Here's why:
* Doppler Effect: Redshift is a result of the Doppler effect, which is the change in frequency of a wave (like light) as the source of the wave moves relative to the observer.
* Redshifting: When a star moves away from Earth, the light waves it emits get stretched out, causing the wavelengths to become longer. Since red light has the longest wavelengths in the visible spectrum, this stretching is referred to as redshift.
* Cosmological Redshift: This is a specific type of redshift observed in light from distant galaxies, which indicates the expansion of the universe.
Therefore, "redshift" is the most accurate and comprehensive term to describe the phenomenon of light waves being stretched as a star moves away from Earth.
