Which of the following statements correctly describes the universe for the entire first 380,000 years of its life?
A) All of the fundamental forces of nature were unified into one force.
B) It was a sea of gradually decreasing nuclear reactions.
C) It was filled with free quarks (not confined inside neutrons or protons).
D) It was opaque to radiation.

Question

Quizplus · Accepted Answer

For the first 380,000 years of its life, the universe was filled with ionized gas, which made it opaque to radiation. This means that light and other forms of electromagnetic radiation couldn't travel very far before being absorbed and re-emitted by the gas, so the universe was effectively "foggy" or "hazy". It wasn't until the universe cooled down enough for atoms to form (which happened around 380,000 years after the Big Bang) that the fog cleared and radiation could travel more freely.

Which of the Following Statements Correctly Describes the Universe for the Entire