The Birth, Life and Death of the Universeand

The Strange and Terrible Accidentof Human Consciousness

The Birth, Life and Death of the Universeand

The Strange and Terrible Accidentof Human Consciousness

Patrick Gaydecki

School of Electrical and Electronic EngineeringUniversity of Manchester

PO Box 88Manchester M60 1QD

United Kingdom

Tel: [UK-44] (0) 161 306 4906

patrick.gaydecki@manchester.ac.uk

www.eee.manchester.ac.uk/research/groups/sisp/research/dsp

SynopsisSynopsis

The universe was formed approximately 13.7 billion years ago from the cataclysmic explosion of a singularity 0.000000000000000000000000003

(2 x 10-27) metres in diameter (much smaller than the diameter of an atom). After just 0.00000000000000000000000000000000001 (10-35) seconds, when the temperature of the nascent universe was ten thousand trillion, trillion degrees Kelvin (1028 K), it underwent a period of ultra-rapid expansion called inflation,

during which it expanded in size by a factor of 1030. This has been likened to the expansion of a DNA molecule to the size of our galaxy, in a trillionth of a trillionth

of the blink of an eye.

After this point, the universe expanded and cooled more gradually, during which the stars, planets and all life emerged.

The visible universe today is 6 x 1025 m (or 3.75 x 1022 miles) in diameter, and contains some 1011 galaxies. Each galaxy contains roughly 1011 stars, most of which are thought to have planets. The universe beyond this point is unknown.

At some distant time in the future, the universe will cool and die, and all life will be extinguished.

Lecture Overview (1)

Sizing the universeThe Steady State TheoryBig Bang TheoryRecession of the galaxiesMicrowave background radiationProblems associated with the Big bang Theory: inflation, dark matter and dark energyFormation of matter and planets: nucleo-synthesisAge and formation of the solar systemNewtonian physics, the nature of light and time, the concept of the aetherEinstein, Special Relativity and General Relativity

Lecture Overview (2)

Problems associated with Maxwell’s interpretation: PlankFormulation of Quantum Theory and The Uncertainty PrincipleThe Standard Model of the UniverseString and M-theoryThe evolution of lifeThe nature of consciousnessMysteries and challenges aheadUltimate fate of the universeThe nature of reality

The Vault of the Heavens

“Thy shadow, Earth, from Pole to Central Sea; Now steals along upon the Moon's meek shine; In even monochrome and curving line; Of imperturbable serenity”

“Thy shadow, Earth, from Pole to Central Sea; Now steals along upon the Moon's meek shine; In even monochrome and curving line; Of imperturbable serenity”

In ancient times the Earth was assumed to be flat. However, by 350 BC, The Greeks had concluded, from many observations, such as the way a ship disappeared over the horizon or the shadow of the Earth on the moon during a solar eclipse, that the earth was spherical. The first recorded, accurate measurement of the circumference of the Earth was made by Eratosthenes of Cyrene (276-196 BC). On June 21, the noonday sun was directly above the city of Aswan, Egypt. At the same time, a stick placed upright in the ground in the city of Alexandria, some 800 km north, cast a short shadow, indicating the sun was 7° past its zenith. From this, Eratosthenes calculated the Earth’s circumference to be:

This was a momentous discovery, and one which began to cast doubt on initial estimates of the size of the cosmos. Today, we know that the mean circumference of the earth is 40,076 km, with a mean diameter of 12,774 km. Quite apart from the minor irregularities cause by mountain ranges, the earth is not truly spherical since it has an equatorial bulge resulting from its rotation.  Strictly speaking therefore, the Earth is an oblate spheroid.

kmnceCircumfere 411438007

360

The Diameter of the Earth

Earth Sizing Principle

Sunlight

7 degrees

The Lunar Distance

Hipparchus of Nicaea (190-120 BC) reasoned that if the sun was much further from the earth than was the moon, then the curvature of the earth’s shadow during an eclipse could be used to estimate the distance to the moon. Using Eratosthenes’ data for the earth’s diameter, he calculated the distance to the moon to be 384,403 km. This was an excellent estimate. Today, we know that the moon is at a mean distance of 382,166 km, with a perigee of 354,341 km and an apogee of 404,336 km.

By exploiting the parallax effect, it was possible to make increasingly accurate measurements of the lunar distance.

By knowing its distance, the diameter of the moon could also be estimated by using, additionally, its apparent size as seen by the eye. The diameter is 3,474 km.

The Parallax Method

The Solar Distance

Attempts by the ancient Greeks to measure the distance to the sun using trigonometry were correct in their method but limited by the absence of appropriate astronomical instruments. By 150 BC, they had gauged the sun to lie at a distance of perhaps 8 million km, and this, they reasoned, was also the approximate size of the celestial sphere (the universe), in which the stars were embedded. Calculating the distance to the planets was not possible. No further progress on the size of the universe was made for 1,800 years.

Almost certainly, significant progress in the sciences was delayed by several hundred years by the destruction of the great Library in Alexandria, the ancient world's single greatest archive of knowledge.

Matters were not helped by the fact that the Greeks believed all celestial bodies to orbit the earth. A new model of the Solar System had to wait until the Polish astronomer Nicolas Copernicus (1473-1543), who reasoned in a book published on the day of his death, that the Sun, not the Earth, was the centre of the Solar System.

Size of the Solar SystemSize of the Solar System

• In 1619 Johannes Kepler (1571-1630) established an accurate model of the Solar System. He found that the average distances of the planets from the Sun were proportional to the times of revolution. Hence, it was possible to say if a plant x was twice as far from the Sun as plant y. With the invention of the telescope by Galileo Galilei (1564-1642), it became possible to measure very small parallaxes. In 1671, Jean Richer (1630-96) and Giovanni Cassini (1625-172) made simultaneous parallax measurements of Mars from Cayenne, French Guiana and Paris.

• From this, they calculated the distance of the Earth to the Sun to be 140,070,000 km (87,000,000 miles). This was pretty good; it is actually at a mean distance of 149,053,800 (92,580,000 miles).

• Modern techniques use radar or laser reflection to measure the distances of planets within our solar system, with great accuracy (less than a centimetre). We know, for example, that the moon is spiralling away from the earth at a rate of 38 mm per year.

• Pluto lies at a mean distance from the sun of 5,910 million km, or 3,671 million miles.

• In 1619 Johannes Kepler (1571-1630) established an accurate model of the Solar System. He found that the average distances of the planets from the Sun were proportional to the times of revolution. Hence, it was possible to say if a plant x was twice as far from the Sun as plant y. With the invention of the telescope by Galileo Galilei (1564-1642), it became possible to measure very small parallaxes. In 1671, Jean Richer (1630-96) and Giovanni Cassini (1625-172) made simultaneous parallax measurements of Mars from Cayenne, French Guiana and Paris.

• From this, they calculated the distance of the Earth to the Sun to be 140,070,000 km (87,000,000 miles). This was pretty good; it is actually at a mean distance of 149,053,800 (92,580,000 miles).

• Modern techniques use radar or laser reflection to measure the distances of planets within our solar system, with great accuracy (less than a centimetre). We know, for example, that the moon is spiralling away from the earth at a rate of 38 mm per year.

• Pluto lies at a mean distance from the sun of 5,910 million km, or 3,671 million miles.

The Nearest Stars

Our Galaxy contains roughly 150 billion stars. The nearest star, Proxima Centauri, is 4.2 light years from us. Since light travels at 299,792,458 m/s, it follows that Proxima Centauri lies at a distance of:

D = 4.2 X 365 X 24 X 3600 X 299792.458 = 39,707,870,810,000 km

i.e. about 24.7 trillion miles.

The distances of the stars are so vast that it was not until relatively recently that the tiny stellar parallaxes could be measured, for even the closest stars. This required taking measurements at opposite points of the earth’s rotation around the sun.

In 1838, Wilhelm Bessel (1784-1846) announced the first parallax measurement of a star, 61 Cygni, in the constellation Cygnus, which was 0.29 seconds of arc. Its distance was 11.1 light years, or 105 trillion km (63.4 trillion miles).

The Doppler EffectThe Doppler effect was first explained accurately in 1842 by Christian Johann Doppler (1803-53). It works like this: if a car travels towards us, the engine noise appears to be raised in pitch, and it falls as it passes. This is because the sound waves bunch up as they travel towards us but get stretched as the car recedes. The same is true for light, but with respect to colour. A white star approaching us appears bluish, but reddish if moving away. In addition, the light from a star has many dark spectral absorption lines, since different elements absorb different frequencies. By observing the spectrum, we can deduce the star’s speed and chemical composition.

By analysing the Sun’s spectrum, and comparing this with the stars, it was confirmed that the sun is indeed an ordinary star.

Identification of Fraunhofer lines.

Fraunhofer Line Element Wavelength (Å)

A - (band) O2 7594 - 7621

B - (band) O2 6867 - 6884

C H 6563

a - (band) O2 6276 - 6287

D - 1, 2 Na 5896 & 5890

E Fe 5270

b - 1, 2 Mg 5184 & 5173

c Fe 4958

F H 4861

d Fe 4668

e Fe 4384

f H 4340

G Fe & Ca 4308

g Ca 4227

h H 4102

H Ca 3968

K Ca 3934

Size of the Milky Way

Stellar parallax cannot be used to determine the distance of more distant stars, simply because they are too small. In 1912, a startling discovery was made by Henrietta Swan Leavitt (1868-1921), one of the greatest unsung heroines of astronomy (there are several others). She discovered that a particular kind of star called a Cepheid Variable varies in brightness at a rate inversely proportional to its absolute luminosity (by observing Cepheids in the Small Magellanic Cloud). The absolute luminosity is determined by distance. Hence, by establishing the distance to one Cepheid, all distances could be known.

By using the Doppler effect in conjunction with Cepheid behaviour, it was for the first time possible to establish absolute distances and the size our galaxy. Many astronomers were involved in this process, and the final shape and distribution emerged in the 1930’s. Our Galaxy has a lens-shaped spiral construction, 16,000 light years thick at the centre and 3,000 light years thick at the position of our sun, which is roughly 2/3 the radius from the centre. The galaxy is approximately 100,000 light years in diameter, i.e. 9.45 x 1017 km, or about one million trillion km (600,000,000,000,000,000 miles).

By 1919, it was not even suspected that there might be other galaxies…

The Milky Way

Our place in the Milky Way

You are here

Echoes of EternityEchoes of Eternity

“If only you could see what I have seen, with your eyes”“If only you could see what I have seen, with your eyes”

Echoes of Eternity: other Galaxies and Galactic RecessionIn the early part of the 20th century, Vesto Slipher (1875-1969), not Edwin Hubble, first discovered galactic red shifts, although at the time they were considered shifts of stars. However, Hubble (1889-1953) used Leavitt’s discovery to show that the supposed stars observed by Slipher were in fact galaxies in their own right. In addition, he discovered that the farther away a galaxy, the faster it is receding (apart from the local cluster including Andromeda and the Magellanic Clouds, due to gravity). From these observations was derived Hubble’s Law:

DHv 0Where v is the recessional velocity, D is the distance of the galaxy to the observer, and H is a constant. Note that our galaxy does not occupy a special position, i.e. all galaxies are receding from one another, like dots on the surface of an inflating balloon (this is a simplification, since the surface of a balloon is two-dimensional, whereas space is 3D).

Implications of an Expanding Universe:The Great Debate

The discovery of an expanding universe was a relief to many but irksome to some. Most important, Einstein’s Theory of Gravitation does not permit a static universe. At the time of its formulation, no other kind was known, so he added a cosmological constant (“the greatest blunder of my life”) to accommodate it. Actually, Newtonian physics does not allow it either.

The expanding universe removed the necessity of the cosmological constant, completing the theory in all its beauty.

However, an expanding universe implied, ineluctably, that it had a beginning as a very small, hot and dense mass. The idea of the big bang was born, first proposed by Georges Lemaitre (1894-1966), a Belgian priest. This was initially dismissed, but later gained increasing acceptance.

However, Fred Hoyle (1915-2001) thought the theory absurd, and developed his own ideas…

The Steady State Universe

Fred Hoyle had no problems with the notion of an expanding universe, but, based on the Cosmological Principle (which states that on a large scale, the universe is homogenous and isotropic, and that we occupy no special position), he maintained that it came into existence by the continuous and spontaneous creation of matter – about 1 atom per cubic metre every 10 billion years, not through a sudden cataclysmic event which he coined “The Big Bang” as a pejorative term during a radio broadcast. In the 1950’s however, evidence began to accumulate in favour of the Big Bang Theory:

• The expansion was consistent with Hubble’s law, at all observed points• The universe contained different features, depending on how far you looked,

i.e. how far back in time.• The amount of helium in the universe; it is the 2nd most common element, but

the Steady State Theory would give far lower concentrations than those predicted by the BBT.

Yet the most important and crucial piece of evident in the Big Bang’s favour occurred quite by accident in the 1960’s...

In 1948 Russian cosmologist George Gamow (1904-68) predicted that if the Big Bang Theory were correct, the heat of the initial violent event would have cooled to around 50° K, but later revised to 5°K (-268°C). Hence the universe would be filled with a steady, constant background radiation in the microwave region. Crucially, the radiation should be very similar, but not identical, in all directions. 

The Cosmic Microwave Background Radiation

In 1965, whilst working on a sensitive microwave antenna at Bell Laboratories, Arno Penzias (1933-) and Robert Wilson (1936-), were plagued by a constant source of microwave interference, no matter how they adjusted and cleaned the instrument. It appeared to come from the sky uniformly, at a temperature of 2.7°K. They were unawareof the significance of this, despite the fact that Robert Dicke at Princeton (locally) was trying to find it. This earned them a Nobel prize and firmly established the BBT.

Implications for the Cosmic Microwave Background Radiation

If the universe had been perfectly uniform during If the universe had been perfectly uniform during expansion, then no stars or galaxies would have expansion, then no stars or galaxies would have formed. Minute fluctuations in the initial conditions formed. Minute fluctuations in the initial conditions would instead lead to granularity and clumping of would instead lead to granularity and clumping of atoms. Hence, the CMBR should contain tiny atoms. Hence, the CMBR should contain tiny fluctuations in temperature – less than one fluctuations in temperature – less than one thousandth of a degree.thousandth of a degree.

In 1998, the Cosmic Background Explorer In 1998, the Cosmic Background Explorer (COBE) probe was launched to detect such (COBE) probe was launched to detect such fluctuations. The data it provided were exciting, fluctuations. The data it provided were exciting, but of low resolution.but of low resolution.

Its successor, the Wilkinson Microwave Its successor, the Wilkinson Microwave Anisotropy Probe (WMAP), was launched in Anisotropy Probe (WMAP), was launched in 2001. It is located 1 million miles from the earth, 2001. It is located 1 million miles from the earth, at Lagrange point 2 (L2, a point of gravitational at Lagrange point 2 (L2, a point of gravitational stability, always looking away from the sun, earth stability, always looking away from the sun, earth and moon at the universe. and moon at the universe.

It includes the most sophisticated microwave It includes the most sophisticated microwave detectors ever made, and has yielded the most detectors ever made, and has yielded the most detailed picture yet of the echo of creation.detailed picture yet of the echo of creation.

Lagrange Point 2 (L2) for WMAP

WMAP Looking back in time 380,000 years after the Big Bang

The universe 380,000 years after the Big Bang

Furnace of the GodsFurnace of the Gods

“Fiery the angels fell, deep thunder rolled around their shores,Burning with the fires of orc”

“Fiery the angels fell, deep thunder rolled around their shores,Burning with the fires of orc”

It burns hydrogen through D-T nuclear fusion. In this process, two atoms of hydrogen are forced together through intense gravitational pressure to create helium. The helium atom is less massive than the two hydrogen atoms, and the mass difference is expressed as energy through Einstein’s celebrated formula E = mc2.

Each second, the sun loses 4.26 million tons in mass, releasing 383 trillion, trillion watts, or 9.15 X 1010 megatons of TNT per second.

The SunThe Sun is an ordinary, 2nd generation (confusingly, a population I) G0-type (main sequence) star, with a mean diameter of 1.292 million km (865,000 miles), and a mass of 2,000 trillion, trillion tons (333,000 times that of the earth).

The sun is approximately 5 billion years old, and will continue to burn normally for a further five billion, when it will swell and become a red giant. The sun does not have sufficient mass to form a supernova, but will eventually throw off most of its outer layers and become a dead white dwarf.

Stellar Nucleosynthesis

In the first phase of the Big Bang, only the lightest elements including hydrogen (74%), helium (23%), lithium (2%), and beryllium (1%) were synthesised. The earliest stars (Population II, i.e. 1st generation), contained none of the heavier elements to start with. These are still visible by observing distant galaxies, which are of course further back in time.

In a series of papers in the 1950’s, Sir Fred Hoyle, with colleagues Fowler and the Burbridges, established the principle of stellar nucleosynthesis. As a star runs out of hydrogen, the helium “ash” in the core contracts and heats to 100 million °K, triggering the fusion of helium. This in turn produces heavier elements, including carbon, oxygen and all the way up to iron, which is a dead end. Each stage requires higher temperatures, and the process becomes progressively less efficient. Sir Fred Hoyle brilliantly solved a theoretical problem with this scheme (concerning the triple-alpha process), which was proven experimentally.

Fowler received a Nobel prize for his work, but to the eternal shame of the Nobel Assembly, Hoyle did not.

Elements beyond iron cannot be synthesised through normal stellar burning because the necessary temperatures cannot be generated. These are only formed in supernova explosions.

Everything that exists was manufactured in the heart of stars. Our star is Population I, meaning it was formed from the debris of earlier supernova.

Kepler's Supernova Remnant

This image was taken by the Hubble Space Telescope. It is the last such object seen to explode in our galaxy, residing about 13,000 light-years away in the constellation Ophiuchus.

Evolution of the Solar System

The formation of the solar system was first proposed by the Pierre-Simon Laplace (1749-1827), and was termed the nebular hypothesis. In this scheme, a great rotating cloud of interstellar dust and gas coalesced under the force of gravity to form the sun, with outer rotating rings collapsing to form the planets. At the time, nuclear fusion was unknown, so details (and mathematical evidence) had to wait. The scheme is essentially correct; as the matter condensed in a central region, the temperature gradually rose, until at 10 million degrees K, nuclear fusion was triggered. The planets underwent countless collisions with other formations and asteroids, as evidenced by craters on the moon, the earth and other worlds in the Solar System.

Stellar Nurseries in the Eagle Nebula

Age of the Solar System

Radiometric dating using uranium-Radiometric dating using uranium-lead analysis was first established lead analysis was first established as a reliable technique for as a reliable technique for determining the age of the earth and determining the age of the earth and indeed the Solar System by Clair indeed the Solar System by Clair Patterson in 1953. Uranium 235 Patterson in 1953. Uranium 235 decays to lead-207 with a half-life of decays to lead-207 with a half-life of about 700 million years, uranium-about 700 million years, uranium-238 decays to lead-206 with a half-238 decays to lead-206 with a half-life of about 4.5 billion years. By life of about 4.5 billion years. By comparing the amount of the parent comparing the amount of the parent material to the daughter material, it material to the daughter material, it is possible to establish the age of is possible to establish the age of the sample. Using the two isotopes the sample. Using the two isotopes above also allows independent above also allows independent cross-checking. The age of the earth cross-checking. The age of the earth is reliably estimated to be 4.54 is reliably estimated to be 4.54 billion years, using meteorite billion years, using meteorite samples. This corresponds closely samples. This corresponds closely with the age of the sun, established with the age of the sun, established through analysis of its nuclear through analysis of its nuclear reaction speeds.reaction speeds.

Where:Where:tt is the age of the sample is the age of the sample DD is the is the number of atoms of the daughter isotopenumber of atoms of the daughter isotopePP is the number of atoms of the parent isotope is the number of atoms of the parent isotopeλλ is the decay constant of the parent isotope is the decay constant of the parent isotope

P

Dt 1ln1

The Gathering StormThe Gathering Storm

“And all who heard should see them there, And all should cry, Beware! Beware!His flashing eyes, his floating hair! Weave a circle round him thrice,And close your eyes with holy dread, For he on honey-dew hath fed,

And drunk the milk of Paradise.”

“And all who heard should see them there, And all should cry, Beware! Beware!His flashing eyes, his floating hair! Weave a circle round him thrice,And close your eyes with holy dread, For he on honey-dew hath fed,

And drunk the milk of Paradise.”

Victorian Certainty

By the close of the 19th century, many scientists thought that the age of scientific discovery was drawing to a close, and that the rest would be merely filling in the details. The Newtonian theory of gravitation had established celestial mechanics as an exact science (nearly), with the astounding equation of

Which Henry Cavendish (1731-1810) had used with great accuracy to weigh the earth. James Clerk Maxwell (1831-1879), widely considered the 4th greatest physicist of all time, had unified the electric and magnetic forces with the electromagnetic wave theory of light, and the theory of acoustics was advancing apace. In short, scientists viewed the universe as a vast, predictable machine, in which, if all the motions of its particles were known, the future could be established with perfect accuracy. Most important, Time was an endless, constantly flowing river, that provided an absolute reference for all phenomena.

2r

MmGF

2r

MmGF

In 1905 An obscure patent officer, Albert Einstein (1879-1955), working in Bern, Switzerland, published in the journal Annalen der Physik a paper entitled “On the Electrodynamics of Moving Bodies”.

In contained almost no mathematics (initially), no references, no historical context and only a single acknowledgement to a colleague, Michele Besso.

It is the single most important publication in the history of science, and completely altered our concept of the universe, time, space, reality and the meaning of existence.

The most extraordinary feature of this work is that Einstein appeared to have deduced this purely by a process of cogitation, independently and, it seems, out of nothing.

It established the Special Theory of Relativity (which Einstein had originally wished to be called Theory of Invariance), which replaced the concepts of space and time with a single entity called Spacetime.

Special Theory of Relativity (I)

your

spe

ed

time

a

bc

The entire SRT may be summarised as follows:The combined speed of a body moving through space and moving through time is always equal to the speed of light.Or:The speed of a body in spacetime is always equal to the speed of light.Hence:

Special Theory of Relativity (II)

• As we move faster in space, time slows, since the spacetime velocity is always constant.

• If two bodies move relative to one another (e.g. trains passing), any clock on the other train appears to be moving more slowly. This is known as time dilation.

• Each train appears to the other to be shortened. This is called the Lorentz contraction.

• The speed of light, c, is absolute and independent of the observer.

• Events which appear simultaneous to one observer will not be so to a second observer who is moving relative to the first.

• If a body accelerates away from another and returns, less time will have passed for the body which accelerated.

• As a body accelerates, its mass increases, so it becomes ever harder to gain speed. At the speed of light, time would stop, mass would be infinite, and the body would have zero width. Hence, this is not possible.

22

222

bca

bac

If you travel at 200,00 km/s, b, for every 4 seconds that

passed for an observer

stationary with respect to you, only 3 seconds passes for you.

Light: 300,000 km/s

You: 200,000 km/s

Although a stationary observer will see the light pass you at 100,000 km/s, you will still see the light pass at 300,000 km/s, since time travels more slowly for moving bodies.

One of the consequences of the Special Theory of Relativity is the relativity of simultaneity. This means that two events which are simultaneous to an observer will not be simultaneous to another if the second is moving relative to the other. This is not apparent, it is real.

In one interpretation of the theory, spacetime is a solid block in which the universe is a static, and all events that have happened and that will happen are forever frozen. time

Special Theory of Relativity (III)

Special Theory of Relativity (IV)

Time dilation for moving bodies was demonstrated experimentally by Joseph Hafele and Richard Keating, who, in 1971, flew a caesium atomic clock on a 747 jet around the world, comparing the results with those of an identical clock at the United States Naval Observatory. As expected, less time had elapsed on the moving clock, by -59 ns, exactly in accordance with the theory.

To build a time machine, simply accelerate away from the earth at an appropriate velocity, for a given time, and return. Depending on the velocity, You might age a day, but the earth will have moved on by 10,000 years.

General Theory of Relativity (I)By 1915, Einstein concluded that acceleration and the force of gravity are equivalent. It therefore follows that time dilation will be experienced by bodies immersed in a gravitational field, i.e. the stronger the gravity, the slower time flows.

In addition, because Einstein had established the concept of spacetime, he concluded that gravity operates by warping the fabric of spacetime in the vicinity of the body. Objects, including light are attracted to a body not in a Newtonian sense, but because they are following the warp of the spacetime in which they move. Immediately, it correctly accounted for the anomalous precession of the perihelion of Mercury.

The GTR is the most tested and accurate theory ever developed. It has many applications in everyday life, including GPS, communications and astronomical observations.

In 1919, Arthur Eddington led an expedition to Principe Island in the Gulf of Guinea, in equatorial Africa, to observe a total eclipse of the sun. In particular, they were attempting to verify the bending of distant starlight by the sun. The measure deviation, 1.76 seconds of arc, was again as predicted by the theory.

General Theory of Relativity (II)

Global Positioning System (GPS) must use an Einsteinian correction factor to account for the fact that the synchronization system on earth runs more slowly than that on the satellite.

Quantum Theory (I)Things were going to get a whole lot worse. Maxwell’s classical theory of electrodynamics relied on smoothly changing, continuous systems. In 1894, an obscure professor named Max Planck (1858-1947) had been commissioned by electric companies to create maximum light from light bulbs with minimum energy. This required a theoretical description of how the intensity of radiation change with frequency. Seemingly an easy problem, it took 6 years to solve. At low frequencies, classical methods failed.

His theory required that light (EM radiation) be emitted as multiples of quanta, which appeared continuous at high energies (like the dots in a photograph). He disliked the idea, thinking it was a fix. However, it was so accurate that he received the Nobel prize in 1918.

In 1905, Einstein independently published a paper describing how the photoelectric effect was caused by absorption of quanta of light (photons); unlike Plank, he immediately saw that the quantum idea was real, and not a mathematical expediency.

Hence light, which for centuries had been considered a wave, also had a discrete microstructure. In the space of less than two decades, the old order had been swept away. wavelength

inte

nsity

E

Quantum Theory (II)

The photoelectric effect, part of quantum theory, dictates that light may act as both a wave and a particle, the photon. Normally, the light that we see contains trillions of photons, and its wave behaviour is dominant. However, if the intensity is turned down below a critical point, we detect individual photons, which, bizarrely, also have wave properties.

In 1905, Einstein confirmed the existence of the atom with his work on Brownian motion. In 1910, Rutherford confirmed the existence of the nucleus.

More strangeness quickly followed. In 1913, Niels Bohr (1885-1962) discovered that electrons in an atom occupied discrete energy levels, and could only move into higher or lower orbits in discrete jumps. This explained why electrons did not lose energy as they orbit the nucleus and hence spiral into it.

Quantum Theory (III)

Wave interference What you expect with quanta... ...What you get

In the above experiment, individual photons of light still behave as waves. Amazingly, so do electrons. Quantum theory came of age with the towering contributions of Erwin Schrödinger (1887-1961) and Werner Heisenberg (1901-1976), who described the laws governing wave-particle duality. In essence, a particle is a wave until measured, when its probability wave function collapses. This is the Wave Equation, the corner stone of Quantum Physics. Heisenberg went on to show that at the quantum level, there is no such thing as certainty – it is fundamentally probabilistic. Einstein was deeply opposed to this.

In 2007, D. Akoury and others, working at the University of Frankfurt , demonstrated wave interference for a molecules. Everything has a wave function, including humans. Quantum theory is one of the most successful, and least understood, theories in physics. It has given us, for example, the transistor, which underpins our entire modern day technology.

A Theory of EverythingA Theory of Everything

“I had a dream, which was not all a dream.The bright sun was extinguish'd, and the stars

Did wander darkling in the eternal space,Rayless, and pathless, and the icy earth

Swung blind and blackening in the moonless air.”

“I had a dream, which was not all a dream.The bright sun was extinguish'd, and the stars

Did wander darkling in the eternal space,Rayless, and pathless, and the icy earth

Swung blind and blackening in the moonless air.”

Conflicting Issues and the Standard Model

By 1979, it was known that the universe comprised four, and only four, fundamental forces: the strong and the weak nuclear, electromagnetic and gravitational force. The objective of a Grand Unified Theory is to combine the forces into a single super force, which will demonstrate their common ancestry. At this point in time, the relationships between all but gravity have been established. This is known as the Standard Model.

Unlike the other forces, gravity is much weaker, and cannot be accounted for yet by the Standard Model. Furthermore, there is an unresolved conflict between the General Theory of Relativity and Quantum Theory. The GTR is superb at predicting the behaviour of gravity at a macroscopic level, but cannot be applied at the particle level. The opposite is true for QT.

A theory of everything would combine all the forces, perhaps involving quantum gravity. In order to test the theories, the Large Hadron Collider has been constructed, which will allow physicists to replicate the conditions soon after the Big Bang.

Interaction Theory Mediators Relative Strength

Range, m

Strong QCD Gluons 1038 10-15

Electromagnetic QED Photons 1036 InfiniteWeak Electroweak W and Z bosons 1025 10-18

Gravitation General Relativity Gravitons (to be discovered)

1 Infinite

The Large Hadron Collider

The LHC will accelerate protons to 99.999999% of the speed of light, giving them a collision energy of 14TeV. On collision, the energy is converted into mass via the formation of new particles. This will replicate conditions very shortly after the Big Bang. Amongst other things, it is hoped that the particle theoretically responsible for producing mass, the Higgs boson, will be found. The speeds are so high that one billionth of a gram of hydrogen has the energy of 8 litres of petrol.

Dark Matter and Dark EnergyIn 1962, Vera Rubin (1928-) discovered that the rotation of many galaxies was so fast that, unless there was some additional unseen matter holding them together, they should fly apart. Initially she was ignored (partly because she was a woman – she had tried to enrol on the graduate program at Princeton but they did allow women until 1975) . However, further observations and theoretical calculations suggested that the universe appeared to be missing about 90% of its matter.

The idea of “dark matter” was born, but as yet there is no direct evidence of its existence.

Similarly, at the present time the inflation of the universe appears to be accelerating. It is proposed that this is due to “dark energy”, but again there is no direct evidence.

Some notable cosmologists, including Mordehai Milgrom, propose Modified Newtonian Dynamics (MOND).

Black Holes and Echoes of HoyleBlack holes are formed by the collapse of super-massive stars, typically after a supernova event. The gravitational field produced is so strong that even light cannot escape. Black holes cannot be described by the GTR, since they are singularities.

Quantum theory dictates that space is a seething mass of particles that flicker into existence and out again every moment (thereby maintaining the law of mass/energy conservation).

However, Stephen Hawking discovered that black holes emit radiation (Hawking Radiation), since , in a particle/antiparticle pair, one may lie within the event horizon, but not the other. Black holes therefore eventually evaporate, over an inconceivable amount of time.

The diameter of an atom is typically 10-10 m. The diameter of its nucleus is typically 10-15, i.e. some 100,000 time smaller. Scaled up, if the nucleus were the size of an orange, then the electrons, each the size of a pea, would be orbiting some 4 km (2.5 miles) away.

Clearly, the vast bulk of matter is empty space.

But what are the fundamental particles made of? String theory, and its latter manifestation, M-theory proposes that all matter ultimately comprises strings of vibrating energy, incomparably smaller than the particles they represent. Different particles arise when the strings vibrate at different fundamental frequencies. But what are strings? How can nothing become something?

String theory so far allows many (possibly an infinite) different manifestations of the universe, and has so far failed to describe ours in a unique way. Hence it has yet to make a single, testable prediction.

(1) Matter (2) Molecules (3) Atoms (4) Electrons (5) Quarks (6) Strings.

Note: protons and neutrons comprise quarks, not electrons.

2.5 miles

The Nothing That is

Dawn of MindDawn of Mind

“Yea, slimy things did crawl with legsUpon the slimy sea.

About, about, in reel and routThe death-fires danced at night;

The water, like a witch's oils,Burnt green, and blue and white.”

“Yea, slimy things did crawl with legsUpon the slimy sea.

About, about, in reel and routThe death-fires danced at night;

The water, like a witch's oils,Burnt green, and blue and white.”

It is widely held that life on earth first evolved around 3.8 billion years ago (the earth is about 4.5 billion years old). This can be inferred from carbon isotopes peculiar to life and apatite, a mineral that is produced and used by biological micro-environmental systems.

The central issue is how it got started.

Amino acids (there are 22 natural ones) will form spontaneously if the conditions are right, but the formation of proteins, from amino acids, is still problematic. These must be assembled in the right order for a meaningful protein to form. The chances of this happening are exceedingly remote.

For life to get going, the proteins must be assembled into self-replicating DNA molecules. And the rest is just evolution…

Two of the most remarkable features of life on this planet are:

• Although life started 3.8 billion years ago, for multi-cellular life such as slime moulds, did not appear until about 1 billion years ago.

• The first Homo species only appeared abou5 2.5 million years ago. Hence if the age of the earth is one day, we appeared in the last minute before midnight.

Evolution Timeline

The human eye is a good example of a structure that

evolution has designed rather poorly.

Although there have been major advances in the study of human consciousness in several narrowly defined areas, the ultimate objective of creating a machine with even a small fraction of the cognitive powers of the human brain, or indeed consciousness, still appears to be beyond the reach of science and Artificial Intelligence (AI).

The neurological basis of human consciousness is now a very important perhaps the most important are of scientific endeavour. It includes important themes such as notions of Cartesian Dualism (now outmoded), The Multiple Drafts Model, Connectionist Theory and The Pandemonium Hypothesis of speech formation, as proposed by Daniel Dennett (1942-).

There is some dispute between those cognitive theories that maintain consciousness is a “hard” problem (Roger Penrose, 1931-), i.e. forever beyond the reach of a fundamental understanding (and therefore replication), and those that argue it has a convergent solution.

Consciousness

The human brain contains around 100 billion neurons, with each neuron containing around 7000 synapses (connections). Your brain therefore has around one thousand trillion interconnections. Many scientists agree that it is the nature of the connections which leads to consciousness.

NightfallNightfall

“Goodnight, Sweet Prince, and flights of angels sing thee to thy rest”

“Goodnight, Sweet Prince, and flights of angels sing thee to thy rest”

There is still some debate amongst cosmologists about whether the universe is open or closed, i.e. whether or not there is sufficient matter to initiate a collapse, or whether it will expand forever.

At the moment, the evidence appears to be in favour of an open universe.

This therefore dictates that the universe will end.

open

flat

closed

Time

Dia

me

ter

Open or Closed?

“Come, Sable Night”

Our sun will die in 5 billion years.

In about 1000 billion years, our Galaxy will consist of dead stars and cold interstellar matter. Other galaxies will continue to recede from

one another.

In 1025 years, 99% of the matter will be ejected from our Galaxy, via collisions. The remaining matter will form a super-massive black hole, equal to 1 billion solar masses. This will also happen to all

other galaxies.

In about 10100 years all black holes will evaporate due to Hawking Radiation.

It is thought that after 10100 years, all other forms of matter will spontaneously collapse into black holes and evaporate.

76

EndEnd

“All these moments will be lost in time, like tears in rain.

Time - to die.”

“All these moments will be lost in time, like tears in rain.

Time - to die.”