Kramers–Heisenberg formula Kramers–Heisenberg formula The Kramers–Heisenberg dispersion formula is an expression for the cross section for scattering of a photon by an atomic electron. It was derived before the advent of quantum mechanics by Hendrik Kramers and Werner Heisenberg in 1925, based on the correspondence principle applied to the classical dispersion formula for light. The quantum mechanical derivation was given by Paul Dirac in 1927. The Kramers–Heisenberg formula was an important achievement when it was published, explaining the notion of "negative absorption" (stimulated emission), the Thomas–Reiche–Kuhn sum rule, and inelastic scattering — where the energy of the scattered photon may be larger
Werner Heisenberg at the University of Würzburg and Jochen a physics professor at the University of New Hampshire. Heisenberg enjoyed classical music and was an accomplished pianist. Heisenberg was raised and lived as a Lutheran Christian. His autobiography starts with the young Heisenberg in his late teenage years, reading Plato's "Timaeus" while hiking in the Bavarian Alps. Heisenberg recounted the philosophical conversations with his fellow students and teachers on understanding the atom while receiving his scientific training in Munich, Göttingen and Copenhagen. In his speech Scientific and Religious Truth (1974) while accepting the Romano Guardini Prize, Heisenberg affirmed: In his late-sixties Heisenberg