If the universe had expanded at its original rate beyond the time when the strong nuclear force became a distinct force (about 10^-35 s after the Big Bang), the isotropy problem would have arisen: Parts of the universe seen in opposite directions would never have been in equilibrium with each other and should not exhibit the degree of isotropy observed in the cosmic microwave background. The proposed solution to this problem is A) the cosmological redshift. B) quark confinement. C) cosmic inflation. D) the Grand Unified Theory (GUT).

Question

Quizplus · Accepted Answer

Cosmic inflation, a rapid expansion of the universe at a rate faster than the speed of light for a brief period shortly after the Big Bang, is the proposed solution to the isotropy problem. It explains how regions of the universe not in causal contact could have the same temperature and density, leading to the observed isotropy in the cosmic microwave background.

If the Universe Had Expanded at Its Original Rate Beyond