Question

which statement accurately describes the origin and expansion of the universe?
○ as the universe continues to expand, it gradually gets warmer.
○ galaxies that are farther away are moving away more slowly.
○ cosmic background radiation is leftover thermal energy from the big bang.
○ stars and galaxies formed almost immediately after the big bang occurred.

Explanation:

• Analyze each option:
• Option 1: As the universe expands, it cools, not warms. So this is incorrect.
• Option 2: Galaxies farther away move away faster (Hubble's law), so this is incorrect.
• Option 3: Cosmic background radiation is indeed leftover thermal energy from the Big Bang. This matches scientific understanding.
• Option 4: Stars and galaxies formed over time, not immediately after the Big Bang. So this is incorrect.

Answer:

C. Cosmic background radiation is leftover thermal energy from the big bang.