Question

How can you prove that the universe is expanding? How can you prove that the universe is expanding?

Answer 1

Answer:

This can only be due to the fact that the Universe is expanding. Further, by measuring the distance to the galaxies, one finds that the velocity of recession is proportional to the distance of the galaxy from us. This is called Hubble law after Edwin Hubble who was the first to discover it.

Answer 2

Answer: you can prove the universe to be expanding by observing the cosmological redshift or by using Albert Einstein’s General Relativity theory