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Earth is a blackbody[1]. We receive heat from the sun in the form of radiation. We also radiate heat out to space. [1] https://en.wikipedia.org/wiki/Black-body
by Brusco_RF 3y ago
Earth is a blackbody[1]. We receive heat from the sun in the form of radiation. We also radiate heat out to space.
[1] https://en.wikipedia.org/wiki/Black-body_radiation https://en.wikipedia.org/wiki/Black-body_radiation
- Timon3 3y agoNo, the earth is not a black-body. As your link says: > Of particular importance, although planets and stars (including the Earth and Sun) are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is still a good first approximation for the energy they emit.
- Brusco_RF 3y agoAll models are incorrect, but some are useful. Fine, you win Timon3, earth is not a blackbody because blackbodies don't actually exist.
- Timon3 3y agoThank you! Party this evening at my place. It's fine to say "the earth behaves similarly to a black-body" or "a black-body is a good approximation for the earth". But that's different from "the earth is a black-body".