Commemorative stamp series - Germany / German Democratic Republic 1987 - 50 Pfennig

Important Personalities, Edition 1987 The Ministry of Posts and Telecommunications of the German Democratic Republic publishes four multicolored special postage stamps with illustrations of important personalities. Special postmark from 5 May to 4 July 1987 50 Pfennig value: Gustav Hertz (1887-1975) The physicist Gustav Hertz succeeded together with James Franck the first experimental confirmation of the at that time (around 1910) very contentious Bohr's postulates on the Structure of the atoms. The detection was carried out by the measurement of energy transfer at collisions of electrons with gas atoms. The experimental setup allows to analyze the energy loss due to inelastic collisions. Contrary to a uniform increase expected on the basis of classical mechanics, the dependence of the anode current on the electron energy (measured in volts) has sharp maxima. This behavior confirms an essential assertion of Bohr's theory that atoms have only discrete states of excitation, and consequently can only absorb certain amounts of energy. Both researchers were awarded the Nobel Prize for Physics in 1925. Gustav Hertz has also become known for the development of the diffusion cascade.