Roland Omnès (born 18 February 1931), is the author of several books which aim to give non-scientists the information required to understand quantum mechanics from an everyday standpoint.

Biography

Omnès is currently Professor Emeritus of Theoretical Physics in the Faculté des sciences at Orsay, at the

Université Paris-Sud Paris-Sud University (French: ''Université Paris-Sud''), also known as University of Paris — XI (or as Université d'Orsay before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, in ...

XI. He has been instrumental in developing the

consistent histories In quantum mechanics, the consistent histories (also referred to as decoherent histories) approach is intended to give a modern interpretation of quantum mechanics, generalising the conventional Copenhagen interpretation and providing a natural i ...

and quantum decoherence approaches in quantum mechanics. In 1959 he received the Paul-Langevin Prize.

Philosophical work

In his philosophical work (especially in ''

Quantum Philosophy ''Quantum Philosophy'' is a 2002 book by the physicist Roland Omnès, in which he aims to show the non-specialist reader how modern developments in quantum mechanics allow the recovery of our common sense view of the world. Book contents * Se ...

''), Omnès argues that: # "Until modern times, intuitive, rational thought was sufficient to describe the world; mathematics remained an adjunct, simply helping to make our intuitive descriptions more precise." # "In the late 19th and early 20th centuries, we arrived at a Fracture between common sense and our best descriptions of reality. Our formal description became the truest picture (most

consistent In classical deductive logic, a consistent theory is one that does not lead to a logical contradiction. The lack of contradiction can be defined in either semantic or syntactic terms. The semantic definition states that a theory is consistent ...

with how things are, experimentally) and common sense was left behind. Our best descriptions of reality are now incomprehensible to common sense alone, and our intuitions as to how things are, are often negated by experiment and theory." # "However it is, finally, possible to recover common sense from our formal, mathematical description of reality. We can now demonstrate that the laws of classical logic, classical probability and classical dynamics (of common sense, in fact) apply at the macroscopic level, even in a world described by a single, unitary wavefunction. This follows from the fundamental principles of quantum mechanics, with no need for extralogical constructs such as wavefunction collapse." "We will never", Omnès believes, "find a common sense interpretation of quantum law itself. Nevertheless, it is now possible to see that common sense and quantum reality are compatible with each other: we can enter the world at either starting point, and we will find that each leads to the other: experiment leads to theory, and the theory can now recover the common sense framework in which the experiment was conducted (and in which our lives are lived)."

The new 'Copenhagen Interpretation'?

Omnès' work is sometimes described as an updating of the

Copenhagen interpretation The Copenhagen interpretation is a collection of views about the meaning of quantum mechanics, principally attributed to Niels Bohr and Werner Heisenberg. It is one of the oldest of numerous proposed interpretations of quantum mechanics, as feat ...

of quantum mechanics. This is somewhat misleading. The relationship between the two accounts is as follows. The Copenhagen interpretation of quantum mechanics (argued for most centrally by

Niels Bohr Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922 ...

) tells us to "shut up and calculate". It says that there are certain questions we simply cannot ask, and that there are inexplicable rules which we have to apply in order to get from a quantum description of reality (which we know is experimentally correct to at least 10 decimal places of accuracy) to the reality of our day-to-day, common sense lives (which seems self-evidently correct, and yet is apparently in contradiction with quantum law). Omnès tells us that we no longer have to shut up in order to calculate: there is now a self-consistent framework which enables us to recover the principles of classical common sense - and to know, precisely, their limits - starting from fundamental quantum law.

Bibliography

The work Omnès presents in his books was developed by Omnès himself, Robert B. Griffiths,

Murray Gell-Mann Murray Gell-Mann (; September 15, 1929 – May 24, 2019) was an American physicist who received the 1969 Nobel Prize in Physics for his work on the theory of elementary particles. He was the Robert Andrews Millikan Professor of Theoretical ...

James Hartle James Burkett Hartle (August 20, 1939) is an American physicist. He has been a professor of physics at the University of California, Santa Barbara since 1966, and he is currently a member of the external faculty of the Santa Fe Institute. Hartle ...

, and others. * ''The Interpretation of Quantum Mechanics'' (Princeton University Press, 1994) - a technical exposition of Omnès's account, for physicists. * ''Understanding Quantum Mechanics'' (Princeton University Press, 1999) - a somewhat less technical revision and updating of the above work, also intended for physicists. * ''

: Understanding and Interpreting Contemporary Science'' (English Edition - Princeton University Press, 1999); (French Edition - Gallimard, 1994) * ''Converging Realities: Toward a Common Philosophy of Physics and Mathematics'' (Princeton University Press, 2004) - Here Omnès presents, in detail, his position on the relationship between mathematics and reality which he started to develop in ''

''. {{DEFAULTSORT:Omnes, Roland French physicists École Normale Supérieure alumni Academic staff of Paris-Sud University Living people 1931 births