxide, so it is important toknow exactly how much is lost. “Theway to [estimate leaked methane] isusing modern atmospheric tech-niques,” Howarth says. “I think youcould come up with a pretty good esti-mate of what the flux might be.”
According to Howarth, physicistscould both help to design measure-ment techniques to calculate the fluxfrom the fracking process and useatmospheric techniques such as “eddycorrelation”, which uses measure-ments of methane and wind velocityto figure out how much methane findsits way into the upper atmosphere.Indeed, Howarth has reason to thinkthis is an important issue: last monthresearchers at the US NationalOceanic and Atmospheric Adminis-tration and the University of Colo-rado, Boulder, estimated thatnatural-gas companies in the Denver–Julesburg Basin, which is centred oneastern Colorado, were losing around4% of their gas to the atmosphere.
Indeed, Howarth’s research sug-gests that, over a 20-year time period,the greenhouse-gas footprint – thetotal amount of emissions from frack-ing – of shale gas is worse than that ofcoal or oil, although other studieshave suggested it has a smaller foot-print. In any case, he says, the scienceis unresolved, and depends on howmuch methane finds its way into theatmosphere. “That sort of [atmos-pheric physics] approach could givethe information that is needed to say,‘We’re way too pessimistic and it’snowhere near that big a problem,’ or,‘We’re too optimistic, and it’s worsethan we thought.’ ”
Without verysmallearthquakes,we would haveno idea whatwas going onundergroundwhen we arefracking
Nan
da N
alin
/Dem
otix
/Cor
bis
Up in arms
Environmental campaigners – suchas those in the FrackMob at an industrygreenwashconference in Londonin November 2011 –warn there are many problems with fracking, includingthe possible contamination ofgroundwater arounddrilling sites.
Helium Recovery System for Portable Liquid Helium Plant
113 Falso Drive, Syracuse, New York, 13211 USA • Ph. 315-455-2555 Fax. 315-455-2544www.cryomech.com [email protected]
LHeEXTRACTION
LIQUID HELIUM PLANT(LHeP)
SUPPLY He > 99.99%
HELIUM PURIFIER
LN2 TRAP
FROM USERCRYOSTAT
HELIUM STORAGE
GAS CYLINDERCOMPRESSORPACKAGE
GAS BAG@ 1 atm
COMPLETE SYSTEM NOW AVAILABLE from Cryomech
Untitled-5 1 22/10/08 15:47:18
Comment
This special issue of Physics World looks at how physics is helping us to understand the
Earth, while our website physicsworld.com hosts an accompanying series of video reports
The devastation unleashed a year ago this month by an earthquake off the eastcoast of Japan was a reminder, if any were needed, of the deadly power of ourplanet. The magnitude-9.0 earthquake, which was one of the strongest of the mod-ern age, triggered a huge tsunami that rose to more than 40 m in places and spreadup to 10 km inland. Together, the earthquake and tsunami killed more than 15 000people, with the rising waters doing the most damage, including crippling theFukushima Daiichi nuclear power plant.
One year on from the Japanese disaster, it is natural that this special issue ofPhysics World on “Physics and the Earth” should include a look at the latestadvances in earthquake forecasting. While we are unlikely to ever be able to predictprecisely when, where and with what magnitude particular earthquakes will strike,
much can be gained from short-term “probabilistic”forecasting, which can give the odds that an earth-quake above a certain size will occur within a givenarea and time (see pp58–63). The virtues of this kindof prediction are also underlined in a series of specialvideo reports that you can watch at physicsworld.com.
Ultimately, the best bet for combating the power ofearthquakes is to ensure that buildings are as struc-turally sound as possible. Indeed, the FukushimaDaiichi plant safely survived last year’s earthquake;
as Mike Weightman – the UK’s chief inspector of nuclear installations – points out(pp19–20), what caused the problems was insufficient flood protection. While theplant’s tsunami defences had recently been increased to cope with a 5.7 m hightsunami, the waves that engulfed it were nearly three times that height. Those wavessubsequently spread right across the Pacific Ocean, vividly depicted in the open-ing image of our Earth-visualization feature (pp30–35).
On a calmer note, this special issue also describes how neutrinos generatedthrough the decay of uranium, thorium and potassium deep within the Earth aregiving us a new technique for understanding our planet (pp44–48). Detecting such“geoneutrinos” is a fiendish task, but two experiments have already managed todo so, in the process revealing new insights into how much heat is generated fromradioactive decay. This heat powers many vital processes on Earth, notably mantleconvection and plate tectonics. Interestingly, some researchers even think that themovement of the Earth’s plates could be linked to one of the long-standing mys-teries in geosciences – why our planet’s magnetic field has reversed at a rate thathas risen and fallen over the years (pp51–55).
Elsewhere, we look at progress in understanding the physical properties of mat-erials in the Earth’s core, which includes the bizarre possibility that it may hidehuge crystals of iron some 10 km long (pp37–41). We also tackle the controversyover “fracking” (pp14–15), which involves pumping sand and chemicals into shaledeposits to release trapped natural gas, and we speak to the head of a project thatseeks to understand what happens to carbon that gets subducted into the Earth’scrust (p13). And finally, if you enjoyed the images in this issue, why not share yourown pictures in the new Physics World “photo challenge” group on Flickr, whichthis month is dedicated to Earth sciences (see p27).
The contents of this magazine, including the views expressed above, are the responsibility of the Editor. They do not represent the views or policies of the Institute of Physics, except where explicitly stated.
Physics World
Temple Circus, Temple Way, Bristol BS1 6BE, UKTel: +44 (0)117 929 7481E-mail: [email protected]: physicsworld.com
Editor Matin DurraniAssociate Editor Dens MilneNews Editor Michael BanksReviews and Careers Editor Margaret HarrisFeatures Editor Louise MayorProduction Editor Kate GardnerWeb Editor Hamish JohnstonMultimedia Projects Editor James DaceyWeb Reporter Tushna Commissariat
Publisher Susan CurtisMarketing and circulation Gemma BaileyDisplay Advertisement Sales Edward JostRecruitment Advertisement Sales Chris ThomasAdvertisement Production Mark TrimnellDiagram Artist Alison ToveyHead of B2B and Marketing Jo AllenArt Director Andrew Giaquinto
Subscription information 2012 volume
The subscription rate for institutions is £330 per annum for themagazine, £625 per annum for the archive. Single issues are £30.Orders to: IOP Circulation Centre, CDS Global, Tower House, Lathkill Street, Sovereign Park, Market Harborough, Leicestershire LE16 9EF, UK (tel: +44 (0)845 4561511; fax: +44 (0)1858 438428; e-mail: [email protected]).Physics World is available on an individual basis, worldwide,through membership of the Institute of Physics
Copyright © 2012 by IOP Publishing Ltd and individualcontributors. All rights reserved. IOP Publishing Ltd permits singlephotocopying of single articles for private study or research,irrespective of where the copying is done. Multiple copying ofcontents or parts thereof without permission is in breach ofcopyright, except in the UK under the terms of the agreementbetween the CVCP and the CLA. Authorization of photocopy itemsfor internal or personal use, or the internal or personal use ofspecific clients, is granted by IOP Publishing Ltd for libraries andother users registered with the Copyright Clearance Center (CCC)Transactional Reporting Service, provided that the base fee of$2.50 per copy is paid directly to CCC, 27 Congress Street, Salem, MA 01970, USA
Bibliographic codes ISSN: 0953-8585
CODEN: PHWOEW
Printed in the UK by Warners (Midlands) plc, The Maltings, West Street, Bourne, Lincolnshire PE10 9PH
The Institute of Physics
76 Portland Place, London W1B 1NT, UKTel: +44 (0)20 7470 4800Fax: +44 (0)20 7470 4848E-mail: [email protected]: www.iop.org
Online Media Awards 2011: Best Specialist Site for Journalism
SIPA UK Awards 2011: Best Editorial and Marketing Collaboration
Our planet in perspective
ESA
physicsworld.com
17Physics World March 2012
Details at http://drama.iop.org
11–13 September 2012Royal Dublin Society, Ireland
Organised by the IOP Instrument Science and Technology Group
This conference brings together leading international researchers in the area of liquid drop analysis, science and technology, including microfludics, as well as providing a showcase for exhibitors.
Conference themes• Commercialisation, microfluidics analysis/
workshop•Drop science•Drop spectroscopy• Fundamental aspects of droplet microfluidics• Instrumentation for small volume
microvolume sample handling and microfluidics
•Microchannel integrated optics devices•Nanotechnology-enabled sensing• Optical metrology, imaging and quantitative
measurement•Standards for microvolume science•Surface science• ISTA School’s competition entitled “Drops
and Nature”•Short courses• Exhibition of product manufacturers,
publishers and companies looking to recruit science graduates
•Public lecture
Plenary speakers• Robert Forster, Dublin City University, Ireland• Reinhard Miller, Max Planck Institute of
Colloids and Interfaces, Germany• Charles Robertson, Nanodrop Corporation,
USA
Public lecturer• Terri Odom, Northwestern University, USA
Key datesAbstract submission deadline – 20 May 2012Notification of acceptance – 18 June 2012Early registration deadline – 3 July 2012Registration deadline – 31 August 2012
EnquiriesConferences department,Institute of Physics,76 Portland Place,London W1B 1NT, UK
Tel +44 (0)20 7470 4840E-mail [email protected]
Untitled-2 1 20/02/2012 08:54
19
physicsworld.com Comment: Forum
Physics World March 2012
At 2.46 p.m. local time on 11 March 2011 thebiggest earthquake recorded in Japanoccurred off the country’s east coast. Themagnitude-9 earthquake was one of half adozen earthquakes greater than magnitude 7to occur on that day. Within an hour, the firstof a series of massive tsunamis hit thatcaused catastrophic damage and loss of lifeacross Japan. The tsunami also led to a seri-ous nuclear accident at the TEPCO Fuku-shima Daiichi site, with repercussions feltacross the international community.
As time went on, the number of dead fromthe earthquake and tsunami started to rise:final estimates suggest 20 000 people died orare missing. More than 100 000 homes weredamaged or destroyed, with whole villagesand towns swept away. The disaster is on ascale that we can only imagine here in theUK. Even for Japan, which experiences highseismic activity, it was unimaginable.
In the UK, the Office for NuclearRegulation (ONR) responded by setting upthe Redgrave Court incident suite to provideexpert advice for the UK government on theimplications for the 17 000 UK citizens inJapan. We also required all of our licensednuclear sites to promptly answer questionsand justify the ongoing safety of their opera-tions. For more than two weeks we operatedour incident suite and provided advice to theCabinet Office Briefing Room – the UK’scrisis response committee – and to JohnBeddington, the UK government’s chief sci-entific adviser. After this, as requested by thesecretary of state for energy and climatechange, we set about producing an interimreport on the implications for the UKnuclear industry.
Getting back on trackAt about the same time, it was with greathonour and no little humility that I acceptedan invitation from the International AtomicEnergy Agency (IAEA) to lead a team ofnuclear experts from around the world on afact-finding mission to Japan from 24 May to1 June 2011.
The earthquake and tsunami particularly
affected the five nuclear plants along theJapanese east coast. My IAEA team visitedthree of them: Tokai, Fukushima Daiichi andFukushima Daini. At all these sites I encoun-tered tales of bravery, leadership andresilience. Workers at the Daini site laid 9kmof heavy power cabling by hand in 16 hoursto ensure initial safety systems worked tocool and control the reactors, while those atthe stricken Daiichi plant had to resort tonovel means, using what they had to hand inattempts to secure cooling of the reactor.
I was particularly impressed by the com-mitment of the several-hundred-strongworkforce at the Daiichi site, who all stayedon for days after the tsunami struck, despitenot knowing whether it had affected their vil-lages and put their families at great risk. Thistype of uncompromising loyalty and deter-mination is commonplace in Japan; it is tes-tament to the country’s spirit that its people
approached the disaster with characteristicstoicism, discipline and organization. Every-one I encountered was willing to help withtotal openness and transparency.
Looking back, the visit achieved its aim toidentify lessons from which the whole worldcan learn. Ultimately, it appears that theJapanese authorities underestimated thehazard presented by the tsunami. This wasdespite adequately estimating the hazardpresented by the earthquake.
The magnitude-9 earthquake causedsevere ground motions that lasted for sev-eral minutes at the Daiichi plant. The meas-ured motions reasonably matched thepredictions of the designers of the seismicprotection measures. Upon detection ofthese ground motions, the safety systems atDaiichi shut down the reactors and startedthe back-up systems. All the evidence I haveseen, including the evidence at the otherJapanese nuclear power plants that wit-nessed similar ground motions, supports theview that the Daiichi plant safely survivedthis massive earthquake.
However, the flood protection measuresat the Daiichi plant were originally designedto withstand a 3.1 m high tsunami, whereasthe largest wave that crashed into the site inMarch inundated it to around 15m. A reviewin 2002 by the operators of the Daiichi plantdid result in increases to the tsunamidefences to enable it to better survive a 5.7 mhigh tsunami. This improvement still proved
Lessons from FukushimaOne year on from an earthquakeand subsequent tsunami thatcrippled the Fukushima Daiichinuclear power plant in Japan,Mike Weightman says that thequest to improve nuclear safetymust never stop
You can never be too careful A man is checked for radiation on arrival at a vehicle-decontamination centre at J-Village in November 2011. This site serves as an operations centre for those battling the nuclear incident inJapan’s Fukushima prefecture.
REU
TERS
/PO
OL
New
All the evidencesupports the viewthat the Daiichi plantsafely survived themassive earthquake
Comment: Forum physicsworld.com
Physics World March 201220
to be inadequate, especially considering thehistory of tsunamis along that coast over thepast century.
Lessons learnedThe IAEA team presented a summaryreport to the Japanese Government on1 June and, later that month, presented itsfull report to a ministerial meeting inVienna, at which the world communitysought to learn lessons from Fukushima. Inresponse to a request from the secretary ofstate, I have produced two reports (with mas-sive help from colleagues in the ONR andelsewhere) on lessons for the UK nuclearindustry – an interim report in mid-May anda final report in September 2011.
My final report reaffirmed the conclusionsand recommendations in my interim reportand added to them, resulting in 17 conclu-sions and 38 recommendations in total.Overall, I remain confident that there are nofundamental weaknesses in the regulationof the UK nuclear industry or indeed in theindustry itself. We have a consistent andwell-founded approach to safety assessmentin the UK , including for extreme naturalhazards. Additionally, the affected reactorsat the Daiichi plant were all boiling-waterreactors, which do not form part of the UKfleet. The UK reactors are either advancedgas-cooled reactors or, in the case of Size-
well B, one of the most modern pressurized-water reactors in the world. The UK is alsofar from any edge of a tectonic plate andtherefore is not at risk from frequent orextreme seismic activity (and their subse-quent tsunamis). Although this is reassuring,this is not a time for complacency, hence my 38 recommendations.
All nuclear power plants in the UK andacross Europe have undertaken a “stresstest” to identify whether any improvementscan potentially be made. We submitted the
UK national report on stress tests inDecember and it is published on the ONRwebsite. I have also required all non-power-plant licensed nuclear installations in theUK to undertake similar tests of relevantsafety margins. The outcome of these stresstests will be added to the outcome of myalready published reports. The aim of allthese activities will be to transparently andopenly ensure that the UK government,nuclear regulator and nuclear industry aredoing all that they can to ensure the highestlevels of nuclear safety both at home andacross the world.
I have always said that safety is founded onthe principle of continuous improvement.The ONR already requires protection ofnuclear sites against the worst-case scenariosthat are predictable for the UK, but no mat-ter how high our standards, the quest forimprovement must never stop. We willensure lessons are learned from Fukushima.In many cases, action has already beentaken, but work will continue to learn the lessons.
Mike Weightman is Her Majesty’sChief Inspector of Nuclear Installationsand executive head of the Office forNuclear Regulation, UK, [email protected]
Safety is founded on the principle ofcontinuousimprovement – nomatter how high ourstandards, the questfor improvementmust never stop
physicsworld.com
Next month in Physics WorldTitanic tale
This April marks 100 years since the RMS Titanic sank after hitting an iceberg, but what fateful chain of events led to the collision in the first place and why did the shipsink so quickly?
Extraterrestrial plants
Flora on other planets – if they exist – might appear verydifferent from those we see on Earth, with plants in red-dwarf star systems probably appearing black, not green
Coffee stains under control
When drinks get spilt, the residue forms a ring in what isknown as the coffee-stain effect. But a new technique thatcould be used to detect biological molecules insteadleaves behind just a single small dot
Plus News & Analysis, Forum, Critical Point, Feedback, Reviews, Careers and much more
Nat
iona
l G
eogr
aphi
c So
ciet
y/Co
rbis
Since 1954, the Kurt J. Lesker Company has been an industry leader in the design, manufacturing and
distribution of vacuum technology products and services.
All Things Vacuum
• Customised vacuum systems & support
• Deposition materials
• Design & engineering services
• Most complete line of vacuum products in the world
www.lesker.com12-028
Untitled-1 1 15/02/2012 10:56
Untitled-6 1 16/02/2012 13:07
23
physicsworld.com Comment: Robert P Crease
Physics World March 2012
In his travel book The Innocents Abroad(1869), Mark Twain describes his visit to theBaptistery of the Duomo of Pisa, where,according to legend, in 1581 the youngGalileo noticed the regularity of the build-ing’s swinging chandelier. Using his pulse asa stopwatch, the then 17-year-old medicalstudent observed that the chandelier tookthe same time to swing back and forthwhether traversing a short or a long arc.Twain marvelled at how “insignificant” thechandelier looked, even though we hadlearned from it that such swinging objectswere not mere lamps but pendulums. Theawestruck Twain concluded that this was nocommon pendulum, “but the old originalpatriarchal Pendulum – the Abraham pen-dulum of the world”.
The principle Galileo noticed – that a pen-dulum’s period, T, depends only on itslength, L – is strictly true only in a vacuum,applies just for small swings, and ignores fric-tion and other factors. Still, the very simpli-city of the principle makes the pendulumuseful as an instrument. Indeed, the pendu-lum is one of the oldest scientific instrumentsstill in service – older, though just barely,than the telescope, the use of which in astro-nomy dates to 1609. (As a historical aside, itis worth noting that the Duomo’s pendulumwas actually replaced in 1587, but if Twainsaw an offspring of the Abraham pendulum,it stood in the same spot and obeyed thesame laws.)
Seeking to study the laws of falling bodies,in 1603–1604 Galileo built his own pendu-lums from heavy balls and cord. He also usedpendulums to measure short time periods,which was their first use as time standards.Others, meanwhile, realized that pendulumscould also be used to create length standards.In 1644 the French scientist and philosopherMarin Mersenne (1588–1648) appears tohave been the first to accurately measure thelength of a “seconds pendulum” – an ordi-nary pendulum but with the special propertythat its swing (half-oscillation or T/2) isexactly 1 s. Luckily, the length of a secondspendulum at standard gravity is almost ametre (99.4 cm), making it a convenientlength for a standard. This result sparkedinvestigations into factors that disturbed thependulum’s simple motion, including string
stiffness, air resistance and suspension.Later, in about 1656, the Dutch scientist
Christiaan Huygens (1629–1695) began cre-ating clocks out of pendulums, vastly increas-ing the accuracy of time measurements andtriggering a revolution in navigation. Becausethe Earth rotates at a known and fixed rate,the longitude of a ship’s position can be deter-mined by comparing the time of some astro-nomical observation as measured on boardship with that at some reference point.However, this only became possible onceclocks that could keep accurate time on shipshad been developed. Huygens also devisedthe theory of the compound pendulum,which does not use a string but a solid rod,and the reversible pendulum – a compoundpendulum that can be turned upside downand swings on two adjustable knife edges(one for each direction) embedded in the rod.
In 1673, in Horologium Oscillatorium,Huygens produced the equation of motionof a simple pendulum: T = 2π √(L/g). Healso proved that if a reversible pendulumswings with an equal period when turnedupside down, the distance between its twoknife edges is equal to the length of an idealor simple pendulum of the same period.Most disturbing factors can then be ignored,allowing pendulums to become valuable sci-entific instruments, sensitive to factors that
disturbed their simple motion.Much of the pendulum’s subsequent his-
tory consists of discoveries and correctionsfor these factors, or of its use to measurethese factors. In 1672, for instance, theFrench astronomer Jean Richer (1630–1696) discovered that the length of a secondspendulum changes with latitude: if g issmaller, as it is at the equator, a pendulumhas to be shortened to keep T/2 to 1 s.Richer’s work revealed that the Earth is notspherical but flattened slightly at the poles,like a pumpkin. Pendulums therefore provedto be multipurpose instruments that couldhelp determine not only laws of motion, butalso the Earth’s shape. “[W]ithout the pen-dulum,” wrote Newton’s biographer Rich-ard Westfall, “there would be no Principia.”
In the 18th century pendulums were in-creasingly used to measure time and speed.In 1784 the English mathematician GeorgeAtwood invented a device, the AtwoodMachine, incorporating a pendulum tomeasure the laws of motion with constantacceleration. Numerous scientists – ThomasJefferson among them – also assumed that aseconds pendulum could be used to define anatural standard of length. In 1851 Jean-Bernard-Léon Foucault (1819–1868) noticedthat the plane of oscillation of a long enoughpendulum slowly drifted over time becauseof the Earth’s spin about its axis. This demon-strated directly and accessibly the Earth’srotation, and “Foucault pendulums” quicklybecame popular science demonstrationsinstalled in museums the world over.
By 1867, the year that Twain witnessed theAbraham pendulum, the pendulum hadbecome the principal instrument used tomeasure the geoid, the shape of the Earth. In1872 the International Geodetic Associationorganized a network of gravimetric surveyswith reversible pendulums in one of the firstlarge-scale international science collabora-tions. Later, in the 19th century and into the20th, a type of pendulum was used in a seriesof experiments to try to detect a differencebetween inertial and gravitational masses.
Today, the geoid is measured from spacewith precise electronic instrumentation ableto detect gravity fluctuations (see p33). Butthis is a recent development. Until theadvent of satellites and electronic equip-ment, the geoid was determined by lowly off-spring of the Abraham pendulum, whichcontinue to serve productively in areasincluding education, engineering, physicsand mathematics.
Robert P Crease is chairman of the Department of Philosophy, Stony Brook University, and historian at the Brookhaven National Laboratory, US, e-mail [email protected]
Critical Point Measuring the EarthThe precise shape of the Earth isnow remarkably well known, but itwas first measured by perhapsthe oldest and most humble ofinstruments – the pendulum.Robert P Crease explains
Simply useful Pendulums proved that the Earth isshaped like a pumpkin.
iSto
ckph
oto.
com
/raw
206
The very simplicity ofthe principle makesthe pendulum usefulas an instrument
Advanced Research Systems
www.arscryo.com
True UHV 10-11 Torr
Surface Science Atomic Resolution
Cold Heads
0.1W, 0.2W, 0.8W 4K Cooling Power
Low Vibration Easy Maintenance
Custom Environments
Sample In Vapor Quick Change
Large Samples High Frequency
Cryogenic Probe Station
Cryogen Free Up to 8 Probes
Modular Design Custom Solutions
UHV
Ultra Low Vibration
MicroRaman
Cryostats
4K-800K Spectroscopy
1.7K-325K XRD & Transport
Helifier™ 18 Liters per Day
Reduce the operating costs of superconducting
magnets and liquid helium cryostats.
Capture liquid helium
exhaust and re-condense it at a fraction of the cost for new liquid
helium.
Helium Liquefier
Tel: 610-967-2120 Fax: 610-967-2395 [email protected]
Advanced Research Systems
www.arscryo.com
True UHV 10-11 Torr
Surface Science Atomic Resolution
Cold Heads
0.1W, 0.2W, 0.8W 4K Cooling Power
Low Vibration Easy Maintenance
Custom Environments
Sample In Vapor Quick Change
Large Samples High Frequency
Cryogenic Probe Station
Cryogen Free Up to 8 Probes
Modular Design Custom Solutions
UHV
Ultra Low Vibration
MicroRaman
Cryostats
4K-800K Spectroscopy
1.7K-325K XRD & Transport
Helifier™ 18 Liters per Day
Reduce the operating costs of superconducting
magnets and liquid helium cryostats.
Capture liquid helium
exhaust and re-condense it at a fraction of the cost for new liquid
helium.
Helium Liquefier
Tel: 610-967-2120 Fax: 610-967-2395 [email protected]
ad.indd 1 17/02/2012 15:49
25
physicsworld.com Feedback
Physics World March 2012
Presidential pledgesI read with interest the article by Robert PCrease on pledges to help voters evaluatepresidential candidates (January p19). As aphysicist working in the UK’s NationalHealth Service (NHS) Cancer ScreeningProgrammes, I was particularly drawn tohis proposed pledge for candidatesopposed to vaccination: “I pledge that I,my descendants and my constituents willshoulder the financial burden of treatingand burying unvaccinated cervical cancerand measles victims”.
Cervical cancer is caused by exposure tocertain strains of the humanpapillomavirus (HPV). HPV infectioncauses approximately 2700 cervical cancersa year in the UK alone. The NHS cervical-screening programme is designed to detectprecancerous changes in the cervix that canbe treated at an early stage. In addition, theNHS has introduced a free cervical-cancervaccination programme for girls aged12–13 years that provides complete protection against the two most commonforms of HPV. The vaccine has thepotential to reduce incidence and mortalityfrom cervical cancer by just under 80%. Inaddition, a number of other cancers arecaused by HPV infection. For example, justover 500 vulva/vaginal cancers and 760anus cancers in the UK are considered tobe due to HPV infection (M J Stanley 2007Journal of Clinical Pathology 60 691).
The vaccine is given to girls before theyare sexually active to maximize the protective effectiveness. Because of this,the introduction of the HPV vaccinationprogramme has been controversial, withthe popular press expressing concerns that
the vaccine encourages promiscuity in theyoung. However, I believe that theseconcerns are far outweighed by the benefitsof the vaccine. On a personal level, both mydaughters have decided to have the vaccineand I can report that it has not suddenlychanged their social activities.Keith Faulkner
Regional director of quality assurance (screening),North East Strategic Health Authority, Newcastle, [email protected]
Crease calls for presidential candidates tosign a series of pledges, one of which statesthat “my decision making (will) be guidedby facts rather than political ideology orfinancial interest”. He goes on to aver thatcandidates “who let ideology trump factsdo not act in the national interest”.However, I believe that such a pledgewould be unworkable and unwise.
For example, there are many possibleways to reduce the threat from climatechange, including geoengineering, morenuclear power, regulations on energy useand different tax rates for more or lessgreen activities, to name only a few. Eachof these proposals has different side-effectsand costs, and our response as citizens toeach is affected by our political opinions.
Equally well-informed people will havedifferent ideologies, and think and vote differently on the same issue. The onlyacceptable way to choose between thesedifferences of opinion is at the ballot box.Of course, politicians should not ignore scientific evidence, and policy-making
should be informed by the best availablescience, but to prioritize scientific “fact” over political ideology is profoundly undemocratic.Jamieson Christie
University College London, [email protected]
Steve RawlingsI appreciate that you did not wish toinclude speculative or distressing details inyour report of the death of the Universityof Oxford astrophysicist Steve Rawlings(February p8), but your report, whichmerely stated that Rawlings’ colleagueDevinder Sivia had been arrested and wasbailed in relation to the death, will leadmany to conclude that Sivia bears moralresponsibility for Rawlings’ demise.
I, too, do not wish to go into detail aheadof the inquest, but as a former colleague ofboth men, I would like to point out that thetwo were good friends and that Rawlings’wife is on record as saying that she does notblame Sivia for Steve’s death. Also,Detective Superintendent Rob Mason ofThames Valley Police has stated that “thedeath may be a matter for a coroner’sinquest rather than a criminal court” and,so far as I am aware, Sivia has not beencharged with any crime.Anthony Garrett
Lyneal, Shropshire, [email protected]
Returning from a career breakI read Jan West’s article “Careers,interrupted” (February pp50–51) withinterest, having taken a career breakmyself, and I would like to share mypositive experience. I graduated fromBristol University in 1989 with a degree inchemical physics and joined a largeengineering firm as part of a graduate-training scheme. Having completed thescheme, I worked for the company in boththe UK and abroad before takingmaternity leave in 1998.
At the end of the maternity leave, I did
Letters to the Editor can be sent to Physics World, Temple Circus, Temple Way, Bristol BS1 6BE, UK, or to [email protected]. Please include your address and a telephone number. Letters should be no more than500 words and may be edited. Comments on articlesfrom physicsworld.com can be posted on the website;an edited selection appears here
Feedback
Superconducting magnets
•Provenrecordofcustomengineeredmagnetsystems
•Cryofreemagnetsupto18T•Cryofreevectorrotatemagnets•Ultra-High-VacuumULT/magnetsystems•New–FasterCryofreemagnetcooldown–reducedbyhalffora15Tmagnet
New optical and spectroscopy systems
•Affordable,economical,flexible•Improvedperformance•DeliveredwiththenewMercuryiTCcryogenictemperaturecontroller
Triton™ Cryofree® dilution refrigerators
•Proventopandbottomloadingdesignswith10mKonthesampleprobeinbothconfigurations
•Integratedmagnetsoperatingfromonepulsetubecoolerincludingvectorrotatemagnetoptions
•Newremoteaccesssoftware
Your partner in innovation
Inspired by the Science of the Future
From best in class standard products to custom built systems
www.oxford-instruments.com/physicsworld
Forfurtherinformation:[email protected]
Visit our booth in March
DPG (Berlin) JSAP (Tokyo) JPS (Kobe)
controller
Visit our boothin March
MercuryiTC
27
physicsworld.com Feedback
Physics World March 2012
not feel ready to return to work, and I wasinitially offered a one-year career break,which was then extended to two years.However, by this time my second son hadarrived, and I was no closer to being readyto return to the workplace. It was not untilhe started school that I began to think ofreturning to work; but after a 7.5-yearbreak, what could I do and in whatcapacity? As West’s article described, myconfidence was low; I had lost myindividual identity; and the revolution incomputing was positively daunting – not tomention the fact that my everydaywardrobe was totally unsuitable!
However, I still had contact with my former colleagues, and a casual query ofwhether they were recruiting saw me backat work within a month, with hours to suitthe school run. On the eve of my return, mynerves were in shreds. What if I couldn’tremember what to do? What if I couldn’tpick up the latest technology? What if theyregretted taking me back? What if I wasn’tup to the job anymore? My colleagues triedto put me at my ease by saying “Well, thefundamental laws of physics haven’tchanged – you’ll pick it up again quickly”,but I had my doubts.
Now, almost six years on, I can honestlysay it was the best move I ever made. Therole has given me confidence, stretched mementally, given me job satisfaction and,most importantly, given me back my ownidentity and sense of self-worth. I certainlyfeel I have proved my worth – and yes, I didpick it up again quickly. What I had failedto appreciate at the time I returned to workwas that I had years of training and experience to offer, and I was highlyskilled; although I felt I was very rusty andout of the loop, this could soon beovercome and I still had potentiallyanother 25-plus years to offer.
Maybe I was lucky that my employer recognized that despite the changes intechnology, the fundamentals – my basicskills, knowledge and capabilities – werestill relevant, and it valued them. Otheremployers would do well to follow its example by recognizing the benefits ofemploying workers who have been out ofthe workplace for one reason or anotherbut who have the skills, the benefit of
experience and the understanding of theirspecialism to adapt to the ever-changingface of technology.Cathy Phipps
Uttoxeter, Staffordshire, [email protected]
Unoriginal talesIn his article “Other-worldly tales”(December 2011 pp18–19), Robert PCrease describes Hugh Everett’s idea ofbranching universes or “many worlds” as“one of the strangest ideas in the history ofthought, and the inspiration for manyscience-fiction stories”. In fact, thisoverstates its originality, since Everett himself was almost certainly inspired by thescience fiction of the 1940s and 1950s, inwhich this idea was commonplace. Thesewriters may not have expressed it aspoetically as Borges in The Garden ofForking Paths (1941), which Crease himselfcites, but the idea of a branching universewas around much earlier. Crease also mentions its occurrence in H G Wells’sMen Like Gods, and it is hard to see what hethinks is fundamentally new in Everett’sversion. As always, what deserves credit isnot having the idea, but working it out.
I would also take issue with Crease’sstatement that “the ground rule ofEverett’s idea is that each world remainsunobserved to, and cannot influence, theothers”. If this were strictly true, Everett’sinterpretation would offer no advantagesover the Copenhagen interpretation: undefined “measurements” would bereplaced by undefined “worlds”, andbranching would be equivalent to collapse.But, at least in the version endorsed byJohn Wheeler in his joint paper withEverett, there is no collapse and thereforeno barrier between the different worlds. Inprinciple, there are interference terms thatcan cause the worlds to influence eachother; however, there is no possibility oftravel between worlds, and certainly noneof the kind that you would need to make ascience-fiction story.Tony Sudbery
University of York, [email protected]
A111
A250
e-mail: [email protected] www.amptek.com
AMPTEK Inc.
FEATURES
THE INDUSTRY STANDARD
-
COOLFET®
STATE-OF-THE-ART
Have you enjoyed the amazing images in thisissue? Or do you think you could do better? Thenwhy not add your own physics-related photos toour Flickr group? Every few weeks we will post anew theme: our first was light in physics and thismonth’s is earth sciences. We look forward to yourphotos – happy snapping!
www.flickr.com/groups/
physicsworldphotochallenge
Physics World photo challenge
Andr
ew D
avid
hazy
, Roc
hest
er In
stitu
te o
f Tec
hnol
ogy
28 Physics World March 2012
Feedback physicsworld.com
INTRODUCINGMODELS 12C, 14C, 18C
CRYOGENICTEMPERATUREMONITORS
Two, Four or Eight input channels. Thermocouples optional.
Operation from <1.0K to over 1500K.
Two 10A dry-contact relay outputs.
Flexible power: Power-Over-Ethernet or 7.5-48V AC/DC.
Embedded web and e-mail servers.
Internal data-logging.
Remote interfaces: 100/10 Ethernet and RS-232.
INTRODUCINGMODELS 12C, 14C, 18C
CRYOGENICTEMPERATUREMONITORS
Do you use social-networking sites or blogs to
share and discuss research? If the answer is
“no”, you are far from alone. According to a report
by the UK’s Research Information Network, most
physical scientists view these services as a
“distraction”, preferring to communicate by
publishing in journals (see “Online tools are
‘distraction’ for science”, 25 January). The report
also found that members of various sub-
disciplines (such as particle physicists and
nanoscientists) use online resources such as
Google Scholar and arXiv differently. So are physical
scientists a bunch of fuddy-duddies, or just good
at avoiding distractions?
Senior researchers grew up and developed theircareer pre-Internet. After doing the same thing for20 years of their lives it’s not surprising theywouldn’t adopt rapidly changing new technologies.They’re going to coast until retirement and let thenext generation use these tools. Also, “publish orperish” still rules, and sharing research doesn’t helpyou win grants at the moment.
Hopefully, some researchers will start using thesetools to their advantage and not view them as athreat. I operate a biology “citizen science” site,Wildlife Sightings, and would be delighted if seniorresearchers participated and lent their support andwisdom. Experience tells me it will be a few yearsbefore they embrace the Internet and citizenscience, though. Hopefully then their peers will recognize the value of openly sharing research andreward researchers for using these new tools, ratherthan discouraging them as the current system does.Wildlife Sightings
There are two sides of research. The first is making aproject work, collecting the data and analysing it in acalm manner. This part is a lonely task away from theglare of publicity. Once the results are there, theyhave to be scrutinized carefully by people who havethe capacity to do this. After this, the publishing andthe publicity come in to make people understandthe significance of the work. If you mix these twosides at once, you risk turning the whole thing intotheatrics...when the information gets more and morewidespread in an undigested manner, it ends inmasses of ignorance and noisy ideological bouts.M Ashgar
Physicists, in general, seem to lead rather cloisteredlives, either publishing only in peer-reviewedjournals, or submitting their “work” to blogs andfringe websites for public consumption. The latterpractice will probably destroy all hope of a “normal”physics career, so it must be an act of insanity ordesperation (perhaps both) that leads people downthat road. But that is why we have sites for fringescience, where advocates claim “if only the workwasn’t suppressed...”. The Internet is full of stuffthat simply isn’t so, as well as stuff that may be sobut isn’t common knowledge. Caveat emptor.
When there is online access to peer-reviewedpublications, it usually requires membership in asociety or a fee to read the material. That tends to
keep the work in the “club”, so to speak.And it isn’t just physicists. I am an electricalengineer, but I can’t read the IEEE publications forfree. It is the same with most other professions:access to online publications is limited to those whocan afford the fees. If there are any Renaissancepeople living today, surely their efforts to learn andto assimilate, to cross-pollinate disparate fields ofendeavour, are more than a little stymied by this sadstate of online affairs here in the 21st century.
One ray of hope: the current generation isn’tafraid to launch new paradigms of investigation andform new associations of professionals. Thus wehave not only biologists, geneticists and medicaldoctors but now also bio-engineers and bio-physicists collaborating and making tools for eachother. Perhaps this new generation will alsoembrace the idea of truly free flow of information. Or not.H B Evans
The reason astrophysicists and high-energyphysicists don’t bother with Web-wide search-and-navigation tools is not that their field is narrow orthat they are set in their ways. It is that with theirhabit of making all their papers free for all online by“self-archiving” them in arXiv, they already haveimmediate focused access to just about everythingthey need in the refereed research-journal literature.In this they are more than two decades ahead ofother disciplines. And they did it of their own accord,because it made sense and its feasibility andbenefits were obvious.
Other disciplines have been far slower in comingto their senses, although what is optimal forphysicists is also optimal for them. They have beencombing through the roughly 20% of the rest of theliterature that is open access in fields other thanphysics and computer science, using Web tools thatdo their best to sort the wheat from the chaff.
It has by now become clear that if the rest of thedisciplines are to do the optimal and inevitable forthemselves before the heat death of the universe, itwill require their funders and institutions to extendtheir existing “publish or perish” mandates to “self-archive to flourish”.StevanHarnad
I think that while an amalgamation of research intomedia such as Google Scholar provides fast andeasy access to new information for scientists andacademics, standards need to be drawn. That iswhy I, and I think most scientists, will use traditionalresource-gathering methods in conjunction withthese newer ones. But to call the newer methods a“distraction” is something I wouldn’t agree withentirely. It is more of an additional resource that canbe called upon depending on the need.drpearson
Comments from physicsworld.com
Read these comments in full and add your own atphysicsworld.com
Vacuum TechnologyBasis for Innovation andProcess Optimization
Oerlikon Leybold Vacuum GmbHBonner Strasse 498D-50968 KölnT +49 (0) 221 - 347 - 0F +49 (0) 221 - 347 - 1250Email: [email protected]/leyboldvacuum
Vacuum is the enabling technology for modern applications and a decisive factor for optimal performance
and manufacturing success. Oerlikon Leybold Vacuum masters all challenges with innovative vacuum
components and systems solutions with ample experience in a wide range of customer applications.
Our range of high-performance
products comprises
■ Vacuum components
■ System solutions
■ Services
www.oerlikon.com/leyboldvacuum
1201_Anz_MAGintegra_TMP_EN_QR.indd 1 16.01.12 11:18
NO
AA/S
cien
ce P
hoto
Lib
rary
Physics World March 2012
Welcome to this special issue of Physics World devotedto our home, Earth. Over the next 34 pages, we take
you on a journey from the crust to the centre of the Earth, encountering earthquake physics, geomagnetic reversal, core conditions and
even geoneutrinos. But first we begin with these fabulous visualizations
from afar, showing planet-wide phenomena in all their glory
Physics and the Earth
Wave power This computer model showsthe maximum wave heights in the PacificOcean in the aftermath of the 2011earthquake in Tohoku, Japan. Colourcoding is from shallow (yellow, 20 cm)through to moderate (red, 60 cm) andlarge (purple, 120 cm, and black,240 cm+). The worst-hit areas in Japanhad surges 3–7 m high. The tsunami didmore damage than the magnitude-9.0earthquake that caused it, with 92.5% ofthe 13 135 fatalities recorded by11 April 2011 having died by drowning.As waves spread across the Pacific theydecreased in height, before growingagain upon reaching coastal areas. This model was produced by the Centerfor Tsunami Research at the PacificMarine Environmental Laboratory of the National Oceanic and Atmospheric Administration.
31
Physics World March 201232
Physics and the Earth: In perspective physicsworld.com
Time travel This artwork transports youback about 300 million years to thePalaeozoic Era, when the Earth’s landmass formed one giant supercontinentwe call Pangaea. About 200 millionyears ago Pangaea broke up, and itsfragments formed the continents as weknow them today. Evidence for this pastincludes fossil records, magnetization ofrock minerals and the obvious match incoastal shapes of, for example, the eastcoast of South America and the westcoast of Africa. Pangaea is not the onlysupercontinent to have formed on Earth,with Columbia here about 2 Gyr ago,followed by Rodinia and then Pannotia.
Hot and cold This view over the Atlanticshows sea-surface temperature, with bluecorresponding to the coldest waters andred to the warmest. The temperature ismeasured by collecting thermal infraredlight using the Advanced Along TrackScanning Radiometer (AATSR)instrument on board the European SpaceAgency’s Envisat satellite. AATSR’sprimary objective is to continue from itspredecessors in creating a near-continuous dataset, which started in1991, of sea-surface temperature with aprecision of 0.3 K or better, which will bea useful resource for climate research.
ESA
Mar
k G
arlic
k/Sc
ienc
e Ph
oto
Libr
ary
Physics World March 2012 33
Physics and the Earth: In perspectivephysicsworld.com
On the pull This peculiar-looking image isthe geoid – the Earth’s surface of equalgravity potential. The sea surface wouldbe this shape if the oceans were at restwith no tides or currents. Using this as areference – the most precise geoid yet –changes in mass distribution can bemeasured using complementarytechniques that measure variations ofthe gravity field with time. Changes in thegeoid could be used to detect depletinggroundwater supplies, melting of the icesheets or the flow of the Earth’s mantle.The data for this image were collectedfrom March 2009 until March 2011 bythe European Space Agency’s GravityField and Steady-State Ocean CirculationExplorer (GOCE).
Under the sea This map of the WesternPacific Ocean, with Australia bottom left,shows seabed depth from shallow (lightblue) on the continental shelves to deep(dark blue) in the ocean basins. The seafloor contains massive mountains as wellas trenches, which cause the oceansurface above to bulge outward andinward, respectively, the height of whichis measured using satellites to map theocean floor. The main features seen hereare the ridges and subduction zonesaround the Pacific Ocean’s “Ring of Fire”,including the Marianas Trench (aboveand left of centre), which contains thedeepest point in the world’s oceans ataround 11 km.
Mar
tin J
akob
sson
/Sci
ence
Pho
to L
ibra
ryES
A/H
PF/D
LR
Physics World March 201234
Physics and the Earth: In perspective physicsworld.com
The hole above This image from NASA’sAura satellite shows the Antarctic ozonehole in September 2006, when it was atits peak. Green shows a healthy layer ofozone while blue/purple indicate an areaof low ozone larger than the size ofNorth America. A previous NASA imagefrom December 1979, when the use ofchlorofluorocarbons (CFCs) was only juststarting to rise, was uniformly green. Theozone layer is incredibly valuable as itabsorbs 97–99% of incident high-frequency ultraviolet light, a high dose ofwhich can be harmful to living things.Although the average hole size is nowdecreasing, a full recovery of ozone overthe Antarctic is not expected until about 2050.
Highs and lows This image shows the firstdataset to merge models of the Earth’sland elevation and its ocean depths thatboth use satellite radar altimetermeasurements. Both use data from theEuropean Space Agency’s EuropeanRemote Sensing satellites, although theocean depths model also uses the USNavy’s Geosat satellite along with depthsoundings collected from ships.
ESA/
NO
AA/D
MU
NAS
A O
zone
Wat
ch
Physics World March 2012 35
Physics and the Earth: In perspectivephysicsworld.com
Sooty skies This image from a NASAcomputer simulation shows the globalspread of airborne soot on 26 September2009. Based on measurements of howmuch incoming sunlight the particlesabsorbed, areas thick with soot areshown in white, while lowerconcentrations are transparent purple.Soot is known to climate scientists as“black carbon” because it absorbsvisible light and could contributesignificantly to global warming. Itsimpact is particularly strong in Asia, with emissions from coal, diesel andbiomass, used for example in cooking.
Fiery flow This 3D computer model showshot magma, heated at the Earth’score–mantle boundary, rising as hotplumes (orange) to the upper mantle.Here, the plumes fan out before sinkingas cooler magma (green), driven byconvective currents. Such mantle plumesare thought to drive plate tectonics aswell as some of Earth’s volcanoes.However, like much of the science of whatis beneath our feet, the exactmechanisms behind mantle plumes arenot fully understood. Clues could comefrom mapping seismic waves, which arepredicted to travel slower through hotmantle than through cooler mantle.
Shux
ia Z
hang
/Shu
o W
ang/
Scie
nce
Phot
o Li
brar
yN
ASA
FORTHCOMING INSTITUTE CONFERENCES MARCH 2012 – JULY 2014
201221–22 March
Electrospinning, Principles, Possibilities and
Practice 2012
Institute of Physics, London, UK Organised by the IOP Dielectrics Group
2–4 April
IOP Nuclear Physics Group Conference 2012
University of Brighton, Brighton, UK Organised by the IOP Nuclear Physics Group
2–5 April
Plasma Physics Group Annual Conference
St Hugh’s College, Oxford, UK Organised by the IOP Plasma Physics Group
14–15 May
Quantum interfaces: integrating light, atoms and
solid-state devices
Chicheley Hall, Milton Keynes, UK Organised by the IOP Quantum Optics, Quantum Information and Quantum Control Group
7–8 June
Topical Research Meetings on Physics:
Swimming and Complexity at low Reynolds
number
Institute of Physics, London, UK
2–6 July
Ultrasonic Standing Waves – manipulating cells,
particles and fluids with sound
Gregynog Hall, University of Wales, UK Organised by the IOP Materials and Characterization Group
9–11 July
Superconductivity Summer School 2012
Wolfson College, Oxford, UK Organised by the IOP Superconductivity Group
20–23 August
IEEE NANO 2012 – 12th International
Conference on Nanotechnology
International Convention Centre, Birmingham, UK
29–31 August
Modern Practice in Stress and Vibration Analysis
Conference (MPSVA2012)
University of Glasgow, Glasgow, UK Organised by the IOP Applied Mechanics Group
3–5 September
Physics meets Biology
University of Oxford, Oxford, UK Organised by the IOP Biological Physics Group
3–6 September
Photon12
Durham University, Durham, UK Organised by the IOP Optics and Photonics Division
3–7 September
24th General Conference of the Condensed
Matter Division of the European Physical Society
(CMMP12, ECOSS-29, ECSCD-11)
Edinburgh International Conference Centre, Edinburgh, UK
10–11 September
Magnetic Tight Binding
Institute of Physics, London, UK Organised by the IOP Computational Physics Group
11–13 September
Drop Reaction and Microfluidic Analysis
(DRAMA)
Royal Dublin Society, Dublin, Ireland Organised by the IOP Instrument, Science and Technology Group
20–21 September
A Celebration of the 50th Anniversary of the
Diode Laser
University of Warwick, Coventry, UK Organised by the IOP Quantum Electronics and Photonics and Semiconductor Physics Groups
26–27 November
Biomolecular Thermodynamics
Institute of Physics, London, UK Organised by the IOP Biological Physics Group
17–18 December
Topical Research Meetings on Physics: Quantum
technologies: taking concepts through to
implementations
Institute of Physics, London, UK
201325–28 March
The 40th IOP Annual Conference on Plasma
Physics
University of York, York, UKOrganised by the IOP Plasma Physics Group
25–28 March
Interdisciplinary Surface Science Conference
(ISSC-19)
East Midlands Conference Centre, Nottingham, UKOrganised by the IOP Thin Films and Surfaces Group
7–10 April
IOP Nuclear Physics Group
Conference 2013
University of York, York, UK Organised by the IOP Nuclear Physics Group
10–12 April
Dielectrics 2013
University of Reading, Reading, UK Organised by the IOP Dielectrics Group
8–12 July
International Conference on Neutron Scattering
(ICNS2013)
Edinburgh International Conference Centre, Edinburgh, UK
3–6 September
Electron Microscopy and Analysis Group
Conference 2013 (EMAG)
University of York, York, UKOrganised by the IOP Electron Microscopy and Analysis Group
9–11 September
Physical Aspects of Polymer Science
University of Sheffield, Sheffield, UKOrganised by the IOP Polymer Physics Group
201421–25 July
ICSOS’11: International Conference on the
Structure of Surfaces
University of Warwick, Coventry, UKOrganised by the IOP Thin Films and Surfaces Group
See www.iop.org/conferences for a full list of IOP one-day meetings.
The conferences department provides a professional event-management service to the IOP Groups and Divisions and supports bids to bring international physics events to the UK.
Institute of Physics, 76 Portland Place, London W1B 1NT, UK Tel +44 (0)20 7470 4800 E-mail [email protected]
Web www.iop.org/conferences
M PW AD 0112 Physics World Conferences_08.indd 1 03/02/2012 14:39
David Appell is anindependent sciencejournalist based inSt Helens, Oregon,US, [email protected]
physicsworld.com Physics and the Earth: High-pressure studies
37Physics World March 2012
Directly beneath your feet lies one of the most mysteri-ous places in the solar system – the inside of the Earth.It is a geological concert orchestrated by huge forcesand immense transfers of heat, where metals can flowlike water and rocks take forms found nowhere else,and if anyone can be said to hold a ticket to this show itis Kei Hirose.
Hirose, a geologist at the Tokyo Institute ofTechnology, is a pioneer in duplicating the conditionsin our planet’s innards – pressures of millions of atmo-spheres and temperatures approaching that of the sur-face of the Sun. What Hirose does sounds simple, in
principle: squeeze materials and heat them. Indeed,he has already solved several enigmas of the Earth’sinner structure and hopes to answer even more, espe-cially the most pressing problem in geoscience: what isthe chemical composition of the Earth’s outer core?
“Kei’s combination of talents – pushing the limits ofhigh-pressure experiments and then exploiting this newcapability to address important questions – has led to astring of startling discoveries,” says Bruce Buffett, a geo-physicist at the University of California, Berkeley. Thatis a bold claim by anyone’s standards, so to see if it stacksup, we first need to remind ourselves what lies beneath.
Gar
y H
inck
s/Sc
ienc
e Ph
oto
Libr
ary
Scorching hot and under immense pressure, the Earth’s core is one of the most unusual and extremeplaces in the entire solar system. David Appell looks at progress in understanding the properties ofmaterials there, which includes the possibility that the core may even contain immense crystals of iron up to 10 km long
A pressing matter
No-one, of course, has ever seen the Earth’s interior,except for characters in books and Hollywood. A“modest proposal” for sending a probe to its depths wasmade in 2003 by planetary physicist David Stevensonfrom the California Institute of Technology, but eventhough his ideas were published in Nature (423 239),Stevenson’s tongue was somewhere in-between zeroand one cheek. The deepest that we have actually man-aged to penetrate beneath our planet’s surface is to thebottom of the Kola Superdeep Borehole – a researchfacility located on the Kola peninsula in north-westernRussia that opened in 1970. Penetrating to 12 262 mbelow the surface, it was four times deeper than anymine then or now (the site was abandoned in 2008). Yetif the Earth were an orange, the Kola borehole wouldstill only be 2% of the way through the peel.
Nonetheless, geologists know a great deal about theEarth’s structure, from rocks that have reached the sur-face, from its gravitational and magnetic fields, fromthe scattering of seismic waves created by earthquakes,and from computer models that combine these datawith models built with increasing details of the expectedphysics. They know that it consists of four principal lay-ers: the crust, mantle, outer core and inner core (fig-ure 1). The inner core is smaller than the Moon, andMars would fit snugly inside the outer core.
The Earth’s density changes abruptly at the bound-aries between these layers, varying from about 2.5 timesthat of water near the surface to a value estimated(from seismic-wave data input into models) to be some13 times that of water near the centre. Temperature and
pressure increase quickly in an imaginary descentthrough the Earth: the bottom of the Kola borehole isalready 180 °C, while at the boundary between the man-tle and the outer core, the temperature rises to about4000 K. There, the pressure is calculated to be animmense 140 GPa (1.4 million atmospheres) from thesheer weight of what lies above, rising to 3.5 millionatmospheres at the centre. A pleasant little Newtoniancalculation finds, assuming a planet of constant den-sity, that the pressure at the very centre is 3g2/8πG,where g is the acceleration due to gravity at the surfaceand G is the gravitational constant – the resulting1.7 million atmospheres is low by a factor of about two,because in reality the density varies with radius.
It is easy to forget just how fresh our knowledge is ofthe Earth’s interior. Plate tectonics came together inthe mid-1960s – more than a decade after the CERNparticle-physics lab was set up – and scientists hadsolved the mysteries of the atom long before the Danishseismologist Inge Lehmann realized in 1936 that theEarth’s inner core must be solid. (Her paper was won-derfully and simply titled “P′”.) Lehmann died in 1993,three months shy of 105.
Lehmann was a master in the art of reading and inter-preting seismic-wave recordings, and most of ourknowledge of the inner Earth has come from what isnow known as “seismic tomography”. Like a shoppertapping on a melon, waves from large earthquakes fanthrough the body of the Earth – longitudinal, com-pressional P-waves and transverse shear S-waves – atspeeds of about 10 km s–1, reflecting and refractingfrom the discontinuities and gradients they encounter.The resulting sounds have enabled researchers to gleanthe density profile of the Earth – an effort that hastaken decades – and, from fundamental principles ofgravitation and thermodynamics, we can deduce whatlies beneath, without needing to drill inside.
Earthquake by earthquake, sublayer by sublayer,geologists puzzled through the Earth’s inner structure.The imaginations of its surface dwellers might haveshifted from the days of Verne’s A Journey to the Centreof the Earth to Asimov’s robots to Spielberg’s ET, butthe rock hounds kept sifting for clues, crushing rocksand improving models, benefiting from the improve-ments of technologies and techniques often used tosearch for petroleum and ores, and trying out theirideas on other planets in the solar system. But puzzlesabout the interior remained. No-one was at fault – forgeologists, however gneiss, take nothing for granite.
The diamond squeeze
Enter Hirose. In 2004 the Tokyo geologist and his col-leagues solved some long-standing problems in earthscience when they discovered a new phase of the mostcommon type of material in the Earth’s lower mantle.Much of the mantle – from about 650km down – is com-posed of the mineral magnesium silicate (MgSiO3) in acrystalline form called “perovskite”, named after theRussian mineralogist Lev Perovski. It had been synthe-sized in the lab as early as 1974 at a pressure of 30 GPa,and geologists originally believed it was the dominantform of rock all the way down to where the mantlemeets the top of the outer core, at a depth of 2890 km.
However, in the 1960s seismic-wave data revealed
physicsworld.comPhysics and the Earth: High-pressure studies
38 Physics World March 2012
From fundamental principles ofgravitation and thermodynamics, we can deduce what lies beneath,without needing to drill inside
Inside knowledge Kei Hirose from the Tokyo Institute of Technologyhas studied how iron behaves at the conditions in the Earth’s core.
Kei
Hiro
se
Physics World March 2012 39
Physics and the Earth: High-pressure studies
some unexpected anomalies in the lower mantle,which extends to the core–mantle boundary. Thingsbecame even stranger in the 1980s when seismic tomo-graphers – who began examining how seismic wavesscatter off the Earth’s interior with ever better resolu-tion – discovered a discontinuity in the lower mantle,about 300 km above the core–mantle boundary.Dubbed the D′′ layer, subsequent work seemed toshow that the discontinuity was due not to the emer-gence of a different structure of rock, but to a suddenchange in the relative abundance of magnesium sili-cates and iron alloys. Unfortunately, that conclusionpresented a problem, because the convection thatkeeps the mantle astir should have created uniformity.
The other problem with a discontinuity was that
rocks at the high temperature (2500 K) and high pres-sure (120GPa) of the D′′ region had never been studiedbefore, which meant that it was impossible to knowwhether the conclusion was true. Intrigued, Hirosebegan to study the problem in the mid-1990s. After astint at the Geophysical Laboratory at the CarnegieInstitute in Washington, DC, he returned to Tokyo andbegan investigating how to generate the pressures andtemperatures necessary to simulate the deepest part ofthe mantle.
Scientists have been generating high pressures in thelab since the late 1950s, following the invention of thediamond-anvil cell at the US National Bureau ofStandards (the forerunner of the National Institute ofStandards and Technology). This device consists of
physicsworld.com
The core of the Earth is a solid, metallic ball (bright yellow) that further out becomes an ocean of white-hot molten iron–nickel alloy (orange) thatis only slightly less viscous than water. Surrounding the core is a 300 km thick boundary (D′′) region (not shown to scale here) that can beobserved by a sudden change in the speed of seismic waves at that depth, while further out still lies the highly viscous lower mantle (red), whichmoves slowly via convection currents carrying heat outwards from the core. A molten transition region (light green) contains minerals that canmelt and flow to the surface as magma through holes in the upper mantle (dark green) to form underwater mountain ranges known as mid-oceanridges. Topping everything is the crust (blue), which consists of roughly equal proportions of mostly silicon, iron, oxygen and magnesium.
1 The Earth in profile
subduction zone
transition region(basaltic magmassource)
0
400650
2,700
2,890
6,378
dept
h (k
m)
5,150
crust
upper mantle
mid–oceanridges
lower mantle
outer core(molten)
inner core(solid)
Dʺ layer
Physics World March 201240
Physics and the Earth: High-pressure studies
opposing, specially cut diamonds that are forcedtogether with a lever arm or tightening screw. The tipsof the diamonds, often less than a millimetre wide, areextremely smooth and finely aligned so that they encasethe sample with identical and opposing forces. A laserwith a fine beam, for which diamond is transparent, isthen shone on the sample to heat it. Hirose began work-ing to push pressures above 120 GPa by modifying theshape of the sub-millimetre-sized diamonds, becauseabove 80 GPa even diamond begins to warp. Helearned how best to bevel the tips of the gem-qualitynatural diamonds – breaking many of them in tests.
“Each year I usually buy about 100 diamonds,”Hirose says. Each diamond is 0.2 carats (40 mg) and hepurchases them to specification from a local company.Tightening the diamond-anvil cells to more than100 GPa always breaks both diamonds on decompres-sion, he says, but interesting science is obtained first.Hirose and his colleagues were able to reach a pres-sure of 120 GPa using only a screwdriver to adjust their apparatus.
Hirose’s team squeezed magnesium-silicate samplesonly 25 µm thick to these ultrahigh pressures, and then
heated them with a laser beam at the SPring-8 syn-chrotron facility in Hyogo. At the same time, the re-searchers shone a beam of X-rays onto the sample todetermine its crystal structure via the resulting diffrac-tion pattern. Hirose’s graduate student, MotohikoMurakami (now at Okayama University in Japan),found that the diffraction pattern of magnesium-silicate perovskite changed drastically at the extremeconditions they generated, taking a previously unimag-ined structure above 120 GPa and 2500 K, with a den-sity about 1% higher.
Hirose and his collaborators spent almost a year try-ing to fit their diffraction patterns to the tens of thou-sands available in crystallography catalogues, surelysatisfying Jules Verne’s notion (from A Journey to theCentre of the Earth), that “in the cause of science menare expected to suffer”. They found one via a computersimulation, dubbed it “postperovskite”, and with thisnew mineral phase, the solution of the D′′ puzzlesnapped into place (2004 Science 304 855).
Faster heat, younger core
The enigma facing geophysicists over the D′′ boundaryregion centred on the transfer of heat. The lower man-tle is only half as dense as the outer core, and little mix-ing of material occurs at their boundary. Heat musttherefore be exchanged across the gap via conduction,which is a very different situation from in the mantle orouter core itself, where convection rules the roost.Although the density of the new postperovskite min-eral structure was only about 1% larger than its per-ovskite form, the Clapeyron equation – which is a wayof characterizing a discontinuous transition betweentwo phases of matter – implied a large flow of energyacross the boundary that Hirose’s team estimated to be5–10 × 1012 W. Numerical simulations by TakashiNakagawa of the University of Chicago and PaulTackley of the University of California, Los Angelesthen found about a 20% faster heat flow through themantle – in turn, speeding up the movement of theEarth’s continents.
The larger rate across the core–mantle boundarymeant that the core must have once been warmer thanwas assumed (in order to be at the temperature it istoday), and so was cooling faster too. That in turnimplied that the inner core may have crystallized lessthan a billion years ago instead of much further back inthe past of the 4.6 billion-year-old Earth. That crystal-lization (the outer core is still molten) made the inter-ior dynamo more stable and Earth’s magnetic fieldstronger. That stronger field in turn diverted harmfulcosmic rays and solar winds, which may have allowedanimals to crawl out from the protective cover of theoceans to one day discover postperovskite.
Hirose, his collaborators and many other earth sci-entists went on to explore the properties of postper-ovskite. In 2008 Kenji Ohta (also of the Tokyo Instituteof Technology), Hirose and others made another dis-covery with important implications – the postper-ovskite form of magnesium silicate has a much higherelectrical conductivity than its perovskite form, byabout four orders of magnitude, varying little with tem-perature (Science 320 89).
This higher conductance meant a much stronger
physicsworld.com
Crystal mystery Deep inside the Naica mine, 300 m below ground in northern Mexico, lies theCave of the Crystals, containing these giant selenite structures that are some of the largestknown crystals. The biggest found to date in the cave is 11 m long, 4 m in diameter and weighs55 tonnes. But these could be nothing compared with the 10 km-long crystals that somescientists think might exist inside the inner core. Unlike those in the Naica cave, thehypothesized crystals would have no empty space between them.
Javi
er T
rueb
a/M
SF/S
cien
ce P
hoto
Lib
rary
Physics World March 2012 41
Physics and the Earth: High-pressure studies
electromagnetic coupling between the core and man-tle. This enhanced the exchange of angular momentumfrom the liquid outer core to the solid mantle, whichoccurs when the liquid streams in the outer core changetheir patterns, akin to the shifting jet stream in theatmosphere. Simulations showed that it was enough toaccount for the Earth’s “nutation” – the small, 18.6-year cyclic variation in the angular speed of the 26 000-year precession of the Earth’s axis of rotation.
A new structure of iron
Hirose and his lab continued to push to ever higherpressures and temperatures, striving to reproducethose at the centre of the Earth by studying the prop-erties of iron. Iron has a simple body-centred cubiccrystalline structure at ordinary pressures and tempera-tures, changing to hexagonal close-packed above15 GPa. There were experimental and theoretical rea-sons to suspect it might change at high pressure andtemperature, but neither approach was able to providea definitive answer for the structure, which was a keymissing ingredient in deciphering the deep inner struc-ture. However, in 2010 Hirose’s team succeeded inpressing iron to an incredible 377 GPa and 5700 K in alaser-heated diamond-anvil cell, which was studiedusing an X-ray beam with a spot only 6 µm wide(Science 330 359). This temperature was well abovethat of the boundary between the inner and outer cores,which lies somewhere between 4850 and 5700 K.
Before this work, no-one had succeeded in pressingiron to such conditions except in dynamical shock-waveexperiments, which inherently did not allow microsec-ond-scale measurement of its properties. Hirose andhis colleagues were able to solve the mystery of whathappens to iron under extreme conditions when theyfound that the hexagonal close-packed structureremained. Moreover, the length to edge-width ratio ofthe crystalline unit, which under normal conditions is√(8/3), remained unchanged at high pressure and tem-perature, meaning that hexagonal close-packed iron islikely to be “elastically anisotropic” – in other words,its strain depends on the crystal’s orientation.
But much about the tiny inner core – which makes upjust 0.7% of the Earth’s volume – remains a mystery.The rate at which waves pass through it depends ontheir direction of travel – seismic P-waves zip throughthe inner core about 3% faster in the direction of theEarth’s polar axis than in its equatorial plane. The mostaccepted hypothesis to explain this anomaly is that theinner core has a texture, with the “fast axis” of iron crys-tals mostly oriented in the north–south direction.
But the inner core also has distinct hemispheres – itsseismic properties are different in its eastern and west-ern halves, despite it having grown through crystalliza-tion for around the last billion years at a current rate ofabout 0.5 mm per year. To explain this asymmetry, agroup led by Marc Monnereau at the University ofToulouse in France has proposed that the crystal“grains” in the inner core vary in size from west to east(2010 Science 328 1014). A grain is essentially a largenumber of crystals, either cubic or hexagonal (but nota mixture); the axes of the component crystals all pointin the same direction, with the orientation of the axesvarying randomly from one grain to another. “From
Hirose’s work, it seems that crystals as large as 10 kmare acceptable from the point of view of mineralphysics,” says Monnereau. “But whatever their struc-ture, they should be at least 10 times larger on the sidefacing Indonesia than the one facing Peru.” Crystalsthat huge put even those in Mexico’s famous Cave ofCrystals to shame.
Higher state
Back in Japan, Hirose is now trying to do to liquids whathe has done to solids – squeeze and heat them, to simu-late the outer core, the precise chemical composition ofwhich is still unknown. Unfortunately, experiments onliquids are much harder than on solids – after all, liquidsmove, even in minute samples, but solids do not. Underpressure and temperature gradients, liquids normallymove away from the high-temperature spot. “So as soonas we melt the sample, the liquid moves away from theheating spot,” Hirose points out. The key, he says, is toapply a very homogeneous temperature field.
Hirose’s laboratory has now attained conditions of400 GPa and 6000 K. “I’m very much interested in theliquid of the core, and measuring the sound velocityand density of liquids at high temperature and pres-sure,” he says. Hirose is not alone of course – theEuropean Synchrotron Radiation Facility in Grenoble,France, for example, opened a beamline late last yearthat is ideal for studying, with microsecond resolution,how materials absorb X-rays at extreme conditions ofup to 10 000 K (figure 2). But if Hirose’s past accom-plishments are any indication, whatever he finds therewill bring the picture of the inner Earth into sharperfocus still. ■
physicsworld.com
2 In a squeeze
The European Synchrotron Radiation Facility in Grenoble, France, has recently opened abeamline that is perfect for studying in real time the behaviour of materials at the extremetemperatures and pressures in the Earth’s core. Called ID24, the 7180m beamline letsresearchers fire X-rays into materials that have been squeezed using diamond-anvil cells beforeheating the pressurized material with short, intense laser pulses to up to 10 000 K. Thebeamline can reveal how crystalline samples absorb X-rays in real time with a resolution of theorder of microseconds, in turn revealing how their structures change.
ESRF
HiCubeTM Pro� Modular pumping station for clean vacuum� Dry, multi-stage ACP roots pump� High performance turbopump with integrated drive� Robust engineering makes for long service life and high reliability
Are you looking for a perfect vacuum solution? Please contact us:
Pfeiffer Vacuum GmbH · Headquarters/Germany T +49 6441 802-0 · F +49 6441 802-202 [email protected]
www.pfeiffer-vacuum.com
A P A S S I O N F O R P E R F E C T I O N
The complete Solution for High Vacuum Applications
12.02.16_Physics_World_HiCube_Pro_GB_213x282_Layout 1 16.02.12 15:42 Seite 1
This map shows the speed of the clockwise Antarctic Circumpolar Currenton 12 May 2006, increasing from slow-moving water (blue) to speedsabove one mile per hour (dark red). Land masses are black and theAntarctic Polar Front, where cold polar air meets warm tropical air, isshown by a solid white line. The Southern Ocean, with the near-continuousstrong winds that churn its surface, is estimated to absorb as much as40% of the carbon dioxide taken in by the world’s oceans, despite onlyaccounting for about 6% of their area.
Churned up
M M
azlo
ff,
MIT
/San
Die
go S
uper
com
pute
r Ce
nter
PWMar12earth-currents-4 16/2/12 15:11 Page 43
The Pulitzer-prize-winning US author John Updike isperhaps best known to physicists for his delightfulpoem about neutrinos. The first few lines of “Cosmicgall” (1960 New Yorker) perfectly capture the elusive-ness and trickiness of these almost ghost-like particles:
Neutrinos they are very small.They have no charge and have no massAnd do not interact at all.The Earth is just a silly ballTo them, through which they simply passLike dustmaids down a drafty hall.
Updike was right that neutrinos are tiny and have noelectric charge. But we now know that they can inter-act with matter, albeit rarely, and we also know thatneutrinos are not entirely massless either. What is per-haps even more interesting is that, thanks to the recentdevelopment of ultrasensitive neutrino detectors, wecan now use these particles to obtain new informationabout the Earth itself. To neutrinos, the Earth may bemuch more than “a silly ball”.
The fact that neutrinos and their antimatter coun-terparts – antineutrinos – interact so weakly with mat-ter produces some surprising behaviour. Whereasindividual photons produced in the Sun, say, can take100 000 years to escape its core – getting continuallyabsorbed and re-emitted as they travel through solarmatter – neutrinos will have escaped the Sun’s clutcheswithin a few seconds. Assuming they can be detected,neutrinos are therefore remarkably useful for probingregions that would otherwise be impossible to reach.Indeed, neutrinos (and antineutrinos) can travel
through the Sun, the Earth and even the whole universewithout being disturbed at all.
Geoneutrinos are a type of antineutrino producedinside the Earth from the radioactive decay of uranium,thorium (and their respective daughter nuclei) andpotassium. As the antineutrinos travel to the surface,they bring precious information about the amount anddistribution of these radioactive elements from deepwithin our planet – information that remains undis-torted on its passage through the Earth. In addition tothe antineutrinos, each radioactive decay produces aknown amount of heat – so detecting the geoneutrinoscould help us to estimate what fraction of the total heatflux through the Earth is produced in this way.
This heat powers many vital processes on Earth,notably mantle convection and plate tectonics, but theproportion from radioactive decay is far from clear.The problem is that we do not know for sure the abun-
physicsworld.comPhysics and the Earth: Geoneutrinos
44 Physics World March 2012
Gianpaolo Bellini isat the IstitutoNazionale di FisicaNucleare (INFN) inMilan and isspokesperson for theBorexinocollaboration at theGran Sasso NationalLaboratory, Italy, e-mail [email protected] Ludhova is alsoat the INFN in Milan
Essential information about the Earth’s thermal energycould be obtained by detecting the almost masslessneutrinos that flit through the Earth’s interior.Gianpaolo Bellini and Livia Ludhova explain how thestudy of “geoneutrinos” is opening up an entire new fieldof interdisciplinary research
Eyeing theEarth withneutrinos
Physics World March 2012 45
Physics and the Earth: Geoneutrinos
dance of uranium, thorium and potassium, and thushow much heat they produce or whether there are anyadditional heat sources. Geophysicists have createdmodels of mantle convection that predict that about70% of the total surface heat flux is from radionuclei,while geochemists think this figure is much less, poss-ibly as little as 25%.
What geoneutrinos could do is give us a way of meas-uring the amount of this “radiogenic” heat directly.Spotting geoneutrinos is extremely challenging, butresearchers have managed to detect them at theKamLAND detector, which is located 1000 m under-ground at the Kamiokande–Mozumi mine in Japan,and at the Borexino experiment at the Gran SassoNational Laboratory beneath the Apennines in centralItaly (of which the present authors are members).Although these experiments were designed to detectinteractions from two very different sources – antineut-
rinos from nuclear reactors in the case of KamLANDand neutrinos from the Sun for Borexino – both theirachievements in observing geoneutrinos have openedup an entirely new interdisciplinary endeavour forstudying the Earth.
Unknown Earth
One reason why geophysicists are interested in know-ing the total heat flux through the Earth is that thisnumber can help us to understand how our planetformed and evolved, and why it has its current struc-ture. To estimate this value, geophysicists currently turnto measurements of the temperature gradient belowthe surface obtained mostly by oil-exploration firmsthat have drilled some 40 000 or so holes to differentdepths across our planet. These data can then be fedinto various models of how our planet has evolved andcooled over the years, each of which makes different
physicsworld.com
Fiendish task TheCounting Test Facilitymeasures the tinyintrinsic radioactivityof the fluid that isused inside theBorexino neutrinodetector at the GranSasso NationalLaboratory in Italy.
INFN
Physics World March 201246
Physics and the Earth: Geoneutrinos
assumptions about factors such as how young under-water volcanoes behave and how heat is transferred.
Researchers have used these models in recent yearsto make different estimates of the total heat fluxthrough the Earth’s surface – but unfortunately theyproduce wildly different results. In 2010 Huw Daviesfrom Cardiff University and Rhodri Davies fromImperial College London suggested that the flux is47 ± 2 TW (Solid Earth 1 5), while an earlier estimatein 2005 by Anne Hofmeister and Robert Criss fromWashington University in St Louis put the figure at31 ± 1 TW (Tectonophysics 395 159). Although theerror bars on each number are small, they refer only tothe uncertainty in the model and do not take intoaccount the intrinsic uncertainties of the hypothesesused to develop the model.
One way to estimate the radiogenic heat flux is to usemodels of the silicate shell surrounding our planet’smetallic iron–nickel core, which involves calculatingthe heat released in the decays of the uranium-238 andthorium-232 radioactive families, and potassium-40.Assuming that the relative abundance of these nucleiin our planet is the same as in meteorites that havelanded on Earth – which is not unreasonable given thateverything in the solar system probably comes from asingle primordial body – these models imply thatradioactive decay in the Earth’s interior accounts for aheat flux of 12–30 TW. As this value is possibly less thanthe total measured experimentally, it means that otherpotential heat sources could exist – for example fromthe original heat remaining from when the Earth wasformed, from materials contracting under gravity orfrom the latent heat generated when, say, two tectonicplates collide. The heat could even come from natur-ally occurring nuclear reactions arising from criticalamounts of uranium-238 at the core–mantle boundary,although this is unlikely.
Detecting geoneutrinos could overcome the discrep-
ancy between the heat fluxes foreseen by the differentmodels because we know how likely it is that a geoneut-rino will interact with a detector. So by recording howmany geoneutrinos we actually detect in a particulartime interval, we can calculate their overall flux. Giventhat every uranium-238 decay chain emits a total of sixantineutrinos, while the thorium-232 decay chain pro-duces four antineutrinos and potassium-40 releases justone, we can therefore use our value of the flux to calcu-late how many of these nuclei are in the Earth, assumingthey exist in the same proportion as in meteorites. Andsince the number of neutrinos from each decay chain isproportional to the emitted energy, we can calculatehow much heat is produced from radiogenic decay.
The thinking is simple – the reality is hard. In partic-ular, when estimating the flux, one has to take intoaccount the local geology and the fact that the compo-sition of radioactive elements within the mantle variesfrom place to place. Much more challenging still isactually capturing a geoneutrino in the first place,which is why only two experiments – Borexino andKamLAND – have so far managed to detect them.
A challenging enterprise
Being such elusive particles, capturing a geoneutrinois an exceptionally tricky task. The Borexino detectoris basically a big tank containing several thousand litresof an organic solvent (1,2,4-trimethylbenzene) plus asmall percentage of another component, known as afluor. KamLAND is similarly large and has the sametwo components, but also a lot of mineral oil that makesup 80% of its total volume. Any particle passingthrough the detector – be it a cosmic ray, an antineut-rino from a nuclear reactor or a geoneutrino – cantransmit energy to a molecule of the solvent by excit-ing it. A small portion of this energy migrates to a fluormolecule, which releases a photon when it decays.Photomultiplier tubes capture the photon and trans-
physicsworld.com
Data source The photomultiplier tubes on the cupola of the stainless-steelsphere that makes up the Borexino detector. When geoneutrinos strike the fluidin the detector, they can produce photons that are converted by these tubes intoelectrical signals that can be digitized and analysed.
Clean through A technician installs photomultiplier tubes and associated optical fibreson the inner wall of the stainless-steel sphere that makes up the Borexino neutrinodetector. The entire sphere is treated as a special clean room to prevent any particulatesor dust from clinging to the wall: their radioactivity could swamp the geoneutrino signal.
Whenestimating theflux, one has totake intoaccount thelocal geologyand the factthat thecomposition of radioactiveelementsvaries
Bot
h im
ages
:IN
FN
Physics World March 2012 47
Physics and the Earth: Geoneutrinos
form it into an electronic pulse.Although such photons can be produced by a variety
of incoming particles, we know we have detected anantineutrino because it produces a characteristic sig-nal when it strikes a proton (a hydrogen nucleus) in thedetecting material. This collision – known as an“inverse β-decay” – creates a neutron and a positron(anti-electron) that decelerates and annihilates almostimmediately on encountering an electron, emitting twogamma rays with an energy of about 0.5 MeV. Theenergy of the gamma rays plus that lost by the positronmake up a unique signature that we call the “prompt”signal. The neutron, however, survives for longer, scat-tering off matter and losing energy until – after about250 µs – it is captured by a proton, releasing a single2.2 MeV gamma ray called the “delayed” signal. So ifwe see the prompt signal followed by the delayed sig-nal about 250 µs later, then we know we have detectedan antineutrino. The fact that these interactions are sowell “tagged” is essential in allowing us to distinguishantineutrinos from the background signal.
That all sounds fine in principle, but to understandjust how challenging it is to detect geoneutrinos, it isworth noting that Borexino observes only one such par-ticle every seven weeks. Even solar neutrinos, whichstrike the Earth at the much higher rate of some 60 bil-lion per square centimetre per second, are fiendishlyhard to detect; Borexino sees only about 45 of these ina single day. With such low statistics, any processes thatcan mimic geoneutrino interactions have to be eithereliminated, or reduced to an extremely low level.
Low signal, high noise
To compensate for the low flux and low rate of detec-tion, any geoneutrino detector has to be installed in alocation where almost no cosmic rays from outer spacecontribute to the signal. In the case of Borexino, thisshielding is achieved thanks to the 1400 m or so of rockthat lies above the Gran Sasso lab, which absorbs vir-tually all incoming cosmic rays such that just a few raysreach every square metre of the detector in a singlehour. The detector also has to be shielded from “fake”signals arising from the natural radioactivity of every-thing from the local underground rocks to the mater-ials used for the floor and even the air. In the case ofBorexino, the detector is shielded by some 2400 m3 ofhighly purified water that absorbs gamma rays, neut-rons and other electrically charged particles.
But the hardest problem is dealing with the intrinsicradioactivity of the detector and of the scintillator itself.Removing signals from these sources involves buildingthe detector – liquid containers, photomultiplier tubes,pipes, valves, pumps and so on – using materials thathave as little natural radioactivity as possible. And,more importantly, the scintillator has to be purified toremove all its radioactive elements. In the case ofBorexino, new techniques have been developed withan unprecedented radiopurity that is some 10–11orders of magnitude lower than most natural materials.
Researchers at KamLAND have also spent muchtime and effort on fine-tuning their scintillator.However, its radiopurity requirements are not as strin-gent as those of Borexino because KamLAND isdesigned to study only antineutrinos. On the other hand,
KamLAND has 1000 tonnes of scintillator fluid – morethan three times the volume at Borexino – which meansthat it captures about three times as many geoneutrinos.
But the problems do not end there because we mustalso deal with antineutrinos from nuclear reactors,which are another source of fake events. This is a par-ticular problem at KamLAND, which has to contendwith an antineutrino flux that is about seven times ashigh as at Borexino as a result of the much higher den-sity and the closer proximity of nuclear reactors inJapan than in Italy. Fortunately, we can in principle dis-entangle the geoneutrino signal from the reactor-anti-neutrino signal because each is spread over a differentrange of energies. Overall, after 18 months of data-tak-ing, Borexino has yielded about 10 geoneutrinos, 11antineutrinos from reactors and about 0.5 backgroundevents, whereas KamLAND has, over a period of 92months, seen 111 geoneutrinos, 485 reactor antineut-rinos and 245 background events (figure 1). The evi-dence of geoneutrinos achieved by Borexino is the
physicsworld.com
Energy spectrum of the geoneutrinos detected by (a) Borexino and (b) KamLAND. the graphsshow the distribution of the energy of the “prompt” signal Ep (see main text) expressed as thenumber of photoelectrons detected by the photomultiplier tubes (Borexino plot) or convertedinto energy (KamLAND plot). The Borexino plot shows geoneutrinos (green), antineutrinosfrom nuclear reactors (pink) and the fake events caused by the natural radioactivity (blue)(2010 Phys. Lett. B 687 29). The red line corresponds to the geoneutrinos once the reactorantineutrino signal is subtracted out. In the KamLAND plot geoneutrinos are shown as green,the antineutrinos from reactors as pink, while fake events caused by the natural radioactivityare blue and red (2011 Nature GeoScience 4 647).
1 Go figure
8
num
ber o
f eve
nts
7
6
5
4
3
2
1
0
light yield of prompt signal (photoelectrons)500
160KamLAND data
Borexino data
even
ts/0
.2 M
eV
120
80
40
01.0 1.2 1.4 1.6 1.8
energy of prompt signal (MeV)
2.0 2.2 2.4 2.6
1000 1500 2000 2500 3000 3500
a
b
Physics World March 201248
Physics and the Earth: Geoneutrinos
same as KamLAND despite the lower volume and theshorter data-taking time, thanks to the almost negli-gible background caused by natural radioactivity andthe lower flux of antineutrinos from reactors.
Act locally
So how do we connect the number of geoneutrinosdetected by an experiment with the overall radioactiv-ity in the crust and mantle? To do so we have to drawon our knowledge of the local geological conditions (atBorexino and KamLAND about half of the signalcomes from within a hemispherical volume with aradius of 100–200 km from the detector) and in partic-ular the thickness and local radioactivity of the crust.The thickness is important so that we know the solidangle over which the detector receives the geoneut-rinos from the mantle: if the crust beneath one detectorwere thinner, it would receive more geoneutrinos fromthe mantle and vice-versa if the crust were thicker. (Infact the crust is about 35 km thick for both Borexinoand KamLAND.)
Taking all factors into account, both KamLAND andBorexino now have very robust evidence for the exist-ence of geoneutrinos to a probability of 99.997%. Butgiven that geoscientists were already aware of the pres-ence of radioactive decays in the crust – based on chem-ical analyses of material in the drill holes – what havethese studies told us that we did not know before? Themain finding to date is that the total heat flux measuredwith geoneutrinos is higher than that suggested byexisting measurements of radioactive decay in thecrust. In other words, we have shown for the first timethat radioactive decays must also be taking place in themantle. In addition, a combined analysis of theKamLAND and Borexino data suggests that the heatfrom radioactive decay makes up about one half of thetotal terrestrial heat flux.
But, more importantly, being able to detect geoneut-rinos from the Earth’s interior gives us a brand new wayof investigating the structure of our planet – for the firsttime we have been able to obtain direct informationabout the inner regions of the Earth below the crust.
Moreover, the presence of uranium and thorium in themantle sheds light on its chemical composition becauseother elements, which have a chemical affinity withthem, in principle will have to be present too.
Fast forward
Although the geoneutrino work at Borexino andKamLAND is a good start, to obtain definitive answersto questions about the radiogenic heat and the abun-dances of radiogenic elements, more data are needed.The existing experiments will continue to take data overthe next three or four years but it would be useful tobuild bigger detectors to increase the number of cap-tured geoneutrinos and so improve the precision of theflux measurement. What would also be interestingwould be to have geoneutrino detectors at different sitesaround the world, each with a different local geology, tounderstand if, for example, the composition of theEarth’s mantle and the distribution of heat from it arehomogenous (or not). If we could estimate the bulk ratioof uranium to thorium in the Earth we could then com-pare this with the same ratio in meteorites, thereby giv-ing us a better understanding of the Earth’s formationand of the distribution of elements in the solar system.
Thankfully, various research groups are designingand even building a new generation of neutrino experi-ments using liquid scintillators. The SNO+ experimentat the Sudbury mine in Canada, for example, will havea target consisting of 1000 tonnes and is set to comeonline next year. The mine is located on an old conti-nental crust and the flux from reactor antineutrinos isabout twice as much as at Gran Sasso. Europe also hasambitious new plans to build a 50 000 tonne detector,dubbed LENA (Low Energy Neutrino Astronomy).The experiment, which might be located in thePyhäsalmi mine in Finland or the Fréjus undergroundlab in France, is designed to detect as many as 1000geoneutrinos per year. Meanwhile, there are interest-ing plans for a 5000 tonne underwater experiment,known as HanoHano, in Hawaii that would sit on theocean crust. As the crust there is particularly thin, mostof the geoneutrinos should come from the mantle,which means that the experiment would provide themost direct information to date about the mantle.
Indeed, these future experiments, coupled with thosecurrently under way, could be a starting point for a net-work of geoneutrino detectors to understand theEarth’s heat distribution and the chemical compositionof the mantle. By working together, earth scientists andnuclear physicists could allow us to understand other-wise inaccessible aspects of what Updike called “oursilly ball”. ■
physicsworld.com
Deep insights The KamLAND detector in Japan has also spotted geoneutrinos.
Being able to detectgeoneutrinos gives us abrand new way ofinvestigating the structureof our planet
Kam
LAN
D
Phone: (614) 891-2244 Fax: (614) 818-1600 i n f o @ l a k e s h o r e . c o m www.lakeshore.com
[email protected] Wilton, NH USA 603-878-1616 www.KimballPhysics.com
Advanced Ultra-High-VacuumMulti-CF ConFlat Fittings
Compact, Large Number of Ports
Mate with Industry Standard ConFlats
Expanded Port IDs, Large Volumes
Groove Grabber Internal Mounting TechnologyDouble Tapped-Hole Sets
Metric Available, Customs Encouraged
Highly Modular, High Rigidity, High Precision
316L Stainless (Titanium Available)Serial Numbered, Traceable
150mm
A Myriadof Parts
In October 2011 NASA scientists discovered amassive crack running across the floating ice shelfof Pine Island Glacier. The crack is an untraversable80 m wide and 60 m deep, and extends for 30 km.This rift will eventually reach the other side of the iceshelf and create a giant iceberg some 900 km2 insurface area. The Pine Island Glacier together withThwaites Glacier drains about one-third of the WestAntarctic ice sheet, which if fully melted would raisethe global sea level by 1 m. Since the consequencesof rapidly changing ice sheets are so large and yetthe physical processes responsible are poorlyunderstood, studying the ice sheets of Antarcticaremains a high priority. (Image courtesyNASA/GSFC/METI/ERSDAC/JAROS and US/JapanASTER Science Team)
Cracked
PWMar12earth-glacier-2 16/2/12 15:15 Page 50
François Pétrélis isin the Laboratoire dePhysique Statistiqueat Ecole NormaleSupérieure in Paris,France, and Jean-Pierre Valet
and Jean Besse areat Institut dePhysique du Globe deParis, France. [email protected]
physicsworld.com Physics and the Earth: Geomagnetic reversal
51Physics World March 2012
The Earth’s magnetic field is becoming weaker. It hasdeteriorated by 10–15% over the last 150 years at a ratethat has recently been speeding up. Doomsday enthu-siasts, who believe some earthshattering event willdestroy humankind in December this year, cite thisweakening field as one of the possible apocalypse scen-arios. They think that the poles might reverse, result-ing in devastation across the world, possibly from a lackof shielding from cosmic rays.
However, there are many things wrong with this pic-ture. First, a reversal takes several thousand years, notjust one. Second, in a reversal the magnetic field doesnot disappear, because many poles form chaoticallyand so even though a compass would be useless, a mag-netic field still exists. And third, a weakening field is nota sign of an impending reversal anyway – it is normalfor the field strength to fluctuate in-between reversals.
But although there is a lot we do know about geo-magnetic reversal – we are pretty sure we know how thefield is generated and how it is able to change polarity
– mystery still surrounds whether reversals are sponta-neous or whether they are caused by some external trig-ger. Another enigma is that the reversal rate changesover time. During one 12-million-year period centredon 15 million years ago, for example, there were a stag-gering 51 reversals, while one 40-million-year periodcentred on 100 million years ago saw none.
The exact reason why such periods of reversal activ-ity are so different is still unclear. But we have discov-ered one possible explanation that could hold the key.To build up a picture of what we speculate and why, wemust first start with the basics – how the Earth’s mag-netic field is generated, and how it reverses.
Molten-metal magnet
Beneath the Earth’s crust, the interior of the planet canbe roughly described by three concentric layers (see fig-ure on p39). The mantle, which lies between the crustand 2890 km deep, is pretty solid, but if you wait longenough, it acts as a slowly moving material. The mantle
iSto
ckph
oto.
com
/DN
Y59
The polarity of the Earth’s magnetic field appears to have flipped randomly throughout history, withvisual representations of these changes looking like product barcodes. But François Pétrélis, Jean-Pierre Valet and Jean Besse have a new insight that could explain a pattern in the rate of reversals
When north heads south
is also an insulator, which is great for allowing us to scru-tinize the field pattern at the surface of the next layerdown, the outer core. (For insulators, the magnetic fieldequation is simple, and so knowing the field at the man-tle’s surface lets you calculate what lies below.) Theouter core is mostly molten iron and a few lighter ele-ments, and lies 2890–5150 km below the surface. Atthese depths, where the temperature reaches 4000 K,this outer-core layer is a fluid and it moves rapidly (abouta few kilometres per year). Finally, at the centre of theEarth is a solid-iron sphere, the inner core, which has aradius of 1228 km.
Scientists and engineers have discovered severalways to generate electric current and magnetic fieldfrom the mechanical energy of a moving electricallyconducting solid. One way to do this is to use the“dynamo effect”, in which a seed magnetic field isamplified by an instability to produce a larger field, andit is this phenomenon that also drives the magnetic fieldof the Earth. The liquid metal that makes up the outercore, which moves in convection cells powered by heat,passes through a small seed magnetic field, whichinduces an electric current to flow within it. This cre-ates another magnetic field that is stronger than thepre-existing field and reinforces it. In turn, more cur-rent flows and the field increases, in a self-sustainingloop called the geodynamo. How the flow in the liquid
core is organized is not clearly known but the Coriolisforce is also expected to play a part. A common modelis that the Earth’s rotation causes the liquid metal ofthe outer core to form spiralling eddies alignednorth–south, allowing the magnetic field generated byseparate cells to join up (figure 1).
On the Earth’s surface, the magnetic field appearsvery much like the dipole field that would be generatedif a huge magnet existed inside the Earth, aligned alongits axis of rotation. This is not exactly the case becausethe axis of the dipole is actually inclined by about 11°with respect to the rotation axis, which is why the polesof the dipole differ from the geographic poles. (Whenaveraged over a few thousand years, however, the dipoleaxis is aligned along the rotation axis so that the geo-graphic and the magnetic poles are at the same loca-tions.) The reason for this discrepancy is that themagnetic field is not a perfect dipole aligned with theaxis of rotation of the Earth, but has extra componentsthat collectively cause the pole to wander. These extracomponents are responsible for the “secular variation”– changes in the strength and location of the field on atimescale on the order of 100 years that represent10–20% of the total field.
Into reverse
The most dramatic and impressive consequences ofsecular variations are geomagnetic reversals. They werediscovered by Bernard Brunhes at the beginning of the20th century, when he noticed that the magnetization ofsome lava flows pointed the “wrong” way. This couldbe explained if the Earth’s magnetic field had pointedin the opposite direction when the lava solidified. Sincethen it has been established that reversals are a perma-nent and dominant feature of the Earth’s magneticfield. Their history has been deciphered using the mag-netization of lava flows or from sequences of sedimentsthat contain small magnetized particles that were ori-ented by the field when the rock was formed. The lastmagnetic-field reversal occurred about 780 000 yearsago, and the detailed reversal timescale is very wellknown for the past 160 million years (myr) and withrather good confidence for the past 300 myr (see box,and blue curve in figure 3 on p55).
At first glance it seems as if the field has reversed in arandom manner. But the “reversal frequency” – thenumber of reversals per million years – has variedmarkedly throughout history. Indeed, between 120 and80myr ago the average reversal frequency was zero, butsince then it has been rising. These long periods withoutany reversals are called “superchrons” and the exis-tence of several of these suggests that long intervalswithout reversals may have punctuated a large part ofour geomagnetic history. The changing reversal fre-quency over time gives us reason to wonder whether itis influenced by some external factor that changes ona similar timescale. The timescale on which super-chrons repeat therefore suggests that processes asso-ciated with geomagnetic-field reversals recur on a200 myr timescale.
As humans have only ever penetrated a tiny fractionof the way through the crust, and seismic waves can onlytell us so much about what lies beneath it, the Earth’sinsides remain pretty hidden from us. Our under-
physicsworld.comPhysics and the Earth: Geomagnetic reversal
52 Physics World March 2012
The Earth’s magnetic field is produced by the movement of liquid metal in the Earth’s outercore. Energy to power this movement comes from heat that is released as material from theouter core slowly freezes onto the solid inner core. This heat powers convection cells in theouter core, which keep liquid metal moving through the magnetic field, thus creating a biggerfield in a feedback effect known as the geodynamo. The Earth’s spinning motion causes theliquid to form spiralling eddies, the alignment of which allows the magnetic field produced ineach to join together to make an even bigger field.
1 At the core of the matter
inner coreoutercore
mantle
Physics World March 2012 53
Physics and the Earth: Geomagnetic reversal
standing of what goes on there has therefore reliedpartly on laboratory and computer experiments thattry to simulate what happens. To gauge whether suchmodels are successful we can measure their behaviourand see whether it matches that of the Earth, such ashaving a magnetic field that flips over time.
In the lab
During the last 30 years, several computer simulationsof the dynamo have attempted to recreate the processesinvolved in the generation of the Earth’s magnetic field.But a major difficulty is that computers do not haveenough processing power to accurately model an objectas large as the Earth. The equations describing thedynamo must therefore be simplified before they canmake any predictions. Yet although these models arenot perfect representations, it is significant that they doproduce fields with similar characteristics to the Earth.
In parallel, much information has been gained duringthe last 10 years from laboratory fluid-dynamo experi-ments that attempt to mimic the Earth’s liquid outercore. In these experiments, moving parts create flow ina container of liquid metal – usually liquid sodiumbecause of its good electrical conductivity and relativelylow density. Properties including the magnetic field aremeasured and finally in 2001 the dynamo effect wasseen in liquid sodium heated above 100 °C in two separ-ate experiments by Robert Stieglitz and Ulrike Müllerat the Karlsruhe Institute of Technology, Germany, andby a group led by Agris Gailitis at the University ofLatvia. These experiments dealt with liquid flowing ina pipe or in an array of pipes.
A different approach was from an experiment thatbegan in 1999 at the CEA research centre in Cadarache,France, in a collaboration with physicists at CEA Saclay,ENS Lyon and ENS Paris. What is known as the VonKármán sodium (VKS) experiment involves a turbu-lent swirling flow of liquid sodium between two counter-rotating discs, aligned along the same axis, within acylindrical container. A later version of the experimentproduced not only the dynamo effect but also sponta-neous reversals of the magnetic field. The reversalsshowed a remarkable degree of repeatability andappeared to be very similar to what is known aboutreversals of the Earth’s magnetic field. Similar behav-iour included a random field distribution, dipole col-
lapse, rapid polarity change, and recovery of the dipoleintensity. Interestingly, reversals were only observedwhen one of the discs rotated faster than the other.
A mechanism that explains why the magnetic fieldreverses in the experiment provides an interesting linkto the reversals of the Earth’s field (F Pétrélis, S Fauve,E Dormy, J-P Valet 2009 Phys. Rev. Lett. 102 144503).We know that in both cases the dipolar field is not theonly field of importance – if it were, the field would bestable – and that there is some non-dipolar contribution.In the VKS experiment a significant role is also playedby a second mode, which is quadrupolar – roughlyspeaking this is like two dipoles facing each other. Thecoupling between the two modes provides a pathway forthe dipole to flip from one polarity to the other: as thedipole field weakens, the quadrupole field grows, andthen as the dipole grows in the opposite direction, thequadrupole field shrinks. If this coupling is strongenough, the magnetic field spontaneously oscillatesbetween the two modes and their opposite polarities,yielding periodic field reversals. We believe that a sim-ilar process is involved in the case of the solar magneticfield, which oscillates with a period of 22 years.
Unlike the Sun, though, the coupling between thedipole and other modes in the Earth is not strongenough to create a regular, periodic oscillation. To trig-ger a reversal, velocity fluctuations in the liquid coreare also needed. For the Earth, a reversal involves twophases: a slow decrease of the dipole amplitude fol-lowed by a rapid recovery towards the opposite polar-ity. At the end of the first phase, the dipole–quadrupoleinteraction mechanism predicts that the magnetic fieldcan either reverse, or increase back to the initial polar-ity, accomplishing what is called an excursion: a rever-sal that begins to take place but is then aborted.
If the dipole does reverse, however, the total fieldnever actually goes to zero: at no point does it “switchoff”. In contrast, the dipolar field continuously changesshape during a reversal because the amplitude of othermodes (including quadrupolar) continuously increasesas the dipole decreases. Once the dipolar componenthas vanished, it is restored with the opposite polaritywhile the amplitudes of the other modes decrease.Paleomagnetic records of geomagnetic reversals showcharacteristics that are consistent with these predictions.
Experiments have therefore helped shed light on the
physicsworld.com
In thelaboratory,reversals wereonly observedwhen one ofthe discsrotated fasterthan the other
This graph shows the polarity of Earth’s magnetic field as far back as the Jurassic period some 160 million years (myr) ago. Purple denotes periodswhen the polarity of Earth’s magnetic field was the same as it is today, and white denotes periods when the polarity was the opposite. So in purple times(like the present) compasses would have pointed north, but in white times they would have pointed south.
Back and forth throughout history
CenozoicMesozoic
QNeogenePaleogeneCretaceousJurassic
01020304050
age (myr)
60708090100110120130140150160170
Physics World March 201254
Physics and the Earth: Geomagnetic reversal
Earth’s inner workings – both the mechanism by whichthe poles flip, and the intriguing fact that in the VKSexperiment reversals were only observed when thediscs rotated at different speeds.
Slow mover
As we have discussed, the Earth’s magnetic field iscaused by the dynamo effect in the liquid outer core,so for reversals we have to wonder what it is that per-turbs the liquid flow to cause the magnetic-fieldchange. One thing we know for sure is that the overallrate at which the Earth’s magnetic field reverses varieson a timescale of about 200 myr. (Note that the polesthemselves flip many times within this timescale:200 myr is the time it takes for the reversal frequencyto vary from zero – a superchron – to a maximum, andback again.)
It is difficult to link the change of reversal rate withturbulent flows within the Earth’s liquid core as thesehave a characteristic timescale of the order of just a fewcenturies, which is much less than 200 myr. Conversely,the variations are too short to be accounted for by theextremely long-term growth of the inner core. Changesin the Earth’s rotation are possible candidates, but theyoccur on timescales four orders of magnitude too short(20 000–100 000 years for Milankovitch cycles).
In the absence of any other mechanisms on thistimescale, could mantle dynamics be related to long-term variations in reversal frequency? In other words,does the key lie in what happens at the core–mantleboundary, where the slow-moving solid mantle meetsthe faster-moving liquid-metal outer core? Indeed,flow velocity of the mantle does not exceed a few cen-timetres per year and the characteristic time for mantleconvection is therefore on the order of 100 myr.
To understand how the mantle has behaved over thelast 300 myr, a good tool is the study of plate tectonics.The large plates that make up the globe (currently eight
major and many minor plates) have moved dramati-cally over the years. For example, 330 myr ago the con-tinents as we know them were assembled as onesupercontinent, Pangaea, which began to break up200 myr ago with the opening of the central Atlantic.Tectonic plates can include continental crust or oceaniccrust, and many plates contain both. Oceanic crust hasa different composition to continental crust and is moredense. As a result of this density stratification, oceaniccrust generally lies below sea level, while the continen-tal crust corresponds to continents.
At certain plate boundaries, the oceanic crust canreturn down into the mantle in a region known as a sub-duction zone, where the oceanic crust then becomesknown as oceanic slab. Seismic tomographic imageshave shown that many, but not all, slabs descend intothe lower mantle. Some may be deflected at around670 km deep and remain at the boundary between theupper and lower boundary, the lower mantle being ofmuch higher viscosity. However, a large number ofslabs do sink into the lower mantle, and can reach thecore–mantle boundary in some 80–100 myr as part ofhuge mantle convection cells. It therefore becomesclear that what happens on the surface of the Earth –specifically the location of plates and subduction zones– could directly relate to the liquid outer core over along enough timescale.
Thus, assuming that heat-flow conditions at thecore–mantle boundary would control reversal fre-quency and also influence mantle convection, we shouldexpect some link between reversal frequency and platetectonics. As in the laboratory experiment where rever-sals only occur when the discs’ velocities are different,we suggest that the reversal frequency of the Earth’smagnetic field is constrained by a similar symmetry-breaking: some unevenness between the mantle flowsof the Earth’s northern and southern hemispheres.
We speculate that the long-term evolution in reversal
physicsworld.com
The authors have found that the geographic distribution of the Earth’s continentsthroughout history seems to be linked to the frequency at which the Earth’smagnetic field reverses (see figure 3). These diagrams show how they defined theparameter they used to describe where the continents were. The continents wereenclosed by their convex envelopes (red) and the distance from the equator of thecentre of masses of these was measured. Examples here show the Earth’scontinents (a) at present, (b) 65 myr ago, (c) 200 myr ago and (d) 260 myr ago. In(a) and (c) there is a larger continental surface in the north and in (b) and (d) thereis more in the south.
2 Continents enclosed
a b
c d
We shouldexpect somelink betweenreversalfrequency andplate tectonics
Pole position This computer simulation by C Gissinger shows the “dynamo effect” inthe Earth’s liquid outer core. This effect generates the Earth’s magnetic field (shownhere by looping lines). The radial component of the magnetic field is represented atthe surface of the model, which corresponds to the core–mantle boundary.
C G
issi
nger
Physics World March 2012 55
frequency is caused by changes at the core–mantleboundary, which are linked to the equatorial symme-try of the geographic distribution of the continents(2011 Geophys. Res. Lett. 38 L19303). To measure this,we considered the convex envelope of the continentsback through history (figure 2) and measured the dis-tance of its centre of mass from the equator. The centreof mass moved north and south of the equator overtime, when the continents were top- or bottom-heavy.
When we compared this parameter with the geo-magnetic reversal frequency, we found striking simi-larities (figure 3). The quantity varies on the sametimescale as the reversal frequency and the two arestrongly correlated. The similarities between the twocurves suggest that a link exists between continentalmotion and the geodynamo processes that take placedeep inside the Earth’s liquid core.
A detailed description of this coupling is not cur-rently possible because the evolution of mantle prop-erties back in time is not yet well known. All we cansuggest is that plate motions are indicators of motionsdeep inside the mantle, and that these motions areassociated with changes in the boundary conditions atthe core–mantle boundary. These changes modify thesymmetry of the liquid flow within the outer core andchange the reversal frequency. The mechanisms thatdrive this correlation are yet to be understood.
The current results suggest that plate tectonics – thevisible motion of the plates together with the mantlemotions that drive them – have exerted a significantcontrol over geomagnetic reversal frequency for atleast the past 300 myr. They thus bring additional evi-dence when assessing the importance of mantle dy-namics in the mechanisms driving long-term dynamoprocesses. The next step is to further constrain the linkbetween plate motions and the mantle, and ultimatelyto be able to relate this to the physical properties at thecore–mantle boundary. ■
physicsworld.com
This graph shows the temporal evolution of geomagnetic reversal frequency (blue)and a parameter that shows the distance from the equator of the centre of mass ofEarth’s continents (red). The frequency at which the Earth’s magnetic poles haveflipped has changed throughout history. At some points in history – at around–300 and –100 myr on this graph, for example – no reversals took place for longperiods of time. In-between these times the rate of reversals seems to rise and fall.The authors speculate that this long-term evolution in reversal frequency is linkedto the equatorial symmetry of the geographic distribution of the continents. Curveswere normalized, and shifted in the vertical direction, for comparison.
3 Reversal frequency meets its match
–300 –200age (myr)
inte
nsity
–100 0
0
IOP Conference SeriesEarth and Environmental Science
Five good reasons why youshould publish your proceedingswith IOP Publishing:
1 Flexible: From plenary to poster papers, large or small events, we can accommodate them all
2 Efficient: Professional support and advice at all stages of the publication process
3 Rapid: Online publication within four to six weeks of receipt of accepted articles
4 High quality: Acknowledged time and time again by our customers
5 Open access: All articles are free to read and free to download as soon as they are published
Call us now on +44 117 930 1252 or visit our website where you can get an instant quote.
conferenceseries.iop.org
PRECISION ENGINEERING AND MECHATRONIC SOLUTIONS IN AMBIENT, VACUUM AND CRYOGENIC ENVIRONMENT.
WWW.JPE.NL
JANSSEN PRECISION ENGINEERING
Flip Mirror Holders– for all orientations –
mountable in all OWIS® systems and on pin
manual or motorized
deflection to left or right
Mad
e in Germ
any
by
D®
OWIS GmbH • D-79219 Staufen • + 49 (0) 76 33 / 95 04 - 0 • www.owis.eu
®
JOIN US FOR THIS FREE WEBINARWednesday 28 March 2012,
3.00 p.m. BST
Simulating charged-particle sources and beams
W E B I N A R S E R I E S
Register now at physicsworld.com/cws/go/webinar28
From electron lithography and ion sources to field-tip emitters for flat-screen displays, the modelling of charged-particle devices is critical in ensuring optimum efficiency and performance. This webinar discusses the modelling of space-charge-limited emission and particle tracking using the Opera software suite. Simulation software lets designers characterize their devices simply and effectively. Coupled multiphysics simulations allow the study of beam charging and current flow in imperfect dielectrics and heating effects from both primary and secondary emission. Advanced interactions can be included in simulations, such as the ionization of a background gas to form plasma ion beams.
We will explore a variety of systems, from simple thermal electron sources to space-charge-compensated ion beams and multispecies plasmas.
This 3D satellite and bathymetry model shows the topography ofthe Earth’s crust over the North Atlantic. Iceland (right of centre)sits on the Mid-Atlantic Ridge – a mid-oceanic ridge that isextremely volcanically active. Lava pushing up beneath thisridge creates new oceanic crust, pushing the North Americanplate (left) and the Eurasian plate (right) apart. Greenland is thepale landmass seen above left, which is mostly covered by theGreenland ice sheet. The British Isles can be seen bottom right,and above right is the mountainous region of western Norway.(Image courtesy German Aerospace Center/DLR/Science Photo Library)
Deep trenches
PWMar12earth-trenches-2 16/2/12 15:20 Page 57
In March 2009 a “swarm” of more than 50 small earth-quakes struck within a few kilometres of the southernend of the San Andreas fault in California. Severalhours after the largest of these, a magnitude-4.8 tremorthat occurred on 24 March, the state’s earthquakeexperts held a teleconference to assess the risk of aneven bigger quake striking in the following days, giventhe extra stress exerted on the fault. They concludedthat the chances of this happening had risen sharply, tobetween 1 and 5%, and therefore issued an alert to thecivil authorities. Thankfully, as expected, no majorquake actually took place.
What happened a week later in the medieval town ofL’Aquila in central Italy was very different. On31 March a group of seven Italian scientists and engi-neers met up as full or acting members of the country’sNational Commission for the Forecast and Preventionof Major Risks to assess the dangers posed by a swarmthat had been ongoing for about four months and whichhad seen a magnitude-4.1 tremor shake the town theday before. The experts considered that the chances ofa more powerful quake striking in the coming days orweeks were not significantly increased by the swarm,and following the meeting local politicians reassuredtownspeople that there were no grounds for alarm.Tragically, in the early hours of 6 April a magnitude-6.3earthquake struck very close to L’Aquila and left 308people dead. The seven commission members are nowon trial for manslaughter, and the then head of Italy’sCivil Protection Department, who set up but was notpresent at the 31 March meeting, is also being investi-gated for the same offence.
In the wake of the L’Aquila earthquake, the CivilProtection Department appointed a group of expertsknown as the International Commission on Earth-quake Forecasting (ICEF) to review the potential ofthe type of forecasting used in California. Known asshort-term probabilistic forecasting, it involves calcu-lating the odds that an earthquake above a certain sizewill occur within a given area and (short) time period.The technique relies on the fact that quakes tend tocluster in space and time – the occurrence of one ormore tremors tending to increase the chance that othertremors, including more powerful ones, will take placenearby within the coming days or weeks.
In a report explaining its findings and recommenda-
tions, published last August, the ICEF points out thatwhile such forecasting can yield probabilities up to sev-eral hundred times background levels, the absoluteprobabilities very rarely exceed a few per cent. Never-theless, the commission believes that this short-termforecasting can provide valuable information to civilauthorities and urged Italy and all other countries inseismically active regions to use short-term-forecast-ing models for civil protection.
Scientists have developed many such models, eachof which makes slightly different assumptions aboutthe statistical behaviour of earthquake clustering. Theyare now trying to work out which of these models is themost accurate, and ultimately hope to enhance the pre-dictive power of these models as we gain a better under-standing of basic earthquake physics.
“In the past there hasn’t been a lot of motivation forgovernments to take this short-term forecasting seri-ously,” says the ICEF’s chairman, Thomas Jordan of theUniversity of Southern California, Los Angeles. “Butthat is changing, partly because of what happened atL’Aquila.” Jordan argues that the tragedy at L’Aquilahighlights how vital it is for us to understand what themost reliable types of forecasting are so that we have thebest possible information at our fingertips. But he alsobelieves it underlines the need for governments to workout exactly how to respond to such forecasts and in par-ticular under what conditions they should issue alarms.
Faulty matters
The development of probabilistic forecasting marks achange in strategy for earthquake scientists. Previously,seismologists had pursued deterministic prediction,which involved trying to work out with near certaintywhen, where and with what magnitude particular earth-quakes would strike. Researchers came to realize, how-ever, just how complex earthquakes are and howdifficult it is to predict them.
Most earthquakes occur on faults separating twoadjacent pieces of the Earth’s crust that move relativeto each other. Normally, the faults are locked togetherby friction, and stresses steadily accumulate over time.But when the faults reach breaking point and two rockfaces suddenly slide past each other, a huge amount ofenergy is released in the form of heat, rock fracture andearthquake-causing seismic waves.
physicsworld.comPhysics and the Earth: Earthquakes
58 Physics World March 2012
As seven Italian experts stand trial on manslaughter charges for underplaying the risk of a majorearthquake, Edwin Cartlidge investigates the latest in earthquake forecasting
How to forecast an earthquake
Edwin Cartlidge is ascience journalistbased in Rome, [email protected]
Physics World March 2012 59
Physics and the Earth: Earthquakesphysicsworld.com
Dav
id P
arke
r/Sc
ienc
e Ph
oto
Libr
ary
Scarred Earth
The San AndreasFault in California.
Physics World March 201260
Physics and the Earth: Earthquakes
Scientists have tried to predict earthquakes on thebasis that the slow build-up and then sudden release ofstress on any given fault occurs cyclically, with nearlyidentically powerful tremors spaced equally in time. Anumber of factors complicate this simple picture,including the fact that a single fault can slip at differ-ent stress levels, and also that interactions betweenneighbouring faults are highly complex.
An alternative route to predicting earthquakes is totry to identify precursors – physical, chemical or bio-logical changes triggered in the build-up to a fault rup-ture. Perhaps the earliest example, often heard infolklore, is the idea that animals flee an area aftersomehow sensing an impending quake. Other possibleprecursors include changes in the rates of strain or con-ductivity within rocks, fluctuations in groundwater lev-els, electromagnetic signals near or above the Earth’s
surface, and characteristic foreshocks (a distinctive pat-tern of smaller quakes that would precede a largerquake). However, the ICEF reported that it is “notoptimistic” that such precursors can be identified in thenear future, and is “not convinced” by the claims ofGioacchino Giuliani, a technician at the Gran SassoNational Laboratory near L’Aquila, who hit the head-lines after claiming to have predicted the L’Aquilaquake using his prediction system based on variationsin the local emissions of radon gas. The committee’sreasoning is based on Giuliani’s treatment of back-ground radon emissions and also the fact that he hasyet to publish his results in a peer-reviewed journal.
An alternative to trying to predict earthquakes aheadof time is to send out a warning once a quake hasstarted, giving people a few seconds’ notice of impend-ing ground-shaking by exploiting the fact that infor-mation can be sent at close to the speed of light whileseismic waves travel at the speed of sound. Japan makesuse of such warning systems, but unfortunately theycannot provide accurate information on an earth-quake’s magnitude, and also cannot alert people closeto the earthquake’s epicentre because the effects thereare so immediate.
Uncertain times
Given the difficulty of earthquake prediction and thelimitations of early warnings, forecasting is the maindefence against earthquakes. And the key forecastingtool is the seismic-hazard map (figure 1). These arebased on long-term time-independent models, whichreveal how often – but not when – a certain-sized earth-quake is likely to occur. The models, and therefore themaps, do not tell us how the probabilities of major earth-quakes change over time as a result of other quakes tak-ing place but instead reveal the expected spatialdistribution of quakes of a certain size happening overa certain time period (usually on the scale of decades).The distribution in space relies on seismographic dataand historical records, while the distribution by size usesa statistical relationship known as Gutenberg–Richterscaling, which says that the frequency of earthquakesfalls off exponentially with their magnitude.
Seismic-hazard maps allow governments to tune theseverity of building regulations according to an area’sseismicity (as well as other factors such as the suscepti-bility of the local terrain to seismic waves) and alsoenable insurance companies to set premiums. However,the underlying models are only as good as the data usedto calibrate them. And unfortunately, seismographicand historical records generally only go back a fractionof the many hundreds of years that typically separatethe occurrence of major quakes on most active faults.
This limitation lay behind the complete failure toanticipate the magnitude-9.0 earthquake that struckthe Tohoku region in Japan in March last year, whichunleashed a devastating tsunami and caused the melt-down of several reactors at the Fukushima Daiichinuclear plant. The country’s current seismic-hazardmaps provide very detailed information about earth-quake probabilities across the whole country but,according to ICEF chairman Jordan, they indicated a“very low, if not zero” probability for such a powerfulquake because no such quake had occurred in the
physicsworld.com
A key tool used in earthquake forecasting is the seismic-hazard map. This map of Italy, basedon one produced by the country’s National Institute of Geophysics and Volcanology, shows theprobability, as of 1 January 2012, that within the next 10 years an earthquake of magnitude5.5 or greater will occur. The map is split into zones in which the “stress field” is fairlyhomogeneous, and so similar probabilities apply. These maps are based on long-term time-independent forecasting models, but we are now seeing a rise in the use of short-term time-dependent models that take into account recent events and give increased probabilities ofmajor quakes. Despite this, seismic-hazard maps remain a useful tool because they allow long-term planning, such as setting building regulations – one of the best defences against loss oflife when an event does strike.
1 Mapping seismic hazard
probalility0 0.12 0.24
Physics World March 2012 61
Physics and the Earth: Earthquakes
Tohoku region within the past 1000 years. “They had amagnitude cut-off in that region of Japan,” Jordanpoints out. In other words, such a high-magnitudeearthquake was never expected to strike there.
Jim Mori, an earthquake scientist at the Universityof Kyoto, says that Japan’s hazard maps are now beingre-evaluated to “consider the possibility of magnitude-9 or larger earthquakes”. However, he believes thatthere are unlikely to be “drastic changes” to Japaneseearthquake research, adding that the inclusion of aone-in-a-thousand-year event like that in Tohokuwould probably not change the maps a great deal.
Short-term solutions
To calculate how the probability of a major earthquakechanges in time by accounting for the occurrence ofother quakes, researchers have developed differentkinds of time-dependent forecasting models. Some ofthese models make forecasts for the long term, i.e. overperiods of several decades. The simplest form of thesemodels assumes that the time of the next earthquakeon a particular fault segment depends only on the timeof the most recent quake on that segment, with arepeating cycle of quakes made slightly aperiodic (totry to match the models with observations) by intro-ducing a “coefficient of variation” into the cycle. Moresophisticated versions of these models make the time tothe next quake also dependent on the past occurrenceof major earthquakes nearby.
For a fault segment that has not ruptured for some-thing approaching its mean recurrence time inferredfrom historical data, these models can yield probabili-ties roughly twice those obtained with the time-inde-pendent models for the occurrence of major quakes.However, such long-term time-dependent models havenot fared well when put to the test. In 1984, for exam-ple, the US Geological Survey estimated with 95% con-fidence that a roughly magnitude-6 earthquake wouldrupture the Parkfield segment of the San Andreas faultin central California before January 1993. This predic-tion was made on the basis that similar-sized earth-quakes had occurred on that segment six times since1857, the last of which took place in 1966. In the end,however, the next magnitude-6 event did not take placeuntil 2004. Similar failures have occurred when tryingto predict earthquakes in Japan and Turkey.
The approach taken with short-term forecasting,which provides probabilities of earthquakes occurringover a matter of days or weeks, is fundamentally dif-ferent. Once an earthquake has taken place and thestress on that particular fault segment relieved, thechances of another comparable quake taking place onthe same fault segment in the short term tends to belower. But the probability of a quake taking place on aneighbouring fault, thanks to the increased stressbrought about by the original tremor, increases.
Short-term models come in a number of differentguises. In single-generation versions, such as the Short-Term Earthquake Probability (STEP) model used bythe US Geological Survey to make forecasts inCalifornia, a single mainshock is assumed to trigger allaftershocks. This contrasts with multiple-generationmodels, such as Epidemic-Type Aftershock Sequence(ETAS) models, in which each new daughter earth-
quake itself spawns aftershocks.When seismic activity is high, short-term time-depen-
dent models can yield probability values that are tensor even hundreds of times higher than those calculatedusing time-independent models. However, scientistsdo not yet know which of the many different types ofshort-term model is the most reliable. Jordan says thateven the California Earthquake Prediction EvaluationCouncil, of which he is a member, does not use prop-erly tested models but instead often relies on “back ofthe envelope calculations” to generate its forecasts.
Testing the data
To improve confidence in the models, in 2007 Jordanset up a programme known as the Collaboratory for theStudy of Earthquake Predictability (CSEP). This pro-vides common software and standardized proceduresto test models against prospective seismic data, usingindependent testers, rather than the authors, to put themodels through their paces. Starting from a single testcentre in California, it now features centres in otherparts of the world, including Italy and Japan, wherefaulting behaviour, and hence models, are different.
In Italy, Warner Marzocchi and Anna MariaLombardi of the National Institute of Geophysics andVulcanology tested an ETAS model against real after-shock data following the L’Aquila earthquake in 2009.Using all of the seismic data since, and including themainshock on 6 April, the researchers updated theirmodel on a daily basis and carried out aftershock fore-casts until the end of September 2009. They found thatthe calculated distributions of aftershocks broadly tal-lied with those actually observed. Marzocchi has sinceteamed up with Jiancang Zhuang of the Institute ofStatistical Mathematics in Tachikawa, Japan, to see ifthe model can in principle be used to forecast main-shocks, as well as aftershocks, on the basis that main-shocks are simply aftershocks that are more powerfulthan their parent tremors, which are then labelled asforeshocks. After comparing real data with the model,Marzocchi concluded “I am reasonably confident that
physicsworld.com
Short-termforecastingprovidesprobabilities ofearthquakesoccurring overa matter ofdays or weeks
Scene of destruction An aerial view of Christchurch Cathedral following the earthquake inChristchurch, New Zealand, in February 2011.
New
Zea
land
Def
ence
For
ce
Physics World March 201262
Physics and the Earth: Earthquakes
we can use this kind of model to forecast mainshocks.”In fact, a few months after the L’Aquila quake
Marzocchi and Lombardi used the same model retro-spectively to see what kind of forecast could have beenmade of the 6 April mainshock. They found that a fewhours before the quake the model would have givenodds of about 1 in 1000 that a powerful tremor wouldstrike within 10 km of L’Aquila within three days, upfrom the long-term time-independent probability of 1 in 200 000.
Researchers in New Zealand, meanwhile, have beenusing probabilistic forecasting to calculate the changingrates of aftershocks in the Canterbury region, follow-ing the magnitude-7.1 mainshock near the town ofDarfield in September 2010 and the more lethal mag-nitude-6.2 aftershock that struck close to Christchurchin February last year. Matthew Gerstenberger and col-leagues at GNS Science, a geophysics research insti-tute in New Zealand, have used an ensemble of short-,medium- and long-term models to keep the public upto date and to revise building codes in the region. Aspointed out by Gerstenberger, who developed theSTEP model, time-independent forecasting on its ownwould be inadequate. “Christchurch was a moderate-to-low hazard region in the national seismic-hazardmodel prior to these earthquakes,” he says. “But theongoing sequence has increased its estimated hazard.”
Dramatic changes to earthquake probabilities havealso been calculated in Japan, following the Tohokuearthquake last year. Shinichi Sakai and colleagues atthe University of Tokyo have worked out that thechances of a magnitude-7 or greater earthquake strik-ing the Tokyo region have skyrocketed to 70% over thenext four years. This contrasts with the Japanese gov-ernment’s estimate of a 70% chance over the next 30years. The researchers have stated that they obtain a
much higher probability because they take into accountthe effects of a fivefold increase in tremors in Tokyosince the March 2011 event.
The limits of modelling
While ETAS- and STEP-like models can improve onthe information available from time-independent fore-casts, they are no panacea. In particular, they oversim-plify the spatial properties of triggering, by representingearthquakes as point, rather than finite-length, sources,while also ignoring earthquakes’ proximities to majoractive faults. According to ICEF member Ian Main ofthe University of Edinburgh, incorporating fault-basedinformation into these models might provide additionalprobability gain compared with time-independent cal-culations, given adequate fault and seismicity data. Butsignificant improvements will only be made by gaininga better understanding of the physics of fault interac-tions. One particular challenge is to understand theextent to which one earthquake triggers anotherthrough the bulk movement of the Earth’s crust andhow much it does so via the seismic waves it generates.“We know roughly how the statistics of earthquakesscale, and that is why we use statistical models,” saysMain. “But the precise physical mechanism that leadsto this scaling is underdetermined.”
Even if models can be significantly improved, theywill, for the foreseeable future at least, only ever pro-vide quite low probabilities of impending majorquakes. That leaves the civil authorities responsible formitigation actions in a difficult position. The ICEF rec-ommends that governments try to establish a series ofpredefined responses, based on cost–benefit analyses,that local or national authorities could automaticallyenact once certain probability thresholds have beenexceeded, from placing emergency services on higher
physicsworld.com
Danger zones This map shows seismic activity from 1900 to 2010. Circles represent earthquakes (their size scaling with magnitude), with the depth of the earthquake’sfocus being 0–69 km (red), 70–299 km (green) or 300–700 km (blue). Yellow triangles are active volcanoes, while the yellow lines are tectonic plate boundaries.
USG
S
Scientists donot yet knowwhich of themany differenttypes of short-term model isthe mostreliable
Physics World March 2012 63
Physics and the Earth: Earthquakes
alert to mass evacuation. But Marzocchi points out thiswill not be easy. “I can say from a scientific point of viewthat such and such is the probability of a certain earth-quake occurring,” he says. “But acting on these lowprobabilities would very likely mean creating falsealarms. This raises the problem of crying wolf.”
Some scientists continue to believe, on the otherhand, that precursors will be found. FriedemannFreund, a physicist at NASA’s Ames Research Centernear San Francisco, is investigating a number of poten-tial precursors, including electromagnetic ones, and hemaintains that the combination of such precursors,even if individually they are “fraught with uncertainty”,will lead “in the not-too-distant future to a robustearthquake forecasting system” (see January 2009pp22–25). He contends that seismologists are “tooproud to admit that other scientific disciplines couldhelp them out”.
Danijel Schorlemmer of the University of SouthernCalifornia, who is joint leader of the CSEP model-test-ing project with Jordan, disagrees. He insists that deter-ministic earthquake prediction will not be possible “inmy lifetime” and adds that, even though he hopes pre-cursors will be identified, “the search has been unsuc-cessful so far”.
For Jordan, as for many other seismologists, ensuringthat buildings are made as resistant as possible remainsthe most important strategy for combating the destruc-tive power of earthquakes. But he believes that short-term probabilistic forecasting, if carried out properly,has an important role to play. “This approach is tricky,”he concedes, “because no-one can quite agree on whichare the best models. So we have uncertainty on uncer-tainty. But can we ignore the information that they giveus? The earthquakes in L’Aquila and New Zealandtaught us we don’t have that luxury.” ■
physicsworld.com
Devastated Building damage in the village of Onna, days after theL’Aquila earthquake struck Italy in April 2009.
Shut
ters
tock
/Fra
nco
Volp
ato TrueSurface™
Microscopy
Topographic Raman Imaging
WITec GmbH, Ulm, GermanyTel. +49 (0)731 [email protected]
www.witec.de
NEWPRODUCT
Automated Raman-AFM System alpha500 with Attached Sensor for Profilometry
Confocal . Raman . AFM . SNOMTrueSurface™ Microscopy
WITec´s new TrueSurface™ Microscopy allows confocal Raman imaging guided by surface topography. The topographic coordinates obtained by an integrated profilometer are used to perfectly follow the sample surface in confocal Raman imaging mode.
The result is an image revealing chemical properties at the surface of the sample,even if it is rough or inclined.
Topographic Raman Image of a Pharmaceutical Tablet
ReviewsReviewsphysicsworld.com
64 Physics World March 2012
There is something about time thatseems to perplex us. Time is every-where, and nowhere; it is easy tomeasure, but hard to define; the pastseems different from the future, butour equations do not tell us why. Nowonder books about the nature oftime have appeared almost as regu-larly as, well, clockwork, fromStephen Hawking’s A Brief History ofTime (1988) to Paul Davies’ AboutTime (1995), Sean Carroll’s FromEternity to Here (2010) and RogerPenrose’s Cycles of Time (2010). Infact, I am guilty of adding to the heapmyself, with In Search of Time (2008).
The latest contribution is anotherbook called About Time, this one writ-ten by Adam Frank, an astrophysicistat the University of Rochester inupstate New York. With all the goodtitles having been taken, Frank canperhaps be forgiven for re-usingDavies’ from 17 years ago. Moreimportantly, he has found a largelyuntapped branch of the temporallandscape to explore. Time, it seems,is the dimension that keeps on giving.
In this ambitious and sprawlingwork, Frank attempts to weavetogether the cosmological and the cul-tural – to show that our theories aboutspace and time, and how we live intime, are deeply intertwined. Oneexample of what Frank calls the“braiding” of cosmology and cultureconcerns the mechanical clock, whichin his view is “without a doubt, themost important invention of the lastthousand years”. Clocks becamewidespread in Europe in the 14th cen-tury, bringing a more structured work-day and, arguably, a more rushed wayof life. But the ubiquitous clock alsochanged the way we imagine the cos-mos itself, as the metaphor of the“clockwork universe” began to takehold. The medieval philosopherNicole Oresme, Frank tells us,described the world as “a regularclockwork that was neither fast norslow, never stopped, and worked insummer and winter”. As for the plan-ets circling above, Oresme foundthem “similar to when a person hasmade a horologe [a clock] and sets it in
motion, and then it moves by itself”.To drive the point home, Frank addsthat “People had refashioned theirdaily, intimate worlds to the beat ofthe clock, so it was only natural thattheir conception of the surroundinguniverse should follow.”
At this point we are about one-quarter of the way into the book. Nextcomes Newton and his postulate ofabsolute space and time, whichformed the foundation for his laws ofmechanics and his law of universalgravitation. Often described as the cli-max of the scientific revolution, this isan oft-told tale, but Frank gives it newlife by telling, in parallel, the story ofAmbrose Crowley. An English indus-trialist and contemporary of Newton,Crowley built an ironworks nearNewcastle that was, in its own way, asrevolutionary as Newton’s physics.This ironworks operation was theforerunner of the modern factory, andFrank argues that it succeeded be-cause of Crowley’s “genius for orga-nizing human activity across spaceand time”.
Frank finds these “braids” every-where. After the scientific revolutioncame the industrial one, accompaniedby the huffing and puffing machinesthat nurtured the study of thermody-namics. And it was the laws of thermo-dynamics that gave rise to ourconception of the “heat death” of theuniverse, a far-off but terrifying (andseemingly inescapable) catastrophe.Then, a few decades later, radio broad-casting gave us, for the first time, a“national now”, just as Einstein’s the-ory of relativity was showing just howfragile the notion of “now” really is.
Frank includes quite a lot of mater-ial here, from the birth of agricultureand the social effect of washingmachines to the pros and cons of mul-tiple universes. Considering the scopeof the text, it is a remarkably tight nar-rative. And he is very much up tospeed on the latest speculations onwhat may have preceded the BigBang, from the “colliding branes”imagined by Paul Steinhardt and NeilTurok in an offshoot of string theoryto the “eternal inflation” modelchampioned by Sean Carroll and oth-ers. But there are a few bumps alongthe way. He loves the phrase “mater-ial engagement” a little too much; inone spot it appears four times inabout a page. In discussing 21st-cen-tury time pressures, a surprisinglylarge chunk of text is devoted to the
Dan Falk
The time of our lives
About Time: From
Sun Dials to
Quantum Clocks,
How the Cosmos
Shapes Our Lives
Adam Frank2012 OneworldPublications, £12.99pb 432pp
In good time
The astronomicalclock on the Old TownHall in Prague.
Shut
ters
tock
/Dan
iel
Korz
enie
wsk
i
physicsworld.com Reviews
65Physics World March 2012
effects of Microsoft Outlook; I foundmyself wondering whether life wouldreally be any less rushed underiCalendar or Windows Live Mail. TheGregorian reform of the calendar,meanwhile, gets barely a mention,while some digressions, such as a dis-cussion of the “Sokal hoax” of 1996,come out of the blue.
Then there is the feel-good ending.Aficionados of popular-physics writ-ing will remember Steven Weinberg’sclaim in The First Three Minutes (1977)that “[The] more the universe seemscomprehensible, the more it seemspointless.” Frank, however, is untrou-bled by such Weinbergian pessimism.Because of the braiding of the culturaland the cosmological, he argues, weare “participants” in the universe; weare its “co-creators”; the universe con-tains “a vital place for us”. For Frank,there is meaning to be found in thisvast, dark cosmos, and “If we can rec-ognize the enigmatic entanglementbetween cultural time and cosmictime, we might stop looking for God inthe form of ‘final theories’ and find our
rightful – and rightfully central – placein the narratives of creation.” Our uni-verse, Frank argues, is “suffused withmeaning and potential”.
Some readers will no doubt warm tothis message. A sceptic, however,might counter that such a reader is likea carpenter who builds their housewith a window, peers out at the worldoutside – and then takes comfort inthe fact that they happen to have built
the window that frames their view ofthe universe. Sure, being humanrequires that we experience the uni-verse in a particular way, but does thatreally make us cosmic “participants”?I will also say that, in a book of thislength, the second-to-last page is a bitlate in the game to suddenly declarethat Buddhism may hold the answer.(The author observes that “Buddhistphilosophy emphasizes a doctrinecalled dependent arising [in which]everything in the universe…dependson everything else. Nothing ever existsentirely alone.”)
For those who have been samplingthe recent “time” books, there ismuch that will be familiar here. Evenso, the book contains enough that isoriginal to keep even seasoned “timebuffs” engaged, and its author is afirst-rate storyteller. Reading AboutTime would be time well spent.
Dan Falk is a science journalist currentlypursuing a Knight Science JournalismFellowship at the Massachusetts Institute ofTechnology, e-mail [email protected]
URL: http://serc.carleton.edu/eet/index.html
So what is the site about?The Earth Exploration Toolbook (EET) website ishome to a series of projects, or “chapters”, that aredesigned to teach older children and young adultsabout geoscience. At the time of writing there were43 different chapters to choose from, on subjectsranging from climate and atmospheric science toplate tectonics and astronomy. Each chapter givesstudents a bit of background on the subject, pointsthem towards online sources of real earth-sciencedata, and then shows them how to analyse thesedata for themselves. According to the site, such“data-rich learning experiences” will help studentslearn to solve real-world problems in the future, andwill also teach them how to design and conduct scientific investigations. In September 2011 thesite received one of Science magazine’s SPOREawards, which recognize excellence in onlinescience education.
What sorts of earth-science data are wetalking about here?Oh, the usual suspects. Earthquake locations andmagnitudes. Air-quality information recorded byNASA satellites. Ocean temperatures measuredduring and after El Niño cycles. Sediment cores.Weather patterns. A few different climate models.In fact, pretty much anything you can think of thatrelates to earth science crops up at least once onEET; one project even requires students to analyseimages of other planets in our solar system. Thecommon thread here is real data, packaged in auser-friendly way.
Who is behind it?Most members of the EET team – including its leadscientist/educator, Tamara Ledley – are part of aUS non-profit organization called TERC, which promotes science and mathematics education. A few team members hold posts at other earth-science institutions, such as the US NationalOceanic and Atmospheric Administration, whileothers are affiliated to the Science EducationResearch Center at Minnesota’s Carleton College.Ledley and her colleagues also work with geoscientists around the world to develop newchapters and revise existing ones.
Can you give me an example of a project?One of the more visually appealing projectsinvolves the IRIS Seismic Monitor, a continuallyupdated, zoomable online map that displays the
location of every earthquake our planet has experienced in the past five years. The most recentquakes are marked with circles (the size of thecircle depicts the earthquake’s magnitude), whilethe older ones show up as tiny pink dots that linethe edges of tectonic plates. The “Ring of Fire”around the Pacific Ocean never looked so good, butpretty pictures are not the goal here: the IRIS map isreally just a way of introducing students to thenascent science of earthquake prediction (seepp58–63). The main aim of the project is to get students to prepare and analyse their ownGeographic Information Systems (GIS) data using some basic software packages – a great “trialrun” for more advanced work.
Why should I visit?That depends on who you are. EET is clearlydesigned for high-school students, first-year undergraduates and their teachers, and these threegroups will undoubtedly benefit most from the site’sintensive, data-rich element. A lot of the chapterswould make great class activities or science-fairprojects. However, visitors who do not wish to godata-digging will still enjoy browsing through thesite’s wealth of background information and ready-made visuals, which include the above-mentionedearthquake map and a QuickTime movie depictingthe extent of Arctic sea ice between 1976 and2006. So if the earth-science articles in this specialissue have piqued your curiosity, and you want tolearn more, this site is a good place to start.
Web life: Earth Exploration Toolbook
I found myselfwonderingwhether life wouldreally be any lessrushed underiCalendar orWindows Live Mail
JOIN US FOR OUR LATEST FREE ONLINE LECTURETuesday 6 March 2012, 4.00 p.m. GMT
Quantum man: Richard Feynman’s life in science
ONLINE LECTURE
Register now at physicsworld.com/cws/go/webinar29
It took a man who was willing to break all the rules to tame a theory that breaks all the rules. This lecture will be based on Lawrence M Krauss’ new book Quantum Man: Richard Feynman’s Life in Science. Krauss will present a scientific overview of the contributions of Feynman, as seen through the arc of his fascinating life. From quantum mechanics to
antiparticles and from Rio de Janeiro to Los Alamos, a whirlwind tour will provide insights into the character, life and accomplishments of one of the 20th century’s most important scientists, as well as an object lesson in scientific integrity.
Tel: +44 (0)1256 467055, Fax: +44 (0)1256 842929, Email: [email protected], www.testbourne.com
Testbourne Ltd
Products for Industry, Research & Development
Unit 2, Hatch Industrial Park, Greywell Road, Hatch, Basingstoke, Hampshire, RG24 7NG, England
Testbourne Ltd has been supplying high purity metals, alloys & compounds to
industries such as photovoltaics, glass coatings, data storage, thin-films,
electronics, electro-optics and research establishments for over 30 years. You
will find an extensive selection of materials available in fabricated forms
including sputtering targets, evaporation materials, powders, wires, rods & sheets.
We can also accommodate any custom requirements you may have.
Visit us at: www.testbourne.com
physicsworld.com Reviews
67Physics World March 2012
My immediate response to the title ofQuantum Physics for Poets is “I am notworthy.” Although I have written acouple of limericks and a particularlydire sonnet, I am hardly a poet.Luckily, the book’s target audience isnot actually so limited. Instead, theauthors’ stated aim is to introducequantum physics in a way that enablesarts students – and presumably poetsare regarded as the ultimate of that ilk– to get their heads around this trulymind-bending subject.
With this principle in mind, I was alittle disappointed with the verboseintroduction, in which drawn-out par-allels are made with revolutions in thearts and politics – as if to prove thatquantum physics is particularly suitedto the intellectual rebel and make itmore palatable to arty types. Thisseems rather condescending. Theintroduction also reflects a problemthat reoccurs throughout the book.Although their intent is to presentinformation in a non-technical way,authors Leon Lederman and Chris-topher Hill struggle to detach them-
selves from their jargon. Theoreticalphysicist Hill and Nobel-prize-win-ning particle physicist Lederman havehad a long involvement in the publicunderstanding of science, but demon-strate here how difficult it is for sci-ence professionals to understand theworldview of the non-scientist.
As an example, I find it difficult tobelieve that anyone with a non-scien-tific background would be comfort-able with this sentence from theintroduction: “Since the location ofJune can be deduced without meas-uring the electron Molly, whose prop-erties are correlated by the initialquantum state of the radioactive par-ent particle, the properties of the par-ticle arriving at Alpha Centauri mustseemingly have an objective reality.”I can imagine an awful lot of poets(and other people) going “Huh?”.
After the introduction, we areeased into the quantum world with abrief historical exploration of classi-cal physics. Galileo and Newton fea-ture heavily here, providing a goodmix of historical context and basic sci-ence. Occasionally, though, the his-tory is something of a caricature; forexample, we are told that Galileodropped balls off the leaning tower ofPisa, an event that most historians ofscience consider unlikely. The explo-ration then moves on to cover light,which introduces the reader to the“ultraviolet crisis” – the predictionfrom 19th-century electromagnetictheory that all atoms should emit vastquantities of high-energy light – andthe origins of quantum physics.
As the book’s scientific side comesto the fore, the historical context isdownplayed, though we do get occa-sional snippets. I found it particularlydelightful to discover that Max Bornwas Olivia Newton-John’s grandfa-ther. But again, there is something ofa tendency to tiptoe around historicalaccuracy. So, for example, we hearthat in 1685 the Danish astronomerOle Rømer’s calculations “yielded the first precise measurement of the speed of light, a whopping300 000 000 m s–1”. In reality, Rømer’svalue was closer to 220 000 000 m s–1.Suggesting otherwise condenses his-tory a little too much.
Once we enter the 20th century, thescience is given considerably moreopportunity to develop, so the reader
is taken with some care throughPlanck’s idea that radiation should besplit up into “bunches, or quanta”. Aninteresting revelation in this section isthat Planck did not really see this asan observation about light itself, butrather a description of the action ofthe atoms in a black body that is radi-ating light. Soon, Einstein enters thepicture, and from this point on, a keypart of the book’s message is the“shock of the new”. Looking back, itis hard to imagine just how much of adeparture from classical thinking wasrequired to begin to grasp quantumtheory, and Lederman and Hill makesure that we really understand thatthe culture shock among physicistswas immense. Indeed, some – Ein-stein and Schrödinger being two obvious examples – were never com-fortable with its implications.
To get this far has taken onlyaround one-third of the book. Nowwe plunge into the structure of theatom, matrix mechanics, the uncer-tainty principle and the Schrödingerequation. A whole chapter is dedi-cated to quantum entanglement andits implications, with an unusuallydetailed exploration of Bell’s theorem– a topic that is often considered tooconfusing for the general reader, asthe authors demonstrate here. Afterexploring Dirac’s relativistic expan-sion of the Schrödinger equation anda quick tour of Feynman’s sum-over-paths approach, the book concludeswith a rapid crescendo of supersym-metry, holographic universes, quan-tum gravity and string theory,climaxing with a brief introduction tosome of the new quantum technol-ogies of quantum cryptography andquantum computing.
Throughout the book, I get theimpression that it is essentially a col-lection of physics lectures for arts stu-dents, generated by simplifyingstandard introductory physics lec-tures. This is acceptable for an actualcourse, for students who are preparedto sit through it to get their credits, butit does not work as well as a sciencebook for the general reader. Such“science-for-the-arts” courses arequite common at US universities, buteven if this were the target audienceof this book, the authors could takelessons in how to go about it fromRichard Muller’s superb Physics for
Brian Clegg
Physics for students, not poets
Quantum Physics
for Poets
Leon Lederman andChristopher Hill2011 PrometheusBooks £24.95/$28.00hb 338pp
Break it down
Quantum Physics forPoets attempts tomake this complexsubject accessible toarts students.
Shut
ters
tock
/dje
m
Physics World March 2012
physicsworld.comReviews
68
Future Presidents, while a more gen-eral audience would benefit muchmore from the approach of a title suchas Marcus Chown’s Quantum TheoryCannot Hurt You. Unfortunately,poets have not been well served here.
This is, nonetheless, a good book.Lederman and Hill provide the reader
with plenty of introductory meat onthe development of quantum physicsand they really bring out the startlingsurprises at the heart of it. But theapproach they take is not for poets. Itwould be much better targeted athigh-school physics students to helpprepare them for university physics.
Rather than quantum physics forpoets, this is quantum physics 101 lite.That is a useful book, and in that roleI would heartily recommend it. But itdoesn’t do what it says on the tin.
Brian Clegg is a science writer based inWiltshire, UK, e-mail [email protected]
The ways of the waveFrom ocean waves and sound waves,to the “muscular waves” of humanheartbeats and Mexican waves thatsweep across a stadium, it is easy tosee how this ubiquitousphenomenon grabbed the attentionof author Gavin Pretor-Pinney. Hedecided to write The Wavewatcher’sCompanion after spending an afternoon at the Cornish seasidewith his daughter – although theprospect of a “research trip” toHawaii may have helped, too,Pretor-Pinney admits. One of themost interesting wave narrativesconcerns the German scientist HansBerger, who conducted the first everelectroencephalograph (EEG) test,apparently on his 15-year-old son,Klaus. Berger carried out furtherexperiments on his daughter as shecompleted her homework, ontoddlers and even on a dying dog; thelast of these experiments allowedhim to see the EEG trace flatline. As Pretor-Pinney wryly observes,Berger “was clearly unable torestrain himself from hooking upanyone he came across”. Othersections of the book deal with sonar,“nasty waves” such as shock wavesand even “sexy waves” such asmating calls and husky humanvoices. Yet despite these attempts atorganization – there are nine “wavetypes” in total, plus an introduction –the book’s individual sections lackdistinct structure. The author’sattention seems to ebb and flowbetween largely unrelated phenomena, and while his prose ischarming in places, a few of hisattempts at humour seem tone-deaf.There is one particularly grating reference to “the type of broad whodrinks, smokes, doesn’t hold backand is up for anything andeverything” in the “sexy waves”chapter. Overall, The Wavewatcher’sCompanion reads like the first draftof what could have been a reallygood book, and it is difficult tounderstand why it won the 2011Royal Society Winton Prize forScience Books. While some readers
might – like the Winton Prize judges– be inclined to “go with the flow”, itis certainly not for everyone.● 2011 Bloomsbury £8.99pb 336pp
A real puzzlerCan you prove that there are at leasttwo people in the city of Tokyo withthe same number of hairs on theirheads? What about demonstratingthat if you take at least one aspirin aday (and 45 aspirin in total) duringthe month of April, there must be astretch of consecutive days overwhich you take precisely 14 aspirin?Or maybe you would prefer to showthat if you select 16 integers between1 and 30, at least two of thoseintegers must differ by exactly 3? Allthree puzzles are examples of the so-called pigeonhole principle inaction, and if they appeal to you,then The Puzzler’s Dilemma will beyour ticket to a pleasantly divertingafternoon. In this slim volume,mathematician and New York Timescrossword setter Derrick Niedermanleads readers through 11 classes ofconundrum, offering sampleproblems and sketching out some ofthe general principles for solvingthem. The pigeonhole principle, forexample, is discussed in a chapter onturning complex conundrums intosimpler ones; other chapters exploresuch topics as probability theory,induction errors and puzzles thatseem easy but are actuallyimpossible. There is even a chapterdevoted to “kangaroo puzzles”,where the statement of the puzzlecontains a clue to the solution, like ajoey in a mother kangaroo’s pouch.Kangaroos notwithstanding,Niederman’s prose certainly hopsalong nicely, making the book afairly effortless read – unless, ofcourse, you stop to solve the puzzlesbefore he reveals their solutions.● 2012 Duckworth Overlook£14.99hb 216pp
Analogy failureAnalogies are tricky things. A goodone will only take you so far, and abad one can be worse than useless.
This lesson was brought home toyour reviewer several years agowhen, as an undergraduate, aclassmate asked a mathematicslecturer to give the class a physicallyintuitive explanation of curl, �×F. “That’s a tough one,” thelecturer replied. “Can you imaginean infinitely small paddle wheelspinning in the middle of a river?”Unfortunately, the class could not,and the lecturer never tried again.Authors Brian Cox and Jeff Forshaware made of sterner stuff, however,and in their new book The QuantumUniverse: Everything That CanHappen Does Happen they workmuch harder to bridge the gapbetween analogy and physics. Aftera promising start, though, they aresoon off into infinitesimal paddle-wheel territory. In their analogy,quantum fields are replaced by aninfinite array of clocks, in which thelength (squared, of course) of theindividual clock hands representsthe probability that a particle will befound in a particular spot, and particles deposit additional clocks asthey move from place to place.Sometimes, the clocks have to shrinkin size for the maths to work out.This is scarcely simpler than theactual physics, and will confuseexperts more than it reassuresnovices. Setting aside the clock analogy for a moment, though, theamount of mathematical detail isfairly high for a popularly orientedbook, which should please those whofelt that Cox’s Wonders series forBBC television lacked rigour. Theauthors are not afraid of theoccasional equation, and the overalllevel is similar to that of Feynman’sQED: the Strange Theory of Light andMatter (a fact that Cox and Forshawacknowledge in the “furtherreading” section at the end of thebook). If you can get past thetortuous clock analogy, you will findthe book a real treat. If not, well,there is always the option ofwatching Cox’s television documentaries instead.● 2011 Allen Lane £20.00hb 256pp
Between the lines
Categorized
In The Wavewatcher’sCompanion, ninetypes of wave areinvestigated.
iSto
ckph
oto.
com
/Epi
cSto
ckM
edia
AFM: Lateral force
Raman map: 2D (G’) band mass center
www.ntmdt.com www.ntmdt-tips.com
NTEGRA8204KC
Untitled-1 1 12/10/2011 08:48
ISSN: 0010-7514
CO
NT
EMPO
RA
RY PH
YSIC
S PhysicsVolume 53 Number 1 January–February 2012
Editor: Professor Sir Peter Knight, FRS
Contemporary PhysicsContemporary
Introducing Recent Developments in Physics
Volum
e 53 Num
ber 1 January–February 2012
TCPH_I_53.qxp:TCPH_I_53_01_COVER 12/15/11 6:11 PM Page 1
www.tandfonline.com/cp
An Essential Resource for Graduates
2010 5-Year Impact Factor: 4.745Ranked 7th in Multidisciplinary Physics
Aims and Scope
FREE ONLINE ACCESSRead a selection of FREE articles including an Editor’s choice, reviews and most read articles.
Visit www.tandfonline.com/cp and click on the banner.
ISSN: 0010-7514
CO
NT
EMPO
RA
RY PH
YSIC
S PhysicsVolume 53 Number 1 January–February 2012
Editor: Professor Sir Peter Knight, FRS
Contemporary PhysicsContemporary
Introducing Recent Developments in Physics
Volum
e 53 Num
ber 1 January–February 2012
TCPH_I_53.qxp:TCPH_I_53_01_COVER 12/15/11 6:11 PM Page 1
Interested in all things Physics?Visit our Physical Science Subject News page regularly to find out about our latest Physics news: explore.tandfonline.com/PhysicalScience
Contemporary Physics presents authoritative, lucid, introductory review articles on important recent developments in physics. The journal is of particular use to undergraduates, teachers and lecturers and those starting postgraduate studies who wish to be introduced to a new area, as well as all professionals within the physical or natural sciences.
Visit the journal homepage to:• recommend the journal
to your library • order back issues• register for table of
content alerts• read an online sample
copy• and much more...
©2011 Thomson Reuters, 2010 Journal Citation Report®
Untitled-2 1 16/02/2012 09:25
GraduateCareersMarch 2012
In association with brightrecruits.com
Finding your first jobin a tough market
Be a front-runner
iSto
ckph
oto.
com
/nic
o_bl
ue
PWMar12careers-5 20/2/12 16:41 Page 71
GraduateCareers
If you have read a newspaper, listened to theradio or browsed the Internet in the last 12months, you could be forgiven for thinkingthat the outlook for new graduates is bleak.Graduate numbers are up, employment fig-ures are down and business confidence isteetering on the edge. But are things reallythat desperate? For this special graduate sec-tion, Physics World set out to discover who ishiring physics graduates – and how you canget your application to the top of the pile.
The good news is that the job market fornew graduates is looking up. “Things havenever been as bad as the headlines mightsuggest,” says Don Murray, a careers adviserat the University of Edinburgh. “From a lowpoint in 2008, we’ve seen a steady rise invacancies year on year.” Brian Staines, headof guidance at the University of Bristolcareers service, agrees. “The situation forgraduates is improving gently,” he explains.“Things have definitely picked up.”
The message from employers is similarlypositive. Data from High Fliers Research, thespecialist graduate-recruitment market-research company, show that the UK’s lead-ing employers expect to increase theirgraduate intakes by an average of 6.4% in2012 compared with 2011. In some sectors,the picture is even more encouraging.Vacancies in engineering and industrial com-panies are up by 22%; in banking and finance,they are up by 16%. This will be promisingnews for many physics graduates, saysMurray, noting that the top three destina-tions for Edinburgh’s physicists are engi-neering, finance and information technology.Data from other universities tell a similarstory (see box on p73).
For graduates who want to pursue theirinterest in science, a range of opportunitiesare available in energy companies, engi-neering firms and the research divisions oflarger manufacturers. And despite plannedcutbacks in government spending, physicsgraduates should not necessarily overlook
the public sector. Recruiters such as the MetOffice and the Defence Science and Tech-nology Laboratory are keen to attract high-quality science graduates.
Despite a post-credit-crunch dip in thenumbers of graduates entering banking andfinance, businesses in this sector remaineager to draw on the numerical skills andproblem-solving ability that science gradu-ates can bring. “We are proactively trying toattract people from outside finance and eco-nomics, as well as those with financial back-grounds,” says Sarah Harper, head ofrecruiting for Europe, Middle East andAfrica at the investment bank GoldmanSachs. She adds that the firm recently held acareers event aimed specifically at studentsof STEM (science, technology, engineeringand maths) subjects.
The not-so-good news, according to HighFliers Research, is that graduate recruitmentis still 6% down on its high point in 2007, andwith 50 000 more graduates taking the firststep onto the career ladder than five years
ago, competition for jobs is fierce. Last year,recruiters from the large, high-profile firmscovered by High Fliers Research received anaverage of 48 applications for each graduateplace, and that figure is likely to be evenhigher in 2012. In such a crowded market,even graduates in the sought-after disciplineof physics are going to have to really standout if they are to find – and secure – theirdream job.
Quality, not quantityGraduates who are trying to boost theirapplications from “good” to “great” will bepleased to know that many of them willalready be more than halfway there, thanksto their educational experience. “We recog-nize that applicants have already been testednumerous times in their journey through theeducation system,” says Robin Harbach,head of human resources at the Met Office,adding that those who have an upper secondfrom a good university are “already 70% ofthe way through the selection process”. Thekey to the remaining 30%, he explains, ismore about an applicant’s attitude than theiraptitude. In other words, they need to con-vince potential employers that they are theright person for that organization, and forthat specific role.
The first step to accomplishing this is tolearn everything you can about the companyand the role that you are applying for. Lookat the organization’s website and read the jobdescription carefully. Visit your university’scareers service to find out what informationthey have. If the company is holding a recruit-ment event, go along and hear what it has tosay. “We expect applicants to know about ourcompany, who we are and how we are struc-tured,” says Vicki Potter, resourcing managerat Oxford Instruments, which recruits physicsgraduates to a range of roles. Kate Water-street, a graduate recruitment adviser atAtkins, an engineering and design consul-tancy, agrees. “You can tell when someone
With graduation looming, it is time tothink about what comes next.Simon Perks examines how physicistscan make themselves stand out in acompetitive graduate job market
iSto
ckph
oto.
com
/DN
Y59
physicsworld.com
72 Physics World March 2012
Finding jobs inhard times
In such a crowdedmarket, evengraduates in thesought-afterdiscipline of physicsare going to have toreally stand out ifthey are to find theirdream job
has really researched what we do,” she says.This level of research can take a while,
however, and it absolutely should not be leftuntil the train journey to your interview. “It isobvious when someone has only started toread the Financial Times over the last week,”observes Harper, of Goldman Sachs. To helpstudents budget their time, careers officerscounsel restraint. “Resist the temptation tobash out 25 mediocre applications,” advisesBristol’s Staines. “Focus on quality, notquantity. Target each application at the spe-cific organization and vacancy.” Recruiters,adds Harper, need to understand why youwant to work in their company and whatexcites you about that role. “We are lookingfor a personal story about why someone isinterested in working at our firm, such as par-ticular deals we have been involved in thathave caught their attention or discussionswith Goldman Sachs professionals who theyhave met at recruiting events,” she says.Above all, says the Met Office’s Harbach,applicants should show that they really, reallywant the job. “If you’re not passionate aboutwhat you want to do,” he asks, “how will any-one else get passionate about hiring you?”
Being passionate, though, is no excuse forbeing sloppy. When preparing your coverletter, CV or application form, you mustmake sure you proof-read it before you sendit off. This really should not need saying, butrecruiters can provide story after story ofpoor spelling and grammar, missing attach-ments and obvious copy-and-paste errors. Agenuine, deep interest in a particular roleand a perfect cover letter will get you
nowhere if you name-check the wrong com-pany in the opening paragraph. “Get thebasics right,” urges Edinburgh’s Murray. “Agood, clear application will stand out.”
The importance of soft skillsIn addition to spell-checking their appli-cations, physics graduates should alsoremember that, although physics is a veryattractive degree from a technical point ofview, employers are looking beyond techni-cal competence. “What you know is half thebattle,” says Harbach. “How you do it is theother half. We need to know how well youcan relate to people.”
This is where skills such as communica-tion, teamwork and leadership can play avital role. However, it is not sufficient just tosay that you have these skills – you need toprove it. This means providing concreteexamples of how you have used these skillsand what you have achieved. So if you havebeen the president of your university’s debat-ing society, worked weekends in a shop orvolunteered for a local charity, now wouldbe a good time to mention it. And the morerelevant these examples are to the job youare applying for, the better. “Target what theemployer wants,” says Murray. “Link yourown experience and skills to that vacancy.Show why you would be a good employee.”
Work experience, in particular, can makethe crucial difference between a good appli-cation and a great one. According to HighFliers Research, recruiters estimate thatone-third of this year’s entry-level positionswill be filled by graduates who have already
worked for their organizations, whetherthrough industrial placements, vacationwork or undergraduate sponsorship. Forinvestment banks, this figure rises to three-quarters, and recruiters warn that graduateswith no previous work experience areunlikely to be successful. “In a highly com-petitive graduate job market, new graduateswho have not had any work experience at allduring their time at university have littlehope of landing a well-paid job with a lead-ing employer,” says Martin Birchall, manag-ing director of High Fliers Research. This istrue, he adds, “irrespective of the academicresults they achieve or the university theyhave attended”.
“Work experience is a key way of beingable to differentiate yourself,” agreesHarper at Goldman Sachs. “[For us], some-thing in an investment bank would be best,even if it is just for a week. But anythingwhere you are challenging yourself is good –something where you are able to demon-strate that you can add value.”
On the upside, many leading employersoffer paid work-experience programmes forstudents and recent graduates. Two-thirdsprovide industrial placements for six to 12months and more than half have paid vaca-tion internships for three weeks or longer.And if your employment history so far hasbeen somewhat lower key, then don’t worry.“Any form of work experience is important,”says Waterstreet, of Atkins. Potter, at OxfordInstruments, makes a similar point. “Wewant people who have experience of dealingwith customers,” she explains, “even if that
20072006
12
16
20
40
50
perc
enta
ge o
f phy
sics
gra
duat
es s
urve
yed
phys
ics
grad
uate
s em
ploy
ed in
sel
ecte
d se
ctor
s (%
)
30
20
10
0
8
4
02008 2009 20102006 2007 2008 2009 2010
% employed% studying for UK higher degree% unemployed
business and finance
scientific research, analysis and development
engineering
ITcommercial, industrial, public sector managers
Employment prospects for UK physics graduates have recovered somewhat since the “credit crunch” of 2008–2009. Left: data from annual surveys conductedsix months after graduation show that the fraction of physics graduates in employment fell during the crunch, while the fraction studying for a higher degree rose.Right: among physics graduates in employment, the business and financial sector remained a popular destination throughout the survey period.
What physics graduates do: 2006–2010
physicsworld.com GraduateCareers
73Physics World March 2012
Sour
ce:
Hig
her
Educ
atio
n St
atis
tics
Agen
cy
is from working in a shop.”If all goes well, the next stage is an inter-
view or assessment. Here, as in the appli-cation, the key to success is preparation.Most recruiters explain on their website whatform the interview or assessment will takeand what you can expect on the day. Yourcareers service can also help you to prepare,by coaching you on interview skills, helpingyou to anticipate questions and directing youto online tests for a bit of practice. For exam-ple, Staines notes that nearly all interviewsare “competency based”, which means thatthe interviewer wants to find out whether youhave the specific skills the employer needs.Because of this, he says, a well-prepared stu-dent should be able to anticipate 70–80% ofthe questions, especially “the obvious ones”that ask you to give examples of occasionswhen you have planned your time effectively,worked in a team or overcome difficulties incompleting a task.
Still, you will also need to demonstrateyour enthusiasm for the industry, the com-pany and the role. “Just answering the ques-tions well will not get you the job these days,”says Harbach at the Met Office, adding thatgraduates need to show that they are “keenand driven”. Potter says that she is alwaysimpressed when an applicant comes armedwith questions about the company’s productsand markets; this shows that they are inter-ested and that they have done their research.
As with many things in life, the key to suc-cess here is hard work. Put in the time, do theresearch and find out what the employer islooking for. Then show how your skills, qual-ifications and experience make you the idealcandidate. It is not easy, but this methodicalapproach pays dividends. If you make “a realeffort” with your application, advises Potter,this will “automatically” put you in the top 10%.
When the right job isn’t thereSometimes, though, things do not go accord-ing to plan. Perhaps you cannot decide whatyou want to do. Maybe you know what youwant but the right vacancy is proving elusive.Or perhaps you have been applying for jobafter job with no success. The key here is notto panic. You do not have to get into yourdream career straight away. Sometimes ittakes time to find and secure the job that you want.
One suggestion from Bristol’s Staines is tolook beyond well-advertised jobs, and sub-mit speculative applications for hands-onwork experience in your chosen sector. Smalland medium-sized businesses may havevacancies, he says, but many do not advertiseheavily with universities. Staines also coun-sels approaching potential employers just foradvice, rather than with a cover letter andCV. “Don’t start by asking ‘Have you got ajob going?’, as they can shut the conversationdown with a simple ‘no’,” he says. Instead,just explain your situation and ask for advice.
Vital statistics for UK graduates
physicsworld.comGraduateCareers
74 Physics World March 2012
Sour
ce:
Hig
h Fl
iers
Res
earc
h, H
ighe
r Ed
ucat
ion
Stat
istic
s Ag
ency
, in
divi
dual
rec
ruite
rs
The increase on last year in the number of graduate vacancies at engineering and design
consultancy Atkins
50%
The increase in the number of new graduates this year compared with 2007
50 000
The proportion of this year's graduate
position that will be filled by people who already have work
experience with that employer
1/3
The proportion of applications for current graduate positions that
come from people who graduated in 2011 or before
1/3The number of
applicants for each graduate vacancy
in 2011
48
The increase in graduate vacancies in the IT and telecoms sector since
2007
45%
Ratio of work experience placements to graduate vacancies in the UK's
leading investment banks
1:1
Proportion of the UK's leading employers who do not offer any form of
work experience placements
5%The increase in graduate
recruitment vacancies since last year among the UK's
top engineering and industrial companies
22.4%
The increase in graduate recruitment vacancies since last year among the UK's
top recruiters
6.4%The increase in the number of graduate
applications received by employers
compared with this time last year
19%
Proportion of leading recruiters who warn that graduates with no work experience would be
unlikely to secure a job offer
52%
Average graduate starting salary in the
UK's leading investment banks
£45000
The median starting salary for a graduate recruit at
the UK's leading graduate employers
£29000
physicsworld.com GraduateCareers
“Most will be more than happy to help – andif they do have any vacancies coming up,they’re likely to let you know, too.” It is alsoworth remembering that many employersrecruit graduates year round, not just imme-diately after graduation.
For those who need more help, universitycareers services are a good port of call (seePhysics World March 2011 pp54–56). Manyservices maintain networks of alumni, forexample, who may be able to advise you onyour application or your career choice. Evenif you have already graduated, it is still worthvisiting, since most careers services continueto support graduates for two or three yearsafter they have left. If you have moved away,and a visit to your own university is not prac-tical, you may find that your local universityis able to step in; nearly all careers servicesare part of a “mutual aid” network and willbe able to advise you as if you were one oftheir own graduates.
If you find that you need to boost yourskills, then it might be worth thinking aboutpostgraduate study. Edinburgh careersadviser Murray urges caution, though.“Postgraduate study is not for everyone,” heexplains. “To do it solely as a stop-gap meas-ure is not a good idea. Think carefully aboutwhere the course will lead you.” Stainesagrees, adding that you should only enterinto further research or study “if it is whatyou want or if it will help you with your jobprospects”. “Look at the destinations of peo-ple who have completed that course and seewhat they are doing now,” he adds.
The main thing, says Potter at OxfordInstruments, is to do something with yourtime while you find the right job. “Find a tem-porary job,” she suggests. “Show that you arewilling to work hard. Travel is fine, too. Butdemonstrate that you are learning somethingfrom it. Do anything. Just don’t do nothing.”
Simon Perks is a freelance science writer (and physics graduate) based in Bristol, UK, [email protected]
75Physics World March 2012
Studying physics or a related subject?
If you’re an undergraduate student you can get free IOP student membership.Join IOP and get free access to and and many excellent student careers resources.
To join our ever-expanding international community of like-minded people, simply go to www.iop.org/students and fill in the short online form.
We look forward to welcoming you to your Institute.
Join today! Visit www.iop.org/students
Digital membership is free for physics undergraduates. Hard copies of Physics World cost an additional £15 per year.Postgraduates can join as Associate Members (AMInstP) for £19 per year (£15 by direct debit). Other rates and grades areavailable. Visit www.iop.org/students for details. Information correct as of September 2011.
Registered charity number: 293851. Charity registered in Scotland: SC040092.
Vacancies in 2012 at key employers
Employer Number of UK vacancies
Arup 140Atkins 240BP 175Deloitte 1200DSTL 70EDF Energy 100Ernst & Young 900Goldman Sachs 300HSBC 150J P Morgan 300KPMG 1000PricewaterhouseCoopers 1250RBS Group 700Shell 100UBS 300
Numbers game
Sour
ce:
Hig
h Fl
iers
Res
earc
h, i
ndiv
idua
l re
crui
ters
GraduateRecruitmentFind all the best graduate jobs, studentships and courses here in Physics World and online at brightrecruits.com
physicsworld.com
www.brightrecruits.com
Physics World March 201276
“The best thing about teaching
physics is how creative you can be.
I love thinking of new ways to teach
a lesson.”
Pragash, dad, marathon runner and trainee teacher.
With our IOP Teacher Training Scholarships, worth £20,000, training to teach physics is more rewarding than ever.
www.iop.org/scholarships
L ED AD 0112 Scholarship PW-6.indd 1 30/01/2012 13:35
We seek highly motivated graduates with an MSc or equivalent in Physics, Chemistry, or Biochemistry.
Impress yourself
PhD ProgrammeUltrafast Imaging & Structural DynamicsInterdisciplinary research | Renowned research institutions | Excellent research conditions | Advanced courses and soft skills training | Language: English | No tuition fees | Funding available.
www.imprs-ufast.deApply now!
PhD studentships in Quantum, Light & Matter physicsThe Quantum, Light & Matter group in Southampton’s Physics and Astronomy department conducts world-class research in the fields of quantum, atomic and semiconductor physics, photonics, magnetism and nanomaterials.
We offer PhD projects in
Fully-funded studentships for UK and EU students include a tax-free bursary of £13,590 pa and tuition fees. For application details and more information:
www.qlm.soton.ac.uk/join.php +44 (0)23 8059 2068 [email protected]
l atom chips & molecular interferometry
l biophotonics & bionanotechnologyl green photonics & energy
conversionl magnetism & superconductivityl laser physics & devices
l nanomaterials & liquid crystalsl plasmonics & nanophotonicsl spintronicsl terahertz sources & devicesl theoretical quantum
optotelectronics
More than
250 000monthly page views
More than 250 000 monthly page views
Jobs for physicists and engineers
More than 23 000 monthly unique visitors
More than
250 000monthly page views
Join us on Twitter for the latest physics and
engineering positions
www.twitter.com/brightrecruits
Connecting motivated jobseekers with high-profile employers
More than 250 000
monthly page views
Physics World March 2012 77
ADVERTORIAL
Teaching is increasingly a career for the most able graduatesMake teaching your first choice career – there’s never been a better time to join the profession.
The Training and Development Agency for Schools (TDA) is committed to recruiting the very best graduates into teaching, so that standards can continue to rise in schools across the country. Last year’s teacher training entrants had the highest proportion of 2:1 degree classifications and above on record: 62 per cent of entrants to university-based training had a 2:1 or better. Not only that, more physics trainees than ever before began training in 2011 – up 30 per cent on 2010.
However, there still remains a shortage of physics teachers in schools. The Institute of Physics (IOP) believe that around 1,000 new specialist physics teachers in England are needed every year for the next 15 years to plug the gap, so that the subject is taught by specialist teachers.
Ideal route into teaching
Physics trainees no longer need to train to teach all of the science subjects. Previously, there were a small number of physics with mathematics postgraduate certificate in education (PGCE) routes offered by providers. These courses have been in great demand, so the TDA is making the physics with mathematics PGCE more widely available by increasing the number of providers that offer it. This is the ideal route into teaching if you are passionate about both physics and mathematics.
Rather than the traditional combination of physics, biology and chemistry; physics with mathematics trainees will focus on the two subjects which are currently undergoing a renaissance in schools. Trainees will gain work experience in schools, including some of the new teaching schools judged as outstanding at training and developing their staff. This will give trainees the best opportunity for employment when they qualify.
The new PGCE courses will start in September 2012 and will be delivered by mainstream PGCE providers. Applications can be made to providers via the Graduate Teacher Training Registry (GTTR) website www.gttr.ac.uk.
If you think you would enjoy teaching younger children but would like to stay close to the subject you are passionate about, brand new training courses from September 2012 are available to become a science subject specialist in primary schools too.
Teacher training is currently offering big tax-free bursaries to high quality graduates, especially in shortage subjects. If you have at least a 2:2 degree, you may be eligible for up to £20,000, if you intend to start a training course in2012/13. The amount of bursary you are entitled to, depends on your degree class and the subject you choose to teach. Physics with mathematics attracts the same bursary as a standard physics course.
Special scholarships
There are special scholarships available for physics trainees from the IOP, offering a package of benefits, including a £20,000 award. Around 100 scholarships will be available for graduates with a 2:1 or first class degree who are intending to do a PGCE course in physics, or physics with mathematics.
The IOP will work with experts in teaching practice to award scholarships. They will hand-pick candidates demonstrating exceptional subject knowledge, enthusiasm for the study of physics, and outstanding potential to teach. The IOP’s relationship with the scholars will continue into their teaching careers. This will develop a group of outstanding physics teachers, all part of a community of physicists across schools, universities and industry.
There are special scholarships available for physics trainees from the IOP. Around 100 scholarships worth £20,000 each will be available for graduates with a 2:1 or first class degree who are intending to do a mainstream physics, or physics with mathematics, Initial Teacher Training (ITT) course.
The IOP will work with experts in teaching practice to award scholarships. They will hand-pick candidates demonstrating exceptional subject knowledge, enthusiasm for the study of physics and outstanding potential to teach. The IOP’s relationship with the scholars will continue into their teaching careers. This will develop a group of outstanding physics teachers, all part of a community of physicists across schools, universities and industry.
Starting salaries in teaching are high compared to average graduate starting salaries, making the profession one of the most financially secure and rewarding career options available. The average starting salary that newly qualified teachers can now expect to receive is £22,800, compared to a range of £17,720–£23,335 for other graduate jobs. What’s more, on average, teachers are seeing their salaries rise by approximately 30 per cent during their first three years in the job.
New experiences
New experiences and performance can see newly qualified teachers achieve rapid career progression. Teachers are twice as likely to be in management positions compared to many of their fellow graduates three and a half years in, with 19 per cent of having management responsibilities, compared to less than 10 per cent of science professionals (6 per cent), legal professionals (6 per cent) and accountants (9 per cent). As an Advanced Skills Teacher you can earn up to £56,000 and head teachers earn upwards of £100,000.
Teachers are very enthusiastic about their careers, enjoying the autonomy, variety and impact. Significantly more trained teachers stay in their chosen profession compared to other popular graduate careers. Research shows that teachers are twice as likely to remain in their chosen profession, with nearly half (44 per cent) of graduates in a range of popular non-teaching roles switching career within their first three and a half years, compared to just 21 per cent of those who choose teaching first time round. Non-teaching graduates suggest a lack of autonomy, limited opportunities for career progression and the routine nature of the work as the main reason for making the switch.
Training places are filling up much more quickly than last year. Apply quickly to ensure that you can start your career in the classroom in 2012/13.
For more information about how rewarding and challenging teaching has become call the Teaching Information Line on 0800 389 2500 or visit www.tda.gov.uk.
Getting into the teaching profession…
Applicants for initial teacher training must demonstrate a standard equivalent to a GCSE grade C or above in English and maths, and in a science subject for those wishing to teach in primary. If you don’t reach this minimum academic standard there are access courses available.
TDA offers a School Experience Programme (SEP), to graduates considering teaching maths, physics, chemistry or a modern foreign language (MFL) at secondary level who hold a 1st, 2:1 or 2:2 degree in a related subject. The programme offers classroom experience in a secondary school for 1 to 10 days, which is agreed between the individual and their host school.
Teacher requirements
Along with a degree, all teachers are required to have qualified teacher status (QTS) to teach in primary and secondary maintained schools and non-maintained special schools. This is attained via either undergraduate or postgraduate courses. An undergraduate route into teaching will offer either a BEd, BA, or BSc, combining degree studies with QTS. You are required to have two A-levels or equivalent in order to enrol on an undergraduate course. Some ITT providers do offer part-time courses; these can be found on the TDA website http://www.tda.gov.uk/Recruit/thetrainingprocess/typesofcourse.aspx.
The postgraduate course will award you with a Postgraduate Certificate in Education (PGCE). A PGCE course mainly focuses on developing your teaching skills, and not on the subject you intend to teach. For this reason, you are expected to have a good understanding of your chosen subject – usually to degree level – before you start training. Entry to most postgraduate courses is through the Graduate Teacher Training Registry, although some training providers accept applications directly.
TDA_advertorial.indd 1 17/02/2012 12:02
The Okinawa Institute of Science and Technology Graduate University is located on a beautiful
subtropical island in the far south of Japan. Our program is based on a firm foundation in the basic
sciences and our non-departmental structure encourages interactions across traditional disciplinary
boundaries. We are searching internationally for students who will flourish in an atmosphere of
encouragement for discovery and innovation. The OIST PhD program is flexible, individualised,
and well-resourced, offering top-notch facilities and close supervision in a supportive community
environment. All students receive an internationally competitive support package.
PhD Program in English in Japan
• experimental and theoretical condensed matter physics
• quantum theory and applications in computing and optics
• nanomaterials and photovoltaic materials
• structural ultramicroscopy and tomography
• mathematical and physical biology
• information in biological systems
• imaging and instrumentation
• catalysis and protein engineering
• marine biophysics and oceanography
Current areas of research focus of interest to physicists include
Visit www.oist.jp or write to [email protected]
for information on how to apply
Visit www.oist.jp or write to [email protected]
for information on how to apply
Visit www.oist.jp or write to [email protected]
for information on how to apply
Visit www.oist.jp or write to [email protected]
for information on how to apply
Visit www.oist.jp
or write to [email protected]
for information on how to apply
Physics World March 201278
In your experience, it’s their experience that counts
At the Institute of Physics, we recognise the importance of identifying and developing top talent, and that graduates with practical work experience present a much more attractive proposition to your business.
Through our ‘Top 40’ bursary scheme, we are offering to fund talented students on an 8 week summer placement with your organisation, so that you can connect with the crème of penultimate year undergraduate physics students.
By taking part in this scheme you can bring new skills and a fresh perspective to your business, gain a skilled and motivated member of staff and ultimately drive productivity.
For more details about the IOP ‘Top 40’ please visit www.iop.org/top40/employers or contact Vishanti Fox on +44 (0) 207 470 4906
TOMORROW’S TALENT TODAY
IP091_SummerPlacements_193x130_v1a_AW.indd 1 19/1/12 14:39:34
In your experience, it’s their experience that counts
At the Institute of Physics, we recognise the importance of identifying and developing top talent, and that graduates with practical work experience present a much more attractive proposition to your business.
Through our ‘Top 40’ bursary scheme, we are offering to fund talented students on an 8 week summer placement with your organisation, so that you can connect with the crème of penultimate year undergraduate physics students.
By taking part in this scheme you can bring new skills and a fresh perspective to your business, gain a skilled and motivated member of staff and ultimately drive productivity.
For more details about the IOP ‘Top 40’ please visit www.iop.org/top40/employers or contact Vishanti Fox on +44 (0) 207 470 4906
TOMORROW’S TALENT TODAY
IP091_SummerPlacements_193x130_v1a_AW.indd 1 19/1/12 14:39:34
79Physics World March 2012
Tessella delivers software engineering and consulting services to leading scientific and engineering organisations across the globe.
We recruit high achievers from leading universities who are passionate about applying their unique knowledge and expertise from their different science and engineering backgrounds to solve real-world problems.
You will enjoy a varied and challenging role, working closely with our clients to understand the business issues they face and helping to design and develop innovative software solutions, being involved in all stages of the software development lifecycle. Projects can range from client based consultancy or IT development to office based client support activities.
We currently have opportunities in Warrington, Stevenage and Abingdon to work on a range of projects in life sciences, energy and other sectors.
You should have:
• BSc (min. 2:1), MSc or PhD in a science, mathematics or engineering discipline
• Programming experience in at least one of our core languages: Java, C#, C++, C or VB.NET
Apply online at http://jobs.tessella.com
Scientific Software Developer
Keep up to date with careers at Tessella:
Visit our careers website: http://jobs.tessella.com
Follow us on Twitter: @TessellaCareers
£23,000-£26,000 BSc/MSc; £26,000-£29,000 PhDup to £40,000 depending on experience
Do you want to study for a doctorate whilst gaining invaluable commercial experience?
The EngD is a 4-year fully funded PhD-level doctorate with an emphasis on research and development in a commercial environment.
Research projects are offered in four themes:
Signal and Image ProcessingOptics and PhotonicsMicrosystems with PhotonicsDigital Tools with Optics
Successful candidates will normally work closely with their chosen sponsoring company, with support from an Academic and Industrial Supervisor. Funds are also available to support company employees who wish to study for an EngD whilst remaining in employment.
Funding
Fees plus a stipend of at least £20,090 (2011/12) are provided for eligible students.
Entry QualificationsMinimum entrance requirement is a 2i Bachelors or Masters degree in a relevant physical science or engineering topic.
Further DetailsFor more details including a list of current projects and eligibility criteria visit www.engd.hw.ac.uk or contact Prof Derryck Reid (e: [email protected]; t: 0131 451 3792)
Engineering Doctorate in Optics and Photonics
Technologieswww.engd.hw.ac.uk
Optics & Photonics Technologies
Industrial Doctorate Centre
Physics World March 201280
TODAY I JOINED DETICA...
INTELLIGENT APPLICATION.TECHNICAL CONSULTANTS ELECTRONIC ENGINEERS SOFTWARE DEVELOPERSCYBER SECURITY CONSULTANTS DATA ANALYSTS
Because of the work we do, we are trusted by governments and large organisations around the world to create intelligence and insight from complex data.
We are a technology and information security company. We mix technical innovation, domain knowledge and our own unique intellectual property to create solutions to complex operational problems. By working in partnership with clients from across the public and private sectors, we help maintain the security of the nation, tackle cyber attacks, combat fraud, and develop an in-depth understanding of customers.
To help our clients achieve exceptional results like these, we recruit only the best graduates – people like you! When starting your career with us, you’ll find yourself involved in projects that are as compelling as they are complex, often challenging the boundaries of what is achievable. You will thrive in our friendly, talented and supportive community. With early responsibility and flexible training, you can shape the way you want your career to develop.
This is an exciting time for us and we want you to be a part of it.
www.baesystemsdetica.com/graduates
Follow us: twitter.com/deticagraduates
Web-based MSc Courses inPlasma Physics and Vacuum TechnologyThe School of Mathematics and Physics at Queen’s University Belfastoffers a range of web-based, taught modules in Plasma Physics andVacuum Technology. The modules can be taken individually or can becombined to form the basis of a
• Master of Science (MSc) in Plasma Physics or a
• Master of Science (MSc) in Plasma and Vacuum Technology. The former course requires a presence at Queen’s University only for a short period in the second semester and possibly for the summer research project.
The latter course is part-time, specifically designed for those in full time employment and does not require attendance at Queen’s University.
Part-time attendance and/or fully remote attendance modes are available. Single-module options are also offered, for know-how upgrade or as foundation courses.
For research students or employees who need to quickly acquire a basic knowledge of plasma physics, there is a 4 week “Introduction to Plasma Physics”. Other modules are taught over 8 or 12 weeks.
Detailed information on the course content and application details can be downloaded at http://www.qub.ac.uk/mp/cpp/MScCourses/.
For further information you may contact [email protected].
Centre for
Plasma Physics
PWMar12Cl_QUB_13x2.indd 1 16/02/2012 16:00
81Physics World March 2012
University of ManchesterMSc in Radio Imaging
and SensingAn excellent preparation for a wide
range of careers
l InnextgenerationradiotelescopessuchastheSquareKilometreArrayl Inremotesensingfromgroundandspacel Insecurityimagingorindustrialinspection
TheJodrellBankCentreforAstrophysicshasdevelopedaone-yeartaughtMasterscoursethatwillgiveyouacomprehensivepracticaltrainingacrossarangeofradioapplications.ItwillprovideyouwithafirmfoundationforajobinahightechcompanyorprovideasteppingstonetowardsaPhD.
Manyofthetechniquesusedinradioastronomy,remotesensingandsecurityapplicationssharethesameprinciples.Theskillsyouwilldeveloponthecoursewillhelptokeepyourcareeroptionsopen.
Thecoursewillinclude:l Observationalmethodsfromradiotosub-mmwavelengthsl Receivingsystemsdesignfromantennastodetectorsl Anintroductiontoactiveimagingsystemsl Signalandimageprocessingtechniquesl Systemdesignandindustrystandardsimulationsoftwarel Stronglinkswithleadingcompaniesl Achoiceofindustry-linkedorradioastronomydissertationprojects
Nextentry:September2012
Furtherinformation:www.jb.man.ac.uk/study/postgrad/MSc-RAMMIS.htmlEmail:[email protected](CourseDirector)[email protected](CourseTutor)
THE UNIVERSITY OF BIRMINGHAM
MSc in Physics and Technologyof Nuclear ReactorsContact: Dr Paul Norman,
School of Physics & Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT
Email: [email protected] Phone: 0121 414 4660http://www.ph.bham.ac.uk/prospective/postgrad/pgptnr.htm
lOne year taught postgrad MSc. Next year starts 24/09/2012.Course structure refined over the 50 years the MSc has run.
lFully integrated labs and tutorials every week to bring together the wide range of subjects and provide practical and written examples and guidance in person.
lStudy courses on Reactor Systems, Reactor Physics and Kinetics, Radiation Transport, Thermal Hydraulics, Reactor Materials and more. PhD programs also possible.
lSummer project, usually taken in industry and in many cases has led to employment.
lSponsored by all the major players in the nuclear industry.
PLACES/FUNDINGCURRENTLYAVAILABLE
Physics World March 201282
EPSRC Wind Energy Systems Doctoral Training Centre
Wind Energy Systems Research
StudentshipsStudy for a PhD with the UK’s leading University wind energy research centre and become qualified to contribute to this dynamic and fast growing sector.The UK Wind Energy Research Centre at the University of Strathclyde is pleased to offer 10 prestigious 4 year research studentships for talented engineering or physical science graduates to undertake a PhD in wind energy research. The students would join the recently established EPSRC Doctoral Training Centre in Wind Energy Systems, which is part of this national centre of excellence at the University.A unique programme combining training and research is provided to help graduates make the career transition into this rapidly expanding area where there is proven and rapidly growing international demand for well qualified people. To prepare for this exciting future, graduates will work closely with manufacturers, developers and researchers. This multidisciplinary programme brings together graduates from different science and technology disciplines to create a unique community of researchers, and includes training in all aspects of wind energy systems including the wider socio-economic context.Studentships are available to UK and eligible EU citizens with (or about to obtain) a 2.1 or better or a Masters degree in Physical Science or Engineering. Studentships will start each year in October and will cover University fees and a highly competitive stipend.For further details on our Centre please visit http://www.strath.ac.uk/windenergy/ To find out more contact Drew Smith, DTC AdministratorTel: 0141 548 2880; Email: [email protected]
EXPLORE......the Earth from its core to its atmosphere
www.see.leeds.ac.uk/study/masters
l MRes Physics of the Earth and Atmospherel MSc Exploration Geophysics
Funding available via Industry and School of Earth and EnvironmentScholarships
The Cockcroft Institute – OPAC
Watch it online nowyoutube.com/brightrecruitsTV
New career video just added
Department of Physics
Postgraduate opportunitiesResearch in the Department of Physics at the University of York spans a wide range of exciting fields in fundamental and applied physics, as well as at the interdisciplinary interface of physics with chemistry, biology, engineering and materials science. Our research is organised into three internationally recognised groups:
n Condensed Matter Physics - Experimental Nanophysics and Condensed Matter �eoryn Nuclear Physics and Nuclear Astrophysicsn Plasma Physics and Fusion
We offer PhD and MSc research degrees, a one-year taught MSc in Fusion Energy and a nine-month Graduate Diploma in Physics.
PhD studentships are currently available with funding from the EPSRC/STFC, the Plasma/Fusion doctoral training centre, industry sponsorship or �e University of York. Eligible PhD applicants can receive funding for any of the research projects on offer. Some funding is also available for the MSc in Fusion Energy.
For more information visit www.york.ac.uk/physics/postgraduate/funding/
For details of the research projects and taught courses and how to apply visit our website: www.york.ac.uk/physics/postgraduateFor informal enquiries, please email the Graduate Admissions Tutor, Dr Yvette Hancock: [email protected]
�e University of York was named University of the Year at the Times Higher Education Awards 2010. �e Department of Physics is growing vigorously, with an
investment package during the last six years of 22 new academic posts, plus major new laboratories and facilities including the York-JEOL Nanocentre, the York Institute for Materials Research, the new Plasma Institute and Astrocampus. In addition to a dynamic and internationally renown research environment, we offer an active programme of post-graduate training including skills and professional development, and an attractive campus environment 2 km from the centre of one of the most beautiful cities in Britain.
14208_Advert.indd 1 20/02/2012 10:00
83Physics World March 2012
www.engineerjobs.co.uk
FREEENTRY
REGISTER
NOW!
27 & 28 April 2012NEC, Birmingham
SCAN THE QR CODE FOR MORE INFO
Recruiting nowHundreds of jobs across every discipline
• CV Clinic• Interview Clinic• Free Careers Advice Lounge• Women in Engineering Forum• Professional Development Hub• Engineering Challenge - win £750*
*Terms and conditions apply. See website for details. All information correct at time of press
In association with: Supported by:
Recruiting companies include:
UK & Ireland
NECR_PW_130X94.indd 1 16/02/2012 14:09
CareersInternational
Engineering ExcellenceLondon, 30-31 March 2012The Engineering Excellence Event connects engineering graduates and professionals (in chemical, civil, electrical, industrial, manufacturing, mechanical or software engineering) with leading global companies looking to tackle tomorrow’s world challenges. We’ll help you seize the right opportunity and meet employers face to face at this invitation-only event. It’s your chance to take your first step to a top-flight exciting career. Apply now!
LIFE IS A JOURNEY. START YOURS ON WWW.CAREERSINTERNATIONAL.COM
APPLY NOW
Some of the participating companies in 2010 and/or 2011:
20120112_Physics World 94x130.indd 1 1/13/2012 12:52:17 PM
84 Physics World March 2012
Register online with brightrecruits.com todaywww.brightrecruits.com/register
Looking for employment?Find your perfect job on brightrecruits.com. With more than 15 specialisms in physics and engineering to choose from, we have something for everyone.
Need some advice?Our Careers insight section offers top tips on everything from writing a CV to succeeding in psychometric tests. Plus there are some great case studies to help you to decide on your future career.
Interested in further studies?We have loads of international postgraduate opportunities just waiting for your application.
GRADUATES!Plan your next move with brightrecruits.com
GraduateCareers October 2012
Don’t missout!
Physics World March 2012 85
RecruitmentThe place for physicists and engineers to find Jobs, Studentships, Courses, Calls for Proposals and Announcements
physicsworld.com
Office for Nuclear Regulation (ONR)
Nuclear Safety and Specialist InspectorsThe Office for Nuclear Regulation
Nuclear Safety Inspector annual salary will be in the range of £59,093 to £74,799
Nuclear Specialist Inspector annual salary will be in the range of £72,517 to £87,371
Starting salary will be negotiated and dependent on relevant skills and experience
Based in Merseyside, Cheltenham & London
‘To protect people and society from the hazards of the nuclear industry.’ That’s our mission.
The Office for Nuclear Regulation (ONR), an Agency within the wider HSE, use highly professional and technical expertise to secure the safety of the UK’s nuclear industry, as well as working to raise international standards. Needless to say, our success is critical. Which is why we need more dedicated and driven professionals like you.
So, could you use your proven track record as a high quality professional to secure and improve nuclear safety through your expertise, experience and personal qualities? If so then visit www.youprotectpeople.co.uk for more information about a fascinating, challenging and highly rewarding career as a Nuclear Inspector.
Be part of the solution Closing date: 23 March 2012.
Interviews will take place during w/c 16 April and 23 April 2012.
HSE is committed to equality of opportunity for all staff and applications from individuals are encouraged regardless of disability, gender, marital status, race, colour, ethnic or national origin, sexual orientation, age, working pattern, religion and/or belief.
Protecting people and society
One team, one purpose
We are looking for highly qualified:
CHIEF INSTRUMENTPROJECT ENGINEERINSTRUMENT PROJECT ENGINEER
See all our positions at: www.esss.se/careers
www.brightrecruits.comTel +44 (0)117 930 1264Fax +44 (0)117 930 1178E-mail [email protected]
Recruitment Advertising
Physics WorldIOP PublishingTemple Circus, Temple WayBristol BS1 6BE
Physics World March 201286
Lancaster University, currently ranked as a top 10 UK University and consistentlyranked in the top one per cent of Universitiesin global rankings, invites applications forthe following:
PHYSICS DEPARTMENT
Lectureship in ExperimentalCondensed Matter Physics£37,012 - £44,166 Ref: A351Applications are invited for a full-time lectureship (equivalent to atenure track assistant professorship) in experimental condensedmatter physics. The Lancaster Physics Department is expanding itsresearch activity in this area, building on its outstanding success in thelast two Research Assessment Exercises (5*A in 2001 and 1st byquality profile in 2008), recent appointments and substantialinvestment in new clean room facilities, as part of a newly formedQuantum Technology Centre http://www.physics.lancs.ac.uk/qtc/ The QTC is being equipped with state-of-the-art fabrication andmeasurement facilities including an electron-beam writer, evaporation,sputtering and etching machines and a helium-free dilution refrigerator,and a new research group is being created under the leadership of Professor Yuri Pashkin.
The research of the new group is focused on, but not limited to,quantum nanoelectronics, quantum metrology andnanoelectromechanics. Applications will be considered in the firstinstance from candidates in any area of quantum nano-electronics,including superconducting circuits, single-electron tunneling or qubits.Experience in low-noise measurements at cryogenic temperatures,measurement automation, nanofabrication including electron-beamlithography, dry etching and metal deposition will be regarded as an advantage.
Closing date: 26 March 2012.
To apply, access further information or register for email job alerts please visit our website.
www.hr-jobs.lancs.ac.uk
Guardian, one of the world’s largest manufacturers of float glass andfabricated glass products, supplying the automotive and building productsindustries, is recruiting a team of Thin Film Coating Engineers to assist inthe set up of a brand new thin film coating facility in Goole, UK.
Guardian is looking for mature self-starters, who are good communicators, with a strong entrepreneurial spirit.
Thin Film Coating Process Engineer, working within a team of engineers providing technical support to the magnetron sputtering line within a continuous 24/7 process driven manufacturing environment.
Essential requirements: • Experience of working within a fast paced manufacturing environment • Degree in Physics, Chemical Engineering, Material Sciences or related engineering discipline • 2 – 5 years experience in optical thin film technologies • Experience in large area sputtering system and/or sputtered optical thin film technologies • Previous experience in Research & Development • Ability to take charge and lead with confidence, control events, clearly present and communicate ideas, concepts and plans across multiple levels • Strong analytical skills, experienced in using effective trouble shooting and problem solving techniques, as well as formulating and implementing corrective actions • Understanding of thin film evaluation and materials testing techniques, such as spectrophotometry, ellipsometry and optical modelling program packages
Benefits:Very progressive global companyInvolvement in the setup of a brand new thin film coating facilityExcellent opportunities for training and developmentStability and longevity
Further information about Guardian can be found at brightrecruits.com/employer/798634/guardian-industries-uk-ltd
Full job specification can be found at: http://brightrecruits.com/job/2929/thin-film-coating-process-engineer
Applicants should address their covering letter and CV to Shirley Wordsworth, [email protected], HR
Alternatively, please write to Shirley Wordsworth, Guardian Industries UK Ltd., Rawcliffe Road, Goole, East Riding of Yorkshire, DN14 8GA.
EUROMAGNET CALL FOR PROPOSALSFOR MAGNET TIME
The next deadline for applications for magnet time atthe LABORATOIRE NATIONAL DES CHAMPS MAGNETIQUES INTENSES
(www.lncmi.cnrs.fr)the HIGH FIELD MAGNET LABORATORY (www.ru.nl/hfml/)and the HOCHFELD LABOR DRESDEN (www.hzdr.de/hld)
is May 15th, 2012.
Applications can be done through an on-line application form on the website: http://www.euromagnet.org from April 15th, 2012.
Scientists of EU countries and Associates States* are entitled to apply under FP7 for financial support according to the rules defined by the EC.*listed on ftp://ftp.cordis.europa.eu/pub/fp7/docs/third_country_agreements_en.pdf
For further information concerning feasibility and planning, please contact the facility of your choice.
Untitled-1 1 10/02/2012 08:59
Academic position in Experimental Physics:Functional and Biophysical Properties of Soft Matter
A full-time academic position is available at the Department of Physics and Astronomy of the University of Leuven, Belgium starting October 1, 2012 in the field of experimental soft matter physics.
More information can be found on the web:
http://www.kuleuven.be/personeel/jobsite/vacatures/science.html
Closing date: March 15, 2012
The full-time position can be offered in one of the academic levels, depending on the qualifications of the candidate.
The K.U.Leuven is an equal opportunity employer. Non-Dutch speaking candidates should be able to teach in Dutch within three
years.
Department of Physics and AstronomyK.U.Leuven, Belgiumhttp://fys.kuleuven.be/english
8x2.indd 1 20/02/2012 09:05
More than
250 000monthly page views
More than 250 000 monthly page views
Jobs for physicists and engineers
More than 23 000 monthly unique visitors
More than
250 000monthly page views
Join us on Twitter for the latest physics and
engineering positions
www.twitter.com/brightrecruits
Connecting motivated jobseekers with high-profile employers
More than 250 000
monthly page views
Physics World March 2012 87
School of Engineering and Physical Sciences
Selex Galileo Chair in Laser Device Physics and EngineeringSalary on the Professorial Scale Ref 09/12/PW(minimum £54,283)
The School of Engineering and Physical Sciences seeks to recruit a senior member of academic staff, to drive forward important research activities in Laser Device Physics and Engineering, as part of a Strategic Alliance between Heriot-Watt University and Selex Galileo. The Chair will be pivotal to the success of this partnership. The successful candidate must have the knowledge, drive and breadth of vision to provide the leadership necessary for the achievement of high impact research in laser device physics and engineering. The candidate must therefore have a research record consistent with the level of appointment, evidenced by quality research publications and by a track record in securing research grant/contract awards. He or she must also have research interests that will help to further cement the relationship between Heriot-Watt and Selex Galileo, specifi cally in novel solid state lasers and their applications.
In addition to research activity, the appointed candidate will be expected to contribute fully to all aspects of School activity, in particular the Physics Bachelors and Masters teaching programmes. In suitable circumstances, there may be the opportunity for linked academic appointments.
Download an application pack from our website www.hw.ac.uk/jobs or contact the Human Resources Offi ce, Heriot-Watt University Edinburgh EH14 4AS tel 0131-451-3022 (24 hours) email [email protected] quoting Ref: 09/12/PW.
Closing date: 23 March 2012.
Heriot-Watt University is a Charity registered in Scotland, SC000278
Distinctly Ambitiouswww.hw.ac.uk
The American Physical Society is conductingan international search for a successor to thecurrent Editor of Physical Review E (PRE).
The position is that of the senior Editor of the journal, responsiblefor editorial standards, policies and direction of the journal, andleadership of the staff of about 15 editors. Physical Review E is alarge multidisciplinary journal specializing in statistical, nonlinear, andsoft matter physics.
The ideal candidate should possess many of the following qualifica-tions: stature in a field of research within the scope of PRE; staturein the PRE author community; experience with scholarly journals;management and interpersonal skills to deal effectively with aninternational array of authors, referees, and editors and with theAPS; advocacy, integrity, and wisdom to lead the journal in respond-ing to important matters and issues.
The Editor may maintain his/her present appointment and locationand devote at least 20% of his/her time to the position. A higherlevel of commitment would be desirable in the initial year of service;several possible levels of long-term commitment, from 20% to50%, are possible.
The initial appointment is for three years with renewal possible afterreview. Salary is negotiable and dependent on time commitment. Thedesired starting date is 1 July 2012. The APS is an equal employmentopportunity employer and especially encourages applications from ornominations of women and minorities. The search is not limited toresidents of the United States. Inquiries, nominations, and applicationsshould be sent by 1 May 2012 to: Jerry Gollub, PRE SearchCommittee Chair, [email protected].
Senior Editor,Physical Review E
APS QT March'12_Layout 1 1/23/12 1:06 PM Page 1
Celebrating five years of publishing cutting edge environmental research.
erl.iop.org
ERLENVIRONMENTAL RESEARCH LETTERS
What is it that characterizes physicists and distinguishesus from other scientists? After a brief pause for everyoneto reply that we are sexier, more sophisticated and sociallybetter-adjusted, we might consider the answer given byErnest Rutherford, who believed it had something to dowith our objectives. Other scientists, he said, collect obser-vations, classify them and identify patterns. Physicists seekto explain those patterns.
This view fits in neatly with Rutherford’s famous aphor-ism that “all science is either physics or stamp collecting”(was that before or after he won the Nobel prize for chem-istry?), but I suggest that we also possess a trait that relatesto our style of doing science, which is our facility with num-bers – specifically, with orders of magnitude and approx-imations. It is characteristic of physicists that we can lookat an equation and instinctively know when to round everyquantity to the nearest power of 10 (or when to say that4π = 10), and when to retain the umpteenth decimalplace. This skill surely stems from our comfort at swap-ping between mathematical descriptions of the world andthe physical reality – or rather, our recognition that thetwo are at some level the same, just expressed differently,so when we are manipulating our equation, we are stillmentally connected to the system it describes.
This in-built, instinctive sensitivity analysis does, how-ever, become more interesting when applied outside ourown discipline. The biochemical complexity of the liquidparacetamol my wife and I force our children to drinkwhen they are ill is beyond my comprehension. But whenthe stated dose is 10 ml, my physicist’s instincts tell me thata quantity expressed in such round numbers cannot bethat precise, and I need not worry about the odd millilitrethat trickles down said children’s necks rather than intotheir mouths. But I have learned that my wife – who isequally well qualified and trained, but in medicine ratherthan physics – takes a less relaxed view.
The strain between our respective opinions on sig-nificant figures becomes even more pronounced in thekitchen. To a physicist, a recipe where every quantity is around number of cups or tablespoons cannot be criticallydependent on these quantities – yet domestic harmonyrequires that I put exactly 600 g of flour in the breadmachine, not slop in 550 or 650 g. As a physicist, I wouldprefer to write 6 × 102 g, conveying a different meaningfrom 6.00 × 102 g. But I don’t think I would sell manyrecipe books.
In real life, quantities cannot be much more precise thanthe increment between successive available values. Theavailable values for UK speed limits are 30, 40, 50 mphetc, so my physicist’s instinct tells me that 1 mph over thelimit probably does not matter, whereas 5 mph – half theincrement – probably does. Perhaps all those people whoseem to think 30 mph really means 40 mph are aspiringphysicists who haven’t quite mastered the skill yet!
In my own professional area, the exposure limit to mag-netic fields produced by electric power systems is aninduced current in the body of 10 mA/m2. Like you, Iinstinctively understand that this means that 2 or 5 mA/m2
would be unnecessarily low and 20 or 50 unacceptablyhigh, so 10 is the ballpark to aim for. After all, if we werestill using imperial units, I do not believe the limit would beexactly 6.45 µA/square inch; it would probably be a nice
round 10 again. But the law sadly lacks the wisdom ofphysicists, and it requires us to say that 9.9 is okay but at10.1 you have to rebuild your power line.
So are round-number quantities always approximateand multiple significant figures always precise? Not nec-essarily. The 568 ml carton of cream that is ubiquitous inBritish supermarkets should, of course, be understood asa pint (one significant figure) and not as 568 ml (three).Similarly, the maximum floor area in a home that UKwiring regulations allow to be served by a single standardpower circuit is 100 m2 – a classic case, you might think, ofchoosing the nearest order of magnitude. But actually,when the regulation was established back in 1943, theavailable copper cables could carry 6.9 kW before over-heating unacceptably. Power demand in homes wasassessed as 1 W per cubic foot of living space, meaning asingle circuit could supply 6900 ft3, which with a 9 ft ceil-ing and allowance for halls and staircases came out as1000ft2 of floor area. This value was subsequently roundedagain to 100 m2 (7% larger). So the physicist’s instinct isonly partly correct: the 100 m2 does indeed represent thenearest order of magnitude – but in the lost-in-the-mists-of-time 1 W/ft3 figure, not in the quantity presented.
I am now nearing the 1000 word limit for this article –except, of course, the limit is not a round 1000 words(which might tempt me to think I could get away with 1100or 1200). Rather, as befits a physics magazine, it is unam-biguously expressed as “900–950 words long”. Alwaystrust a physicist’s instinct for the true value to be attachedto numbers! After all, we are people who comfortablydeal with quantities that can range over 30 or more ordersof magnitude, such as resistivity or density, yet we can alsomake measurements of hyperfine transition frequencies(for example) that are accurate to better than one part in10–14. But my wife is still better than me at following a recipe.
John Swanson is a physicist at the UK National Grid, [email protected]● Readers are invited to submit their own Lateral Thoughts. Articlesshould be 900–950 words long, and can be e-mailed to [email protected]
Baking, speed limits and circuits
To a physicist,a recipe whereevery quantityis a roundnumber ofcups ortablespoonscannot becriticallydependent onthesequantities
iSto
ckph
oto.
com
/red
hum
v
physicsworld.comLateral Thoughts: John Swanson
88 Physics World March 2012
Untitled-1 1 07/12/2011 08:57
Untitled-2 1 06/02/2012 09:05
![India Construction - Mar12 - BNP Paribas[1]](https://static.documents.pub/doc/80x56/577cde4c1a28ab9e78aed6c8/india-construction-mar12-bnp-paribas1.jpg)
![Hair Mar12-10 [Itay Ziv on Ben Caspit]](https://static.documents.pub/doc/80x56/577d38b91a28ab3a6b985d6d/hair-mar12-10-itay-ziv-on-ben-caspit.jpg)
