Does the color in infrared always correspond to temperature? Like, more so than it does in the visible spectrum?
In: Physics
> Does the color in infrared always correspond to temperature? Like, more so than it does in the visible spectrum?
The color of the radiation corresponds to its temperature totally irrespective of where the human visual spectrum begins and ends.
I think the question reflects a slight misunderstanding about what color is. The color of a given light (or really, it’s wavelength/frequency) is precisely what *makes* it part of the visible spectrum or not. If you go further up the frequency scale you get additional “colors,” ultraviolet, that are outside of human perception, and if you go further down, you get infrared “colors”.
The hotter something is, the higher frequency of radiation it glows in. Things which are warm, the kinds of temperatures that human bodies and habitats are, glow in the infrared. Things which are very hot, start to glow in the visible spectrum. When they’re super super hot, you get ultraviolet and higher frequency radiation. That’s really the only rule that physics cares about here, hotter = higher frequency/shorter wavelength. Visible/invisible doesn’t really come into it.
TL;DR: Seeing in regular visible light is also ‘heat vision’, it’s just that thermal radiation in this band only comes from much hotter things like lightbulb filaments and the sun.
(note: I’m using “color” as basically interchangeable with “wavelength” here; whether it’s really correct to call UV and IR light frequencies “colors” is kinda a question of perceptual philosophy.)
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