Stefan-Boltzmann Law
The physical law asserting that total radiant power emitted per unit surface area of a blackbody is proportional to the fourth power of its absolute thermodynamic temperature.
Governing formula
E = σ T⁴, σ = 5.670374 × 10⁻⁸ W/(m²·K⁴)
SI unit
W/m²
In depth
Doubling a surface's Kelvin temperature increases its radiant energy output by a factor of $2^4 = 16$.
Examples in the real world
Calculating total energy radiated by stellar surfaces like the Sun ($T ≈ 5778 K$).