1824-1887

German-Russian physicist who made fundamental contributions toward the understanding of electricity and light. Kirchoff developed the concept of a "black body," an idealized body that emits light whose color is based solely on temperature. This concept helped lead to the development of quantum theory in the early twentieth century. Kirchoff's work in electrical theory demonstrated that electrical and magnetic forces are related through a constant—the speed of light in vacuum—suggesting that electromagnetism and light are related.