Why is it that visible light is shifted to lower frequencies but gamma rays aren’t? Shouldn’t they have become X rays after all that distance?
Stephen Wood Orlando, Fla.
All wavelengths are redshifted. That means that high-energy gamma rays beyond a detector’s energy range would get shifted into the detectable range by cosmic expansion, while slower-energy gamma rays would get shifted to below the detector’s range
.—R. Cowen
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