47.75, 7.34
Pierre-Ernest Weiss (25 March 1865, Mulhouse – 24 October 1940, Lyon) was a French physicist who specialized in magnetism. He developed the domain theory of ferromagnetism in 1907. Weiss domains and the Weiss magneton are named after him. Weiss also developed the molecular or mean field theory, which is often called Weiss-mean-field theory, that led to the discovery of the Curie–Weiss law. Alongside Auguste Piccard, Pierre Weiss is considered one of the first discoverers of the magnetocaloric effect in 1917.Pierre Weiss made several experimental discoveries that led to the development of the strongest electromagnets of the beginning of the 20th century. He worked at the universities of Rennes, Lyon, ETH Zurich where he was raised, and finally at Strasbourg. In these academic institutions he founded several renown laboratories.