Which of the following observations cannot be explained by the Big Bang theory unless we assume that an episode of inflation occurred?
A)the fact that the universe is expanding
B)the fact that the temperature of the cosmic microwave background is almost the same everywhere
C)the existence of the cosmic microwave background
D)the fact that about 25% of the ordinary matter in the universe consists of helium

Question

Quizplus · Accepted Answer

The Big Bang theory explains the expansion of the universe, the existence of the cosmic microwave background, and the abundance of helium. However, the nearly uniform temperature of the cosmic microwave background across vast regions of space is best explained by the theory of inflation, which posits a rapid expansion of the universe shortly after the Big Bang. This rapid expansion would make the universe look the same in all directions (homogeneous and isotropic) at large scales, explaining the uniform temperature observed today.

Which of the Following Observations Cannot Be Explained by the Big