Black Hole

A black hole is a region of spacetime where gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that marks the point of no return. It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics. Quantum mechanics predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater.

Objects whose gravity field is too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was not fully appreciated for another four decades. Long considered a mathematical curiosity, it was during the 1960s that theoretical work showed black holes were a generic prediction of general relativity. The discovery of neutron stars sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.

Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may form. There is general consensus that supermassive black holes exist in the centers of most galaxies.

Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter and with light and other electromagnetic radiation. Matter falling onto a black hole can form an accretion disk heated by friction, forming some of the brightest objects in the universe. If there are other stars orbiting a black hole, their orbit can be used to determine its mass and location. These data can be used to exclude possible alternatives (such as neutron stars). In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the core of our Milky Way galaxy contains a supermassive black hole of about 4.3 million solar masses.

Read more about Black Hole:  History, Properties and Structure, Formation and Evolution, Observational Evidence

Other articles related to "black hole, black holes, hole":

Black Hole - Open Questions - Information Loss Paradox
... List of unsolved problems in physics Is physical information lost in black holes? Because a black hole has only a few internal parameters, most of the ... It does not matter if it is formed from television sets or chairs, in the end the black hole only remembers the total mass, charge, and angular momentum ... As long as black holes were thought to persist forever this information loss is not that problematic, as the information can be thought of as existing inside the black hole, unaccessible from the outside ...
... A black hole spin-flip occurs when the spin axis of a rotating black hole undergoes a sudden change in orientation due to absorption of a second (smaller ... of galaxy mergers, when two supermassive black holes form a bound pair at the center of the merged galaxy and coalesce after emitting gravitational waves ... are significant astrophysically since a number of physical processes are associated with black hole spins for instance, jets in active galaxies are believed to be launched parallel to the ...
Safety Of Particle Collisions At The Large Hadron Collider - Large Hadron Collider - Safety Reviews - Other Publications
... the "Astrophysical implications of hypothetical stable TeV-scale black holes", where they develop arguments to exclude any risk of dangerous black hole production at ... On 9 February 2009, a paper titled "Exclusion of black hole disaster scenarios at the LHC" was published in the journal Physics Letters B ... The article, which summarizes proofs aimed at ruling out any possible black hole disaster at the LHC, relies on a number of new safety arguments as well as certain ...
Super Turrican 2 - Story
... The location is a small star system floating in the endless spiral arms of a black hole ... challenge, the ships prepare to enter a black hole in order to reach the attacked system ... one of the ships manage to escape the dangerous influence of the black hole ...
Superman (Kingdom Come) - Fictional Character Biography - Justice Society of America
... inadvertently by Starman when he opened a black hole to stop a raging mystical fire the Justice Society couldn't contain that was coming from the hole in the chest of ... Starman creates a black hole and places Goth inside of it ... Goth's powers harmlessly erupt in the black hole, causing a rip in the dimension which brought this Superman to New Earth ...

Famous quotes containing the words hole and/or black:

    The more supple vagabond, too, is sure to appear on the least rumor of such a gathering, and the next day to disappear, and go into his hole like the seventeen-year locust, in an ever-shabby coat, though finer than the farmer’s best, yet never dressed.... He especially is the creature of the occasion. He empties both his pockets and his character into the stream, and swims in such a day. He dearly loves the social slush. There is no reserve of soberness in him.
    Henry David Thoreau (1817–1862)

    Chastity prays for me, piety sings,
    Innocence sweetens my last black breath,
    Modesty hides my thighs in her wings,
    And all the deadly virtues plague my death!
    Dylan Thomas (1914–1953)