event horizon


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event horizon

The boundary of a black hole: for a nonrotating black hole it is a spherical ‘surface’ having a radius equal to the Schwarzschild radius for a body of a given mass. The event horizon marks the critical limit where the escape velocity of a collapsing body becomes equal to the speed of light and hence no information can reach an external observer. Calculations predict that a body shrinking within its event horizon – or indeed any body that falls inside the event horizon of another – inevitably contracts to a singularity at the precise center of the black hole.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

event horizon

[i′vent hə‚rīz·ən]
(relativity)
The boundary of a region of space-time from which it is not possible to escape to infinity. Symbolized +.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Indeed, Einstein's theory and equations predicted that event horizons around black holes are circular, while other theories of gravity predict squashed ones.
The scientists will be looking for a ring of light -- disrupted matter and radiation circling at tremendous speed at the edge of the event horizon -- around a region of darkness representing the actual black hole.
New observations show clumps of gas swirling around at about 30% of the speed of light on a circular orbit just outside its event horizon -- the first time material has been observed orbiting close to the point of no return, and the most detailed observations yet of material orbiting this close to a black hole.
However, particles on the event horizon have different properties.
much shorter than the event horizon of the Universe (r [much less than] a), the formula for the photon's frequency becomes (6.28)
[24] observed that GSLT is verified at apparent horizon but not at event horizon for a specific model of dark energy.
If it were a stellar-mass black hole, you'd be dead before you passed the event horizon. That's because, if you think of a black hole as a pit, a stellar-mass black hole has steeper sides than a supermassive black hole.
Raleigh, NC, October 21, 2016 --(PR.com)-- Mims Distributing Company, a leading wholesale beverage distributor in North Carolina, and Olde Hickory Brewery, a Hickory, North Carolina-based brewing company offering more than 14 handcrafted beers, announced that its annual imperial stout, The Event Horizon, will be available in the Triangle the week of Monday, Oct.17.
While some physicists, like Lee Smolin, speculated that black holes spawned baby universes at their singularities, we also learned that black holes can grow in mass by consuming matter and that they can radiate, due to quantum effects near the event horizon of the black hole.
In this paper we show that there exists a physical model of a family of time-dependent null horizons of GRW space-time which may evolve into a black hole event horizon. See Sections 3 and 4 for a brief account on event horizons, recent works on time-dependent null horizons of Duggal [8-10] and Sultana and Dyer [11, 12], and more cited therein.
Hawking and two collaborators claim that the contents of a black hole are inventoried on a hologram on the black hole's boundary, the event horizon. Unlike previous descriptions of this hologram, the researchers say, their proposal lays out a specific mechanism for storing information that applies to every black hole in the universe.
Space marines are sent to investigate an intergalactic massacre in this sci-fi horror best described as a ho-hum hybrid of Aliens and Event Horizon.