Antony Valentini
Encyclopedia
Antony Valentini is a theoretical
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...

 physicist
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

 and a professor at Clemson University
Clemson University
Clemson University is an American public, coeducational, land-grant, sea-grant, research university located in Clemson, South Carolina, United States....

. He is known for his work on the foundations of quantum physics.

Education and career

Valentini obtained an undergraduate degree from Cambridge University, then earned his Ph.D. with Dennis Sciama at the International School for Advanced Studies
International School for Advanced Studies
The ' is an international, Italian-state-supported post-graduate teaching and research institute with a special statute, located in Trieste ....

 (ISAS) in Trieste
Trieste
Trieste is a city and seaport in northeastern Italy. It is situated towards the end of a narrow strip of land lying between the Adriatic Sea and Italy's border with Slovenia, which lies almost immediately south and east of the city...

, Italy. In 1999, after seven years in Italy, he took up a post-doc grant to work at the Imperial College with Lee Smolin
Lee Smolin
Lee Smolin is an American theoretical physicist, a researcher at the Perimeter Institute for Theoretical Physics, and an adjunct professor of physics at the University of Waterloo. He is married to Dina Graser, a communications lawyer in Toronto. His brother is David M...

 and Christopher Isham.

He currently works at the Perimeter Institute for Theoretical Physics
Perimeter Institute for Theoretical Physics
Perimeter Institute for Theoretical Physics is an independent, resident-based research institute devoted to foundational issues in theoretical physics located in Waterloo, Ontario, Canada. Perimeter Institute was founded in 1999 by Mike Lazaridis...

. Since February 2011, he is professor of physics and astronomy at Clemson University.

Together with Mike Towler, Royal Society research fellow of the University of Cambridge's Cavendish Laboratory
Cavendish Laboratory
The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the university's School of Physical Sciences. It was opened in 1874 as a teaching laboratory....

, he organized a conference on the de Broglie-Bohm theory the Apuan Alps Centre for Physics in August 2010, hosted by the Towler Institute located in Vallico di Sotto
Fabbriche di Vallico
Fabbriche di Vallico is a comune in the Province of Lucca in the Italian region Tuscany, located about 70 km northwest of Florence and about 20 km northwest of Lucca....

 in Tuscany
Tuscany
Tuscany is a region in Italy. It has an area of about 23,000 square kilometres and a population of about 3.75 million inhabitants. The regional capital is Florence ....

, Italy, which is loosely associated with the Theory of Condensed Matter group
Theory of Condensed Matter group
The Theory of Condensed Matter group is the principal theoretical, as opposed to experimental, branch of the Cavendish Laboratory in the University of Cambridge.-Research:...

 of the Cavendish Laboratory. Among the questions announced for discussion, the organizers included “Why should young people be interested in these ideas, when showing interest in quantum foundations still might harm their careers?”

Work

Valentini has been working on an extension of the causal interpretation of quantum theory
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...

. This interpretation had been proposed in conceptual terms in 1927 by Louis de Broglie, was independently re-discovered by David Bohm
David Bohm
David Joseph Bohm FRS was an American-born British quantum physicist who contributed to theoretical physics, philosophy, neuropsychology, and the Manhattan Project.-Youth and college:...

 who brought it to a complete and systematic form in 1952, and was expanded on by Bohm and Hiley
Basil Hiley
Basil Hiley, born 1935, is a British quantum physicist and professor emeritus of the University of London.- Work :Hiley published a paper in 1961 on the random walk of a macromolecule, which was followed by further papers on the Ising model, and lattice constant systems defined in graph theoretical...

. Emphasizing de Broglie's contribution, Valentini has consistently referred to the causal interpretation of quantum mechanics underlying his work as the “de Broglie–Bohm theory”.

Quantum equilibrium, locality and uncertainty

In 1991, Valentini provided indications for deriving the quantum equilibrium hypothesis which states that in the frame work of the pilot wave theory. Valentini showed that the relaxation may be accounted for by a H-theorem constructed in analogy to the Boltzmann H-theorem of statistical mechanics. Valentini showed that his expansion of the De Broglie–Bohm theory would allow “signal nonlocality
Nonlocality
In Classical physics, nonlocality is the direct influence of one object on another, distant object. In Quantum mechanics, nonlocality refers to the absence of a local, realist model in agreement with quantum mechanical predictions.Nonlocality may refer to:...

” for non-equilibrium cases in which . According to Valentini, the universe is fundamentally nonlocal, and quantum theory merely describes a special equilibrium state in which nonlocality is hidden in statistical noise. He furthermore showed that an ensemble of particles with known wave function and known nonequilibrium distribution could be used to perform, on another system, measurements that violate the uncertainty principle
Uncertainty principle
In quantum mechanics, the Heisenberg uncertainty principle states a fundamental limit on the accuracy with which certain pairs of physical properties of a particle, such as position and momentum, can be simultaneously known...

.

In 1992, Valentini extended pilot wave theory to spin- fields and to gravitation.

Background and implications

Valentini has been described as an “ardent admirer of de Broglie”. He noted that “de Broglie (rather like Maxwell) emphasized an underlying ‘mechanical’ picture: particles were assumed to be singularities of physical waves in space”. He emphasized that de Broglie, with the assistance of Erwin Schrödinger
Erwin Schrödinger
Erwin Rudolf Josef Alexander Schrödinger was an Austrian physicist and theoretical biologist who was one of the fathers of quantum mechanics, and is famed for a number of important contributions to physics, especially the Schrödinger equation, for which he received the Nobel Prize in Physics in 1933...

, had constructed pilot wave theory, but later abandoned it in favor of quantum formalism.

Valentini's derivation of the quantum equilibrium hypothesis was criticized by Detlef Dürr and co-workers in 1992, and the derivation of the quantum equilibrium hypothesis has remained a topic of active investigation.

“Signal nonlocality
Nonlocality
In Classical physics, nonlocality is the direct influence of one object on another, distant object. In Quantum mechanics, nonlocality refers to the absence of a local, realist model in agreement with quantum mechanical predictions.Nonlocality may refer to:...

”, which is forbidden in orthodox quantum theory, would allow nonlocal quantum entanglement
Quantum entanglement
Quantum entanglement occurs when electrons, molecules even as large as "buckyballs", photons, etc., interact physically and then become separated; the type of interaction is such that each resulting member of a pair is properly described by the same quantum mechanical description , which is...

 to be used as a stand-alone communication channel without the need of a classical light-speed
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...

 limited retarded signal to unlock the entangled message from the sender to the receiver. This would be a major revolution in physics and would possibly make the cosmic landscape string theory
String theory
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...

 Popper falsifiable.

Publications

  • Guido Bacciagaluppi, Antony Valentini: Quantum theory at the crossroads: Reconsidering the 1927 Solvay Conference, Cambridge Univ. Press, 2009, ISBN 9780521814218
  • Antony Valentini, Hans Westman: Dynamical origin of quantum probabilities, Proceedings of the Royal Society A 8, vol. 461, no. 2053 p. 253-272, January 2005, DOI: 10.1098/rspa.2004.1394
  • Antony Valentini: Subquantum information and computation, 2002, Pramana Journal of Physics, vol. 59, no. 2, August 2002, p. 269–277
  • Antony Valentini: Signal-locality in hidden-variables theories, Physics Letters A, vol. 297, no. 5-6, 20 May 2002, p. 273-278 online from arxiv.org
  • Antony Valentini: Hidden Variables, Statistical Mechanics and the Early Universe, Chance in Physics, Lecture Notes in Physics, Springer 2001, Volume 574/2001, 165-181, DOI: 10.1007/3-540-44966-3_12 online from arxiv.org
  • Antony Valentini: On Galilean and Lorentz invariance in pilot-wave dynamics, Physics Letters A, 228, 215–222, 1997 online from arxiv.org
  • Antony Valentini: Pilot-wave theory of fields, gravitation and cosmology, in: James T. Cushing
    James T. Cushing
    James T. Cushing was a US-American theoretical physicist and philosopher of science. He was professor of physics as well as professor of philosophy at the University of Notre Dame....

    , Arthur Fine, Sheldon Goldstein (eds.): Bohmian mechanics and quantum theory: an appraisal, Kluwer Acedemic Publishers, 1996, p. 45–66 (a brief outline by Valentini of his work of 1991-1996 on the de Broglie–Bohm theory)
  • Antony Valentini: On the Pilot-Wave Theory of Classical, Quantum and Subquantum Physics, Ph.D. Thesis, ISAS, Trieste 1992
  • Antony Valentini: Signal-locality, uncertainty, and the sub-quantum H-theorem, II, Physics Letters A, vol. 158, no. 1, 1991, p. 1–8
  • Antony Valentini: Signal-locality, uncertainty, and the sub-quantum H-theorem, I, Physics Letters A, vol. 156, no. 5, 1991
  • Antony Valentini: Resolution of causality violation in the classical radiation reaction, Physics Review Letters vol. 61, no. 17, p. 1903–1905, 1988

External links

  • Antony Valentini at the Perimeter Institute
  • Cover story on Antony Valentini in New Scientist
    New Scientist
    New Scientist is a weekly non-peer-reviewed English-language international science magazine, which since 1996 has also run a website, covering recent developments in science and technology for a general audience. Founded in 1956, it is published by Reed Business Information Ltd, a subsidiary of...

  • http://www.sciencemag.org/cgi/reprint/324/5934/1512.pdf "Is quantum mechanics tried, true, wildly successful, and wrong?" from Science magazine.
  • James T. Cushing: Quantum mechanics: historical contingency and the Copenhagen hegemony, therein: Appendix 2 Valentini's H-Theorem, The University of Chicago Press, 1994, ISBN 0-226-13202-1, p. 171–173
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