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:
\(h\) (
h
) isplanck
.\(c\) (
c
) isspeed_of_light
.\(k_\text{B}\) (
k_B
) isboltzmann_constant
.
Conditions:
The black body is isolated from the environment.
Links:
- 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:
- \[w_{f} = \frac{8 \pi h f^{3}}{c^{3}} \frac{1}{\exp{\left(\frac{h f}{k_\text{B} T} \right)} - 1}\]