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A blackbody is a solid object that absorbs all visible light wavelengths. Because no light is reflected, it appears black at low temperatures. A blackbody’s emission is temperature dependent, and at high temperatures, it will release a spectrum of photon energies across the visual range, making it seem white. An example of a high-temperature blackbody is the Sun.
A blackbody absorbs all of the radiation that strikes it. Thus, black is both a perfect absorber α=1 and an emitter.
Blackbody Radiation theory
Radiation will be emitted at the highest rate from such a body that absorbs all of the radiation it receives. Blackbody radiation is the radiation released by a blackbody. The radiation inside an enclosure with its inner walls kept at a constant temperature has the same qualities as blackbody radiation and is referred to as such. A blackbody radiator is also known as an ideal radiator.Â
A perfect blackbody, which absorbs 100% of the radiation that strikes it, is purely a theoretical concept. Lampblack is the closest material to a blackbody among the materials. It only reflects roughly 1% of the radiation that hits it. If the inside of an enclosure is painted black and a small hole is drilled in the wall, the hole will be visible.
Mathematical formula of blackbody radiation
Joseph Stefan computed the  radiation energy released by a blackbody per unit time and per unit surface area in 1879 and stated it as
temperature of the surface is in K. is known as the blackbody emissive power. It’s worth noting that the emission of thermal radiation is proportional to the absolute temperature to the fourth power.
Blackbody Emissivity
Emissivity is a fractional representation of the amount of energy emitted by a material compared to the amount of energy emitted by a blackbody at the same temperature. The value
The amount of radiation released by actual surfaces is lower than the amount emitted by a blackbody. The value of emissivity of a surface is in the range of 0 to 1, and it indicates how closely a surface resembles a blackbody, for which ε=1. The temperature of an actual surface, the wavelength, and the direction of the emitted radiation all affect its emissivity.
Spectral blackbody emissive power
The quantity of radiation energy released by a blackbody at an absolute temperature T per unit time, per unit surface area, and per unit wavelength about the wavelength λ is called the spectral blackbody emissive power.Â
Absorptive power of blackbody
When heat strikes an object’s surface, some of it is absorbed and the rest is reflected. Because it absorbs the radiant energy of all wavelengths incident on it, a black body has an absorptive power of one. A good emitter is also an excellent absorber.Â
In most cases, absorbed radiation is transformed into thermal energy, which raises the object’s temperature. A Black body, for example, absorbs all incident radiation and has the power of absorption of one. As a result, the body with the greatest absorptive power also has the most emissive power. The makeup of the body determines how much heat it absorbs.
Applications of blackbody radiation
The black bodies are used in  applications such as lighting, heating, security, thermal imaging, and testing and measuring.
Conclusion
Thus, this article provides an overview of blackbody radiation which is a theoretical concept stating that black bodies are surfaces that emit continuously throughout the visual spectrum with the use of terms emissivity, and absorptivity. Important definitions, concepts, and formulas will help to understand the blackbody radiation more precisely and efficiently. There are different uses of blackbody radiation to make certain objects because of the blackbody property of being a perfect absorber like thermal imaging.
