In quantum gravity, a virtual black hole is a black hole that exists temporarily as a result of a quantum fluctuation of spacetime. It is an example of quantum foam and is the gravitational analog of the virtual electron-positron pairs found in quantum electrodynamics. Theoretical arguments suggest that virtual black holes should have mass on the order of the Planck mass, lifetime around the Planck time, and occur with a number density of approximately one per Planck volume.
If virtual black holes exist, they provide a mechanism for proton decay. This is because when a black hole's mass increases via mass falling into the hole, and then decreases when Hawking radiation is emitted from the hole, the elementary particles emitted are, in general, not the same as those that fell in. Therefore, if two of a proton's constituent quarks fall into a virtual black hole, it is possible for an antiquark and a lepton to emerge, thus violating conservation of baryon number.
The existence of virtual black holes aggravates the black hole information loss paradox, as any physical process may potentially be disrupted by interaction with a virtual black hole.
Famous quotes containing the words virtual, black and/or hole:
“Neither dead nor alive, the hostage is suspended by an incalculable outcome. It is not his destiny that awaits for him, nor his own death, but anonymous chance, which can only seem to him something absolutely arbitrary.... He is in a state of radical emergency, of virtual extermination.”
—Jean Baudrillard (b. 1929)
“Ladies and gents. The time has passed. The time has passed. Got to be a better way. I say to you, can’t any longer, oh no, can’t any longer, play off black against old, young against poor.
This country cannot house its houseless. Feed its foodless. They’re demanding a government of the people. Peopled by people. Our faith. Our compassion. Our courage on the gridiron. The basic
indifference that made this country great.”
—Jeremy Larner, U.S. screenwriter, and Michael Ritchie. Bill McKay (Robert Redford)
“Imperious Caesar, dead and turned to clay,
Might stop a hole to keep the wind away.
O that that earth which kept the world in awe
Should patch a wall t’expel the winter’s flaw!”
—William Shakespeare (1564–1616)