Astronomy. a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.
Also called Black Hole of Calcutta. a small prison cell in Fort William, Calcutta, in which, in 1756, Indians are said to have imprisoned 146 Europeans, only 23 of whom were alive the following morning.
(lowercase) any usually wretched place of imprisonment or confinement.
The World’s Greatest Books, Vol VII Various
The Virginians William Makepeace Thackeray
The Daisy Chain Charlotte Yonge
Ned Myers James Fenimore Cooper
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It Is Never Too Late to Mend Charles Reade
It Is Never Too Late to Mend Charles Reade
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Bible Romances George W. Foote
an object in space so dense that its escape velocity exceeds the speed of light
any place regarded as resembling a black hole in that items or information entering it cannot be retrieved
An extremely dense celestial object whose gravitational field is so strong that not even light can escape from its vicinity. Black holes are believed to form in the aftermath of a supernova with the collapse of the star’s core. See also event horizon, See more at star.
Our Living Language : When a very massive star ends its life in a supernova explosion, the remaining matter collapses in upon itself. If there is enough mass in this collapsed star, it becomes a black hole. A black hole is so dense that its gravitational forces are strong enough to prevent anything that comes close enough to the region known as the event horizon from escaping. Even light cannot escape, since the escape velocity (the velocity needed for an object to escape some larger object’s gravitational field) necessary to escape a black hole is greater than the speed of light. Black holes are extremely dense: for the Sun, which has a diameter of about 1,390,000 kilometers (862,000 miles), to be as dense as a black hole, its entire mass would have to be squeezed down to a ball fewer than 3 kilometers (5 miles) across. Some theorists postulate that the material in a black hole may be compressed to a single point of infinite density called a singularity. Because astronomers cannot directly observe a black hole, they infer its existence from the effects of its gravitational pull. For example, when a black hole results from the collapse of one star in a binary star system, it attracts material from the remaining star. This material forms an accretion disk, which compresses and heats up until it emits detectable x-rays. Black holes are thought to reside in the centers of many galaxies, including our own Milky Way.
Note: Figuratively, the term black hole is used to refer to a total disappearance: “They never saw the man again — he might as well have fallen into a black hole.”
A wretched prison cell or other place of confinement. For example, The punishment is solitary confinement, known as the black hole. This term acquired its meaning in 1756 with the event known as the Black Hole of Calcutta. On the night of June 20, the ruler of Bengal confined 146 Europeans in a prison space of only 14 by 18 feet. By morning all but 23 of them had suffocated to death. Although historians since have questioned the truth of the story, it survives in this usage.
A great void or abyss. For example, Running a single small newspaper ad to launch a major campaign is useless; it amounts to throwing our money into a black hole. This usage alludes to a region, so named by astronomers, whose gravitational field is so intense that no electromagnetic radiation can escape from it. [ Late 1970s ]
Also called Black Hole of Calcutta. a small prison cell in Fort William, Calcutta, in which, in 1756, Indians are said to have imprisoned 146 Europeans, only 23 of whom were alive the following morning. (lowercase) any usually wretched place of imprisonment or confinement. noun an object in space so dense that its escape velocity […]
noun a hairy unpleasant-smelling chiefly Mediterranean plant, Ballota nigra, having clusters of purple flowers: family Lamiaceae (labiates)
noun a type of thatched house, usually made of turf, formerly found in the highlands and islands of Scotland Historical Examples The Clansman Thomas Dixon Katharine Frensham Beatrice Harraden The Story of Bruges Ernest Gilliat-Smith Katharine Frensham Beatrice Harraden The Children’s Book of Thanksgiving Stories Various Gairloch In North-West Ross-Shire John H. Dixon, F.S.A. Scot […]
a low eastern North American shrub, Gaylussacia baccata, of the heath family, having yellowish-green leaves with resinous dots on the underside, clustered orange-red flowers, and shiny, black, edible fruit.