Franz Ernst Neumann (11.09.1798-23.05.1895) was a German theoretical physicist and a member of the Berlin Academy of Sciences (1858). He was born in Joachimsthal. In 1825 he received the degree of Doctor of Philosophy at the University of Berlin. In 1829 —73 he worked at the University of Königsberg (professor from 1829).
His main work was on electricity, optics and magnetism. He developed (1845—48) the first mathematical theory of electromagnetic induction, established the law of electromagnetic induction for closed conductors, derived the formula for the coefficient of mutual induction and introduced the concept of the vector potential. He studied polarisation and double refraction, and reflection from metals. His work also concerned elasticity, heat conduction, crystal physics and molecular physics. He established the connection between the symmetry of the physical properties of a crystal and the symmetry of its form (Neumann's principle).
In the 1840s he organised at his own expense a physics laboratory at the University of Königsberg, one of the first in Europe. In 1834, together with C. Jacobi, he founded at the university the first colloquium on theoretical physics and mathematics. His pupils included G. Kirchhoff, C. Neumann, W. Voigt and others. A corresponding member of the St Petersburg Academy of Sciences (1838), and a Fellow of the Royal Society and a member of the Paris Academy of Sciences. Copley Medal (1887).