A victim of an incurable disease， Stephen Hawking is almost completely paralysed， confined to a wheelchair， and unable to speak. Yet， he has overcome every obstacle and achieved far more than most able-bodied people ever dream of accomplishing and become one of the greatest physicists of our time.

    Roaming the Cosmos by Le0on Jaroff

    Darkness has fallen on Cambridge， England， and on a damp and chilly evening king's Parade is filled with students and faculty. Then， down the crowded thoroughfare comes the University of Cambridge's most distinctive vehicle， bearing its most distinguished citizen. In the motorized wheelchair， boyish face dimly illuminated by a glowing computer screen attached to the left armrest， is Stephen William Hawking， 46， one of the world's greatest theoretical physicists. As he skillfully maneuvers through the crowd， motorists slow down， some honking their horns in greeting. People wave and shout hello.

    A huge smile lights up Hawking's bespectacled face， but he cannot wave or shout back. Since his early 20s， he has suffered from amyotrophic lateral sclerosis （ALS）， a progressive deterioration of the central nervous system that usually causes death within three or four years. Hawking's illness has advanced more slowly， and now seems almost to have stabilized. Still， it has robbed him of virtually all movement. He has no control over most of his muscles， cannot dress or eat by himself and has lost his voice. Now he "speaks" only by using the slight voluntary movement left in his hands and fingers to operate his wheelchair's built-in computer and voice synthesizer.

    While ALS has made Hawking a virtual prisoner in his own body， it has left his courage and humor intact， his intellect free to roam. And roam it does， from the infinitesimal to the infinite， from the subatomic realm to the far reaches of the universe. In the course of these mental expeditions， Hawking has conceived startling new theories about black holes and the disorderly events that immediately followed the Big Bang from which the universe sprang. More recently， he has shaken both physicists and theologians by suggesting that the universe has no boundaries， was not created and will not be destroyed.

    Most of Stephen Hawking's innovative thinking occurs at Cambridge， where he is Lucasian professor of mathematics， a seat once occupied by Isaac Newton. There， in the Department of Mathematics and Theoretical Physics， he benevolently reigns over the relativity group， 15 overachieving graduate students from nine countries. On his office door is a small plaque irreverently reading QUIET， PLEASE. THE BOSS IS ASLEEP.

    Hardly. From midmorning until he departs for dinner around 7 p. m.， Hawking follows a routine that would tax the most able-bodied， working in his book-lined office， amid photographs of his wife Jane and their three children. When he rolled into the department's common room one morning last month， his students were talking shop around low tables. Maneuvering to one of the tables， Hawking clicked his control switch， evoking tiny beeps from his computer and selecting words from lists displayed on his screen. These words， assembled in sequence at the bottom of the screen， finally issued from the voice synthesizer： "Good morning. Can I have coffee？" Then， for the benefit of a visitor： "I am sorry about my American accent." （The synthesizer is produced by a California company.）

    When the conversation shifted to creativity and how mathematicians seem to reach a creative peak in their early 20s， Hawking's computer beeped. "I'm over the hill，" he said， to a chorus of laughter.

    Hawking was born on Jan. 8， 1942-300 years to the day， he often notes， after the death of Galileo. As a small boy， he was slow to learn to read but liked to take things apart though he confesses that he was never very good at putting things back together. When he was twelve， he recalls humorously， "one of my friends bet another friend a bag of sweets that I would never come to anything. I don't know if this bet was ever settled and， if so， who won.

   Fascinated by physics， Stephen concentrated in the subject at Oxford's University College， but did not distinguish himself. He partied， took a great interest in rowing and studied only an hour or so a day. Moving on to Cambridge for graduate work in relativity， he found the going rough， party because of some puzzling physical problems； he stumbled frequently and seemed to be getting clumsy.

    Doctors soon gave him the bad news： he had ALS， it would only get worse， and there was no cure. Hawking was overwhelmed. Before long， he needed a cane to walk， was drinking heavily and ignoring his studies. "There didn't seem to be much point in completing my Ph. D.，" he says.

    Then Hawking's luck turned. The progress of the disease slowed， and Einsteinian space-time suddenly seemed less formidable. But what really made the difference， he says， "was that I got engaged to Jane，" who was studying modern languages at Cambridge. "This gave me something to liver for." As he explains， "if we were to get married， I had to get a job. And to get a job， I had to finish my Ph. D. I started， working hard for the first time in my life. To my surprise， I found I liked it."

    What particularly interested Stephen was singularities， strange beasts predicted by general relativity. Einstein'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 becomes a "black hole，" from which —— because of that immense gravity —— nothing， not even light， can escape.

    Scientists years ago found compelling evidence that black holes exist， but they were uncomfortable 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 mini-black 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 mini-black 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 H-bombs.

    Hawking has visited the U. S. 30 times， made seven trips to Moscow， taken a round-the-word journey， and piloted his wheelchair on the Great Wall of China. On the road， the activities occasionally deviate somewhat from physics. One night Stephen accompanied a group to a Chicago discotheque， where he joined in the festivities by wheeling onto the dance floor and spinning his chair in circles.

    Recently， Hawking， who has no qualms about recanting his own work if he decides he was wrong， may have transcended his famous proof that singularities exist. With Physicist James Hartle. He has derived a quantum wave describing a self-contained universe that， like the earth's surface， has no edge or boundary. If that is the case， says Hawking， Einstein's general theory of relativity would have to be modified， and there would be no singularities. "The universe would not be created， not be destroyed； it would simply be，" he concludes， adding challengingly， "What place， then， for a Creator？"

    roam v.  go from one place to another without a goal or purpose； wander 漫游

    cosmos n.  the whole universe considered as an ordered system 宇宙

    cosmic a.

    damp a.  slightly wet； moist

    chilly a.  rather cold； unpleasantly cold

    chill n.

    faculty n.  all the teachers of a school or college

    thoroughfare n.  a busy main road 通衢

    distinguished a.  showing remarkable qualities 杰出的