with the need for a luminiferous aether to explain the transmission of light. Although a physical medium was no longer required, the concept of aether still did not entirely vanish. It remained necessary to assign properties to the vacuum for various purposes. In some respects vacuum and aether are treated as synonyms by science. In modern quantum field theory, a completely empty vacuum is not at zero-point energy, the lowest possible energy state. First proposed by Paul Dirac in 1927, the lowest energy state has constant random vacuum fluctuations which bring into existence short-lived virtual particles. This is somewhat reminiscent of early philosophical plenum ideas, and means that vacuum and nothing are certainly not synonyms. See also A Universe from Nothing Absolute zero Action at a distance Big Bounce Cosmogony Dark matter Empty (disambiguation) Empty set Eternal inflation Everything Ex nihilo False vacuum Meontology Meaning of life Mu (negative) Negation (linguistics) Negative theology Nihilism No Nobody (disambiguation) Nothing comes from nothing Quantum vacuum fluctuations Ultimate fate of the universe Vacuum Vanitas Vacuous truth Void (disambiguation) Zero Notes References Hsu, Jong-Ping, Einstein's Relativity and Beyond: New Symmetry Approaches, World Scientific, 2000 . Milonni, Peter W., The Quantum Vacuum: An Introduction to Quantum Electrodynamics, Academic Press, 2013 . Pieper, Josef; Wald, Berthold, For the Love of Wisdom: Essays on the Nature of Philosophy, Translator: Roger Wasserman, Ignatius Press, 2006 . Russell, Bertrand. History of Western Philosophy, Routledge, 1995 . Schaffner, Kenneth F., Nineteenth-Century Aether Theories, Elsevier, 2016 . Whittaker, Edmund Taylor, A History of the Theories of Aether and Electricity from the age of Descrates to the Close of the Ninenteenth Century, London: Longmans Green & Co, 1910 . Further reading External links Existentialist concepts Perception Ontology Concepts in metaphysics