HISTORY OF PHYSICS

Author: PUIG PLA CARLES.
Year: 2005.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: CEHIC-FACULTAD DE CIENCIAS (UAB).

Summary: This thesis has been discussed as they started, formalizing and developed the first lessons científicos-técnicas of a public nature, related to physics, which were established in Catalonia in the late eighteenth century and the early nineteenth century. Specifically, it has been studied instituiconalizaicón of public education in astronomy watercraft, mechanics, machinery and experimental physics at four schools created for the Board of Trade of Catalonia (Nautical School, School of Engineering School of Experimental Physics) . Furthermore, we have studied the role played by artisans in construcicón of the first machines and tools necessary scientific pair wing teaching physics, as well as their collaboration with scientists Catalans during the illustration. There has been a first approximation to the directions (sections) físico-matemáticas of the Academy of Natural Sciences and Arts of Barcelona and has been identified and characterized the collective formed by the partners of this artistic institution in the period (1766-1824). Additionally, it has conducted an analysis of the changing historical significance of the concepts: physics, mathematics and art, in the study period.

Author: PÉREZ CANALS ENRIC.
Year: 2006.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAT DE FÍSICA.
Place of preparation: FACULTAT DE FÍSICA.

Summary: The question that has inspired has come to give this work has been: What role was assumed adiabática Paul Ehrenfest in the development of quantum theory? It has attempted to define the meaning of the same assumptions and has rebuilt a kind of "path adiabática" towards quantum theory. Ultimately, it has located the origin, brought the background, the impact, and so on. Of this contribution Ehrenfest. The first part deals with the development of the hypothesis adiabática. It gives a brief overview of the scenario in which it took place, the birth and early evolution of the quantum hypothesis, which was introduced into physics by Max Planch in the year 1990. Ehrenfest published his first work on quantum theory in 1905 and 1906. They found a harsh criticism to the draft planckiano to account for the irreversibility in the system of radiant cavity. In 1991 Ehrenfest publishes a vast analysis of the theory of thermal radiation Planck, in an article that surely somewhere in the origin of the hypothesis adiabática. Other results found in this article are: exhaustive comparison between Einstein quantum hypothesis (assumption quanta of energy) and Planck (quantization and justification of the form (of the frequency dependence) quantum. In the second part reconstructs the process Ehrenfest arrived to make the car's hypothesis in 1916. scenario corresponds to the years 1913-1918, and could be characterized as the year extension and generalization of the quantum hypothesis. thesis also discusses articles Ehrenfest of 1913 and 1914 in which almost all the results that are published together a couple of years later. Shown little impact dela work Ehrenfest in investigations of physicists made quantization rules, as sommerfeld, Planck and Einstein, among others. Discusses the influence of the assumptions adiabática on the theory that bohr published in 1918, in the extensive article "On the quantum theory of line-spectra." was compared to the use of this property (invariance adiabática) they both Ehrenfest as Bohr. The third part is a first recognition of the state of affairs in the years 1919-1926, years in which the hypothesis Ehrenfest was cited more than ever. Bohr's intervention prompted many of physicists involved in the discussions of quantum cited, since 1918, the articles of Ehrenfest the years 1905, 1906, 1911, 1913 and 1916, which until then had barely received mention. In the year 1926, born enunciated the adiabatic theorem in quantum mechanics similar formally assumed Ehrenfest in the context of the new mechanics. In this new context became a deductible result from the principles of the theory, contraponiéndose thus the hypothetical nature that had accompanied him during his years life in the old quantum theory. theorem This is the only vestige of the hypothesis that Ehrenfest made in 1916.