Ludvig Valentin Lorenz (18.01.1829-9.06.1891) was a Danish theoretical physicist. He was born in Elsinore. He graduated from the Technical University in Copenhagen (1852). From 1866 he was professor at the Danish Military Academy. He was also professor at the University of Copenhagen.
His research was mainly in the field of optics and of the thermal and electrical conductivity of metals. In 1869 he proposed a formula relating the refractive index of a substance to the electronic polarisability of its particles (the Lorenz — Lorentz formula). Independently of J. Maxwell, and without knowing his theory, he constructed (1867) an electromagnetic theory of light.
A member of the Paris Academy of Sciences.