The concept of redshift is crucial in understanding the universe's expansion, indicating that galaxies are moving away from us. This phenomenon provides insight into the speed at which these celestial bodies recede, highlighting that the universe is not static. However, redshift alone does not offer information about the actual distance of these galaxies from Earth, creating a gap in our understanding of their spatial relationship.

In his book 'A Short History of Nearly Everything,' Bill Bryson emphasizes this distinction. While redshift is an essential tool for astronomers, it only reflects one piece of the cosmic puzzle. Consequently, additional methods and measurements are necessary to accurately determine how far galaxies are from us, illustrating the complexity of our universe and the ongoing quest for knowledge in astronomy.