The story
It was published in 1919, by the German physicist Albert Betz.
Etymology from Wiktionary, CC BY-SA 4.0.
Betz's law
Today it means: A law describing the maximum power that can be extracted from the wind. It states that no turbine, regardless of its design, can capture more than 16/27 (59.3%) of the kinetic energy in wind. Full definition →