{c}
{wiki=Planck–Einstein_relation}

= Planck relation
{c}
{synonym}
{title2}

Photon energy is proportional to its frequency:
$$
energy = (plancks \space constant) * (frequency)
$$
or with common weird variables:
$$
E = h * \nu
$$

This only makes sense if the <photon> exists, there is no classical analogue, because the energy of classical waves depends only on their amplitude, not frequency.

Experiments that suggest this:
* <photoelectric effect>
* <Compton scattering>


Planck-Einstein relation