Karl Schwarzschild solved equations for a point mass or point source of gravity, and it is to him the credit is given for the black hole. The ideas, based on Einstein's theories, were set down in 1915. It should be noted that in 1783, John Michell, and English geologist, wrote a letter (that was later published by the Royal Society) to Henry Cavendish which said: "If the semi-diameter of a sphere of the same density as the Sun were to exceed that of the Sun in the proportion of 500 to 1, a body falling from an infinite height towards it would have acquired at its surface greater velocity than that of light, and consequently supposing light to be attracted by the same force in proportion to its vis inertiae, with other bodies, all light emitted from such a body would be made to return towards it by its own proper gravity." You may disagree, but that letter, written about 130 years before Schwarzschild made his calculations, describes a black hole quite well.
The idea of a black hole was first enunciated by physicist John Michell in a letter published in 1783. Later, the term "black hole" was coined by physicist John Archibald Wheeler in 1967.
That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.
The term "Black hole" first appeared in print in an article by Ann Ewing in "Black Holes in Space" published in 1964 after a meeting of a group of scientists. John Wheeler often gets credit because he used the term in a lecture in 1967, because of which the phrase entered widespread use.
One common term used is black hole evaporation. This relates to a mechanism wherein the black hole's mass is gradually lost through Hawking radiation; but the rate of loss is inversely proportional to the black hole's size and thus accelerates as it shrinks. At the moment it vanishes it is thought to do so with a burst of gamma radiation; the Fermi space telescope is intended to search for such gamma flashes.
Your category is the answer, that thing is black hole
The term 'black hole' is particularly appropriate in its application to the astrophysical phenomenon of the same name due to the property of the escape velocity exceeding the speed of light. This means that no light or matter escapes a black hole.
Quasars have a large black hole, called a "supermassive black hole". The term "supermassive black hole" simply means that it has millions or even billions of solar masses.
No non-fictional astronomical body know as black circle. If the question is meant to employ the term 'black hole' in space, what a black hole does is to exist.
No. And the term is "black hole," not "dark hole."
Black Hole
A black hole is a void in space-time where gravity is so strong that no matter or energy can escape the effects of its force.
The idea of a black hole was first enunciated by physicist John Michell in a letter published in 1783. Later, the term "black hole" was coined by physicist John Archibald Wheeler in 1967.
As a natural phenomenon, black holes were not invented, but they are first known to have been theorised in the 1780s by John Michell. The current concept of a black hole, based on general relativity, was first posited by Karl Schwarzschild in 1916.
You are referring to the "event horizon" of a black hole. At this point, nothing, not even light, can escape the gravity of the singularity (or black hole). If you were so unlucky to be there, your body would be stretched from the part that is closest to the black hole. Eventually, your body would be one long string of atoms swirling into the black hole. This is called "spaghettification" and is an actual scientific term.
That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.That depends exactly how you interpret the term "strong". In its vicinity, the black hole distorts space more than anything that is NOT a black hole; so much that nothing can get out of the black hole. But at some standard distance, a galaxy, for example, would have more gravitational attraction than a black hole, simply because it has more mass. At least, so far no black hole of the mass of an entire galaxy has been found.
The term black hole is a misnomer that implies the notion of a hole; there is no hole, so there is no end (or exit). A black hole is a spherical volume of immense density. Somewhat like the Earth, everything within its gravitational field is attracted to its essense. And just as pressure increases towards the center of Earth, the pressure increases on a more more dramatic scale towards the center of a black hole. However since the subsistence of a black hole is unknown, it might be said that the black hole ends in energy transformation.
I believe that would be exactly the term - "active supermassive black hole". The term "active galaxy" or "active radiogalaxy" is also used for a galaxy that produces large amount of certain radiations; however, such radiation is really caused by the supermassive black hole.