Apparent horizon
Horizon Ho*ri"zon, n. [F., fr. L. horizon, fr. Gr. ? (sc. ?) the bounding line, horizon, fr. ? to bound, fr. ? boundary, limit.] 1. The line which bounds that part of the earth's surface visible to a spectator from a given point; the apparent junction of the earth and sky. [1913 Webster]

And when the morning sun shall raise his car Above the border of this horizon. --Shak. [1913 Webster]

All the horizon round Invested with bright rays. --Milton. [1913 Webster]

2. (Astron.) (a) A plane passing through the eye of the spectator and at right angles to the vertical at a given place; a plane tangent to the earth's surface at that place; called distinctively the sensible horizon. (b) A plane parallel to the sensible horizon of a place, and passing through the earth's center; -- called also {rational horizon} or {celestial horizon}. (c) (Naut.) The unbroken line separating sky and water, as seen by an eye at a given elevation, no land being visible. [1913 Webster]

3. (Geol.) The epoch or time during which a deposit was made. [1913 Webster]

The strata all over the earth, which were formed at the same time, are said to belong to the same geological horizon. --Le Conte. [1913 Webster]

4. (Painting) The chief horizontal line in a picture of any sort, which determines in the picture the height of the eye of the spectator; in an extended landscape, the representation of the natural horizon corresponds with this line. [1913 Webster]

5. The limit of a person's range of perception, capabilities, or experience; as, children raised in the inner city have limited horizons. [PJC]

6. [fig.] A boundary point or line, or a time point, beyond which new knowledge or experiences may be found; as, more powerful computers are just over the horizon. [PJC]

{Apparent horizon}. See under {Apparent}.

{Artificial horizon}, a level mirror, as the surface of mercury in a shallow vessel, or a plane reflector adjusted to the true level artificially; -- used chiefly with the sextant for observing the double altitude of a celestial body.

{Celestial horizon}. (Astron.) See def. 2, above.

{Dip of the horizon} (Astron.), the vertical angle between the sensible horizon and a line to the visible horizon, the latter always being below the former.

{Rational horizon}, and {Sensible horizon}. (Astron.) See def. 2, above.

{Visible horizon}. See definitions 1 and 2, above. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Apparent horizon — Apparent Ap*par ent, a. [F. apparent, L. apparens, entis, p. pr. of apparere. See {Appear}.] 1. Capable of being seen, or easily seen; open to view; visible to the eye; within sight or view. [1913 Webster] The moon . . . apparent queen. Milton.… …   The Collaborative International Dictionary of English

  • Apparent horizon — An apparent horizon is a surface defined in general relativity as the boundary between light rays which are directed outwards and moving outwards, and those which are directed outwards but moving inwards.Apparent horizons are not invariant… …   Wikipedia

  • apparent horizon — regimasis horizontas statusas T sritis Standartizacija ir metrologija apibrėžtis Tariamoji Žemės ir dangaus susikirtimo linija, kurią mato stebėtojas. atitikmenys: angl. apparent horizon; sensible horizon; visible horizon vok. sehbarer Horizont,… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • apparent horizon — regimasis horizontas statusas T sritis fizika atitikmenys: angl. apparent horizon; sensible horizon; visible horizon vok. scheinbarer Horizont, m; sichtbarer Horizont, m; Sichthorizont, m rus. видимый горизонт, m pranc. horizon apparent, m;… …   Fizikos terminų žodynas

  • apparent horizon — horizonto linija statusas T sritis Gynyba apibrėžtis Matoma linija, skirianti žemę (jūrą) ir dangų. atitikmenys: angl. apparent horizon pranc. horizon apparent …   NATO terminų aiškinamasis žodynas

  • apparent horizon — noun the line at which the sky and Earth appear to meet • Syn: ↑horizon, ↑visible horizon, ↑sensible horizon, ↑skyline • Hypernyms: ↑line • Part Holonyms: ↑perspective, ↑ …   Useful english dictionary

  • apparent horizon — The visible line of demarcation between land/sea and sky …   Military dictionary

  • apparent horizon — The visible line of demarcation between land or the sea and the sky …   Aviation dictionary

  • Horizon — Ho*ri zon, n. [F., fr. L. horizon, fr. Gr. ? (sc. ?) the bounding line, horizon, fr. ? to bound, fr. ? boundary, limit.] 1. The line which bounds that part of the earth s surface visible to a spectator from a given point; the apparent junction of …   The Collaborative International Dictionary of English

  • Apparent — Ap*par ent, a. [F. apparent, L. apparens, entis, p. pr. of apparere. See {Appear}.] 1. Capable of being seen, or easily seen; open to view; visible to the eye; within sight or view. [1913 Webster] The moon . . . apparent queen. Milton. [1913… …   The Collaborative International Dictionary of English

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