Question

According to the Big Bang theory of the origin of the universe, the universe has expanded from a hot dense state into a vast, cooler state. What would be considered scientific evidence supporting this theory?
A) Galaxies are moving toward each other.
B) Galaxies are moving away from each other.
C) Cosmic background X-ray radiation was detected in space.
D) The existence of common elements throughout the universe.

Answer 1

The correct option is option B, Galaxies are moving away from each other

It was discovered by Edwin Hubble in 1920, that galaxies are moving away from each other in proportion to the distance between them. The greater the distance at which a galaxy  exists, the faster is the distance with which it is moving away. Hubble established the Hubble’s constant which establishes expansion rate which is also helpful in determining the age and size of the universe.