Jacob Bekenstein

Jacob Bekenstein at Harvard
Born	May 1, 1947 (1947-05-01) (age 60) Mexico City, Mexico
Residence	Jerusalem, Israel
Field	Theoretical physics
Institutions	Hebrew University of Jerusalem
Alma mater	Polytechnic University of New York
Academic advisor	John Wheeler
Known for	black hole thermodynamics
Notable prizes	Rothschild Prize in Physics Israel National Prize
Religion	Jewish

Jacob David Bekenstein (born May 1, 1947) is a physicist who has contributed to the foundation of black hole thermodynamics and to other aspects of the connections between information and gravitation. He was born in Mexico City, Mexico. He is Polak Professor of Theoretical Physics at the Hebrew University of Jerusalem, a member of the Israel Academy of Sciences and Humanities and of The World Jewish Academy of Sciences, and a recipient of the Rothschild Prize in Physics and of the Israel National Prize. Jacob Bekenstein at Harvard - I took that picture (Lumidek) and dedicated it to the public domain This image has been released into the public domain by the copyright holder. ... is the 121st day of the year (122nd in leap years) in the Gregorian calendar. ... Year 1947 (MCMXLVII) was a common year starting on Wednesday (link will display full 1947 calendar) of the Gregorian calendar. ... Image File history File links Flag_of_Mexico. ... Nickname: Motto: Ciudad en movimiento Location of Mexico City in south central Mexico Coordinates: , Country Federal entity Boroughs The 16 delegaciones Founded c. ... For other uses, see Jerusalem (disambiguation). ... Theoretical physics employs mathematical models and abstractions of physics, as opposed to experimental processes, in an attempt to understand nature. ... The Hebrew University of Jerusalem (‎, Arabic: ) is one of Israels oldest, largest, and most important institutes of higher learning and research. ... Polytechnic University (Brooklyn Poly, Poly, or Polytech), located in the Borough of Brooklyn in New York City, is the United States second oldest private technological university, founded in 1854. ... John Archibald Wheeler (born July 9, 1911) is an eminent American theoretical physicist. ... This article or section is in need of attention from an expert on the subject. ... is the 121st day of the year (122nd in leap years) in the Gregorian calendar. ... Year 1947 (MCMXLVII) was a common year starting on Wednesday (link will display full 1947 calendar) of the Gregorian calendar. ... Not to be confused with physician, a person who practices medicine. ... This article or section is in need of attention from an expert on the subject. ... Physical information refers generally to the information that is contained in a physical system. ... “Gravity” redirects here. ... Nickname: Motto: Ciudad en movimiento Location of Mexico City in south central Mexico Coordinates: , Country Federal entity Boroughs The 16 delegaciones Founded c. ... Theoretical physics employs mathematical models and abstractions of physics, as opposed to experimental processes, in an attempt to understand nature. ... The Hebrew University of Jerusalem (‎, Arabic: ) is one of Israels oldest, largest, and most important institutes of higher learning and research. ...

Education

Bekenstein received his undergraduate education in the Polytechnic University in Brooklyn, New York. He received his PhD from Princeton University in 1972, supervised by John Wheeler. Polytechnic University (Brooklyn Poly, Poly, or Polytech), located in the Borough of Brooklyn in New York City, is the United States second oldest private technological university, founded in 1854. ... Princeton University is a private coeducational research university located in Princeton, New Jersey. ... John Archibald Wheeler (born July 9, 1911) is an eminent American theoretical physicist. ...

Major contributions to physics

In 1972, Bekenstein was the first to suggest that black holes should have a well-defined entropy. Bekenstein also formulated the generalized second law of thermodynamics black hole thermodynamics for systems including black holes. Both contributions were affirmed when Stephen Hawking proposed the existence of Hawking radiation two years later. For a less technical and generally accessible introduction to the topic, see Introduction to entropy. ... This article or section is in need of attention from an expert on the subject. ... Stephen William Hawking, CH, CBE, FRS, FRSA, (born 8 January 1942) is a British theoretical physicist. ... In physics, Hawking radiation (also known as Bekenstein-Hawking radiation) is a thermal radiation thought to be emitted by black holes due to quantum effects. ...

Based on his black-hole thermodynamics work, Bekenstein also demonstrated the remarkable fact that there is a maximum to the amount of information that can potentially be stored in a given volume, and that this maximum is proportional to the area that bounds this volume and not to the volume itself. In physics, the Bekenstein bound imposes a limit on the entropy S or information that can be contained within a three-dimensional volume. ... The ASCII codes for the word Wikipedia represented in binary, the numeral system most commonly used for encoding computer information. ... The terms storage (U.K.) or memory (U.S.) refer to the parts of a digital computer that retain physical state (data) for some interval of time, possibly even after electrical power to the computer is turned off. ... The volume of a solid object is the three-dimensional concept of how much space it occupies, often quantified numerically. ... The word proportionality may have one of a number of meanings: In mathematics, proportionality is a mathematical relation between two quantities. ... Area is a physical quantity expressing the size of a part of a surface. ...

In 1982, Bekenstein was the first person to develop a rigorous framework to generalize the laws of electromagnetism to handle inconstant physical constants. His framework replaces the fine structure constant by a scalar field. However, this framework for changing constants did not incorporate gravity. Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... In physics, a physical constant is a physical quantity of a value that is generally believed to be both universal in nature and not believed to change in time. ...

In 2004, Bekenstein greatly boosted Mordehai Milgrom's theory of Modified Newtonian Dynamics (MOND) by developing a relativistic version. It is known as TeVeS for Tensor/Vector/Scalar and it introduces three different fields in space time to replace the one gravitational field.

See also

• Bekenstein bound
• Black hole thermodynamics

In physics, the Bekenstein bound imposes a limit on the entropy S or information that can be contained within a three-dimensional volume. ... This article or section is in need of attention from an expert on the subject. ...

References

• Jacob D. Bekenstein, Information in the Holographic Universe. Scientific American, Volume 289, Number 2, August 2003, p. 61.
• J. D. Bekenstein and M. Schiffer, "Quantum Limitations on the Storage and Transmission of Information", Int. J. of Modern Physics 1:355-422 (1990).
• J. D. Bekenstein, "Entropy content and information flow in systems with limited energy", Phys. Rev. D 30:1669-1679 (1984). [citeseer]
• J. D. Bekenstein, "Communication and energy", Phys. Rev A 37(9):3437-3449 (1988). [citeseer]
• J. D. Bekenstein, "Black holes and the second law", Nuovo Cimento Letters 4:737-740 (1972).
• J. D. Bekenstein, "Entropy bounds and the second law for black holes", Phys. Rev. D 27(10):2262-2270 (1983). [citeseer]
• J. D. Bekenstein, "Specific entropy and the sign of the energy", Phys. Rev. D 26(4):950-953 (1982). [citeseer]
• J. D. Bekenstein, "Black holes and everyday physics", General Relativity and Gravitation, 14(4):355-359 (1982). [citeseer]
• J. D. Bekenstein, "Universal upper bound to entropy-to-energy ratio for bounded systems", Phys. Rev. D 23:287-298 (1981). [citeseer]
• J. D. Bekenstein, "Energy cost of information transfer", Phys. Rev. Lett 46:623-626. (1981). [citeseer]
• J. D. Bekenstein, "Black-hole thermodynamics," Physics Today, 24-31 (Jan. 1980).
• J. D. Bekenstein, "Statistical black hole thermodynamics", Phys. Rev. D12:3077- (1975). [citeseer]
• J. D. Bekenstein, "Generalized second law of thermodynamics in black hole physics", Phys. Rev. D 9:3292-3300 (1974). [citeseer]
• J. D. Bekenstein, "Black holes and entropy", Phys. Rev. D 7:2333-2346 (1973). [citeseer]
• J. D. Bekenstein, "Nonexistence of baryon number of static black holes", ii. Phys. Rev. D 5:2403-2412 (1972). [citeseer]
• Bekenstein's papers list at ArXiv with links to the full papers.