John Michell, a British geologist and astronomer, designed the experiment made by Henry Cavendish to measure the mass of the earth. Cavendish published the results of the experiment in 1798.
At the end of the eighteenth century Michell and Laplace independently came to the conclusion that if the mass of a star large enough its gravity would not allow light to escape.
Michell published his work in 1783, that showed that a star, that has the same density of the sun, but 500 time as big, would have such a gravity, that "All light emitted from such a body would be made to return towards it".
Pierre-Simon Laplace, got to the same conclusion in 1795, and explained it by saying that "It is therefore possible that the greatest luminous bodies in the universe are on this very account invisible".
Michell took to account a body that has the density of the sun, which equals to the density of water, while Laplace took to account a body that has the density of the earth, which is 5.5 more dense that water.
In 1967 in his public lecture John Archibald Wheeler coined the name ‘black hole’. Soon after that this name was adopted enthusiastically by everybody. It reflects picturesquely the remarkable properties of the object.
The people who believed light was composed of only small particles, compared it to a cannon shell, and said that if a cannon shell was pulled after some time to the earth, so would the light. But this comparison isn't completely true, because a cannon shell was also slowed down, while the light's speed is stable.
The first really main theory that dealt with gravity's effect on light was Einstein's General Theory of Relativity in 1905. Even then, it took time until it was used to see the effect of big stars on light.
In 1939, the American physicist J Robert Oppenheimer established a mass limit for neutron stars. When it has exhausted thermonuclear sources of energy, a sufficiently heavy star will collapse indefinitely, unless it can reduce its mass.
In 1974, Hawking came up with the concept that ‘black holes aren’t black” – that is, he thinks that black holes can slowly bleed radiation. Possibly black holes may evaporates like snowballs in the sun.
Hawking has pioneered the application of quantum mechanics to black hole theory, and he has come up the idea that matter can be created in ‘virtually’ empty space at the event horizon.
Several scientists have recently claimed to have discovered black holes, including one at the center of Milky Way Galaxy and in one at the center of galaxy Centaurus A.
History of The Black Hole Theory
