# Stefan-Boltzmann Law

## $\LARGE J={\sigma}T^4$

### The Terms

$J$ - Energy radiated per unit area of a black body per unit time [Units: J m-2 s-1]

$\sigma$ - Stefan-Boltzmann constant [Value: 5.67 x 10-8 J s-1 m-2 K-4]

$T$ - Absolute temperature [Units: K]

### What Does It Mean?

This law states that the energy radiated from a black body is proportional to the fourth power of the absolute temperature. A black body is one which absorbs and emits radiation at all frequencies, with characteristic continuous emission spectra.

### Further information at Warwick

The Stefan-Boltzmann Law is covered in the first year module "PX101 Quantum Phenomena".