What are two pieces of evidence supporting the Big Bang Theory?

The Big Bang Theory is supported by a variety of observational evidence, with two significant pieces being cosmic background radiation and the Doppler effect.

Cosmic background radiation refers to the faint glow of radiation that fills the universe, which is a remnant heat signature from the early hot, dense state of the universe just after the Big Bang. This radiation is uniform and isotropic, meaning it is observed equally in all directions, and its existence was predicted by the Big Bang model. In 1965, this radiation was discovered, providing strong evidence that the universe underwent a hot, dense beginning.

The Doppler effect, in the context of astronomy, refers to the observed change in frequency or wavelength of light from objects in space based on their movement relative to us. When galaxies are moving away from us, the light they emit appears redshifted—a phenomenon observed by Edwin Hubble. This redshift indicates that the universe is expanding, which is a critical prediction of the Big Bang Theory. The observation that distant galaxies are receding from us suggests that the universe has been expanding since its inception, further supporting the idea that it began from a highly concentrated point.

Both cosmic background radiation and the Doppler effect provide compelling evidence for the Big Bang Theory, confirming the