Red Shift: Waves of light or sound are stretched out or compressed by motion:
+
Red Shift: [[Waves]] of light or [[sound]] are stretched out or compressed by [[motion]]:
−
Stretching a wave makes the wavelength longer; in the case of sound, it makes the note deeper; for light, it shifts the wavelength toward the red end of the spectrum.
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Stretching a wave makes the wavelength longer; in the case of sound, it makes the note deeper; for light, it shifts the wavelength toward the red end of the [[spectrum]].