Thermal radiation
(Redirected from Black body radiation)
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Thermal radiation
- physics mostly uses uses this to to "if it is above 0 Kelvin, then it emits some electromagnetism"
- in an everyday sense we mostly think about the heat component
Black-body radiation is basically the same thing, but with a few more assumptions to formalize it, because thermal radiation's real-world math becomes easier if we add some assumptions such as
- assuming a uniform temperature
- assuming a uniform absorber of energy
- (which also helps it have a smooth spectrum.)
- assuming it's not really interacting in other ways
- frequently assuming an object out in space, because the way we see it is affected largely by heat (and not also a mess of other things)
- https://en.wikipedia.org/wiki/Black-body_radiation
Incandescence is also sort of the same thing -- but zoomed in to care only about the human-visible-light range of that EM emission
- usually with a temperature between 500K (below which you don't see much) and 15000K (some xenon lamps? Practically the ~6000K sun is what we see most often)
In the context of lighting,
- incandescent lightbulbs are wires that glow when given mains voltage, and continue glowing for a while.
- incandescent lighting is perhaps mainly contrasted with luminescence, which is roughly the "light for any other reason" category (and contains a handful of specific reasons).
If you wanted a "all things that happen at high temperature" view, there are some further things to list, such as thermionic emission.