The red shift. A Doppler effect (used in speed trap radar) showing that all (except for a few close ones) galaxies are moving away from us - and the farther away they were the faster they were moving.
As proven by Edwin Hubble, the universe is expanding.
Edwin Hubble
universe is expanding
The universe is expanding!
Edwin Hubble
Edwin Hubble was responsible for the concept of the universe expanding.
Edwin Hubble
Edwin Hubble.
Edwin Hubble.
Edwin Hubble determined that the universe was expanding by observing the redshift of light from distant galaxies. He found that most galaxies exhibited a redshift, indicating they were moving away from Earth, and the farther away a galaxy was, the faster it appeared to be receding. This relationship, known as Hubble's Law, suggested that the universe is expanding uniformly, leading to the conclusion that it originated from a singular point in the Big Bang.
Edwin Hubble
Edwin Hubble.