black hole

¹

[blak hohl]

noun

1. 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.

2. a deep, immeasurable space into which people or things vanish; an abyss.

   I use earphones every day, but hate digging around for them in my black hole of a purse.

Black Hole

²

[blak hohl]

noun

1. 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.

2. (lowercase),  any usually wretched place of imprisonment or confinement.

black hole

noun

1. an object in space so dense that its escape velocity exceeds the speed of light

2. any place regarded as resembling a black hole in that items or information entering it cannot be retrieved

black hole

1. 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.

2. See also event horizon See more at star

black hole

1. In astronomy, an object so massive that nothing, not even light, can escape its gravitation. Black holes were given their name because they absorb all the light that falls on them. The existence of black holes was first predicted by the general theory of relativity. Supermassive black holes have been found in the centers of many galaxies. Stellar black holes are thought to arise from the death of very massive stars. Astronomers expect to find many stellar black holes in the Milky Way.

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.”

Word History and Origins

Origin of black hole¹

First recorded in 1940–45 black hole for def. 2; 1960–65 black hole for def. 1

A Closer Look

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.

Idioms and Phrases

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]

Example Sentences

"If you can demonstrate the value... and it's not going into a big black hole plugging a deficit, that's what people want," he said.

From BBC

Then came “Two and a Half Men,” and a black hole of downward spiral exhaustively covered in the media.

From Salon

She rather robustly dismissed speculation about Budget measures, large black hole forecasts, and had some sharpish words even for the Office for Budget Responsibility, which we will come back to.

From BBC

He’s a black hole of a human being who will never willingly give up the presidency unless someone offers him the title and power of world leader.

From Salon

The chancellor chose to dismiss the suggestion of a "£50bn black hole", and talk of a need for a visit to the International Monetary Fund to request a bailout.

From BBC

Related Words

• supernova 
• void