Jacob David Bekenstein

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fórmula de Bekenstein-Hawking

S = Akc3 / 4Għ

 

 

Black hole entropy

Black hole entropy is the entropy carried by a black hole.

If black holes carried no entropy, it would be possible to violate the second law of thermodynamics by throwing mass into the black hole. The only way to satisfy the second law is to admit that the black holes have entropy whose increase more than compensates for the decrease of the entropy carried by the object that was swallowed.

Starting from theorems proved by Stephen Hawking, Jacob Bekenstein conjectured that the black hole entropy was proportional to the area of its event horizon divided by the Planck area. Later, Stephen Hawking showed that black holes emit thermal Hawking radiation corresponding to a certain temperature (Hawking temperature). Using the thermodynamic relationship between energy, temperature and entropy, Hawking was able to confirm Bekenstein's conjecture and fix the constant of proportionality at 1/4:

S_{BH} = \frac{kA}{4\ell_{\mathrm{P}}^2}

where k is Boltzmann's constant, and \ell_{\mathrm{P}}=\sqrt{G\hbar / c^3}is the Planck length. The black hole entropy is proportional to its area A. The fact that the black hole entropy is also the maximal entropy that can be squeezed within a fixed volume was the main observation that led to the holographic principle. The subscript BH either stands for "black hole" or "Bekenstein-Hawking".”(Wikipedia May 25, 2009)

http://en.wikipedia.org/wiki/Black_hole_thermodynamics#Black_hole_entropy

 

 

 

Jacob David Bekenstein

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 to Israeli Jewish settlers…

…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...” (Wikipedia May 25, 2009)

http://en.wikipedia.org/wiki/Jacob_Bekenstein

 

Jacob David Bekenstein

Jacob David Bekenstein (nacido el 1 de mayo de 1947 en la Ciudad de México) es un físico teórico que investiga la relación entre los agujeros negros, su entropía y su relación con la teoría de la información.” (Wikipedia, 29/viii/2010)

http://es.wikipedia.org/wiki/Jacob_D._Bekenstein

 

 

 

Bekenstein bound

“In physics, the Bekenstein bound is a conjectured limit on the entropy S or information that can be contained within a region of space containing a known energy. It implies that information must be material, requiring finite size and energy. In computer science, this implies that there is a maximum information processing rate and that Turing machines, with their (by definition) infinite memory tape, are physically impossible if they are to have a finite size and bounded energy. The bound was originally found by Jacob Bekenstein in the form

S \leq 2 \pi E R,

where R is loosely defined as the radius of the region, and E is the energy of the contained matter as measured when the matter is moved to an infinite distance, i.e., accounting for binding force potential energies. Note that while gravity plays a significant role in its enforcement, the bound is independent of Newton's Constant G.” (Wikipedia May 25, 2009)

http://en.wikipedia.org/wiki/Bekenstein_bound

 

 

Black Holes and Entropy

Jacob D. Bekenstein, Phys. Rev. D 7, 2333 - 2346 (1973)
Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08540
Center for Relativity Theory, The University of Texas at Austin, Austin, Texas 78712

Received 2 November 1972

“There are a number of similarities between black-hole physics and thermodynamics. Most striking is the similarity in the behaviors of black-hole area and of entropy: Both quantities tend to increase irreversibly. In this paper we make this similarity the basis of a thermodynamic approach to black-hole physics. After a brief review of the elements of the theory of information, we discuss black-hole physics from the point of view of information theory. We show that it is natural to introduce the concept of black-hole entropy as the measure of information about a black-hole interior which is inaccessible to an exterior observer. Considerations of simplicity and consistency, and dimensional arguments indicate that the black-hole entropy is equal to the ratio of the black-hole area to the square of the Planck length times a dimensionless constant of order unity. A different approach making use of the specific properties of Kerr black holes and of concepts from information theory leads to the same conclusion, and suggests a definite value for the constant. The physical content of the concept of black-hole entropy derives from the following generalized version of the second law: When common entropy goes down a black hole, the common entropy in the black-hole exterior plus the black-hole entropy never decreases. The validity of this version of the second law is supported by an argument from information theory as well as by several examples.”

(Abstract)

http://prola.aps.org/abstract/PRD/v7/i8/p2333_1

 

 

fórmula de Bekenstein-Hawking

 S = Akc3/4Għ

http://foro.migui.com/phpbb/viewtopic.php?p=21850&sid=97badedd794728486288b8dbd82579c4

http://foro.migui.com/phpbb/viewtopic.php?t=1676&sid=d9c73bcc71714a1389819d31c82ab093

http://scienceworld.wolfram.com/physics/Bekenstein-HawkingFormula.html

 

http://scienceworld.wolfram.com/physics/h-Bar.html

 

 

The Black Hole Information Loss Problem

Original by Warren G. Anderson 1996., Usenet Physics FAQ

“In 1975 Hawking and Bekenstein made a remarkable connection between thermodynamics, quantum mechanics and black holes, which predicted that black holes will slowly radiate away.  (see Relativity FAQ Hawking Radiation).  It was soon realized that this prediction created an information loss problem that has since become an important issue in quantum gravity.”

http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/info_loss.html

 

Black hole information paradox

“The black hole information paradox results from the combination of quantum mechanics and general relativity. It suggests that physical information could "disappear" in a black hole, allowing many physical states to evolve into precisely the same state. This is a contentious subject since it violates a commonly assumed tenet of science—that in principle complete information about a physical system at one point in time should determine its state at any other time.” (Wikipedia May 25, 2009)

http://en.wikipedia.org/wiki/Black_hole_information_paradox#cite_ref-0

 

Black hole thermodynamics

“In physics, black hole thermodynamics is the area of study that seeks to reconcile the laws of thermodynamics with the existence of black hole event horizons. Much as the study of the statistical mechanics of black body radiation led to the advent of the theory of quantum mechanics, the effort to understand the statistical mechanics of black holes has had a deep impact upon the understanding of quantum gravity, leading to the formulation of the holographic principle.” (Wikipedia May 25, 2009)

http://en.wikipedia.org/wiki/Black_hole_thermodynamics

 

Holographic principle

“The holographic principle is a property of quantum gravity theories which resolves the black hole information paradox within string theory. First proposed by Gerard 't Hooft, it was given a precise string-theory interpretation by Leonard Susskind.[1][2][3]

The principle states that the description of a volume of space should be thought of as encoded on a boundary to the region, preferably a light-like boundary like a gravitational horizon. For a black hole, the principle states that the description of all the objects which will ever fall in is entirely contained in surface fluctuations of the event horizon…

1.    ^ Susskind, L., "The Black Hole War - My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics", Little, Brown and Company (2008)

2.      ^ Lloyd, Seth (2002-05-24). "Computational Capacity of the Universe". Physics Review Letters; American Physical Society 88 (23): 237901. doi:10.1103/PhysRevLett.88.237901. http://link.aps.org/abstract/PRL/v88/e237901. Retrieved on 2008-03-14. 

3.      ^ Davies, Paul. "Multiverse Cosmological Models and the Anthropic Principle". CTNS. http://www.google.com/search?hl=en&lr=&as_qdr=all&q=holographic+everything+site%3Actnsstars.org. Retrieved on 2008-03-14.” 

(Wikipedia May 25, 2009)

http://en.wikipedia.org/wiki/Holographic_principle#cite_note-0

 

 

Information in the Holographic Universe.  (A fundamental Article, FGS May 31, 2009)

Jacob David Bekenstein, Scientific American, Volume 289, Number 2, August 2003

Theoretical results about black holes suggest that the universe could be like a gigantic hologram.

http://www.sciam.com/article.cfm?articleid=000AF072-4891-1F0A-97AE80A84189EEDF.

 

Information in the Holographic Universe 

JACOB D. BEKENSTEIN, Istanbul- August 10th 2003, http://gulizk.com

Scientific American, August 2003

http://www.sufizmveinsan.com/fizik/holographic.html

 

La información en el universo holográfico (Inicio del artículo)

Jacob D. Bekenstein,, Scientific American Latinpamerica, año 2 N. 15, Octubre de 2003, pág. 38-45
”Los resultados teóricos relativos a la entropía de los agujeros negros llevan a concluir que el universo podría ser un inmenso holograma.
Si preguntamos de qué se compone el mundo físico, se nos responderá que de "materia y energía". Pero quien sepa algo de ingeniería, biología y física nos citará también la información como elemento no menos importante. El robot de una fábrica de automóviles es de metal y plástico, pero no hará nada útil sin abundantes instrucciones que le digan qué pieza ha de soldar a otra. Un ribosoma de una célula se construye con aminoácidos y alimenta con la energía generada por la conversión del ATP en ADP, pero no podría sintetizar proteínas sin la información suministrada por el ADN del núcleo celular. Un siglo de investigaciones nos ha enseñado que la información desempeña una función esencial en los sistemas y procesos físicos. Hoy, una línea de pensamiento iniciada por John A. Wheeler, de la Universidad de Princeton, considera que el mundo físico está hecho de información; la energía y la materia serían accesorios.
Este punto de vista invita a reconsiderar cuestiones fundamentales. La capacidad de almacenamiento de la información de los discos duros y demás dispositivos de memoria ha ido creciendo a toda velocidad. ¿Cuándo se parará este progreso? ¿Cuál es la capacidad de información última de un dispositivo que pese, digamos, menos de un gramo y ocupe un centímetro cúbico (ése viene a ser el tamaño del chip de un ordenador)? ¿Cuánta información se necesita para describir todo un universo? ¿Podría tal descripción caber en la memoria de un ordenador? ¿Podríamos, tal como escribió William Blake, "ver el mundo en un grano de arena", o esas palabras sólo han de tomarse como una licencia poética?”

En

La información en el universo holográfico

Bekenstein, Jacob D., Temas Investigación y Ciencia año 2006: 43 -Fronteras de la física

http://www.investigacionyciencia.es/03044803000557/La_informaci%C3%B3n_en_el_universo_hologr%C3%A1fico.htm

 

Información y Entropía

Guillermo Agudelo Murguía, José Guillermo Alcalá Rivero, Evolución y Ambiente

(Comentarios al artículo La Información en el Universo Holográfico. Jacob D. Bekenstein. Scientific American Latinoamérica Año 2 No. 15 octubre de 2003)

http://www.iieh.com/Informacion/articulos_informacion01.php

 

 

Relación de la entropía con la Teoría de la información

“Recientes estudios han podido establecer una relación entre la entropía física y la entropía de la teoría de la información gracias a la revisión de la física de los agujeros negros. Según la nueva teoría de Jacob D. Bekenstein el bit de información sería equivalente a una superficie de valor 1/4 del área de Planck. De hecho, en presencia de agujeros negros la segunda ley de la termodinámica sólo puede cumplirse si se introduce la entropía generalizada o suma de la entropía convencional (Sconv) más un factor dependiente del área total (A) de agujeros negros existente en el universo, del siguiente modo:
S_{tot} = S_{conv} + \frac{kc^3}{4G\hbar}A
Donde, k es la constante de Boltzmann, c es la velocidad de la luz, G es la constante de la gravitación y \hbares la constante de Planck racionalizada.” (Wikipedia, 31 de Mayo del 2009)

http://es.wikipedia.org/wiki/Entrop%C3%ADa_(termodin%C3%A1mica)#Relaci.C3.B3n_de_la_entrop.C3.ADa_con_la_Teor.C3.ADa_de_la_informaci.C3.B3n

 

 

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Creación de la página  Cd. de México, 25 de Mayo del 2009
Ultima actualizacion 25 de Mayo del 2009

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