Black holes hole is a region of spacetime where gravity is so strong that nothing – no particles or even electromagnetic radiation such as light – can escape from it.
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Black holes hole is a region of spacetime where gravity is so strong that nothing – no particles or even electromagnetic radiation such as light – can escape from it.
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Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity.
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Black holes correctly noted that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies.
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Black holes's arguments were opposed by many of his contemporaries like Eddington and Lev Landau, who argued that some yet unknown mechanism would stop the collapse.
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Simplest static black holes have mass but neither electric charge nor angular momentum.
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Non-rotating charged black holes are described by the Reissner–Nordstrom metric, while the Kerr metric describes a non-charged rotating black hole.
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Black holes are commonly classified according to their mass, independent of angular momentum, J The size of a black hole, as determined by the radius of the event horizon, or Schwarzschild radius, is proportional to the mass, M, through.
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However, a minority of relativists continued to contend that black holes were physical objects, and by the end of the 1960s, they had persuaded the majority of researchers in the field that there is no obstacle to the formation of an event horizon.
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The Kerr solution, the no-hair theorem, and the laws of black hole thermodynamics showed that the physical properties of black holes were simple and comprehensible, making them respectable subjects for research.
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Conventional black holes are formed by gravitational collapse of heavy objects such as stars, but they can in theory be formed by other processes.
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In order for primordial black holes to have formed in such a dense medium, there must have been initial density perturbations that could then grow under their own gravity.
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In principle, black holes could be formed in high-energy collisions that achieve sufficient density.
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Black holes can merge with other objects such as stars or even other black holes.
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Stellar-mass or larger black holes receive more mass from the cosmic microwave background than they emit through Hawking radiation and thus will grow instead of shrinking.
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However, the extreme gravitational lensing associated with black holes produces the illusion of a perspective that sees the accretion disc from above.
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Evidence for stellar black holes strongly relies on the existence of an upper limit for the mass of a neutron star.
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Evidence for the existence of stellar and supermassive black holes implies that in order for black holes to not form, general relativity must fail as a theory of gravity, perhaps due to the onset of quantum mechanical corrections.
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