What conceptual connections can be drawn between the vacuum proposed by quantum field theory and the nineteenth-century electromechanical ether? Approaching the former from the perspective of the latter is not only possible but also instructive to distinguish the physical notion of the quantum vacuum from the everyday concept of nothingness, highlighting how contemporary quantum fields preclude the existence of an absolute vacuum. This article thus proposes a conceptual genealogy of the vacuum in quantum field theory that, rather than developing through the notion of vacuum, proceeds via the notion of ether, particularly in its electromechanical formulation. To this end, the article suggests that conceiving Paul Dirac’s quantum vacuum (the Dirac sea) as a “probabilistic plenum” allows us to frame this model as a conceptual hinge between the nineteenth-century electromechanical ether and the vacuum of contemporary quantum field theory.
