# apparent horizon

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Related to apparent horizon: visible horizon

n.

## apparent horizon

The visible line of demarcation between land/sea and sky.
Dictionary of Military and Associated Terms. US Department of Defense 2005.
ThesaurusAntonymsRelated WordsSynonymsLegend:
 Noun 1 apparent horizon - the line at which the sky and Earth appear to meetlinear perspective, perspective - the appearance of things relative to one another as determined by their distance from the viewerline - a spatial location defined by a real or imaginary unidimensional extent
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
They represented the equality of apparent horizon and event horizon for de Sitter universe.
If [[theta].sub.+] = 0 or [[theta].sub.-] = 0, then S is referred to as a future or past apparent horizon. These surfaces naturally arise as boundaries of future or past trapped regions.
Part I describes numerical techniques for different types of problems, including 3+1 or N+1 formulations, finite-differencing methods, matter field equations, initial-value problems, deriving gravitational waves, and locating the apparent horizon of a black hole.
Hawking smashes the idea of a black hole by saying that instead of there being an inescapable event horizon, they should think of a far less total "apparent horizon".
Saha and Mondal [56] have studied thermodynamics on apparent horizon with the help of gravitationally induced particle scenario with constant specific entropy and particle creation rate [GAMMA].
For a first approximation of the Moon's altitude, the differences in these elevations allowed us to calculate that the photograph's apparent horizon, formed by the distant Clark Range roughly nine miles from Glacier Point, was raised about 5[degrees]above the ideal geometric horizon.
The surface gravity on the apparent horizon is given by
"What was really amazing," says Suen, "is that you could see the apparent horizon pop out faster than the shock waves." The apparent horizon is the surface that defines the edge of the newly forming black hole.
Akbar and Cai [19] found that the Friedmann equations at the apparent horizon can be written in the form dE = TdS + WdV (E, V, and W are the energy, volume inside the horizon, and work density, resp.) in general relativity (GR), GB gravity, and the general Lovelock theory of gravity.
You might improve your chances by observing from extreme elevations, where you can lower your apparent horizon by at least a half degree.
One such boundary is the apparent horizon with the radius (for the spatially flat universe),
It is notable that starting from the Clausius relation to the apparent horizon along with the modified dispersion relation, one can easily get the modified Friedmann equation with bounce solution to the FRW universe [14,15], but the answer is not direct in Padmanabhans conjecture in the emergent universe.

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