Seminar on History and Philosophy of Science

In this talk, I will give an overview of my current manuscript project, More Than Nothing: a history of the vacuum in theoretical physics, 1925-1980. It begins with Paul Dirac's quantum mechanics of electrons at relativistic speeds; in the early 1930s Dirac argued that his theory required that all of space be filled with electrons, and further, that currents flowed in the "vacuum sea." These currents would affect experimenters' measurements of the charged particles within the atom. This was, I think, the beginning of a physical picture of the vacuum as _active_ in the world. The manuscript follows this "active" vacuum through the fields of relativistic quantum theory and general relativity. Central figures include Richard Feynman, Julian Schwinger, John Archibald Wheeler, Roger Penrose, Sidney Coleman, and Vladimir Fock. The manuscript ends with Yaakov Zeldovich's work in 1980, on the cusp of the new field of particle (inflationary) cosmology. I will discuss one figure or moment in some detail.