The cosmic microwave background radiation is a snapshot of the radiation in the universe at a redshift of z$\approx$1,000 when the universe was:
A) 1,000 times smaller than it is today
B) 10 times smaller than it is today
C) 2 times smaller than it is today
D) the same size as it is today

Question

Quizplus · Accepted Answer

The cosmic microwave background radiation corresponds to a time when the universe was about 1,000 times smaller than it is today, at a redshift of z ≈ 1,000, shortly after the Big Bang.

The Cosmic Microwave Background Radiation Is a Snapshot of the Radiation