Hubble’s Law: Measuring the Universe’s Growth

Hubble’s Law shows that galaxies are moving away from us at speeds proportional to their distance.
It was first proposed by Edwin Hubble in 1929, revolutionizing our view of the cosmos.
The law is expressed as v = H₀ × d, where v is velocity, H₀ is the Hubble constant, and d is distance.
This discovery proved the universe is expanding, supporting the Big Bang theory.
The Hubble constant measures the rate of expansion in kilometers per second per megaparsec.
Different methods of measuring H₀ give slightly different values, sparking today’s “Hubble tension.”
Hubble’s Law turned galaxies from “island universes” into markers of cosmic expansion.
The farther we look, the faster galaxies appear to recede, some faster than light due to expanding space.
It provides the foundation for the cosmic distance ladder and measuring the universe’s size.
Hubble’s Law transformed astronomy into cosmology—the science of the universe itself.