How is red-shift explained?
The red-shift of starlight is a decrease in the energy of the light. This energy decrease results in a lengthening of the wavelength of the light, measured with an instrument called a spectrometer. Red is the rainbow color with the longest wavelength, hence the name “red-shift.” Stars do not actually become red in appearance since the wavelength change is usually slight. Almost every star and galaxy is found to be red-shifted. The following list summarizes some of the alternative explanations for the origin of this stellar red-shift. 1. Stellar Motion. If a star moves outward from the earth, its light energy will be reduced and its wavelength stretched or red-shifted. Stars and entire galaxies show varying amounts of red-shift, therefore implying a variety of speeds for these objects. Police actually use this same effect with radar to measure the speed of cars. Stellar motion is often taken as evidence in support of the Big Bang theory. Stars are assumed to be speeding outward as a res
