A hole black is a region of space-time that is characterized by a large concentration of mass in its interior, with huge increase in density, resulting in a gravitational field so intense that any particle of matter, even photons of light, can escape. The force of gravity causes a singularity surrounded by a closed surface, called the event horizon. The event horizon separates the black hole region from the rest of the universe and is the boundary of space from which no particle can leave, including light. This curvature of spacetime is studied in general relativity, which predicted the existence of black holes and was its first indication. In the 70's, Hawk ing, Ellis and Penrose proved several important theorems on the occurrence and geometry of black holes. Previously, in 1963, Roy Kerr had shown that in a space-time four-dimensional black holes all had to have a quasi-spherical geometry determined by three parameters: its mass m its total electric charge and and its angular momentum L .
is believed that the center of most galaxies, including the Milky Way, there are supermassive black holes. The existence of black holes is supported by observation astronomical ones, especially through the emission of X-ray binary stars and active galaxies.
formation process
The origin of black holes is raised by the astrophysicist Stephen Hawking in his book Black Holes and the history of time. There he says about the process that gives rise to the formation of these singularities of space-time.
This process begins subsequent to the death of a red giant star of type (massive star) is called the death a total extinction of its energy. After several billion years of life, the gravitational pull of the star begins to exert force on itself, causing a mass concentrated in a small volume, thereby becoming a white dwarf. At this point the process can continue until the collapse of the star by the gravitational attraction car ends up turning to the white dwarf into a black hole. This process just putting together a force of attraction so strong that even light trapped in it.
history.
The concept of a body so dense that even light could escape, was described in a paper submitted in 1783 to the Royal Society for an English geologist named John Michell. In those e S o Newton's theory of gravitation and the concept of escape velocity were well known. Michell computed that a body with a radius 500 times that of the Sun and the same density, would, on its surface escape velocity equal to that of light and be invisible. In 1796, the French mathematician Pierre-Simon Laplace explained in the first two editions of his book Exposition du Systeme du Monde the same idea though, to gain the idea that light was a wave with no mass in the nineteenth century was discarded in later editions.
In 1915, Einstein developed his theory of relativity generates ly showed that light was influenced by the gravitational interaction. A few months later, Karl Schwarzschild found a solution to Einstein's equations, where a heavy body would absorb the light. We now know that the Schwarzschild radius is the radius of event horizon a non-rotating black hole, but this was not well understood at the time. Schwarzschild himself thought it was just a mathematical solution, not physical. In 1930, Subrahmanyan Chandrasekhar showed that a body with a critical mass (now known as the Chandrasekhar limit) and does not emit radiation, would collapse under its own gravity because there was nothing known that could slow it down (for this mass the gravitational attraction would be greater than that provided by the Pauli exclusion principle). However, Eddington opposed the idea that the star would reach a size zero, implying a naked singularity of matter, and should be something that will inevitably put a brake on collapse, line adopted by most scientists.
In 1939, Robert Oppenheimer predicted that a massive star could suffer a gravitational collapse and, therefore, black holes could be formed in nature. This theory was not given much attention until the late 60 because, after the Second World War, he was more interested in what happened at the atomic scale.
In 1967, Stephen Hawking and Roger Penrose proved that black holes are solutions to Einstein's equations and in some cases could not be created to prevent a black hole from collapse. The black hole idea gained momentum with experimental and other scientific advances that led to the discovery of pulsars. Soon after, in 1969, John Wheeler coined the term "black hole" during a meeting in New York cosmologists to describe what used to be called "star in gravitational collapse complete ".
formation process
The origin of black holes is raised by the astrophysicist Stephen Hawking in his book Black Holes and the history of time. There he says about the process that gives rise to the formation of these singularities of space-time.
This process begins subsequent to the death of a red giant star of type (massive star) is called the death a total extinction of its energy. After several billion years of life, the gravitational pull of the star begins to exert force on itself, causing a mass concentrated in a small volume, thereby becoming a white dwarf. At this point the process can continue until the collapse of the star by the gravitational attraction car ends up turning to the white dwarf into a black hole. This process just putting together a force of attraction so strong that even light trapped in it.
history.
The concept of a body so dense that even light could escape, was described in a paper submitted in 1783 to the Royal Society for an English geologist named John Michell. In those e S o Newton's theory of gravitation and the concept of escape velocity were well known. Michell computed that a body with a radius 500 times that of the Sun and the same density, would, on its surface escape velocity equal to that of light and be invisible. In 1796, the French mathematician Pierre-Simon Laplace explained in the first two editions of his book Exposition du Systeme du Monde the same idea though, to gain the idea that light was a wave with no mass in the nineteenth century was discarded in later editions.
In 1915, Einstein developed his theory of relativity generates ly showed that light was influenced by the gravitational interaction. A few months later, Karl Schwarzschild found a solution to Einstein's equations, where a heavy body would absorb the light. We now know that the Schwarzschild radius is the radius of event horizon a non-rotating black hole, but this was not well understood at the time. Schwarzschild himself thought it was just a mathematical solution, not physical. In 1930, Subrahmanyan Chandrasekhar showed that a body with a critical mass (now known as the Chandrasekhar limit) and does not emit radiation, would collapse under its own gravity because there was nothing known that could slow it down (for this mass the gravitational attraction would be greater than that provided by the Pauli exclusion principle). However, Eddington opposed the idea that the star would reach a size zero, implying a naked singularity of matter, and should be something that will inevitably put a brake on collapse, line adopted by most scientists.
In 1939, Robert Oppenheimer predicted that a massive star could suffer a gravitational collapse and, therefore, black holes could be formed in nature. This theory was not given much attention until the late 60 because, after the Second World War, he was more interested in what happened at the atomic scale.
In 1967, Stephen Hawking and Roger Penrose proved that black holes are solutions to Einstein's equations and in some cases could not be created to prevent a black hole from collapse. The black hole idea gained momentum with experimental and other scientific advances that led to the discovery of pulsars. Soon after, in 1969, John Wheeler coined the term "black hole" during a meeting in New York cosmologists to describe what used to be called "star in gravitational collapse complete ".
Source: Wikipedia
Photos: GM & Photoshop
Photos: GM & Photoshop
