Hendrik Anthony Kramers

Born in Rotterdam on February 17, 1894, Hendrik Anthony Kramers studied physics in Leiden under Paul Ehrenfest before joining Niels Bohr's institute in Copenhagen. There he became part of the small circle of researchers building the foundations of quantum theory in the 1910s and 1920s.

Kramers made important contributions to atomic physics, quantum mechanics, and statistical physics. He worked on the old quantum theory, helped explain atomic spectra, collaborated with Bohr, and later developed ideas that became known as the Kramers-Kronig relations and Kramers degeneracy. He also wrote for wider audiences, including the popular science book The Atom and the Bohr Theory of Its Structure with Helge Holst.

Later in his career, he held a professorship in Utrecht and became one of the Netherlands' most respected theoretical physicists. He died in Oegstgeest on April 24, 1952, but his influence remains strong in both the history of quantum theory and the language physicists still use today.