Transcript transition

We have now completed the first step
So where are we?
The universe is a cooling expanding sea of
photons and small pieces of slightly clumped
The Universe remains ionized as the electrons
can not yet recombine with the protons to make
neutral hydrogen.
When the temperature cools to 3000K,
recombination happens, the surface of last
scattering is reached, and the radiation
dominated era is over.
Matter can now clump
Element Formation
Only H and He exist – to make heavier
elements we need to make stars.
Star formation occurs through the
gravitational collapse of gas clouds.
We have not container yet for gas clouds
We must make the container.
Growth of Galaxies
Mostly still an unknown process
Matter clumps around surviving density
Eventually a network of clumps starts to
gravitationally interact
Somehow this process produced the
highly clustered and filamentary galaxy
Galaxy Formation
Many details of this process are still
unknown although Hubble space
telescope keeps finding the proto-galactic
building blocks.
Galaxies are containers for Life
They Nurture the process of star formation
Stars build heavy elements via fusion.
And Heavier Elements
This Process continues up until
Then weirdness happens
Then a Miracle Happens
Neutron Capture makes Uranium,
Gold, Titanium, Rare Earths