October 17, 1887 - Death of Gustav Kirchhoff, investigated the emission of black body radiation and co-discovered caesium and rubidium

During his time at the University, he became interested in electrical induction and electric currents, and while teaching, he rectified what was hitherto believed about electric and electrostatic currents.

He is appointed extraordinary professor at the University of Wroclaw (now Wroclaw) and moves to another city. In the same year, he solves several problems concerning the deformation of elastic plates and meets the chemist Robert Bunsen, and they become friends. In 1854, Bunsen worked in Heidelberg and offered Kirchhoff to join him as a professor of physics. From then on, they worked together very fruitfully.

In 1862, Kirchhoff proposed the name ‘blackbody radiation’ and postulated two sets of fundamental laws, in classical electrical circuit theory and in thermal emission. Although both are known as ‘Kirchhoff's Laws’, this name is probably more common in the field of electrical engineering.

His research on blackbody radiation was fundamental to the development of quantum theory by introducing his law that for a given atom or molecule, the emission and absorption frequencies are the same.

In 1861, Kirchhoff and Bunsen studied the spectrum of the Sun in 1861, identifying the chemical elements in the solar atmosphere and discovering two new elements in the course of their research, caesium and rubidium.

Kirchhoff is known for being the first to explain the dark lines in the Sun's spectrum as the result of the absorption of particular wavelengths as light passes through the gases in the solar atmosphere, thereby revolutionising astronomy.

If you want to know more about this scientist, click on the following link: Gustav Robert Kirchhoff