Spectral energy density at all frequencies

Planck’s radiation law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature when there is no net flow of matter or energy between the body and its environment.

Notation:

  1. \(h\) (h) is planck.

  2. \(c\) (c) is speed_of_light.

  3. \(k_\text{B}\) (k_B) is boltzmann_constant.

Conditions:

  1. The black body is isolated from the environment.

Links:

  1. Wikipedia.

spectral_energy_density

spectral_energy_density.

Symbol:

w_f

Latex:

\(w_{f}\)

Dimension:

energy/(frequency*volume)

radiation_frequency

temporal_frequency of the radiation.

Symbol:

f

Latex:

\(f\)

Dimension:

frequency

equilibrium_temperature

Equilibrium temperature of the ensemble.

Symbol:

T

Latex:

\(T\)

Dimension:

temperature

law

w_f = 8 * pi * h * f^3 / c^3 / (exp(h * f / (k_B * T)) - 1)

Latex:
\[w_{f} = \frac{8 \pi h f^{3}}{c^{3}} \frac{1}{\exp{\left(\frac{h f}{k_\text{B} T} \right)} - 1}\]