“Theorie der Lichterzeugung und Lichtabsorption” [and] “Prinzip von der Erhaltung der Schwerpunktsbewegung und die Trägheit der Energie” in Annalen der Physik, 4. Folge, Band 20

Contemporary half dark green roan. Rubbed, some chipping, separation at upper joint. Library markings.

FIRST EDITION of "On the Theory of Light Production and Light Absorption" (pp. 199-206). This classic in the history of physics is Einstein's second paper on the photoelectric effect. Einstein reconciles his and Planck's independent derivations of the blackbody formula E=hν. Planck's derivation of this formula ascribed it to a restriction on the energy changes possible when radiation is produced or absorbed by matter, which implied no restriction on the energies of either matter or radiation. Einstein's 1905 derivation ascribed it to a restriction on the energy of radiation alone, but in this paper, he proposes the modern idea that the energies of both matter and radiation are quantized, which led to his work on quantum specific heats.

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FIRST EDITION of "The Principle of Conservation of Motion of the Center of Gravity and the Inertia of Energy" (pp. 627-633). In this "ingenious thought experiment involving energy transport in a hollow cylinder, Einstein returned to the relationship between inertial mass and energy, giving more general arguments for their complete equivalence" (Calaprice, The Einstein Almanac). This is the first statement that the conservation of mass is a special case of the conservation of energy.