Editing David Bohm (section)

=== Quantum theory and Bohm diffusion ===
{{main|Bohm diffusion|De Broglie–Bohm theory}}
[[File:doppelspalt.svg|thumb|180px|The Bohmian trajectories for an electron going through the two-slit experiment. A similar pattern was also observed for single photons.<ref>[https://www.science.org/doi/10.1126/science.1202218 Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer].</ref>]]
During his early period, Bohm made a number of significant contributions to physics, particularly [[quantum mechanics]] and [[relativity theory]]. As a postgraduate at Berkeley, he developed a theory of [[plasma (physics)|plasmas]], discovering the [[electron]] phenomenon known as [[Bohm diffusion]].<ref>D. Bohm: ''The characteristics of electrical discharges in magnetic fields'', in: A.&nbsp;Guthrie, R.&nbsp;K. Wakerling (eds.), McGraw–Hill, 1949.</ref> His first book, ''Quantum Theory'', published in 1951, was well received by Einstein, among others. But Bohm became dissatisfied with the orthodox interpretation of quantum theory he wrote about in that book. Starting from the realization that the [[WKB approximation]] of quantum mechanics leads to deterministic equations and convinced that a mere approximation could not turn a probabilistic theory into a deterministic theory, he doubted the inevitability of the conventional approach to quantum mechanics.<ref>[[Maurice A. de Gosson]], Basil J. Hiley: ''Zeno paradox for Bohmian trajectories: the unfolding of the metatron'', 3 January 2011 ([http://www.freewebs.com/cvdegosson/ZenoPaper.pdf PDF]&nbsp;– retrieved 16 February 2012).</ref>

Bohm's aim was not to set out a deterministic, mechanical viewpoint but to show that it was possible to attribute properties to an underlying reality, in contrast to the conventional approach.<ref>B. J. Hiley: [http://www.bbk.ac.uk/tpru/BasilHiley/History_of_Bohm_s_QT.pdf ''Some remarks on the evolution of Bohm's proposals for an alternative to quantum mechanics''], 30 January 2010.</ref> He began to develop his own interpretation (the [[De Broglie–Bohm theory]], also called the [[pilot wave]] theory), the predictions of which agreed perfectly with the non-deterministic quantum theory. He initially called his approach a [[hidden variable theories|hidden variable]] theory, but he later called it ''ontological theory'', reflecting his view that a [[stochastic process]] underlying the phenomena described by his theory might one day be found. Bohm and his colleague [[Basil Hiley]] later stated that they had found their own choice of terms of an "interpretation in terms of hidden variables" to be too restrictive, especially since their variables, position and momentum, "are not actually hidden".<ref>David Bohm, Basil Hiley: ''The Undivided Universe: An Ontological Interpretation of Quantum Theory'', edition published in the Taylor & Francis e-library 2009 (first edition Routledge, 1993), {{ISBN|0-203-98038-7}}, [https://books.google.com/books?id=vt9XKjc4WAQC&pg=PA2 p. 2].</ref>

Bohm's work and the [[EPR paradox|EPR argument]] became the major factor motivating [[John Stewart Bell]]'s [[Bell's inequality|inequality]], which rules out [[locality principle|local]] hidden variable theories; the full consequences of Bell's work are still being investigated.