Sur L'Electrodynamique Des Corps En Mouvement and L'inertie d'un corps dépend-elle de sa capacité d'énergie, 1925

Paris: Gauthier-Villars, 1925. First French edition of Zur Elektrodynamik bewegter Korper (On the Electrodynamics of Moving Bodies) and 1st die Tragheit eines Korpers von seinem Energieinhalt abhangig? (Does the Inertia of a Body Depend on its Energy Content?). Both 1905 treatises are "beyond compare and without precedent, one of the greatest scientific achievements in content and one of the most brilliant in style" (Gosling, Albert Einstein).

The first paper is "a landmark in the development of physics, one of the two papers that laid out the theory of special relativity, formulated a new conception of time. By assuming that the speed of light is the same to every observer moving at a constant velocity, Einstein showed that space and time were not independent: spacetime was born. According to Hermann Weyl in 1918, this theory ‘led to the discovery that time is associated as a fourth coordinate on an equal footing with the other three coordinates of space, and that the scene of material events, the world, is therefore a four-dimensional, metrical continuum.' It was a revolutionary piece of scientific work" (Calaprice, The Einstein Almanac, 15).

In the second work, Einstein uses "the postulates of the special theory of relativity, Einstein showed that energy radiated is equivalent to mass lost... For the first time he concluded that ‘the mass of a body is a measure of its energy content'" (ibid, 16). CONDITION & DETAILS: Paris: Gauthier-Villars, 1925. Small 8vo. [4], 56, [2], 6 (catalog). ILLUSTRATION: Frontispiece portrait of Einstein. EXTERIOR: Complete issue bound in original light brown stiff wraps. Some light surface dirt on the front wraps and a small area in the lower right where a piece of tape has been removed. Two barely visible repairs at the spine. Tightly bound. INTERIOR: Complete. Very small spot at the upper margin of page 3. Otherwise very good condition throughout.