Glossary term: Thermal Radiation
Description: In a physical system that has reached what is called thermal equilibrium, each way the system can change (each "degree of freedom") has, on average, the same energy. The measure of how large that average energy is corresponds to the system's temperature. In a gas in equilibrium, for instance, all atoms have, on average, the same kinetic energy. Electromagnetic fields are a part of any physical system, and when a system reaches thermal equilibrium, some of its energy will be in the form of electromagnetic radiation with a characteristic spectrum. This radiation is called thermal radiation. For a system that can absorb and emit at all wavelengths, the resulting characteristic thermal radiation is called blackbody radiation. Its spectrum depends only on the system temperature.Related Terms:
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Term and definition status: This term and its definition is still awaiting approval
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