Black body
Article
A black body is an idealised physical object that absorbs all electromagnetic radiation incident upon it, regardless of frequency or angle. Because it reflects and transmits none of the incoming radiation, it is considered a perfect absorber.
A black body also emits thermal radiation with a spectrum determined only by its temperature. As the temperature rises, the total emitted energy increases and the peak of the spectrum moves towards shorter wavelengths.
The spectral distribution is described by Planck's law, while the total radiated power follows the Stefan–Boltzmann law and the peak wavelength follows Wien's displacement law. These relationships were central to the development of quantum theory.
Real objects approximate black-body behaviour to varying degrees. Stars, furnaces, heated cavities, planets, and laboratory sources are often analysed using black-body models to estimate temperature and radiation output.
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- Source / publisher: Wikipedia
- URL type: WWW
- Credits: Wikipedia
- URL: https://en.wikipedia.org/wiki/Black_body