When did it all start? About 13.7 billion years ago
Extrapolating
the Hubble Constant backwards (allowing for acceleration)
Also
get the temperature
and density
The theory that describes the
physics is called the Big Bang
This
is NOT an explosion!!
Grand Unified Theory GUT All the forces were the same when the energy is high
Inflation - a sudden expansion of spacetime about 1050
It flattens our piece of the universe.
Evidence
Cosmic Microwave Background
What we see the CMB sky ‘zoom’ b
H He abundance in Population II stars
Number of neutrons sets amount of H vs. He
Baryonic matter only about 4%
Persistent problems
Why is the universe so smooth? [ to about .01%]
Where did the small fluctuations come from?
Why is the universe so close to the critical density
Solved by Inflation
Current parts of CMB used to be much closer
Why not perfectly flat?
Quantum fluctuations get ‘inflated’ to be the current size of the lumps
If all this happened we should see the lumps in the CMB and their size should tell us what the density was at that time. (Was it the critical density?)
WMAP Sky and results (higher resolution made it possible)
According to WMAP:
Baryonic matter is 4.4%
Total matter is 27%
Flatness implies dark energy makes up other 73%
Universe age is 13.7 billion years
The Future
An
accelerating universe runs down
If
protons decay all ordinary matter falls apart
Eventually
even black holes evaporate so only particles and photons exist
