Loránd Eötvös

Loránd Eötvös
Loránd (Roland) Eötvös
Born	27 July 1848 Buda
Died	8 April 1919(1919-04-08) (aged 70) Budapest
Nationality	Austro-Hungarian
Fields	Physics
Institutions	University of Budapest
Alma mater	University of Heidelberg
Doctoral advisor	Hermann Helmholtz
Known for	Eötvös experiment Eötvös rule Eötvös pendulum
Children	Jolán Rolanda Ilona

Baron Loránd Eötvös de Vásárosnamény (Hungarian: vásárosnaményi báró Eötvös Loránd Ágoston or Loránd Eötvös, pronounced [ˈloraːnd ˈøtvøʃ]; 27 July 1848 – 8 April 1919), more commonly called Baron Roland von Eötvös in English literature, was an Austro-Hungarian physicist of ethnic Hungarian origin. He is remembered today largely for his work on gravitation and surface tension, and the invention of the torsion pendulum.

Eötvös Loránd University, the Loránd Eötvös Mathematics Competition, and the Eötvös crater on the moon are named after him.

Born in 1848, the year of the Hungarian revolution, Eötvös was the son of József Eötvös, a well-known poet, writer, and liberal politician, who was cabinet minister at the time, and played an important part in 19th century Hungarian intellectual and political life.

Loránd Eötvös first studied law, but soon switched to physics and went abroad to study in Heidelberg and Königsberg. After earning his doctorate, he became a university professor in Budapest and played a leading part in Hungarian science for almost half a century. He gained international recognition first by his innovative work on capillarity, then by his refined experimental methods and extensive field studies in gravity.

Eötvös is remembered today for his experimental work on gravity, in particular his study of the equivalence of gravitational and inertial mass (the so-called weak equivalence principle) and his study of the gravitational gradient on the Earth's surface. The weak equivalence principle plays a prominent role in relativity theory and the Eötvös experiment was cited by Albert Einstein in his 1916 paper The Foundation of the General Theory of Relativity. Measurements of the gravitational gradient are important in applied geophysics, such as the location of petroleum deposits. The CGS unit for gravitational gradient is named the eotvos in his honor.