Stefan-Boltzmann law

1979 Stefan-Boltzmann law

The book of science

Tom Sharp

Josef Stefan, Ludwig Boltzmann thermodynamics Stefan-Boltzmann law

Stefan-Boltzmann law

Black-body radiant exitance is directly proportional to the fourth power of the body’s thermodynamic temperature, where the constant of proportionality is derived from the Boltzmann and Planck’s constants, and the speed of light in a vacuum.

The Stefan-Boltzmann law

gives us the temperature of the surface of the sun, radii of the stars, radiation from black holes, and helps calibrate modern pyrometers to read an object’s temperature from a distance.

From a distance

I see by your outfit that you are a cowboy. I see by my eyes from a trick of the light. The glints in your eyes hint of your passion. They show you’ve been wronged and can’t make it right.

How much a non-reflective object radiates its heat is a matter of fundamental laws of physics, known precisely and related to the object’s temperature.

See also in The book of science:

Readings in wikipedia: