In general relativity, an apparent horizon is a surface that is the boundary between light rays that are directed outwards and moving outwards, and those directed outwards but moving inwards.
Apparent horizons are not invariant properties of a spacetime. They are observer-dependent, and in particular they are distinct from absolute horizons.
See, however, the articles on ergosphere, Cauchy horizon, the Reissner-Nordström solution, photon sphere, Killing horizon and naked singularity; the notion of a horizon in general relativity is subtle, and depends on fine distinctions.
Read more about Apparent Horizon: Definition, Differences From The (Absolute) Event Horizon
Famous quotes containing the words apparent and/or horizon:
“[Women’s] apparent endorsement of male supremacy is ... a pathetic striving for self- respect, self-justification, and self-pardon. After fifteen hundred years of subjection to men, Western woman finds it almost unbearable to face the fact that she has been hoodwinked and enslaved by her inferiors—that the master is lesser than the slave.”
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Dead, with all the music:
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