• WordNet 3.6
    • n horizon the range of interest or activity that can be anticipated "It is beyond the horizon of present knowledge"
    • n horizon the line at which the sky and Earth appear to meet
    • n horizon the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth
    • n horizon a specific layer or stratum of soil or subsoil in a vertical cross section of land
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: A rainbow can occur only when the sun is 40 degrees or less above the horizon
    • Horizon 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 .
    • Horizon (Astron) A plane parallel to the sensible horizon of a place, and passing through the earth's center; -- called also rational horizonorcelestial horizon.
    • Horizon (Astron) 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.
    • Horizon (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.
    • Horizon (Geol) The epoch or time during which a deposit was made. "The strata all over the earth, which were formed at the same time, are said to belong to the same geological horizon ."
    • Horizon The limit of a person's range of perception, capabilities, or experience; as, children raised in the inner city have limited horizons .
    • Horizon 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. "And when the morning sun shall raise his car
      Above the border of this horizon ."
      "All the horizon round
      Invested with bright rays."
    • Horizon (Astron) The unbroken line separating sky and water, as seen by an eye at a given elevation, no land being visible.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: Over billions of years, black holes become white holes and they spit out all of the things they sucked in. the atoms are completely jumbled, so no one knows what will ever come out. Theoratically they'll also turn into a white hole. If you were unfortunate enough to fall within one, you would never actually hit -- because time would stop at some point within the event horizon (space outside) of the black hole. Thanx De Composed
    • n horizon The circle which at sea forms the apparent boundary between sea and sky, and on land would bound the sky were all terrestrial obstructions down to the sea-level removed. Called the apparent, sensible, or visible horizon, in distinction from the astronomical horizon (which see, below).
    • n horizon Hence The line that bounds the view; the limit of vision.
    • n horizon Figuratively, the limit of intellectual perception, of experience, or of knowledge.
    • n horizon In geology, a stratum or group of strata characterized by the presence of a particular fossil not found in the underlying or overlying beds, or of a peculiar assemblage of fossils. Such a bed or series of beds is often designated as the zone of the fossil or group of fossils in question, and such a distinctly marked division is sometimes called a horizon, as forming a convenient plane of reference for other groups of strata occurring above and below, and not so definitely marked by peculiar fossil contents.
    • n horizon In zoology and anatomy, a level or horizontal line or surface: as, the horizon of the teeth; the horizon of the diaphragm
    • horizon To limit or bound by a horizon.
    • ***
Chambers's Twentieth Century Dictionary
  • Interesting fact: What we call the sky is merely the limit of our vision into the atmosphere. The sky, like the horizon, is always as far away as one can see.
    • n Horizon ho-rī′zun the circular line formed by the apparent meeting of the earth and sky—in astronomical phrase, the sensible, apparent, or visible horizon, as opposed to the astronomical, true, or rational horizon, the circle formed by a plane passing through the centre of the earth, parallel to the sensible horizon, and produced to meet the heavens:
    • n Horizon ho-rī′zun (geol.) a stratum marked by the presence of a particular fossil not found in the overlying or underlying beds: any level line or surface: the limit of one's experience or apprehension
    • ***


  • Henry Kissinger
    “For other nations, utopia is a blessed past never to be recovered; for Americans it is just beyond the horizon.”
  • Edgar F. Magnin
    Edgar F. Magnin
    “You are the one who can stretch your own horizon.”
  • Ethel Barrymore
    Ethel Barrymore
    “You must learn day by day, year by year, to broaden your horizon. The more things you love, the more you are interested in.”
  • Franklin D. Roosevelt
    “We have always held to the hope, the belief, the conviction that there is a better life, a better world, beyond the horizon.”
  • Konrad Adenauer
    Konrad Adenauer
    “We all live under the same sky, but we don't all have the same horizon.”
  • Lord Byron
    “Between two worlds life hovers like a star, twixt night and morn, upon the horizon's verge.”


Cloud on the horizon - If you can see a problem ahead, you can call it a cloud on the horizon.


Webster's Revised Unabridged Dictionary
F., fr. L. horizon, fr. Gr. (sc. ) the bounding line, horizon, fr. to bound, fr. boundary, limit
Chambers's Twentieth Century Dictionary
Fr.,—L.,—Gr. horizōn (kyklos), bounding (circle), horizein, to bound—horos, a limit.


In literature:

Here and there showers of rain fell, showing white against huge masses of purple cloud piled up along the horizon.
"The History of Sir Richard Calmady" by Lucas Malet
The horizon hid them.
"Talents, Incorporated" by William Fitzgerald Jenkins
The barometer was falling now and dark, snowy-looking clouds were piling up on the western horizon.
"The Root of Evil" by Thomas Dixon
The sky is of a cloudless azure, with a hazy appearance towards the horizon.
"A Boy's Voyage Round the World" by The Son of Samuel Smiles
Suddenly his guides rise in their stirrups and look anxiously towards the horizon.
"The Western World" by W.H.G. Kingston
The fog was gone and a blue, sailless sea stretched out to the horizon.
"The Wreck of the Titan" by Morgan Robertson
Next day they started again, at dawn, and the road, always the same, stretched out, uphill, to the verge of the horizon.
"Bouvard and Pécuchet" by Gustave Flaubert
The Evening Star declines slowly in its turn toward the western horizon.
"Astronomy for Amateurs" by Camille Flammarion
He could tell you were arriving before you got above the horizon.
"Frontier Boys on the Coast" by Capt. Wyn Roosevelt
Underneath the storm cloud, far ahead, the jagged tops of a range of mountains projected above the horizon.
"The Fire People" by Ray Cummings
The snow had gone, and a vast expanse of grass ran back to the horizon!
"Masters of the Wheat-Lands" by Harold Bindloss
It was growing very dark, and the lightning on the horizon became vivid and intense.
"The Riflemen of the Ohio" by Joseph A. Altsheler
Circles parallel to the horizon, and supposed to pass through every degree of the meridian.
"The Sailor's Word-Book" by William Henry Smyth
For the last time I examined the horizon.
"Adventures of a Young Naturalist" by Lucien Biart
In the moonglade, which reached from my feet to the far horizon, the waters heaved and curled, most silvery, as if they were alive.
"A Poor Man's House" by Stephen Sydney Reynolds
Sirius never rises very high above the horizon.
"Myths and Marvels of Astronomy" by Richard A. Proctor
Forty-two ships, sailing at nearly equal distances from one another, appeared on the horizon.
"The Corsair King" by Mór Jókai
Though clouds banking on the horizon threatened a violent Pyrran storm.
"Deathworld" by Harry Harrison
The sea looked blue and unruffled, with little sparkles and gleams of light, and white sails glimmered on the horizon.
"Not Like Other Girls" by Rosa N. Carey
The horizon to the west was an undulating black silhouette.
"The Saracen: Land of the Infidel" by Robert Shea

In poetry:

Over the orange-tinted brae,
Against that wondrous north-west sky,
Over the far sea golden-gray,
Where no horizon we descry.
"An Autumn Evening" by William Bell Scott
Courage! Look out, beyond, and see
The far horizon's beckoning span!
Faith in your God-known destiny!
We are a part of some great plan.
"Fifty Years (1863-1913)" by James Weldon Johnson
See where upon the horizon's brim,
Lies the still cloud in gloomy bars;
The waning moon, all pale and dim,
Goes up amid the eternal stars.
"The Waning Moon" by William Cullen Bryant
Stirred by joy his breathing quickens,
His eight eyes quiver with flame.
His fire-matted hair sweeps the horizon,
Bright as a million suns.
"Brahmā, Vişņu, Śiva " by Rabindranath Tagore
Purple and grey the horizon walls them round
With purpler clouds.
They wander in it like guests gently astray
In a house deep mystery shrouds.
"Need Of Storm" by Cale Young Rice
And still the stream of life flows on,
Laughing beneath the century new.
God's promise gilds the horizon;
Mercy shall reign; his word is true.
"Gone" by Nancy Rebecca Campbell Glass

In news:

Food and Drink Features Jenn Scott Holidays are on the horizon, and a crowd-pleaser is always cheese.
Rain falls on oil sheen on the surface of the Gulf of Mexico near the site of the Deepwater Horizon oil well leak off the coast of Louisiana Thursday, July 15, 2010.
Which are filled with oil from the BP Deepwater Horizon oil spill.
The Deepwater Horizon oil spill has surpassed the size of the 1969 Santa Barbara spill and the Exxon Valdez.
New electronic stabilizers account for roll and orient themselves to the horizon.
Local ambient post-rock duo Hammock has a double LP by the name of Departure Songs on the horizon.
The patent-pending HeliBars Horizon Multi-Axis Adjustable Handlebar system from Heli Modified provides four parameters of adjustment to give Harleys a custom fit.
The demands, the screams, the ringing phone that elicit a Pavlovian response—it's all there in Headland 's trippy, raucous new comedy Assistance at Playwrights Horizons.
A trippy, raucous new workplace comedy at Playwrights Horizons.
Could a cure for HIV be on the horizon.
Holidays are on the horizon, and a crowd-pleaser is always cheese.
Changes on the Horizon for OSU's Horse Barn .
New Horizons Hospitality's Hilton Garden Inn (Houston).
As these developments unfolded, reports emerged that implicated gas liberated from methane hydrates as a likely cause of the explosion and fire that destroyed the Deepwater Horizon.
Backed by South African producer Anant Singh's Distant Horizon and French-owned, British-based production house Pathe, the movie will detail the former president's life story.

In science:

We test the consistency of our decoupling/near-horizon limits of the OBLSTs by connecting five different bound-states and their decoupling/near-horizon limits through S- and T-dualities.
Open Branes in Space-Time Non-Commutative Little String Theory
Second, one uses a shift vector that keeps the horizon roughly in the same coordinate location during the evolution (“horizon tracking”, see ).
Simple excision of a black hole in 3+1 numerical relativity
D3 brane metric near the horizon (this is similar to the result of section 4 where AdS2 × S 2 arised as the near-horizon geometry of the extremal Reissner-Nordstrom black hole).
Large N field theories from superstrings
Here, rh and rc are respectively the radii of the black hole horizon and cosmological horizon , found from f (rhorizon ) = 0.
Black Holes Must Die
At the horizon, the metric is exactly the same as for a Schwarzschild black hole (this can be seen from the fact that α = 0 at the horizon).
Local and global properties of conformally flat initial data for black hole collisions
Indeed the horizon Killing vector field ensures that isolated horizon are (quasi) locally in equilibrium, but they are allowed to admit nearby radiation.
The First Law of Isolated Horizons via Noether Theorem
From the definition of the variation of energy we can obtain a first principle for rigidly rotating horizons, which are defined as (weakly) isolated horizons with an internal symmetry, generated by a vector field tangent to the cross sections.
The First Law of Isolated Horizons via Noether Theorem
In this Section we are going to recall the definitions of isolated horizon, weakly isolated horizon and rigid ly rotating horizon.
The First Law of Isolated Horizons via Noether Theorem
We can admit isolated horizons with radiation infinitesimally near the horizon surface, meaning non-stationary spacetimes.
The First Law of Isolated Horizons via Noether Theorem
Physical examples of isolated horizons can be found in collapsing stars or in cosmological horizons in de-Sitter spacetime (see for a review on the matter); in the latter case no singularities are present in spacetime, but it is still possible to define thermodynamics for such surfaces.
The First Law of Isolated Horizons via Noether Theorem
Notice that k(l) is the counterpart for isolated horizons of the surface gravity for Killing horizons .
The First Law of Isolated Horizons via Noether Theorem
Definition 5 A weakly isolated horizon (∆, [l]) is said to be a rigid ly rotating horizon (∆, [l], ϕ) if it admits a rotational simmetry ϕ (with ϕ tangent to the surfaces ∆) with closed and circular orbits, such that £ϕ lα = 0, £ϕωα = 0 and £ϕqαβ = 0.
The First Law of Isolated Horizons via Noether Theorem
We stress however that properties holding for weakly isolated horizons are also true for isolated horizons.
The First Law of Isolated Horizons via Noether Theorem
In fact it is easy to show that every isolated horizon is a weakly isolated horizon (see for details ).
The First Law of Isolated Horizons via Noether Theorem
This property, together with the zero principle and the boundary conditions which define the geometry of a rigidly rotating horizon, will ensure that the parameters Φ(l) , k(l) , Ω(l) , which appear in the first principle of thermodynamics for rigidly rotating horizons, are constant on ∆.
The First Law of Isolated Horizons via Noether Theorem