Word: generality
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Dates: during 1970-1979
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When they are confronted with such a situation, scientists are often inclined to toss out the suspect equations, along with the physical theories underlying them. Yet general relativity has withstood many other tests since it was devised by Einstein more than half a century ago, and more and more scientists believe that the evidence in the skies is rapidly piling up in favor of the reality of black holes...
...shortly after Einstein formulated his theory, a German colleague named Karl Schwarzschild considered one of general relativity's consequences. If a star were to become sufficiently compact and dense, Schwarzschild found, its gravity would so warp space and time around it that the 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...
According to general relativity, such violent activity as stellar collapse and the collision of certain types of black holes should release gravity waves. These waves are to the gravitational force what light and radio waves are to the electromagnetic force...
...late 1960s, as a research fellow at Cambridge, he and a colleague, Roger Penrose, showed more convincingly than ever before that if Einsteinian general relativity is correct, gravitational collapse will result in "singularities" that are totally hidden inside black holes. But Hawking did not stop there. Following up the work of John Wheeler's student, Jacob Bekenstein, he pointed out that there are important mathematical analogies between the bizarre otherworld of black holes and the familiar physical rules of thermodynamics, notably the idea of entropy-which says, in effect, that the universe is running down like an unwinding clock...
...uncovered flaws in his elaborate mathematics. Indeed, many theorists believe that with this work Hawking may well have qualified for the Nobel Prize by taking the first step toward a goal that has long been a dream of physicists: the consummation of what Wheeler calls the "fiery marriage" between general relativity-the great theoretical system for studying the large-scale structure of the cosmos-and quantum mechanics-the mathematical tool for analyzing the diminutive world of the atomic nucleus...