出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/07/19 08:30 UTC 版)
In physics (especially astrophysics), redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum. More generally, where an observer detects electromagnetic radiation outside the visible spectrum, "redder" amounts to a technical shorthand for "increase in electromagnetic wavelength" — which also implies lower frequency and photon energy in accord with, respectively, the wave and quantum theories of light.