Aerospace Engineering Special Seminar Series (AESS)Seminar Series (AESS)
Astronomy, Cosmology, Particle Physics and The
UniverseProf. David Toback
&M Texas A&M UniversityMitchell Institute for
David Toback, AESS Seminar 1September 2014
Fundamental Physics and AstronomySeptember 2014
Prologueg(Apologies for the simplistic definitions)• Astronomy is the study of things we can see through telescopes Stuff in can see through telescopes… Stuff in Universe (space)C l i b i • Cosmology is about trying to understand the origin and evolution gof the Universe
• Particle Physics is about trying to • Particle Physics is about trying to understand the smallest things that
k th t ff i th U imake up the stuff in the UniverseSeptember 2014 David Toback, AESS Seminar 2
Prologue Continued: Dark MattergWe live in a remarkable time where
scientists have a good understanding of each
We are arrogant enough to think that it is possible to solve major problems in p j pAstronomy, Cosmology and Particle Physics with a single discoveryg y
Idea: Dark Matter is a particle that was created right after the Big Bang and has created right after the Big Bang and has had a major impact on the evolution of the Universe and the stuff in it
September 2014 David Toback, AESS Seminar 3
the Universe and the stuff in it
Overview of the TalkWill talk about this exciting possibility by
i ti b answering some questions one-by-one: • What IS Dark matter and what is some
of the evidence for it? • What IS the Big Bang Theory?What S the B g Bang heory?• What does Dark Matter have to do with
the Big Bang and the evolution of the the Big Bang and the evolution of the Universe?What are scientists doing today to • What are scientists doing today to discover Dark Matter?
Fi l Th h4
Final ThoughtsSeptember 2014 David Toback, AESS Seminar
What is Dark DMatter? Matter?
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Dark Matter
What is What is some of some of
the the evidence evidence for Dark for Dark matter?
6matter?September 2014 David Toback, AESS Seminar
How Stars Move in Galaxies• Start by considering the case that there IS no Dark Matter in galaxiesDark Matter in galaxies
• Can use laws of gravity to predict two things: – 1) The orbits of planets as they move around ) f p ythe solar system and
– 2) Stars as they move around a galaxy • Prediction: both have very massive centers so we expect the data to look consistent with thatD t• Data:– For the solar system, the data agree perfectlyperfectly
– For the stars in the outer part of galaxies, the prediction doesn’t work at all
January 2014 7David Toback, AESS Seminar
p
http://people phyhttp://people.physics.tamu.edu/toback/Talks/Video/Lab4 SS1 video/Lab4_SS1_video
.swf
8September 2014 David Toback, AESS Seminar
As the Galaxy Turnsy
http://faculty.physics.tamu.edu/toback/Talks/Video/Lab4 GX1 video slow sw/Talks/Video/Lab4_GX1_video_slow.sw
f
9September 2014 David Toback, AESS Seminar
Data well explained by lots of Data well explained by lots of “Dark Matter” we can’t see
This is where it gets its nameI th i In some sense, the name is a
statement of almost all we know statement of almost all we know about it (it doesn’t interact
h l h d h )with light, and it has mass)Lots of other evidence for dark matter like gravitational
10September 2014 David Toback, AESS Seminar
Lots of other evidence for dark matter like gravitational lensing, but that’s for another day…
Our Place in the UniverseYou are here The Dark Matter The Dark Matter
surrounds the galaxy like the
water in a fishbowl surrounds a fish in the middle of the the middle of the
bowlNot exactly the Not exactly the same… denser in
the middle because of the pull of
gravity
What is the Big gBang Theory? Bang Theory?
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Not that Big Bang Not that Big Bang TheoryTheory
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A Big Bang A Big Bang Occurred… Then
What?The Story of The Story of the Universe the Universe
since the Beginning
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Observe lots of galaxies ith th ld’ b t with the world’s best
telescopetelescopeWe notice that All the far away ones are moving away
from us VERY quicklyfrom us VERY quickly
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So What?
All the stuff in the galaxies t h f appears to have come from a
single point in space ~13 7 What happened in the past? single point in space 13.7 billion years ago
What happened in the past? Run the clock backward in timeName this time The Big Bang A f C i A moment of Creation
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Slightly more complicated than that…
• As best as we understand the As best as we understand the Universe began with a Big BBang–A REALLY Big Bang–A REALLY Big Bang
• Then what?• How did we get from the bang to the Universe we have today?today?
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A Brief History of Timey• The Big Bang
produces lots of • Zero
p fparticles
• Quarks combine to form • One millionth of one protons and neutrons
• Protons and Neutrons combine to form the
second after the Bang• A few minutes
combine to form the nucleus of an atom
• Nuclei and electrons • A few hundred Nuclei and electrons combine to form atoms
• Atoms combine to form
A few hundred thousand years
• 100 million to 1 billion Stars and Galaxies
• The Earth and our solar f
years• 9 billion years
David Toback, AESS Seminar 18
system forms• You listen to me talkSeptember 2014• ~13.7 billion years
Artists Conception of the Big Bangp g g
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The very early Universey yLots of free particles just hanging around…Universe is so hot that quarks can’t combine Universe is so hot that quarks can t combine
to make protons/neutrons
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Later, Quarks Combine to Form NucleonsNucleons
Q kqqq Proton
Quark
ProtonNuclear Reaction
Quark Quark
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A Millionth of a Second after the Big BangBang
The quarks have combined to form Protons and Neutrons
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Creating Heavier NucleigProton Proton + Proton DeuteriumProton roton roton D ut r um
DeuteriumNuclear Reaction
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A couple hundred thousand years later: Atomslater: Atoms
P tProton
HydrogenAtom
ElectroMagnetic Reaction Atom
Electron
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Wait a Billion Years
After about Our galaxy, the Milky Way
After about half a billion
years, because of gravity of gravity,
atoms combine to form the
fi t t d first stars and galaxies
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galaxiesSeptember 2014 David Toback, AESS Seminar
Aft b ut After about 9 billion 9 billion years our years our
solar solar system and y mthe Earth
formDavid Toback, AESS Seminar 26September 2014
Recent History: Life on Earthy• Earth is about 4 or 5 billion years oldE id th t i bi l t i • Evidence that microbial tracings existed on Earth about 3.5 billion years agoH id lik “L ” i t d • Humanoids, like “Lucy” existed a mere 3 million years ago m m y g
• Homo-sapiens at around 100,000
27
years agoSeptember 2014 David Toback, AESS Seminar
What does Dark Matter have to do with the Big Bang Theory?g g y
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The Known Particles– No known particles have
the properties of Dark the properties of Dark Matter
– Other reasons to believe – Other reasons to believe there are new fundamental particles to be discoveredparticles to be discovered– For example, we just di d th Hi discovered the Higgs Boson
– Maybe Dark Matter is a New Particle!
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What IS the Dark Matter?We don’t know
Hypothesis: The Dark Matter in the Universe is made up of LOTS of particles
We don t know…p f f p
that we haven’t discovered yet!Best Guess: Huge numbers got created in the Early Universe like everything else y y g
and are still here today!
Today: Observe 5 times more
David Toback, AESS Seminar 30September 2014
Today: Observe 5 times more Dark Matter than Atoms (by
mass) in the Universe
What are scientists doing today to di D k M tt ?discover Dark Matter?
Just mention two of the fun experiments being done here at
Texas A&M! Texas A&M!
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Some Sources of Dark Matter Chare Cheap
You are here O You are here Our Sun is Moving Moving
through our Galax Galaxy…
Lots of Dark Lots of Dark Matter is hittin th hitting the Earth every
David Toback, AESS Seminar 32
ysecond
September 2014
ExperimentpDark Matter
Particle
PingI saw it! Eureka!
Atom in Detector
Ping
Low TemperaturepDetector
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Can we Make and Discover Dark Matter?
Hi h lli i b t • High energy collisions between particles in the Early Universeparticles in the Early Universe
• Recreate the conditions like they were RIGHT AFTER the Big Bang Big Bang
• If we can produce Dark If we can produce Dark Matter in a collision then we
David Toback, AESS Seminar 34September 2014can STUDY it
More Expensive Dark Matter? High Energy Collisions Dark Matter ParticlesHigh Energy Collisions Dark Matter Particles
LHC ≈1 ps after the Big BangDetectorDetector
Proton ProtonProton Proton
Ok… Its more complicated than this since Dark Matter than this since Dark Matter
Particles don’t easily interact with detectors…
David Toback, AESS Seminar 35September 2014
Nor do we usually produce them directly
Aerial View of the LHC27 km in Circumference!
One of the largest and th t l i tifi
Collides high energy protons
Lake LemanCMS
the most complex scientific instrument ever conceived &
built by humankind
gy p
Two huge detectorsGeneva Airport
pp
p
ATLAS
David Toback, AESS SeminarSeptember 2014 36
How does it do it? Accelerates Accelerates protons to REALLY REALLY high
i energies, then bashes them together
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togetherSeptember 2014
http://people.physics.tamu.edu/toback/Talks/Video/particle_event_full_ns.avi
Fi l Th htFinal Thoughts
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Interested in learning more?g• Physics department now offers a
course entitled “Big Bang & Black Holes” Black Holes
(ASTR/PHYS 109)– Covers Stephen Hawking’s p g
“Brief History of Time”– Origin and Evolution of the
UniverseUniverse– How do stars form?– What is Dark Matter? Dark W D M D
Energy?– What are Black Holes?– General Relativity & Quantum
Mechanics– Particle Physics
David Toback, AESS Seminar 39
– Particle Physics
September 2014http://faculty.physics.tamu.edu/toback/109/
http://people.physics.tamu.edu/toback/TalkScience/
Conclusions• It’s an incredibly exciting time to be a scientist!
• Astronomy Cosmology and Particle Astronomy, Cosmology and Particle Physics are all comingP h d t d th l f • Perhaps we understand the role of Dark Matter in the Universe since the Big Bang!
• If our understanding is correct a If our understanding is correct, a major discovery may be just around th !
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the corner!September 2014 David Toback, AESS Seminar
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AbstractScientists have entered a golden age of discovery. We are
starting to be able to answer some of the most exciting starting to be able to answer some of the most exciting questions ever asked, including questions that touch on the Big Bang, the fundamental building blocks of nature, and the Dark Matter that fills the Universe. In this talk I will talk about Astronomy, Cosmology, Particle Physics and The Universe and the reasons to think that Physics and The Universe and the reasons to think that the biggest things in the Universe (like the Universe itself) and the smallest things (like quarks and electrons) are inextricably linked Indeed many of us electrons) are inextricably linked. Indeed, many of us believe there is a new, fundamental particle just around the corner waiting to be discovered that could all these things together
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