White hole
A white hole is a hypothetical astronomical object that presents itself as the opposite of a black hole . It ejects mass, and it is impossible to cross the event horizon from the outside in, as it would require a speed greater than the speed of light . Igor Novikow and Juval Ne'eman examined this theory in greater detail for the first time in 1965.
properties
Equivalent to the hypothetical tachyons , there are white holes, strikingly called cosmic geysers , as possible mathematical solutions for the equations of general relativity . However, the mere fact that there is this mathematical solution to the equations does not mean that white holes actually exist. An important commonality with black holes is the so-called singularity in the center. A singularity describes a place where the amount of a physical quantity diverges towards infinity .
Theories
The possible existence of white holes is associated with several assumptions and inferences. One consideration is that these solutions to Einstein's field equations are black holes running in the opposite direction to the time axis. Another idea is that a black hole and a white hole together can form a wormhole . Accordingly, matter that falls into a black hole in another universe, or perhaps even in another part of this universe - spatially and / or temporally, also in the past - would be ejected from a white hole again. The Big Bang could also be seen as a white hole or as a consequence of its existence.
Practical results
White holes have not yet been detected. Although objects such as quasars were still associated with white holes a few decades ago , it has been proven that these are more like black holes into which matter falls from their surroundings. Today, white holes are very popular with scientists, especially for checking new equations and theories, because they represent an extreme situation.
literature
- Jayant Narlikar: White holes: cosmic energy machines. New Scientist, February 24, 1983 ( limited preview in Google Book search).
- Jayant Narlikar: The Lighter Side of Gravity. Cambridge University Press, 1996, ISBN 0-521-56565-0 , pp. 148-156.
- Richard A. Matzner (Ed.): Dictionary of Geophysics, Astrophysics, and Astronomy. CRC Press, 2010, ISBN 978-1-4200-5023-3 , p. 515 ( limited preview in Google book search).
- Roger Penrose: The Road to Reality. Random House, New York, 2005, ISBN 0-679-77631-1 , p. 831.
Web links
- Ask an astronomer: What is a white hole? Cornell.edu
- White Holes and Wormholes. Schwarzschild wormholes. ( Memento of March 28, 2010 in the Internet Archive ) colorado.edu
Individual evidence
- ↑ Penrose diagram of a Kerr black hole . Joint Institute for Laboratory Astrophysics
- ^ Philip Gibbs: A White Hole Model of the Big Bang . 1998, bibcode : 1998gr.qc ..... 3014G , arxiv : gr-qc / 9803014 .