L8 The History of the Universe

Essential Pre-Uni Physics L8.1
A. 4*10^17 s

Essential Pre-Uni Physics L8.2
A. H: 75%  He: 25%

Essential Pre-Uni Physics L8.3
A. 1 ms

Essential Pre-Uni Physics L8.4
A. 300,000 years
B. 3*10^3 K
C. Ultra Violet
D. Light could not travel through the universe then because it would have been scattered by charged particles.
E. Cosmic microwave background

Essential Pre-Uni Physics L8.5
A. gravity - strong - weak - electromagnetic

Essential Pre-Uni Physics L8.6
A. (3(H_0)^2)/(8*pi*G)

Essential Pre-Uni Physics L8.7
A. The universe will expand at just the right rate to avoid ever collapsing.
B. Universe expands to a maximum size, then contracts under gravity

Essential Pre-Uni Physics L8.8
A. It will expand for a long time but then eventually begin to collapse

Essential Pre-Uni Physics L8.9
A. homogeneous (the same at every point) and isotropic (the same in all directions you look)

Essential Pre-Uni Physics L8.10
A. infinite and static