Final answer:
Edwin Hubble's contributions to the Big Bang theory include the discovery of Hubble's law, which shows galaxies moving away from us with speeds proportional to their distances, indicating an expanding universe, and the finding of cosmic microwave background radiation, both supporting the concept of the universe originating from a singular, explosive event.
Step-by-step explanation:
One of Edwin Hubble's significant findings that supports the Big Bang theory is the observation that all galaxies, except those in our local group, appear to be moving away from us, and their speed is proportional to their distance. This relationship, known as Hubble's law, is deduced from the observed red shifts in the light spectra of galaxies, which suggest an expanding universe. The greater the red shift, the faster the galaxy is moving away, indicating that the universe is not static but rather expanding.
This expansion suggests a singular beginning - commonly referred to as the Big Bang. Moreover, the discovery of the cosmic microwave background radiation (CMBR) with a blackbody spectrum characteristic of a temperature of 2.725 K, is further compelling evidence of the universe's origin from a dense and hot initial state, as predicted by the Big Bang theory.