Braunschweig: Friedr. Vieweg & Sohn, 1914. 1st Edition. FIRST EDITION, FULL VOLUME, OF THE FRANCK-HERTZ EXPERIMENT: THE FIRST ELECTRICAL MEASUREMENT TO CLEARLY SHOW THE QUANTUM NATURE OF ATOMS – PROOF OF THE QUANTIZED MODEL OF THE BOHR ATOM & OF PLANCK’S QUANTUM THEORY. Note that this volume includes both the first and second Franck-Hertz experiment. In the first they demonstrate that atoms can only absorb and be excited by specific amounts of energy; in the second experiment performed the same year, they demonstrate that the frequency of the light emitted following the collision of electrons with mercury atoms corresponds precisely with the energy lost by the electrons in the collision. Franck and Hertz received the Nobel Prize for this work, specifically, "for their discovery of the laws governing the impact of an electron upon an atom" (Nobel Prize Committee).
Of equal import, this volume also contains a paper by Einstein in which he uses the light quantum hypothesis to give new derivations of Planck's radiation law and Nernst's third law of thermodynamics. His “proofs introduced the quantum hypothesis” (Calaprice, The Einstein Almanac, 40).
In 1914, James Franck and Gustav Hertz were working together in the Physics Institute of Berlin and were “particularly interested in ionization, i.e., in the process in which an electron is removed from an atom” (The Harvest of a Century", p. 102-103). The experiment they devised, now known commonly as the Franck-Hertz experiment is “a vivid illustration of the quantization of energy” that relied on methodology so simple “that it is now carried out regularly by undergraduates. They accelerated electrons through a low-pressure gas of mercury. When the electrons’ energy reach the energy of a stationary state of mercury they gave up a quantum of energy to the mercury, resulting in a stepwise shape to the curve of current through the apparatus. This demonstrated that atoms could absorb energy only in discrete amounts” (Peacock, The Quantum Revolution, 40).
“[Franck and Hertz] had not only shown for the first time that electrons lose their kinetic energy to mercury atoms in energy quanta, but also that these energy quanta are equal to the energy of the light emitted by the same atoms if interpreted with Einstein’s light-quantum hypothesis…This was the first experimental determination of Planck’s constant not using blackbody radiation” (Brandt, 103). Item #1199
CONDITION & DETAILS: Braunschweig: Friedr. Vieweg & Sohn. 8vo. Unobtrusive stamp on front paste down and title page. In-text figures throughout. Tightly bound in leather over marbled paper boards; gilt-lettered and tooled at the slightly faded and spotted spine (which looks worse in the image due to the bright light than it does to the eye). Unusually beautiful marbled paper edges. Bright and very clean throughout. Near fine.