Stefan–Boltzmann law

In quantum physics, the Stefan-Boltzmann law (sometimes called Stefan's Law) states that the black-body radiation energy emitted by a given object is directly proportional to the temperature of the object raised to the fourth power. The equation for this law is:
R=σ"T"4
where σ is the Stefan-Boltzmann constant, which is equal to 5.670 373(21) x 10-8 W m-2 K-4, and where R is the energy radiated per unit surface area and per unit time. "T" is temperature, which is measured in Kelvin scale. Although this law is accurate and helpful, it is only usable for the energy radiated by blackbodies.