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How does the earth act as a black body?
The Earth climate system maintains a balance between solar energy absorbed and IR (blackbody) energy radiated to space. The so-called Greenhouse effect distributes the temperature in the atmosphere so that the surface is much warmer than the mean radiative temperature.
Does the earth display characteristics of a blackbody?
Although a blackbody does not really exist, we will consider the planets and stars (including the earth and the sun) as blackbodies. Even though by definition, they are not perfect blackbodies, for the sake of understanding and simplicity we can apply the characteristics of blackbodies to them.
What is the blackbody temperature of Earth?
The black body temperature of the Earth is -23°C, but the actual surface temperature is about 15°C. The difference (38°C) is the amount by which the planet is warmed by the absorption of radiation within its atmosphere, by the natural greenhouse effect.
What is a black body in physics?
blackbody, also spelled black body, in physics, a surface that absorbs all radiant energy falling on it. The term arises because incident visible light will be absorbed rather than reflected, and therefore the surface will appear black.
What is earth albedo?
Albedo is the portion of solar energy reflected from the surface of the Earth back into space. When the solar radiation passes through the atmosphere, a certain amount of it is scattered, reflected and absorbed. The reflected sum of radiation is called the albedo of the earth.
Is black hole a black body?
Yes, black holes are supposedly near-perfect black bodies. They emit thermal radiation called Hawking radiation, which, however, does not originate from beyond the event horizon, but is a consequence of the interaction of the strong gravitational field outside the horizon with the vacuum.
What are the characteristics of black body?
As a consequence of this definition, the blackbody has three properties: (a) it is the surface that emits most for a given temperature and wavelength, (b) blackbody radiation does not depend on the direction, that is, blackbody radiation is diffuse, and (c) total blackbody radiation in a vacuum depends only on …
Which of the following is the characteristic of a black body?
Answer: A black body is something that emits or absorbs electromagnetic radiation with 100\% efficiency at all wavelengths. The amount of radiation energy flux emitted by a black body depends on the absolute temperature of the black body.
What is Earth albedo?
Is Moon a black body?
Because the moon has a temperature, it emits “black body radiation’, which is electromagnetic radiation with a spectrum characteristic of the temperature. The composition and microstructure of the surface can modify that spectrum. Also, as you guessed, sunlight reflects off the moon’s surface.
Is Sun a black body?
As with all matter, the sun emits a “black body spectrum” that is defined by its surface temperature. A black body spectrum is the continuum of radiation at many different wavelengths that is emitted by any body with a temperature above absolute zero. So one might say that the sun is blue-green!