The red shift indicates that the galaxy is moving away from the Earth , and that the universe is expanding. W.M. Slipher first noted the red shift in 1914 . A similar phenomen, except related to sound, is the Doppler Effect . If object is moving toward you, the wavelengths are compressed, which causes high pitched sound or shorter wavelengths. If object is moving away, the wavelengths are elongated, which causes low pitch or shorter wavelengths.
Same thing works with light as sound.
Both travel in waves. Light reaching us from distant receding galaxies has shifted toward the red end of the spectrum. Density of matter in the universe remains relatively constant. Expansion and contraction alternate. C. Formation of stars, galaxies, solar systems, planets Material begins to clump together as it moves away from the center of the Big Bang.