|Compare: blueshift a shift in the lines of the spectrum of an astronomical object towards a longer wavelength (the red end of an optical spectrum), relative to the wavelength of these lines in the terrestrial spectrum, usually as a result of the Doppler effect caused by the recession of the object|
|Main Entry:||red shift|
|Part of Speech:||n|
|Definition:||in astronomy, an increase in the wavelength of radiation emitted by astronomical objects, causing a shift of features in their spectra towards longer wavelengths due to their recession from the observer|
See under Doppler effect.
Note: The red shift that can be observed in light from distant galaxies suggests that the universe is expanding, and thus supports the Big Bang theory.