Black holes capture, what a face. From subatomic particles to stars, solids, gases, liquids and even light — all that is in them falls, and disappears. And likewise, black holes capture the popular imagination. Thinking about space ever since humans first saw points of light that adorn the night sky, forcing the mind to imagine things that are impossible to see here on Earth. And black holes to expand the imagination more than any other miracle of astronomy.
Looks like a black hole?
A black hole is a cosmic vacuum cleaner, the suction Stardust in the abyss, bend space-time, causing an irresistible gravitational pull, oblivion, which can wipe off the face of the earth.
It’s a hole in space. Black because light cannot escape its pull. And therefore invisible. Unimaginable.
And yet black holes tried to imagine — before I learned that they actually exist. In 1784, an English geologist and clergyman (and Amateur astronomer) John Michell suggested that for large and dense enough stars Newtonian gravity is too strong to allow light to leave her. He believed (like Newton) that light is a stream of particles (then a thought). Michell calculated that the speed of light particles will be insufficient to escape the gravity of a star is the same dense as the sun but 500 times its diameter. “The can’t come to us,” he wrote.
About ten years later the French mathematician Pierre-Simon Laplace also speculated that space may exist the “invisible body”. Laplace imagined a star with the density of the Earth is 250 times wider than the sun. Its Newtonian gravitational attraction would not allow light to leave the surface. “Thus, the largest bodies in the universe may be invisible because of their size,” he said.
These same black holes arise not from Newtonian gravity and Einstein’s theory of gravitation — the General theory of relativity. Einstein hid black holes (even from himself) in their equations. But the German astronomer Karl Schwarzschild used this concept during the First world war, shortly before he died after an illness on the Russian front. Schwarzschild, however, could not imagine that the star may shrink to such an extent that will exceed the density required in order to make it invisible. This feat of imagination was carried out by Robert Oppenheimer and Hartland Snyder in 1939 (the same year when Einstein published a paper in which he denied the possibility of the existence of black holes). Oppenheimer and Snyder calculated that a sufficiently massive star can collapse under its own gravity. “Thus, the star will be closed against any communication with the remote observer; there will be only a gravitational field,” they wrote.
Shortly Oppenheimer started the Manhattan project to create atomic bombs, and nobody paid much attention to it collapsing star to the 1960-ies. In December 1963, they were discussed at the Symposium in Dallas a few weeks — at the meeting in Cleveland. Someone even uttered the phrase “black hole” to refer to them.
But this name was not popular until John Archibald Wheeler did not say in his speech in 1967. Then began a serious scientific study of black holes. Stephen Hawking studied them, showing that they can emit a weak form of radiation, which was named in his honor. Astronomers have been looking for black holes, collecting impressive evidence that those do exist, based on the movement of the stars and other substances in the vicinity of black holes. (Actually, Michelle had suggested this approach to detect the presence of invisible stars). In 2016, gravitational waves have provided accurate evidence of the collision of two black holes.
Now almost nobody doubts that they exist. ButMichelle, Oppenheimer, Wheeler, Hawking and many others have provided what should be a black hole, none of them never saw her.
And then, just in April, Event Horizon Telescope collaboration presented the image: the darkness of a black hole, surrounded by light in its vicinity. This image confirms what was already known: that black holes are not just a figment of the imagination, it is the truth, originally introduced by minds imbued with a kind of scientific spirit, a faith in the ability to discover a cosmic phenomenon, of not being in space.
History of science remembers other cases of imaginary phenomena that defy the imagination even before its opening. Paul Dirac imagined the antimatter before it was found in nature. Alexander Friedman imagined expansion of the Universe before astronomical observations have confirmed it. Ancient Greek philosophers imagined the atoms for 2500 years before microscopy is complex enough to photograph them. All of these a good imagination is regarded by some as an insult to common sense or ordinary logic. They are confirmed as a new image of a black hole, confirm the lesson that the apparent absurdity is not a convincing argument against the existence of the phenomenon.
Perhaps the fact that the human imagination has come to the existence of black holes, despite their absurdity, is one of the reasons why black holes fascinate anyone thinks about them. The black hole was the proof of the existence of the incredibly incomprehensible astronomical phenomena.