If we "reverse" Hubble expansion, we see that the universe should have been very dense in the distant past, and so it must have been ________ than it is today, and we should be able to
Observe ________ as a result.
A) much colder; cosmological redshift
B) much colder; the cosmic microwave background
C) much hotter; gravitational redshift
D) much hotter; the cosmic microwave background
E) much hotter; black holes

Question

Quizplus · Accepted Answer

Reversing the Hubble expansion implies that the universe was denser and hotter in the past. This leads to the prediction and observation of the cosmic microwave background, which is the remnant radiation from the hot, dense early universe.

If We "Reverse" Hubble Expansion, We See That the Universe