black hole(redirected from Blackhole)
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Related to Blackhole: white hole, Supermassive black hole
1. A massive star in the last phase of its evolution, in which the star collapses, creating a volume of spacetime with a gravitational field so intense that its escape velocity equals or exceeds that of light.
2. A great void; an abyss: The government created a bureaucratic black hole that swallows up individual initiative.
1. (Astronomy) 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
1. 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 void into which things vanish permanently.
An extremely dense celestial object that has a gravitational field so strong that nothing can escape, not even light. A black hole is formed by the collapse of a massive star's core in a supernova. See more at star.
Did You Know? One of the strangest objects in the universe is the burnt-out remnant of a large star, known as a black hole. The name comes from the fact that the star collapses into itself, becoming so dense that its gravitational pull keeps even light from escaping. And if light can't get out, then nothing that ever enters the black hole would ever escape. Rockets to the moon or Mars need to achieve what is called escape velocity, the speed necessary to overcome the Earth's gravity. But since nothing can ever go faster than the speed of light, nothing could ever go fast enough to reach the escape velocity necessary to pull out of a black hole. Here's how dense a black hole is: the sun has a diameter of about 864,000 miles (1,391,000 kilometers); for it to be as dense as a black hole, its entire mass would have to be squeezed down to a ball less than two miles across.
An object with large mass but small size, from which no light can escape; formed in the first moments in the life of the universe. Also called a collapsar.