Evolution of the Universe from 13 to 4 Billion Years Ago

Evolution of the Universe from 13 to 4 Billion Years Ago - Transcript

Evolution of the Universe from 13 to 4 Billion Years Ago
Prof Dr Harold Geller hgeller gmu edu http physics gmu edu hgeller Department of Physics and Astronomy George Mason University

Unity in the Whole Structure
How is it possible by any methods of observation yet known to the astronomer to learn anything about the universe as a whole It is possible only because the universe vast though it is shows certain characteristics of a unified and bounded whole science shows unity in the whole structure and diversity only in details
Simon Newcomb 1906

What I m Going to Talk About
The Big Bang Theory of the Formation of the Universe
Radiation Matter and the Physical Laws
Kirchoff s Spectroscopic Laws Planck s Radiation Curves Stefan Boltzmann Law Newton s Law of Motion Maxwell s Equations for Electromagnetism Hubble s Law Einstein s General Theory of Relativity Bohr s Atom Wien s Law Kepler s Laws of Planetary Motion Newton s Law of Universal Gravitation Doppler Effect Einstein s Special Theory of Relativity Gamow s Big Bang

The Formation of Galaxies and Stars The Nebular Condensation Theory and the Formation of the Solar System The Formation of the Earth The Precursors of the Formation of Life

The Big Bang Begats
Macrocosmos Quantum Fluctuation Radiation Electron Positron Higgs Fields Inflation Cosmos Universe Strong Force Proton Nuclear Fusion Beta Radioactivity Gas Electric Charge Rocks Life Field Cosmic Background Radiation Particles Particle Anti particle Interactions False Vacuum Spontaneous Symmetry Breaking Big Bang Quarks Neutron Alpha Radioactivity Atom Gravity Magnetism Air Humans

Some Basic Physics
Kirchoff s Spectral Laws
Continuous Spectrum
any body ideal blackbody that is at a temperature above 0 K

Emission Spectrum
any low pressure gas that you place a high voltage across

Absorption Spectrum
any low pressure gas placed between a blackbody and the observer

Bohr s Atom
Best described the workings of the Hydrogen atom
one proton and one electron around the proton moving in orbits that are discretized quantized so that no intermediate orbits are allowed
Absorption Emission

Planck s Radiation Curves
A way to depict frequency inverse of wavelength versus intensity

Intensity

Frequency

Wien s Law
Peak wavelength is inversely proportional to the temperature of the blackbody

Cooler Body
Peak Wavelength

Hotter Body Intensity Frequency

Stefan Boltzmann Law
Energy radiated by blackbody is proportional to the temperature to the 4th power

E eg v T me tue n r y s e p ra r
600 00

500 00

Energy

E

4 T

400 00

300 00

200 00

100 00

0 0 2 4 6 8 1 0 1 2 1 4 1 6

T me tue e p ra r

Kepler s Laws
Kepler s First Law of Planetary Motion
planets orbit sun in an ellipse with sun at one focus

Kepler s Second Law of Planetary Motion
planets sweep out equal areas in equal times
travel faster when closer slower when farther

Kepler s Third Law of Planetary Motion
orbital period squared is proportional to semimajor axis cubed P2 a3

Newton s Laws I
Newton s First Law of Motion
body at rest tends to stay at rest and body in uniform motion will stay in straight line uniform motion unless acted upon by an outside force

Newton s Second Law of Motion
the acceleration of a body is proportional to the force being applied

F ma

Newton s Laws II
Newton s Third Law of Motion
for every force there is an equal and opposite force action and reaction

Newton s Law of Gravitational Attraction
force is proportional to masses and inversely proportional to the distance squared

F G m M r2

Doppler Shift
A change in measured frequency caused by the motion of the observer or the source
classical example of pitch of train coming towards you and moving away

Maxwell s Electromagnetism
Electricity according to Gauss
relates electricity to electric charge

Faraday s Law
relates electric fields to magnetic fields

Magnetism according to Gauss
relates magnetism to electricity

Ampere Maxwell Law
relates magnetic field to electricity

Einstein s Relativity Theories
Special Theory of Relativity
speed of light constant in all reference frames
time dilation and simultaneity length and mass addition of velocities

General Theory of Relativity
Principle of Equivalence curvature of space time

Hubble s Law
The further away a galaxy is the greater its recessional velocity and the greater its spectral red shift

v H0d
There is a simple linear relationship between the distance a galaxy is from the Earth and the redshift of that galaxy which is a measure of the speed with which a galaxy is moving away from the Earth

The value of the Hubble constant H0 is not known with certainty but best value today is approximately 67 km s Mpc

Hubble s Conculsion
From Hubble s Law we can calculate a time in the past when universe was a point Big bang occurred about 13 15 billion years ago
big bang formally proposed by Gamow based upon such evidence
Big bang theory progenitors existed in looser manner

Gamow s Big Bang and Hoyle s Steady State
Steady State Universe
universe looks same and will look same
continuous creation

Big Bang Universe
universe began in big bang or ylem
single point of creation

In The Beginning
In the beginning God created the particles and the antiparticles Now the temperature was high and the particles and the antiparticles were in equilibrium And God said Let there be light and He separated the photons from the particles and antiparticles God called the photons bosons and the particles and antiparticles He called fermions And there was pair production and there was photon creation the first 10 43 seconds
Eric Schulman from A Briefer History of Time

Details of the Big Bang
The littlest of physics The Big Bang ensuing Cosmic Eras
The Vacuum Era
The Planck Epoch and The Inflationary Epoch

The Radiation Era
Light and Baryons The Electroweak Epoch and The Strong Epoch Decoupling and the creation of matter

The Matter Era
Transition to matter Galaxy Formation Epoch and Stellar Epoch

The Degenerate Dark Era
Dead Star Epoch and Black Hole Epoch

Whither the future

The Littlest of Physics
Space Time Matter and Forces Types of Matter
Quarks Baryons
protons neutrons

Electrons Leptons
electrons neutrinos muons

Types of Forces
gravity electromagnetism strong weak

Back to the Beginning
The universe began as an infinitely dense cosmic singularity which began its expansion in the event called the Big Bang which can be described as the beginning of time During the first 10 43 second after the Big Bang the universe was too dense to be described by the known laws of physics

The Vacuum Era
The Planck Epoch
10 43 sec and about 1019 GeV 1 GeV 1013K we just don t know

The Inflationary Epoch
10 43 sec 10 10 sec expansion driven by repulsive gravity

Inflation was one of several profound changes that occurred in the very early universe

Four basic forces explain all the interactions observed in the universe

Grand unified theories GUTs are attempts to explain three of the forces in terms of a single consistent set of physical laws A supergrand unified theory would explain all four forces GUTs suggest that all four physical forces were equivalent just after the Big Bang

The Radiation Era
Creation of light Creation of baryonic matter Electroweak epoch Strong epoch Decoupling of weak interaction Creation of nuclei of the light elements Decoupling of radiation spectrum

When the temperature of the radiation fell below 3000 K protons and electrons could combine to form hydrogen atoms and the universe became transparent

The Matter Era
Transition from radiation domination to matter domination Last scattering Dark Ages Galaxy Formation Epoch Bright Ages

The Degenerate Dark Era
Whither the future
death of stars black hole domination What will happen to the remaining matter in the universe
Ultimately sucked into black holes Ultimately all black holes combine Ultimately all spit out in a new big bang

Summary Timescale
Era The Vacuum Era Epochs Main Event Time after bang 10 43 sec 10 10 sec 10 10 sec 10 4 sec 1 sec 1 month 1 2 billion years 2 15 billion years 20 100 billion yrs 100 billion Planck Epoch Quantum Inflationary Epoch fluctuation Inflation

The Radiation Era Electroweak Epoch Formation of Strong Epoch leptons bosons Decoupling hydrogen helium and deuterium The Matter Era Galaxy Epoch Galaxy formation Stellar Epoch Stellar birth The Degenerate Dark Era Dead Star Epoch Black Hole Epoch Death of stars Black holes engulf

A Thoughtful Break
The grand aim of all science is to cover the greatest number of empirical facts by logical deduction from the smallest number of hypotheses or axioms
Albert Einstein 1950

The Evidence So Far
Evidence for a Big Bang
expansion of the universe
galaxies receding from us
everywhere the same

remnants of the energy from the Big Bang
a very hot body that has cooled
2 7 K cosmic background radiation

the primordial abundance of chemical elements

What CMB means
Cosmic Microwave Background
Remember Wien s Law Remember Doppler COBE results

Cosmic Background
How hot would the cosmic background radiation be
close to 3 K
first detected by Penzias and Wilson of Bell Labs
Didn t know what it was Explained by Robert Dicke of Princeton Didn t get a piece of the Nobel Prize with Penzias and Wilson

confirmed by COBE satellite

Putting it into context
Taking the perspective of the universe with you at the center

The CMB remainder
Using COBE DIRBE data for examining the fine differences
fine structure of the universe
led to the galaxies and their location

Astronomers use supercomputers to simulate how the large scale structure of the universe arose from primordial density fluctuations

Linking the CMB to the Galaxies

Galaxies are grouped into clusters rather than being scattered randomly throughout the universe

String Theories Attempt to Unify Physical Forces
The search for a theory that unifies gravity with the other physical forces suggests that the universe actually has 11 dimensions ten of space and one of time seven of which are folded on themselves so that we cannot see them The idea of higher dimensions has motivated alternative cosmological models No evidence to support string theories at this time

What I Talked About
The Big Bang and Everything Within The Evidence for the Big Bang
Hubble s Law Cosmic Microwave Background Abundance of chemical elements

A touch of strings