Josef Stefan Death Anniversary

Josef Stefan, who passed away on 7 January 1893, was a Carinthian Slovene physicist, mathematician, and poet of the Austrian Empire.

In 1879, Stefan formulated a law which states that the radiant energy of a blackbody - a theoretical object that absorbs all radiation that falls on it—is proportional to the fourth power of its temperature. His law was one of the first important steps toward the understanding of blackbody radiation, from which sprang the quantum idea of radiation.