Here's why this is significant:
* Doppler Effect and Light: Just like sound waves, light waves can be shifted in frequency depending on the relative motion between the source and the observer. If the source is moving towards the observer, the light waves are compressed, resulting in a higher frequency (blueshift). If the source is moving away from the observer, the light waves are stretched, resulting in a lower frequency (redshift).
* Hubble's Discovery: Hubble observed that light from distant galaxies was consistently shifted towards the red end of the spectrum. This meant that these galaxies were moving away from us.
* Expansion of the Universe: Hubble's discovery was groundbreaking because it provided strong evidence that the universe is expanding. The farther away a galaxy is, the faster it appears to be moving away from us. This observation led to the development of the Big Bang theory, which explains the origin and evolution of the universe.
