Bidspirit auction | DE BROGLIE LOUIS: (1892-1987) De

DE BROGLIE LOUIS: (1892-1987) De Broglie compares the theory of relativity and wave mechanics - DE BROGLIE LOUIS: (1892-1987) French theoretical physicist, Nobel Prize winner for Physics, 1929. An excellent A.L.S., Louis de Broglie , to the recto and verso of an oblong 8vo correspondence card, Neuilly-sur-Seine, 28th September 1956, to a fellow physicist, in French. De Broglie´s letter, which contains two mathematical formulae, compares the theory of relativity and wave mechanics, explaining ´Il est parfaitement exact qu´en théorie de la Relativité la fréquence d´une horloge en mouvement avec la vitesse βc est [formule mathématique] Tandis que la fréquence d´une onde se transforme, quand on change de système de référence, suivant la formule [formule mathématique] (Translation: ´It is perfectly correct that, in the theory of relativity, the frequency of a clock moving at a speed βc is [mathematical formula], whilst the frequency of a wave changes, when one changes the reference frame, according to the formula [mathematical formula]´) and further remarking ´Ceux deux formules de transformation sont différentes et c´est bien en réfléchissant à cette différence que je suis arrivé autrefois aux conceptions de base de la Mécanique ondulatoire´ (Translation: ´These two transformation formulas are different, and it was indeed by reflecting on this difference that I arrived, some time ago, at the basic concepts of wave mechanics´ ). De Broglie concludes his letter by writing ´Mais contrairement à ce que vous semblez affirmer, ces deux formules ne sont nullement contradictoires : elles sont toutes deux exactes et se justifient entièrement du point de vue de la théorie de la Relativité. Elles sont d´ailleurs connues depuis bien longtemps. C´est pour ces raisons que je n´ai pas pu attacher beaucoup d´intérêt à votre travail´ (Translation: ´However, contrary to what you seem to be suggesting, these two formulae are by no means contradictory : they are both correct and are fully justified from the point of view of the theory of relativity. Moreover, they have been known for a very long time. It is for these reasons that I was unable to take much interest in your work´ ). A letter of fine scientific content. Two file holes to the left edge, only very slightly affecting a couple of letters of text and not the signature, otherwise VG