- /blak"bod"ee/, n., pl. blackbodies. Physics.a hypothetical body that absorbs without reflection all of the electromagnetic radiation incident on its surface. Also called perfect radiator.[1700-10]
* * *Theoretical surface that absorbs all radiant energy that falls on it, and radiates electromagnetic energy at all frequencies, from radio waves to gamma rays, with an intensity distribution dependent on its temperature.Because all visible light falling on such a surface is absorbed without reflection, the surface will appear black as long as its temperature is such that its emission peak is not in the visible portion of the spectrum. See also absorption.
* * *▪ physicsin 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. The concept of such a perfect absorber of energy is extremely useful in the study of radiation phenomena.The best practical blackbody is a small hole in a box with a blackened interior, because practically none of the radiation entering such a hole could escape again, and it would be absorbed inside. A surface covered with lampblack will absorb about 97 percent of the incident light and, for most purposes, can be considered a blackbody. Polished metal surfaces, on the other hand, absorb only about 6 percent of the incident radiation, reflecting the rest.
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Look at other dictionaries:
blackbody — [blak′bäd′ē] n. an ideal surface or body that can absorb completely all the radiation striking it … English World dictionary
blackbody — a body with a surface emissivity of 1. Such a body will emit all of the thermal radiation it can (as described by theory), and will absorb 100% of the thermal radiation striking it. Most physical objects have surface emissivities less than 1 and… … Mechanics glossary
blackbody — noun Date: 1710 an ideal body or surface that completely absorbs all radiant energy falling upon it with no reflection and that radiates at all frequencies with a spectral energy distribution dependent on its absolute temperature … New Collegiate Dictionary
blackbody — noun a theoretical body, approximated by a hole in a hollow black sphere, that absorbs all incident electromagnetic radiation and reflects none; it has a characteristic emission … Wiktionary
blackbody — Смотри абсолютно черное тело (а. ч. т.) … Энциклопедический словарь по металлургии
blackbody — n. object which absorbs all wavelengths of electromagnetic radiation and is also the most efficient emitter of all wavelengths (Physics) … English contemporary dictionary
Blackbody — An ideal substance that absorbs all radiation falling on it, and reflecting nothing … Energy terms
blackbody — black•bod•y [[t]ˈblækˈbɒd i[/t]] n. pl. bod•ies. phs a hypothetical body that absorbs without reflection all of the electromagnetic radiation incident on its surface • Etymology: 1700–10 … From formal English to slang
Blackbody — A perfect radiator which absorbs and re emits all radiation that strikes it … The writer's dictionary of science fiction, fantasy, horror and mythology
blackbody — noun a hypothetical object capable of absorbing all the electromagnetic radiation falling on it a black body maintained at a constant temperature is a full radiator at that temperature because the radiation reaching and leaving it must be in… … Useful english dictionary