BROGLIE, LOUIS de. - DISCOVERY OF THE WAVE THEORY OF MATTER AND CREATION OF WAVE-MECHANICS.

# A Tentative Theory of Light Quanta.

lyn46950

London, Taylor and Francis, 1924. Later full buckram, gilt lettering to spine. In: Philosophical Magazine conducted by Oliver Joseph Lodge etc.", Vol. 47. - Sixth Series. VIII,1168 pp. and 8 plates. (Entire volume offered). De Broglie's paper: pp. 446-458. Internally clean and fine.

* First English version of the papers which ESTABLISHED A NEW ERA IN PHYSICS by introducing the epochal new principle that particle-wave duality should apply not only to radiation but also to matter and thus CREATING QUANTUM MECHANICS. The English paper is a translation of de Broglie's 3 "Notes " which he published in "Comptes Rendus" in September and October 1923 (Ondes et quanta. - Quanta de lumière, diffraction et interférences. - Les quanta, la théorie cinétique des gaz et le principe de Fermat). These 3 papers were extended to form his doctoral thesis of 1924 "Recherches sur la Théorie des Quanta." - This English edition (of the papers) was published before his thesis of 1924 as the paper is dated October 1, 1923, and published here in the Februar issue of Philosophical Magazine, months before the thesis.The English version contains furthermore an addition, a postscript, which contains a generalization of the theory which is consistent with the special theory of relativity, and NOT published in "Comptes Rendues" in 1923.With the three communications to the Academy of Sciences (the 3 Comptes Rendus papers) in the fall of 1923 de Broglie had presented the main ideas of his unified dynamics of light quanta and atoms. He was confident enough about his results that he submitted them also in English in the offered paper. At the end of the paper he summarized his results. De Broglie relates "After long reflection in solitude and meditation, I suddenly had the idea, during the year 1923, that the discovery made by Einstein in 1905 should be generalized by extending it to all material particles and notably to electrons" (Preface to his PhD thesis 1924)."He made the leap in his September 10, 1923, paper: E=hv should hold not only for photons but also for electrons, to which he assigns a 'fictitious associated wave'. In his September 24 paper, he indicated the direction in which one 'should seek experimental confirmations of our ideas': a stream of electrons traversing an aperture whose dimensions are small compared with the wavelenght of the electron waves 'should show diffraction phenomena' ."(Pais "Subtle is the Lord", pp. 425-436).In the third paper (October 8) he discusses "The interplay between the propagation of the particle and of the waves could be expressed in more formal terms as an identity between the fundamental variational principles of Pierre de Fermat (rays), and Pierre Louis Maupertuis (particles) as de Broglie discussed it further in his last communication . Therein he also considered some thermodynamic consequences of his generalized wave-particle duality. He showed in particular how one could, using Lord Rayleigh’s 1900 formula for the number of stationary modes for phase waves, obtain Planck’s division of the mechanical phase space into quantum cells.Louis de Broglie achieved a worldwide reputation for his discovery of the wave theory of matter, for which he received the Nobel Prize for physics in 1929. His work was extended into a full-fledged wave mechanics by Erwin Schrödinger and thus contributed to the creation of quantum mechanics. After an early attempt to propose a deterministic interpretation of his theory, de Broglie joined the Copenhagen school’s mainstream noncausal interpretation of the quantum theory."(DSB)."This idea [i.e. de Broglie's that matter might behave as waves] was tested and confirmed by Davisson and Germer in 1927... Thus the duality of both light and matter had been established, and physicists had to come to terms with fundamental particles which defied simple theories and demanded two sets of 'complementary' descriptions, each applicable under certain circumstances, but incompatible with one another." (Printing and the Mind of Man, 417).This volume of Philosophical Magazine contains another importent paper in the history of Quantum Mechanics": "The Quantum Theory of Radiation" by BOHR, KRAMERS AND SLATER, pp. 785-802. "After Kramers had succeeded in extending the scope of the correspondence argument to the theory of optical dispersion "thus rounding off a treatment of the interaction of atomic systems with radiation that accounted for all emission, absorption, and scattering processes" Bohr ventured to propose a systematic formulation of the whole theory, in which what he called the virtual character of the classical model was emphasized. In this he was aided by Kramers and a young American visitor, J. C. Slater, and the new theory was published in 1924 under the authorship of all three. The most striking feature of this remarkable paper, "The Quantum Theory of Radiation," was the renunciation of the classical form of causality in favor of a purely statistical description. Even the distribution of energy and momentum between the radiation field and the "virtual oscillators" constituting the atomic systems was assumed to be statistical, the conservation laws being fulfilled only on the average. This was going too far: the paper was hardly in print before A. H. Compton and A. W. Simon had established by direct experiment the strict conservation of energy and momentum in an individual process of interaction between atom and radiation. Nevertheless, this short-lived attempt exerted a profound influence on the course of events; what remained after its failure was the conviction that the classical mode of description of the atomic processes had to be entirely relinquished." (DSB).*

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