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 temperature of the cosmic microwave background is almost the same everywhere
B) The fact that about 25% of the ordinary matter in the universe consists of helium
C) The existence of the cosmic microwave background
D) The fact that the universe is expanding

Question

Quizplus · Accepted Answer

The Big Bang theory without inflation cannot explain why the temperature of the cosmic microwave background radiation is almost uniform in all directions. The inflation theory suggests that the universe went through a brief period of exponential expansion, smoothing out any temperature variations that may have existed before inflation.

Which of the Following Observations Cannot Be Explained by the Big