Jacob Bekenstein | |
|---|---|
יעקב בקנשטיין | |
.JPG) Bekenstein in 2009 | |
| Born | Jacob David Bekenstein (1947-05-01)May 1, 1947 Mexico City, Mexico |
| Died | August 16, 2015(2015-08-16) (aged 68) Helsinki, Finland |
| Education | Polytechnic Institute of Brooklyn Princeton University |
| Known for | |
| Awards |
|
| Scientific career | |
| Fields | Theoretical physics |
| Institutions | Hebrew University of Jerusalem Ben-Gurion University of the Negev |
| Doctoral advisor | John Wheeler |
Jacob David Bekenstein (Hebrew:יעקב דוד בקנשטיין; May 1, 1947 – August 16, 2015) was a Mexican-born American-Israelitheoretical physicist who made fundamental contributions to the foundation ofblack hole thermodynamics and to other aspects of the connections betweeninformation andgravitation.[1]
Jacob Bekenstein was born inMexico City to Joseph and Esther (née Vladaslavotsky),Polish Jews who immigrated to Mexico.[2] He moved to the United States during his early life, gainingU.S. citizenship in 1968.[3] He was also acitizen of Israel.[4]
Bekenstein attended thePolytechnic Institute of Brooklyn, now known as theNew York University Tandon School of Engineering, obtaining both an undergraduate degree and aMaster of Science degree in 1969. He went on to receive aDoctor of Philosophy degree fromPrinceton University, working under the direction ofJohn Archibald Wheeler, in 1972.[5]
Bekenstein had three children with his wife, Bilha. All three children, Yehonadav,[a] Uriya and Rivka Bekenstein, became scientists.[2] Bekenstein was known as a religious man and a believer, being quoted as saying: "I look at the world as a product ofGod, He set very specific laws and we delight in discovering them through scientific work."[7]
By 1972, Bekenstein had published three influential papers about the black hole stellar phenomenon, postulating theno-hair theorem and presenting a theory on black hole thermodynamics. In the years to come, Bekenstein continued his exploration of black holes, publishing papers on theirentropy andquantum mass.[4]
Bekenstein was a postdoctoral fellow at theUniversity of Texas at Austin from 1972 to 1974. He thenimmigrated to Israel to lecture and teach atBen-Gurion University inBeersheba. In 1978, he became a full professor and in 1983, head of theastrophysics department.
In 1990, he became a professor at theHebrew University of Jerusalem and was appointed head of its theoretical physics department three years later.[4] He was elected to theIsrael Academy of Sciences and Humanities in 1997.[8] He was a visiting scholar at theInstitute for Advanced Study in 2009 and 2010.[9]
In addition to lectures and residencies around the world,[5] Bekenstein continued to serve as Polak professor of theoretical physics at the Hebrew University until his death at the age of 68, inHelsinki, Finland.[10] He died unexpectedly on August 16, 2015, just months after receiving theAmerican Physical Society'sEinstein Prize "for his ground-breaking work on black hole entropy, which launched the field of black hole thermodynamics and transformed the long effort to unify quantum mechanics and gravitation".[3][8][11] He died inHelsinki by falling down a flight of stairs, having refused to turn on the lights on aShabbat.[12]
In 1972, Bekenstein was the first to suggest that black holes should have a well-definedentropy. He wrote that a black hole's entropy was proportional to the area of its (the black hole's) event horizon. Bekenstein also formulated the generalized second law of thermodynamics, black hole thermodynamics, for systems including black holes. Both contributions were affirmed whenStephen Hawking (and, independently, Zeldovich and others) proposed the existence ofHawking radiation two years later. Hawking had initially opposed Bekenstein's idea on the grounds that a black hole could not radiate energy and therefore could not have entropy.[13][14] However, in 1974, Hawking performed a lengthy calculation that convinced him that particles can indeed be emitted from black holes. Today this is known as Hawking radiation. Bekenstein's doctoral adviser, John Archibald Wheeler, also worked with him to develop theno-hair theorem, a reference to Wheeler's saying that "black holes have no hair," in the early 1970s.[15] Bekenstein's suggestion was proven unstable, but it was influential in the development of the field.[16][17]
Based on his black-hole thermodynamics work, Bekenstein also demonstrated theBekenstein bound: there is a maximum to the amount of information that can potentially be stored in a given finite region of space which has a finite amount of energy (which is similar to theholographic principle).[18]
In 1982, Bekenstein developed a rigorous framework to generalize the laws ofelectromagnetism to handle inconstantphysical constants. His framework replaces thefine-structure constant by ascalar field. However, this framework for changing constants did not incorporate gravity.[19]
In 2004, Bekenstein boostedMordehai Milgrom's theory ofModified Newtonian Dynamics (MOND) by developing a relativistic version. It is known asTeVeS for Tensor/Vector/Scalar and it introduces three different fields in space time to replace the one gravitational field.[20]
Quotations related toJacob Bekenstein at Wikiquote| International | |
|---|---|
| National | |
| Academics | |
| People | |
| Other | |
