How does the expansion of the universe impact light wavelengths?

The expansion of the universe has a significant impact on the wavelengths of light. As the universe expands, the wavelengths of light traveling through it are stretched, causing them to appear redder. This phenomenon is known as redshift and is a key piece of evidence supporting the Big Bang theory.

The redshift of light is due to the fact that space itself is expanding. As light travels through space, the space itself expands, which causes the wavelength of the light to stretch. This stretching of the wavelength causes the light to shift towards the red end of the spectrum.

The amount of redshift that occurs depends on the distance between the observer and the source of the light. Objects that are farther away will experience a greater redshift than objects that are closer. By measuring the amount of redshift in the light coming from distant objects, astronomers can determine how fast the universe is expanding.