How can we tell if the universe is expanding?

1 Answer
chandramohanPanakkal
Sep 16, 2017

Astronomers study the spectrum of distant galaxies and find the red shift.

Explanation:

The Doppler effect is used to find the red shift..When a galaxy is moving away from us the light waves get elongated The far way galaxies are moving faster than near ones. obeying Hubble law..enter image source here
perfect astronomy.com. picture.

Related questions
See all questions in Expansion of the Universe
Impact of this question
1448 views around the world
You can reuse this answer
Creative Commons License