According to the Doppler effect:the wavelength of light is shifted to a shorter wavelength if the source of light is moving toward you.the wavelength of light is shifted to a longer wavelength if the source of the light is moving toward you.the wavelength of peak emission of light from a source changes as the temperature of the source changes.spectral lines are split into two or more wavelengths when the source of the light is in a strong magnetic field.
