Stefan-Boltzmann Constant

#Physics

$\displaystyle \sigma_{B}=\frac{\pi ^{2}k_{B}^{4}}{60\hbar ^{3}c^{2}}\approx 5.670374419\cdot10^{-8}\mathrm{\frac{W}{m^{2}K^{4}}}$

$\displaystyle s_{B}=\frac{\pi ^{2}}{15\hbar ^{3}c^{2}}$