Take the tour ×  The Stefan-Boltzmann equation states $e=\sigma
T^4$, but how do we interpret this?  Is this completely wrong: A
body of size $s^2$ generates the radiation/temperature $T^4$ for
a given size and a given temperature or something similar?
share|improve this question add comment  2 Answers  up vote 3
down vote accepted  The Stefan-Boltzmann law governs the
irradiance (radiant power per unit area). The total energy is
not sigma*T^4, but rather the total power $P$ of a body with
surface area $A$ and temperature $T$ is given by
\begin{equation} P=A\sigma T^4 \end{equation} This result may be
surprising, but it is correct. The reason irradiance rises so
quickly is because the wavelengths of light decrease with
increasing temperature, carrying away more energy with each
photon (on average). At the same time, higher temperatures cause
the photon emission rate from the surface to increase. It is the
increase in the energy of the photons coupled with the increase
in photon production rate that gives the