Planck's law
Planck's law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T. The law is named after Max Planck, who proposed it in 1900. It is a pioneering result of modern physics and quantum theory.
Planck's Law Media
The Sun approximates a black body radiator. Its effective temperature is about 5777 K.
Freeze-out of high-energy oscillators
Log-log plots of radiance vs. frequency for Planck's law (green), compared with the Rayleigh–Jeans law (red) and the Wien approximation (blue) for a black body at 8 mK temperature.
Solar spectrum compared to black-body at 5775 K
