Um recorte histórico das contribuições de Erwin Schrödinger para a Mecânica Quântica

Erwin Schrödinger (1887-1961) foi um físico austríaco, um grande cientista que viveu em um contexto europeu de mudança e turbulência, mas isso não o impediu de ter uma vida muito intensa, tanto em sua pesquisa científica quanto em sua vida pessoal. Seu trabalho mais famoso, publicado em 1926, inclui sua teoria da mecânica ondulatória, no qual consta a famosa equação que tem hoje o seu nome. Ele mostrou que a equação funcionava adequadamente para calcular os níveis de energia do átomo de hidrogênio. Em outros trabalhos, publicados no mesmo período, mostrou outras aplicações designadas ao oscilador harmônico e uma generalização para o caso dependente do tempo. Sua dedicação aos sistemas quânticos lhe rendeu o Prêmio Nobel em 1933. É sobre esse homem fascinante e complexo que se apresenta um recorte histórico com potencial para atrair não apenas os cientistas, mas qualquer pessoa interessada na história de nossos tempos, na vida e no pensamento de um dos maiores cientistas do século XX. O presente artigo nasceu do fato de que, embora muito se fale sobre Schrödinger, não há textos em língua portuguesa que ultrapassem os limites biográficos, apesar de sua extrema relevância teórica para a pesquisa acadêmica. Nesse sentido, tem-se por objetivo visitar algumas obras que relatam os acontecimentos ou fatos econômicos, políticos, sociais e culturais que resultaram no período mais produtivo da carreira de Schrödinger.A historical overview of Erwin Schrödinger’s contributions to Quantum MechanicsAbstractErwin Schrödinger (1887-1961) was an Austrian physicist, a great scientist who lived in a European context of change and turmoil, but this did not stop him from living a very intense life, both in his scientific research and in his personal life. His most famous work, published in 1926, includes his theory of wave mechanics, which contains the famous equation that bears his name today. He showed that the equation worked properly for calculating the energy levels of the hydrogen atom. In other works, published in the same period, he showed other applications assigned to the harmonic oscillator and a generalization for the time dependent case. His dedication to quantum systems won him the Nobel Prize in 1933. It is about this fascinating and complex man who presents a historical snippet with the potential to attract not only scientists, but anyone interested in the history of our times, life and thought from one of the greatest scientists of the 20th century. This article was born from the fact that, although much is said about Schrödinger, there are no texts in Portuguese that go beyond biographical limits, despite its extreme theoretical relevance for academic research. In this sense, the objective is to visit some works that report the economic, political, social and cultural events or facts that resulted in the most productive period of Schrödinger's career.Keywords: Quantum mechanics; Schrödinger; History of Physics.

Derivation of Second Order Partial Differential Equation Indicating Wave and Heat Equation through the Use of the Navier Stoke’s Equation for Unsteady and Incompressible Flow

In this paper, we have tried to approach the concepts of two-dimensional wave equation and one dimensional heat equation through the means of the Navier Stoke’s equation for unsteady and incompressible flow. Our pursuit to do so has been supported with ample justifications and analytic discussions. The strong relation shared by the fluid dynamics, wave mechanics and heat flow has been brought to light through our attempts.

Application of Einstein’s Methods in a Quantum Theory of Radiation

Einstein showed in his seminal paper on radiation that molecules with a quantum-theoretical distribution of states in thermal equilibrium are in dynamical equilibrium with the Planck radiation. The method he used assigns coordinates fixed with respect to molecules to derive the A and B coefficients, and fixed relative to laboratory coordinates to specify their thermal motion. The resulting dynamical equilibrium between quantum mechanical and classically defined statistics is critically dependent upon considerations of momentum exchange. When Einstein’s methods relating classical and quantum mechanical statistical laws are applied to the level of the single quantum oscillator they show that matrix mechanics describes the external appearances of an atom as determined by photon-electron interactions in laboratory coordinates, and wave mechanics describes an atom’s internal structure according to the Schrödinger wave equation. Non-commutation is due to the irreversibility of momentum exchange when transforming between atomic and laboratory coordinates. This allows the “rotation” of the wave function to be interpreted as the changing phase of an electromagnetic wave. In order to describe the momentum exchange of a quantum oscillator the Hamiltonian model of atomic structure is replaced by a Lagrangian model that is formulated with equal contributions from electron, photon, and nucleus. The fields of the particles superpose linearly, but otherwise their physical integrity is maintained throughout. The failure of past and present theoretical models to include momentum is attributed to the overwhelming requirement of human visual systems for an explicit stimulus.