Book Chapter — An Ether by Any Other Name? Paul Dirac’s Æther
Abstract #
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.