unit-7-roaming-the-cosmos課文翻譯大學(xué)英語五(存儲版)
【正文】 izer is produced by a California pany.)When the conversation shifted to creativity and how mathematicians seem to reach a creative peak in their early 20s, Hawking39。s equations indicated that when a star several times larger than the sun exhausts its nuclear fuel and collapses, its matter crushes together at its center with such force that it forms a singularity, an infinitely dense point with no dimensions and irresistible gravity. A voluminous region surrounding the singularity bees a black hole, from which because of that immense gravity nothing, not even light, can escape.Scientists years ago found pelling evidence that black holes exist, but they were unfortable with singularities, because all scientific laws break down at these points. Most physicists believed that in the real universe the object at the heart of a black hole would be small (but not dimensionless) and extremely dense (but not infinitely so). Enter Hawking. While still a graduate student, he and Mathematician Roger Penrose developed new techniques proving mathematically that if general relativity is correct, singularities must exist. Hawking went on to demonstrate again if general relativity is correct that the entire universe must have sprung from a singularity. As he wrote in his 1966 Ph. D. thesis, There is a singularity in our past.Stephen later discerned several new characteristics of black holes and demonstrated that the amazing forces of the Big Bang would have created miniblack holes, each with a mass about that of a terrestrial mountain, but no larger than the subatomic proton. Then, applying the quantum theory (which accurately describes the random, uncertain subatomic world) instead of general relativity (which, it turns out, falters in that tiny realm), Hawking was startled to find that the miniblack holes must emit particles and radiation. Even more remarkable, the little holes would gradually evaporate and, 10 billion years or so after their creation, explode with the energy or millions of Hbombs.Hawking has visited the U. S. 30 times, made seven trips to Moscow
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