Several key pieces of evidence support the Big Bang Theory:
Cosmic Microwave Background Radiation (CMB): Discovered by Arno Penzias and Robert Wilson in 1965, the CMB is the residual thermal radiation from the Big Bang, uniformly detected throughout the universe. Hubble's Law: Edwin Hubble's observation that galaxies are moving away from us at speeds proportional to their distances, indicating that the universe is expanding. Abundance of Light Elements: The observed proportions of hydrogen, helium, and lithium in the universe match the predictions made by Big Bang nucleosynthesis. Large Scale Structure of the Universe: The distribution of galaxies and clusters of galaxies can be explained by the initial density fluctuations after the Big Bang.
