An Ether by Any Other Name?

This chapter examines Paul Dirac’s 1951 proposal that ‘we are rather forced to have an æther’, arguing that it was a purposeful use of anachronism, meant to shock his contemporaries in relativistic quantum theory. The chapter considers the context for Dirac’s proposal in physics and astronomy during his education, and in the journal Nature. Dirac’s ‘æther’ was distinct from the ether proposed by E. T. Whittaker and Arthur Eddington, as it was more physical and substantial. In the conclusion, the chapter argues that the historical progression of physical theory was central to Dirac’s æther proposal. If, in 1905, Einstein ushered in one revolution which removed the possibility for an ether, the later quantum revolution made a new ‘æther’ possible. In the Manchester Guardian, Léon Rosenfeld described Dirac as conjuring ‘the ghost of the “aether”’. In fact, Dirac attempted a resurrection.

The New World

On December 19, 1938, Otto Hahn wrote to Lise Meitner in Stockholm, asking her if she could propose some “fantastic explanation” for his and Fritz Strassmann’s finding of barium when bombarding uranium with neutrons. She and Otto Robert Frisch found such an explanation for what he called “nuclear fission” over the Christmas holidays, based on Gamow’s liquid-drop model of the nucleus. Bohr was astonished by this, but in 1936 he had speculated that the uranium nucleus would just explode. He, his son Erik, and his associate Léon Rosenfeld then took a ship to New York, arriving on January 16, 1939. Rosenfeld reported the discovery of fission that evening to the Princeton physics journal club. On January 26, physicists everywhere learned about this stunning discovery when Bohr and Fermi reported it at a conference in Washington, D.C. Physicists entered the New World of Nuclear Physics, taking Humanity with them.

Pode Sustentar-se o Argumento de Que Exista uma Dialéctica Quântica da Natureza?

Resumo Autores como os físicos Léon Rosenfeld, Gerald Holton e Franco Selleri, bem como o filósofo Miguel Reale perceberam já que, no interior da mecânica quântica, o princípio da complementaridade de Niels Bohr pode ser aproximado á noção filosófica de dialéctica (numa perspectiva não hegeliana, entretanto). Além de buscar contribuir para robustecer tal linha de interpretaoção do famoso principío bohriano, neste paper tentaremos compreender dialecticamente a relaoção de Louis de Broglie e a de desigualdade de Werner Heisenberg. Por fim, argumentaremos a favor de um enfoque realista do principío em causa.

‘Dialectical materialism and modern physics’, an unpublished text by Max Born

A previously unpublished manuscript by the physicist Max Born, one of the creators of quantum mechanics, is presented. The manuscript was addressed to Born's colleague Léon Rosenfeld and criticized his attempt to show that Niels Bohr's doctrine of complementarity was an example of dialectical materialism and as such in perfect agreement with Marxist philosophy. Besides illustrating the deep political divisions among defenders of the ‘Copenhagen spirit’ in quantum physics, the manuscript is also a valuable source illuminating Max Born's philosophical position about scientific methodology and epistemology.