02 Jul 2009 974 views
supporter of
atom rss 1.0 rss 2.0
web browser google del.icio.us digg technorati
| lost password
birth date
photoblog image BLaCKHOLE


BLackHOLE = Cosmic body with gravity (see gravitation) so intense that nothing, not even light, can escape. It is suspected to form in the death and collapse of a star that has retained at least three times the Sun's mass. Stars with less mass evolve into white dwarf stars or neutron stars. Details of a black hole's structure are calculated from Albert Einstein's general theory of relativity: a “singularity” of zero volume and infinite density pulls in all matter and energy that comes within an event horizon, defined by the Schwarzschild radius, around it. Black holes cannot be observed directly because they are small and emit no light. However, their enormous gravitational fields affect nearby matter, which is drawn in and emits X rays as it collides at high speed outside the event horizon. Some black holes may have nonstellar origins. Astronomers speculate that supermassive black holes at the centres of quasars and many galaxies are the source of energetic activity that is observed. Stephen W. Hawking theorized the creation of numerous tiny black holes, possibly no more massive than an asteroid, during the big bang. These primordial “mini black holes” lose mass over time and disappear as a result of Hawking radiation. Although black holes remain theoretical, the case for their existence is supported by many observations of phenomena that match their predicted effects. (http://www.reference.com)

comments (0)

no comments yet, be the first to write one!

Leave a comment

must fill in
[stop comment form]
for this photo I'm in a positive comments icon ShMood©
camera Canon EOS-1Ds Mark III
exposure mode full manual
shutterspeed 1/1.6666s
aperture f/4.0
sensitivity ISO800
focal length 40.0mm