In The Beginning

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In The Beginning
Big Question what is the origin of the
Universe? began as pure energy converted to
radiation (photons) matter initial explosion
WHY is unknown
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Cosmic Clues
Clues 1. the Universe has matter --- hadrons
(p, no) and leptons (e, ?) 2. abundances of
H, D, He, Li 3. the Universe is large, and is
expanding, cooling, less dense 4. galaxies
exist and are younger at greater distance 5.
stars exist and some globular cluster stars are
10 Gyr old 6. cosmic microwave background has
T 2.73 K 7. cosmic microwave background has
minor anisotropies 8. SN Type I at large
distances Limits 1. cannot see before
380,000 years after the Big Bang 2.
information cannot travel faster than
c Mysteries 1. dark matter 23 vs. 4 normal
matter (27 of critical) 2. dark energy 73
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Ingredients of Universe
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Background Universal Components
Components radiation ? ? matter by pair
production photons ?
matter E mc2 matter ?
photons MORE ENERGY? MORE
MASS! protons first then electrons
e
e
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Background 4 Forces
1. Gravity pull due to mass all
matter long range 1/R2 2. Strong
Nuclear holds nuclei together
glue protons, neutrons short range
1015 m 3. Weak Nuclear nuclear reactions
radioactivity electrons, neutrinos very
short range 1017 m 4. Electromagnetic pull
due to charge charged particles only! long
range 1/R2
Gravity ? SuperGUT (long way off) Strong ?
GUT (working) Weak ? electroweak
(done!) Electromagnetic
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Separating Forces in Early Universe
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8 Epochs
Planck 1 force GUT 2
forces Electroweak 3 forces
Particle Building
Nuclear
Building
Atomic Building

Galactic Familiar
Stellar
Familiar
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8 Epochs of the Universe
8 Epochs RADIATION dominant for first 5 MATTER
dominant for last 3 Why Change? expansion
cooling density drops
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3 Earliest Epochs
1. Planck no info available no working theory
SuperGUT? String Theory? until Universe
1043 seconds old 1032 K BREAK
gravity separates from other three forces 2.
GUT dark matter origin? exotic massive
WIMPS? until Universe 1035 to 1029 seconds
old 1029 to 1028 K BREAK strong
nuclear force separates Universe experiences
phase transition inflates because
strong/electroweak break releases energy
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Cosmic Inflation
Electroweak
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3 Earliest Epochs
1. Planck no info available no working theory
SuperGUT? String Theory? until Universe
1043 seconds old 1032 K BREAK
gravity separates from other three forces 2.
GUT dark matter origin? exotic massive
WIMPS? until Universe 1035 to 1029 seconds
old 1029 to 1028 K BREAK strong
nuclear force separates Universe experiences
phase transition inflates because
strong/electroweak break releases energy 3.
Electroweak radiation/matter exchange continues
but abating until Universe 1010 seconds old
1015 K BREAK electromagnetic and weak
nuclear forces separate particle physics
experiments match epoch-ending predictions
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Here Come the Particles
4. Particle protons and neutrons form (made up
of quarks) until Universe 103 seconds old
1012 K temp drops too low for more hadrons
(pair production) electrons and neutrinos
form Universe a few minutes old 109 K temp
drops too low for more leptons (pair
production) BREAK matter annihilates
antimatter All matter we see today was created
out of radiation as the cosmos expanded and
cooled.
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Here Come the Nuclei
5. Nuclear nuclei form D (deuterium), He, Li,
Be, B fusion occurs in plasma at 109 K He, D,
Li abundances set explains primordial
abundances He 25 oldest
stars D 0.002 UV spectra toward
stars
first 15 minutes of Universe far too much
He to be explained by stellar evolution
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Density Evidence
a. D used easily b. more D less mass
in Universe c. traces of Li d. limits normal
mass density to 4 critical
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Density Evidence
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Here Come the Atoms

• Atomic atoms remain intact photons flying free
• starts when Universe 380,000 years old 3000
  K
• THE MOMENT WEVE ALL BEEN WAITING FOR
• electrons combine with nuclei to make atoms
• radiation and matter decouple!
• edge of OBSERVABLE Universe
• cosmic microwave background photosphere

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Radiation-Matter Decoupling
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Cosmic Microwave Background
leftover heat heat from the Big Bang T 2.73
K nearly isotropic (identical everywhere)
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COBE (Cosmic Background Explorer)
COBE (Cosmic Background Explorer)
working 1989-1993 spectrum of CMB T 2.725
0.002 K anisotropy of CMB 1 part in
100,000
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Temperature Maps
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Cosmic Temp Curve
perfect blackbody fit T 2.725 0.002 K ? Big
Bang !!! ? Nobel Prize 2006 !!! Mather
Smoot
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WMAP (Wilkinson Microwave Anisotropy Probe)
Goals launched 2001 map microwave background
better than COBE determine age of
Universe determine ingredients of
Universe determine geometry of Universe
density
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WMAP Launch and Orbit
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COBE vs. WMAP
today 13.73 0.12 Byr old
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Ingredients of Universe
Normal Matter
Normal Energy photons
almost all in cosmic microwave background
only 10-4
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2 Familiar Epochs
7. Galactic large scale structure galaxies
form at about 1 billion years supermassive
black holes form? 8. Stellar stars brown
dwarfs planets life
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Universal History
Electroweak Particle
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History of the Universe
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