Bernard d'Espagnat (22 August 1921 – 1 August 2015) was a French theoretical
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...
,
philosopher of science
Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...
, and author, best known for his work on the nature of reality. The
Wigner–d'Espagnat inequality is partially named after him.
''Quote'': "The doctrine that the world is made up of objects whose existence is independent of human
consciousness
Consciousness, at its simplest, is awareness of a state or object, either internal to oneself or in one's external environment. However, its nature has led to millennia of analyses, explanations, and debate among philosophers, scientists, an ...
turns out to be in conflict with
quantum mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...
and with facts established by experiment."
Early life
d'Espagnat was born on 22 August 1921 in Fourmagnac, France, but spent most of his early years in Paris, where his father, a post-impressionist painter, and mother imbued him with a love of classic literature and the arts. Attending school in Paris, he was drawn to the humanities, especially philosophy. Despite his love of philosophy, d'Espagnat focused on science and mathematics, believing that advances in philosophy would require the knowledge and practice of contemporary science.
In 1939, as d'Espagnat made plans to enter the
Ecole Polytechnique, World War II put his education on hold.
[BioDetails from](_blank)
John Templeton Foundation
Education and career
D'Espagnat obtained his Ph.D. from the
Sorbonne at the
Institut Henri Poincaré under the guidance of
Louis de Broglie. He was a researcher at the Centre National de Recherche Scientifique
CNRS, 1947–1957. During this period he also worked with
Enrico Fermi in Chicago, 1951–1952, and on a research project led by
Niels Bohr
Niels Henrik David Bohr (, ; ; 7 October 1885 – 18 November 1962) was a Danish theoretical physicist who made foundational contributions to understanding atomic structure and old quantum theory, quantum theory, for which he received the No ...
at the Institute in Copenhagen, 1953–1954. He then pursued his scientific career as the first theoretical physicist at the European Organization for Nuclear Research (
CERN) in Geneva, 1954-59.
From 1959 until his retirement in 1987, D'Espagnat was a senior lecturer at the Faculty of Sciences at the
Sorbonne University. He was director of the Laboratory of Theoretical Physics and Elementary Particles at the
University of Paris XI (Orsay), 1980-87. He was a visiting professor at the
University of Texas at Austin
The University of Texas at Austin (UT Austin, UT, or Texas) is a public university, public research university in Austin, Texas, United States. Founded in 1883, it is the flagship institution of the University of Texas System. With 53,082 stud ...
in 1977, and at the
University of California - Santa Barbara in 1984.
He has been a member of the Brussels
International Academy of the Philosophy of Science since 1975, and of the French
Academy of Moral and Political Sciences since 1996. His experiments with
Bell's inequalities to further his concept of veiled reality won the attention of the
John Templeton Foundation. D'Espagnat became the 2009
Templeton Prize winner in March for his "work which acknowledges that science cannot fully explain 'the nature of being.'"
Philosophical outlook
D'Espagnat remained troubled by the scant attention most physicists paid to the interpretational questions raised by
quantum mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...
. His first book, ''Conceptions of Contemporary Physics'' (1965), asked these questions and sketched possible resolutions, underscoring his insistence that scientists face the issues raised by their own pursuits.
Subsequently, d'Espagnat was an early interpreter of the deep philosophical significance of experimental research agendas in quantum physics. In his 1979 Scientific American article, "The Quantum Theory and Reality," and best-selling 1979 book, ''À la recherche du réel, le regard d'un physicien'' (''In Search of Reality, the Outlook of a Physicist''), he encouraged physicists and philosophers to think afresh about questions long considered marginal but which today serve as the foundation for new fields of research into the
nature of reality.
In ''Le réel voilé, analyse des concepts quantiques'' (''Veiled Reality, An Analysis of Present-Day Quantum Mechanical Concepts''), d'Espagnat coined the term "veiled reality" and explained why significant experiments over the past decade had not restored conventional realism. ''On Physics and Philosophy'' (published in France in 2002 as ''Traité de physique et de philosophie'') was hailed as "surely the most complete book to have been written on this subject and one likely to last a long time…" by
Roland Omnès. His most recent book is ''Candide et le physicien'' (''Candide and the Physicist''), written with Claude Saliceti and published in 2008, a layperson's guide that answers 50 questions which pinpoint and correct preconceived ideas of contemporary physics and examine the many conceptual and philosophical changes those ideas reveal.
D'Espagnat was a
transcendental realist. He suggested that transcendental realism offers a new argument for the existence of God.
Books by d'Espagnat
* 1965 - ''Conceptions de la physique contemporaine; les interprétations de la mécanique quantique et de la mesure''. Paris: Hermann.
* 1976 - ''Conceptual Foundations of Quantum Mechanics'', 2nd ed. Addison Wesley.
* 1979 - ''À la recherche du réel - Le regard d'un physicien''. Gauthier-Villars
* 1982 - ''Un atome de sagesse: Propos d'un physicien sur le réel voilé''. Paris: Le Seuil.
* 1983 - ''In Search of Reality''. Springer. Trans. of ''A la recherche du réel, le regard d'un physicien''.
* 1984 - ''Nonseparability and the Tentative Descriptions of Reality''.
* 1989 - ''Reality and the Physicist :Knowledge, Duration and the Quantum World''. Cambridge Univ. Press., 284 pages, by Bernard D'Espagnat;J C Espagnat Bernard D'Whitehouse . Transl. of ''Une incertaine réalité; le monde quantique, la connaissance et la durée''.
* 1990 - ''Penser la science ou les enjeux du savoir''.
* 1990 - ''Georges d'Espagnat''.
* 1993 (with others) - ''Regards sur la matière des quanta et des choses''.
* 1994 - ''Le Réel voilé, analyse des concepts quantiques''. English Transl. (2003), ''Veiled Reality: An Analysis of Quantum Mechanical Concepts'', 2003, Westview Press, Boulder, Colorado, 494 pages.
* 1997 - ''Physique et réalité, un débat avec Bernard d'Espagnat''. Atlantica Séguier Frontieres. .
* 1998 - ''Ondine et les feux du savoir. Carnets d'une petite sirène''.
* 1999 - ''Conceptual Foundations of Quantum Mechanics'', Westview Press, Second Edition, Paperback · 352 pages,
* 2006 - ''On physics and philosophy''. Princeton University Press. Translation of 2002, ''Traité de physique et de philosophie''.
* 2008 - ''Candide et le physicien'' (''Candide and the Physicist''), with Claude Saliceti.
References
{{DEFAULTSORT:Espagnat, Bernard d'
1921 births
2015 deaths
20th-century French physicists
21st-century French physicists
People associated with CERN
École Polytechnique alumni
French male non-fiction writers
French National Centre for Scientific Research scientists
20th-century French philosophers
21st-century French philosophers
Members of the Académie des sciences morales et politiques
French theoretical physicists
University of California, Santa Barbara faculty
University of Paris alumni
Academic staff of the University of Paris
University of Texas at Austin faculty
French expatriates in the United States