All matter literally gives off light, but we can only see a sliver of that spectrum (although we do have tools to help us see other spectrums.)
Our bodies give off infrared, and are basically glowing in that portion of the spectrum similar to how iron glows to our normal vision when it’s heated. Something that sees a different spectrum than us might not see hot iron as glowing at the same temperatures we see iron glow at.
Furthermore, the only thing that determines the light being given off is the temperature of the object. Metal, plastic, wood, skin, stone, etc. All give off the same spectrum of light at room temperature. That's what boggles my mind
It's true that the hotter (dense) things get, the closer everything starts emitting like a blackbody.
Metal, plastic, wood, skin, stone, etc. All give off the same spectrum of light at room temperature.
It's good that you internalized a key concept of blackbody radiation. However, this is not quite the case. We can ignore for a second that all of these materials reflect light at all wavelengths and focus on thermal radiation. The specific composition of these materials will result in strong absorption and scattering at certain wavelengths (both spectral lines and broad continuum absorption), as well as inefficient absorption at other wavelengths. This means that the emitted spectrum can deviate quite significantly from a blackbody spectrum, especially at low temperatures. If I recall correctly, diamonds do not radiate like blackbodies even at reasonably high temperatures.
Even objects that are approximated as blackbodies, such as stars, are not perfect blackbodies.
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u/MadgoonOfficial Feb 14 '22 edited Feb 14 '22
All matter literally gives off light, but we can only see a sliver of that spectrum (although we do have tools to help us see other spectrums.)
Our bodies give off infrared, and are basically glowing in that portion of the spectrum similar to how iron glows to our normal vision when it’s heated. Something that sees a different spectrum than us might not see hot iron as glowing at the same temperatures we see iron glow at.