| Line 1: |
Line 1: |
| | [[Image:Iu8969hu.jpg|right|thumb|300px|Artist's conception of a binary system consisting of a black hole and a main sequence star. The black hole is drawing matter from the main sequence star via an [[accretion disk]] around it, and some of this matter forms a gas jet.]] | | [[Image:Iu8969hu.jpg|right|thumb|300px|Artist's conception of a binary system consisting of a black hole and a main sequence star. The black hole is drawing matter from the main sequence star via an [[accretion disk]] around it, and some of this matter forms a gas jet.]] |
| − | A '''black hole''' is a region of [[spacetime]] into which light and other matter can enter, but out of which nothing can ever emerge. Black holes were first hypothesized in 1783<ref name="r1">http://www.aps.org/publications/apsnews/200911/physicshistory.cfm</ref>, but the first mainstream scientific theory to predict them was the [[general theory of relativity]] in 1915. Black holes are popular topics for magazines, the science page of the [[New York Times]], and scientists on the cutting edge of astronomy and cosmology, as well as being a popular device in science. However, because they cannot be directly observed, no black hole has been conclusively found. | + | A '''black hole''' is a theoretical prediction of the [[theory of relativity]]. As with the related theoretical concept of a "[[wormhole]]",<ref>The prediction of the existence of wormholes, and its naming in 1957, predates the prediction and naming (1967) of a black hole.[http://www.nytimes.com/2008/04/14/science/14wheeler.html?pagewanted=print]</ref> it is impossible to prove that a black hole does not exist, and thus it fails the [[falsifiability]] requirement of science. Nevertheless, the theoretical black hole has become an increasingly popular topic for magazines, the science page of the [[New York Times]], and science fiction. |
| | | | |
| − | ==Historical Models== | + | Support and interest in black holes has grown over time. [[Albert Einstein]] and [[Arthur Eddington]], the two most prominent scientists associated with the [[theory of relativity]], rejected the suggestion that black holes exist.<ref>http://amazing-space.stsci.edu/resources/explorations/blackholes/lesson/whatisit/history.html</ref> [[Karl Schwarzschild]], whose name is given to the radius of black holes, developed the theory for them but likewise rejected the possibility that they physically exist. Yet today black holes are frequently depicted on the covers of science magazines. |
| | + | |
| | + | ==Nature of a Black Hole== |
| | The theoretical model of what we now call a black hole has evolved considerably over the centuries. The [[corpuscular theory of light]] held that light was made up of invisibly small particles, and that these particles moved along ballistic trajectories, like tiny bullets. In this framework, it was believed possible that a distant star could be so massive that light emitted from its surface would be dragged back down again. This theory was first advanced by John Michell, who wrote in 1783, "If the semi-diameter of a sphere of the same density as the Sun in the proportion of five hundred to one, and by supposing light to be attracted by the same force in proportion to its [mass] with other bodies, all light emitted from such a body would be made to return towards it, by its own proper gravity."<ref name="r1" /> | | The theoretical model of what we now call a black hole has evolved considerably over the centuries. The [[corpuscular theory of light]] held that light was made up of invisibly small particles, and that these particles moved along ballistic trajectories, like tiny bullets. In this framework, it was believed possible that a distant star could be so massive that light emitted from its surface would be dragged back down again. This theory was first advanced by John Michell, who wrote in 1783, "If the semi-diameter of a sphere of the same density as the Sun in the proportion of five hundred to one, and by supposing light to be attracted by the same force in proportion to its [mass] with other bodies, all light emitted from such a body would be made to return towards it, by its own proper gravity."<ref name="r1" /> |
| | | | |