Carlo Rovelli
Encyclopedia
Carlo Rovelli is an Italian 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...

 who has worked in Italy, the USA, and France. His work is mainly in the field of quantum gravity
Quantum gravity
Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...

. He is among the founders of the Loop Quantum Gravity
Loop quantum gravity
Loop quantum gravity , also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the theories of quantum mechanics and general relativity...

 theory.

Life and career

Carlo Rovelli was born in Verona, Italy, in 1956. In the 1970s he participated in the student political movements in Italian universities. He was involved with the free political radio stations Radio Alice
Radio Alice
Radio Alice was an Italian free radio broadcasting from Bologna at the end of the 1970s. It started transmitting on February 9, 1976 using an ex-military transmitter on a frequency of 100.6 MHz. The station was closed by the carabinieri on March 12, 1977. Radio Alice then re-opened again for two...

 in Bologna and Radio Anguana in Verona, which he helped found. In conjunction with his political activity, he was charged, but later released, for crimes of opinion related to the book Fatti Nostri, which he co-authored with Enrico Palandri, Maurizio Torrealta, and Claudio Piersanti. In 1981 he graduated with a BS/MS in Physics from the University of Bologna
University of Bologna
The Alma Mater Studiorum - University of Bologna is the oldest continually operating university in the world, the word 'universitas' being first used by this institution at its foundation. The true date of its founding is uncertain, but believed by most accounts to have been 1088...

, and in 1986 he obtained his PhD at the University of Padova, Italy. He refused military service, which was compulsory in Italy at the time, and was therefore briefly detained in 1987. He held postdoctoral positions at the University of Rome and at Yale University. He was on the faculty of the University of Pittsburgh from 1990 to 2000. He is currently at the Université de la Méditerranée, in the Centre de Physique Théorique, in Marseille
Marseille
Marseille , known in antiquity as Massalia , is the second largest city in France, after Paris, with a population of 852,395 within its administrative limits on a land area of . The urban area of Marseille extends beyond the city limits with a population of over 1,420,000 on an area of...

, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

. He has also long held the post of Professor in the Department of History and Philosophy of Science of the University of Pittsburgh
University of Pittsburgh
The University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...

.

Loop Quantum Gravity

In 1988 Carlo Rovelli, 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 Abhay Ashtekar
Abhay Ashtekar
Abhay Vasant Ashtekar is an Indian theoretical physicist. He is the Eberly Professor of Physics and the Director of the Institute for Gravitational Physics and Geometry at Pennsylvania State University. As the creator of Ashtekar variables, he is one of the founders of loop quantum gravity and its...

 introduced a theory of quantum gravity called loop quantum gravity
Loop quantum gravity
Loop quantum gravity , also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the theories of quantum mechanics and general relativity...

. In 1995 Rovelli and Smolin obtained a clear basis of states of quantum gravity, labelled by Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...

's spin networks, and using this basis they were able to show that the theory predicts that area and volume are quantized. This result indicates the existence of a discrete structure of space at very small scale. In 1997 Rovelli and Michael Reisenberger introduced a "sum over surfaces" formulation of theory, which has since evolved into the currently popular covariant "spinfoam" version of loop quantum gravity
Loop quantum gravity
Loop quantum gravity , also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the theories of quantum mechanics and general relativity...

. The theory is today considered a leading candidate for a quantum theory of gravity
Quantum gravity
Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...

 and finds tentative applications in areas such as quantum cosmology
Quantum cosmology
In theoretical physics, quantum cosmology is a field attempting to study the effect of quantum mechanics on the formation of the universe, or its early evolution, especially just after the Big Bang...

 and quantum black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...

 physics.

Other major works

In his 2004 book Quantum Gravity, Rovelli developed a formulation of classical and quantum mechanics that does not make any explicit reference to the notion of time. Rovelli defends the idea that such a timeless formalism is needed to describe the world in the regimes where the quantum properties of the gravitational field cannot be disregarded. This is because the quantum fluctuation of spacetime itself make the notion of time unsuitable for writing physical laws in the conventional form of evolution laws in time.

This position has lead him to face the following problem: if time is not part of the fundamental theory of the world, then how does time emerge? In 1993, in collaboration with Alain Connes
Alain Connes
Alain Connes is a French mathematician, currently Professor at the Collège de France, IHÉS, The Ohio State University and Vanderbilt University.-Work:...

, Rovelli has proposed a solution to this problem called the thermal time hypothesis. According to this hypothesis, time emerges only in a thermodynamic or statistical context. If this is correct, the flow of time is an illusion, one deriving from the incompleteness of knowledge.

In 1994 Rovelli introduced the relational interpretation of quantum mechanics
Relational quantum mechanics
Relational quantum mechanics is an interpretation of quantum mechanics which treats the state of a quantum system as being observer-dependent, that is, the state is the relation between the observer and the system. This interpretation was first delineated by Carlo Rovelli in a 1994 preprint, and...

, based on the idea that the quantum state of a system must always to be interpreted as relative to another physical system (like the "velocity of an object" is always relative to another object, in classical mechanics). The idea has been developed and analyzed in particular by Bas van Fraassen and by Michel Bitbol
Michel Bitbol
Michel Bitbol is a French researcher in philosophy of science, born on March 12, 1954.He is "Directeur de recherche" at CNRS, in the Centre de Recherche en Epistémologie Appliquée of École polytechnique ....

.

History and philosophy of science

Rovelli has also worked in the history and philosophy of science. He has written a book on the Greek philosopher Anaximander
Anaximander
Anaximander was a pre-Socratic Greek philosopher who lived in Miletus, a city of Ionia; Milet in modern Turkey. He belonged to the Milesian school and learned the teachings of his master Thales...

, published in France in June 2009 and scheduled for publication in the US, Italy, Brazil and Greece in 2011. Using the historical figure of Anaximander as a starting point, the book analyses the main aspects of scientific thinking and articulates Rovelli's views on science. Anaximander is presented in the book as a main initiator of scientific thinking. For Rovelli, science is a continuous process of exploring novel possible views of the world; this happens via a "learned rebellion," which always builds and relies on previous knowledge but at the same time continuously questions aspects of this received knowledge. The foundation of science, therefore, is not certainty but the very opposite, a radical uncertainty about our own knowledge, or equivalently, an acute awareness of the extent of our ignorance.

Main recognitions

  • Senior member of the Institut Universitaire de France (IUF)
  • Honorary Professor of the Beijing Normal University, in China.
  • Member of the Académie Internationale de Philosophie des Sciences
  • Honorary member of the Accademia di Scienze Arti e Lettere di Verona
  • 1995 International Xanthopoulos Award for his contributions to theoretical physics.
  • 2009 First 'community' prize of the FQXi contest on the 'nature of time'.

Books

  • "Fatti Nostri", Bertani editore, 1977, (re-edited Rimini, Nda Press, 2007), ISBN 978-88-89035-17-7
  • "Quantum Gravity", Cambridge University Press, ISBN 0-521-83733-2
  • "What is time, what is space?", Di Renzo Editore, 2006, ISBN 88-8323-146-5.
    • "Qu'est-ce le temps? Qu'est-ce l'espace?", Bernard Gilson éditeur, ISBN 2-87269-159-6.
    • "Che cos'è il tempo? Che cos'è lo spazio?", Di Renzo Editore, ISBN 88-8323-082-5
  • "The first scientist. Anaximander and his legacy", Westholme Publishing, 2011.
    • "Anaximandre de Millet, ou la naissance de la science", Dunod, 2009. ISBN 978-2-10-052939-1.
    • "Che cos'è la scienza. La rivoluzione di Anassimandro", Mondadori Università, 2011 ISBN 9788861840751

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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