THE EXCEEDINGLY RARE FIRST PRINTING, FIRST APPEARANCE IN ORIGINAL WRAPPERS of Einstein’s major paper on his derivation of Planck's law and the theoretical basis for the laser.
"Einstein used Bohr's model as the foundation for a series of papers in 1916, the most important of which [was] 'On the Quantum Theory of Radiation’... Einstein began with a thought experiment in which a chamber is filled with a cloud of atoms. They are being bathed by light (or any form of electromagnetic radiation). Einstein then combined Bohr's model of the atom with Max Planck's theory of the quanta. If each change in an electron orbit correspond to the absorption or emission of one light quantum, then--presto!--it resulted in a new and better way to derive Planck's formula for explaining blackbody radiation. As Einstein boasted to Michele Besso, 'A brilliant idea dawned on me about radiation absorption and emission. It will interest you. An astonishingly simple derivation, I should say the derivation of Planck's formula. A thoroughly quantized affair.'
"Atoms emit radiation in a spontaneous fashion, but Einstein theorized that this process could also be stimulated... This process of stimulated emission would, almost forty years later, be the basis for the invention of the laser, an acronym for 'light amplification stimulated by emission of radiation'" (Isaacson, Einstein).
This first appearance in Mitteilungen der Physikalischen Gesellschaft Zurich is of legendary rarity, particularly in original wrappers. Weil 78. IN: Mitteilungen der Physikalischen Gesellschaft Zurich, Vol 18, pp. 47-62. Zurich: 1916. Octavo, original wrappers; custom box. The complete journal issue. Small rectangle of residue (likely from label removal) on front wrapper, a little chipping at spine ends. An outstanding copy of one of the great rarities of Einstein collecting.