The Big Bang. Where do we come from, where are we going?. Goals. What’s the cosmological principle? Where did things begin? Where will things end? What’s the temperature of space?. Hubble’s Law. Recall: All galaxies are moving away from us. The farther away the faster they go.
Where do we come from, where are we going?
Farther away we look, further back in time we see!
Every line of sight should end at the surface of a star.
time = distance / velocity
velocity = Ho x distance
time = distance / (Ho x distance)
time = 1/Ho
T ~ 15 billion years
Dividing line is the critical density.
Wo is the ratio of measured density to the critical density.
If Wo > 1then closed, Wo < 1 then open.Critical Density
AcceleratingAre we Slowing down?
Satellite measured the intensity of energy from space at a range of frequencies.COBE
10 x more energy in background than everywhere else.