Distance-Redshift Relation

The distance-redshift relation explains how the universe's expansion causes distant galaxies to appear shifted toward red light, known as redshift. As galaxies move away from us, their light stretches, shifting to longer wavelengths. The farther a galaxy is, the faster it appears to be receding, resulting in greater redshift. By measuring this redshift, astronomers can estimate how far away the galaxy is. This relationship helps us understand the universe's expansion rate, providing insight into its history and evolution, and is fundamental in cosmology for mapping the universe's structure.