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In physics, black hole thermodynamics [1] is the area of study that seeks to reconcile the laws of thermodynamics with the existence of black hole event horizons.As the study of the statistical mechanics of black-body radiation led to the development of the theory of quantum mechanics, the effort to understand the statistical mechanics of black holes has had a deep impact upon the ...
The Penrose process (also called Penrose mechanism) is theorised by Sir Roger Penrose as a means whereby energy can be extracted from a rotating black hole. [1] [2] [3] The process takes advantage of the ergosphere – a region of spacetime around the black hole dragged by its rotation faster than the speed of light, meaning that from the point of view of an outside observer any matter inside ...
Pulsars had already been discovered and black holes were no longer considered mere textbook curiosities. [15] Cygnus X-1, the first solid black-hole candidate, was discovered by the Uhuru X-ray space telescope in 1971. [1] Jeremy Bernstein described it as "one of the great papers in twentieth-century physics." [14]
According to the Bekenstein bound, the entropy of a black hole is proportional to the number of Planck areas that it would take to cover the black hole's event horizon.. In physics, the Bekenstein bound (named after Jacob Bekenstein) is an upper limit on the thermodynamic entropy S, or Shannon entropy H, that can be contained within a given finite region of space which has a finite amount of ...
In the theory of general relativity, the Gibbons–Hawking effect is the statement that a temperature can be associated to each solution of the Einstein field equations that contains a causal horizon.
A black hole is a region of spacetime where gravity is so strong that there is no known existing physical quantity or thing of any type that can escape it. [2] Albert Einstein's theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. [3] [4] The boundary of no escape is called the event ...
In 1972, Bekenstein was the first to suggest that black holes should have a well-defined entropy. 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.
A black hole of one solar mass (M ☉ = 2.0 × 10 30 kg) takes more than 10 67 years to evaporate—much longer than the current age of the universe at 1.4 × 10 10 years. [22] But for a black hole of 10 11 kg, the evaporation time is 2.6 × 10 9 years. This is why some astronomers are searching for signs of exploding primordial black holes.