Two key points clarifying the interrelation between Hubble's study and the Big Bang theory are:

1. Redshift and Expanding Universe: Edwin Hubble's observations of distant galaxies showed that they were moving away from us, with their light exhibiting a redshift. This indicated that the universe is expanding. Hubble's findings provided crucial evidence for the idea that the universe was once much smaller and denser, supporting the concept of the Big Bang theory.

2.Cosmic Background Radiation: Hubble's work laid the groundwork for further investigations into the universe's early state. The Big Bang theory suggests that the universe began from a hot, dense point and expanded. This expansion explains the uniform cosmic microwave background radiation detected later, which is considered a remnant of the initial explosion and further supports the Big Bang theory as the origin of the universe.