The existence of the cosmic background radiation tells us that the early universe was
A) much hotter than it is today.
B) much colder than it is today.
C) composed entirely of radiation at early times.
D) composed entirely of stars at early times.
E) about the same temperature as today but much more dense.

Question

Quizplus · Accepted Answer

The cosmic background radiation is the remnant heat from the Big Bang, indicating that the early universe was much hotter than it is today.

The Existence of the Cosmic Background Radiation Tells Us That