Word: holing
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Dates: during 1970-1979
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...boundary marking that no-escape distance depends on the mass of the deceased star. Typically, this frontier is an imaginary sphere tens of kilometers across that defines the size of the black hole. It is the point of no return that scientists call the black hole's "event horizon." Anything crossing this border would be stretched spaghetti-thin, pulverized by gravitational tidal forces, and sucked into the singularity. To an observer outside?say an astronaut watching his abandoned craft plunge into the black hole?the result would be different. Because of relativistic effects, the spacecraft would appear to move ever...
Subsequently, two imaginative University of Texas researchers suggested that a tiny black hole had passed through the earth in 1908, causing the mysterious blast that leveled trees for miles around in the Tunguska region of Siberia. But most scientists doubt that explanation. Says Princeton's Ostriker: "A hit by a mini-black hole would have blown up the entire earth...
...even more brilliant mathematical tour de force, Hawking has gone on to point out that black holes apparently violate the cherished no-escape doctrine. Contrary to expectations, Hawking's mini-black holes are gradually "evaporating," leaking subatomic particles and high-energy gamma rays back into the universe and rising in temperature. After billions of years, according to Hawking's calculations, the minuscule hole, unlike its large brother, can no longer sustain the buildup of heat and expires in a Gotterdammerung-like blast comparable to the explosion of millions of H-bombs...
Incredible as it may seem, scientists are now postulating supergiant black holes as well, monsters with event horizons millions of miles across and formed from a mass equal to that of billions of suns. Observations with the big telescopes at California's Palomar and Arizona's Kitt Peak National observatories strongly support the likelihood that at least one such heavyweight exists in M87, a galaxy that appears to be spewing out a great jet of matter. Astronomers found that M87's center is ten times as bright as the rest of the galaxy, and is surrounded by stars orbiting...
...star would literally enclose itself. For a celestial body of the sun's mass, the critical radius turned out to be about 3 km (2 miles). If the star shrunk beyond that, it would vanish. This so-called Schwarzschild radius, or event horizon, is in effect the black hole's boundary. Any matter crossing it simply disappears...