About Leo Graetz
Leo Graetz (September 26, 1856 – November 12, 1941) was a German physicist. He was born in Wrocław (Breslau), Poland as the son of the historian Heinrich Graetz.
Graetz was one of the first to investigate the propagation of electromagnetic energy. The Graetz number (Gz), a dimensionless number describing heat flow, is named after him, as is the diode bridge rectifier circuit he invented.
In 1880 he confirmed the Stefan–Boltzmann law.
Graetz died in Munich at age 85.