Cosmology and the Origin of Life

Remember the basic problem:

• One billion photons per baryon
• Matter/Anti-Matter Assymetry has produced the observable universe
• Average energy per photon is very high

After t = 15 minutes:

• Temperature = one million degrees
• Fusion stops
• Universe consists of:
  • H,2(H),3(He),4(He),7(Li)
  • Still a long way to go to reach The Periodic Table
  • Note; nuclei with 5 or 6 nucleons are very unstable and can't exist very long

• The Universe is completely ionized at this point; no electrons are bound to atoms
• Universe is an expanding sea of mostly photons in which are mixed small amounts of atomic nuclei and free electrons

So How do we make GALAXIES ????

The First Problem:

• Matter and Radiation are coupled
• Coupling mechanism is photon scattering off of free electrons
• Scattering is the random change of direction of a photon. Watch the Blue photon
• The problem in the early universe now is that there is no place for the photons to go - they can't escape the matter.
• Radiation and matter temperature are the same due to momentum transfer between the photons and matter --> Therefore the matter is also at a temperature of one million degrees.
• This momentum transfer between the radiation and the matter will not allow the matter to clump together

To build a galaxy we need to grow a density fluctuation ! --> How is this going to happen?

The tight coupling between the radiation and matter means that the matter should be distributed like the radiation and we know, from observations of the MWB, that the distribution of radiation is very smooth.

So How come there are galaxies?

Next Page ___________________________________________________________________

The Electronic Universe Project

e-mail: nuts@moo.uoregon.edu