AVS 64th International Symposium & Exhibition
    Vacuum Technology Division Wednesday Sessions
       Session VT-WeM

Paper VT-WeM12
The Modern View of the Vacuum

Wednesday, November 1, 2017, 11:40 am, Room 7 & 8

Session: Transfer and Ultraclean Systems, Particle Control, and History
Presenter: H. Frederick Dylla, American Institute of Physics
Correspondent: Click to Email
The concept of the vacuum has evolved from ancient to modern times. Ancient Greeks did not believe in the concept of vacuum-empty space in which nothing exists. With their early formulation of atom-like particles, they believed that matter was completely space filling. As civilization moved into the “Enlightenment” and the early industrial age, a practical definition of vacuum became any space evacuated to a pressure less than ambient. This is still a practical definition of vacuum in contemporary times, where state-of-the-art techniques can produce extreme vacuum levels-approaching matter densities of less than a molecule/cm3. However, from the standpoint of contemporary physics, we have moved back to a view that the vacuum is not empty space devoid of content. Paul Dirac’s theory of Quantum Electrodynamics, the most precisely experimentally benchmarked theory in science, portrays empty space as being filled with quantum fluctuations: virtual particle-antiparticle pairs appearing and disappearing on extremely short (Planck) time scales. The present status of cosmology research adds additional complexity to the concept of a perfect vacuum. Quantum fluctuations underpin Alan Guth’s inflationary model of the universe’s expansion following the primordial Big Bang. His widely accepted analysis explains the high uniformity of matter density in the observable universe-a part in 104. Quantum fluctuations in space drove an immense (1028) expansion of the primordial universe using the latent energy in a so-called false vacuum. Over the last two decades additional observations of the universe’s expansion rate, have shown that the visible components of the universe (matter and radiation) account for only about 1% of the content- 30% resides in dark matter and 70% in dark energy. Characterizing these latter two components remains on the forefront of modern physics research, and clearly a perfect vacuum is far from empty.