术语的发光辐射到一个黑体——地球科学堆栈交换江南电子竞技平台江南体育网页版 最近30从www.hoelymoley.com 2023 - 07 - 08 - t21:11:05z //www.hoelymoley.com/feeds/question/15123 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/15123 2 辐射到一个黑色的东西在发光的身体 J凯利 //www.hoelymoley.com/users/2440 2018 - 09 - 17 - t17:09:26z 2018 - 09 - 18 - t04:48:57z < p >我想我有挂的黑体辐射:黑体辐射被动地接收然后发出的一部分(地球释放存储太阳能热量,例如)。< / p > < p >有一个平行的术语类似太阳辐射产生自己的?< / p > //www.hoelymoley.com/questions/15123/-/15124 # 15124 4 Camilo Rada回答的术语的发光辐射黑体 卡米洛·Rada //www.hoelymoley.com/users/11908 2018 - 09 - 17 - t17:32:03z 2018 - 09 - 18 - t04:48:57z < p >太阳也被认为是一个黑色的身体。任何身体散发出的能量后< a href = " https://en.wikipedia.org/wiki/Planck%27s_law " rel = " nofollow noreferrer " >普朗克黑体辐射定律< / >,和吸收所有波长的能量可以被认为是一个黑色的身体。这是一个理想化,但是如果地球近似黑体,太阳也可以被认为是一个。< / p >

The case of the sun is not very different to that of Earth: The stuff that makes up both is mostly opaque (plasma for the sun rock for the Earth), but at some point both bodies become transparent (in the Sun when it is cold enough such that electrons recombine with atomic nucleus and form gases, in the Earth at the base of the atmosphere), the base of the transparent layer and the transparent layers themselves emit electromagnetic radiation according to their temperature following Planck's law of black-body radiation, and absorb pretty much any incoming radiation regardless of its wavelength.

The concept of black body (or gray body) only refers at the fact that a body absorb all (or a constant fraction for a gray body) the energy it receives regardless of the wavelength (color), therefore it looks black. Similarly, it must emit in all wavelength too, with the intensity at each wavelength (color) following Planck's law of black-body radiation.

Therefore a mirror is not a black body, neither is a fluorescent lamp, nor a tomato. Because a tomato reflects red light more than green. However, if the thermal balance of a tomato is mainly controlled by the exchange of infrared radiation, you can treat it as a black body, because it acts as one in the infrared spectrum (i.e. if your eyes were sensitive to infrared radiation only, a tomato would look black or gray). In the same way, despite the fact that Earth isn't black, it can be approximated to a black body and with such approximation you can get very accurate results of its energy balance.

Going back to your point. Black bodies can have internal energy sources (like the Sun), and in the absence of the Sun, the hot interior of Earth would also act as an energy source and the Earth would emit more energy than it receives, in the same way the Sun does.

So anything can shine radiation onto a black body, that is precicely because it is a black body and absorb all kinds of electromagnetic radiation. I hope this clarifies your doubt.

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