## FANDOM

48 Pages

Plank's law describes the amount of electromagnetic energy with a certain wavelength radiated by a black body in thermal equilibrium.

$B _\nu (T) = \frac {[energy]}{[time][distance]^2[solidangle][Hz]}$
$B _\lambda (T) = \frac {[energy]}{[time][distance]^2[solidangle][Angstrom]}$
$B _\nu (T) = \frac {2h {\nu}^3}{c^2} \frac {1}{e^{h\nu /(kT)} - 1}$
$B _\lambda (T) = \frac {2hc^2}{\lambda^5} \frac {1}{e^{hc/(\lambda kT)} - 1}$