How do we know that the universe is expanding?
A. The distance from the Sun to the Earth is increasing.
B. The speed of light is slowing down.
C. Distant galaxies appear to be moving away faster than nearby galaxies.
D. Distant galaxies appear to be much younger than nearby galaxies.
Answer:C
How do we know that the universe is expanding?
A. The distance from the Sun to the Earth is increasing. B. The speed of light is slowing down. C. Distant galaxies appear to be moving away faster than nearby galaxies. D. Distant galaxies appear to be much younger than nearby galaxies.