He has two grown children and one grandson, goes to work every day, regularly travels abroad, sends and reads e-mail, watches TV news and enjoys classical music. But Prof. Stephen William Hawking - one of the greatest scientists since Albert Einstein - is unique. He is unrivaled in what he can't do. The 64-year-old University of Cambridge theoretical physicist - diagnosed with the incurable amyotrophic lateral sclerosis (ALS) at 21 and told he had two or three years left to live - embodies the potential hidden within "disabled" people. He symbolizes the right of every individual to the means for meeting his potential. His extreme disability and courageous way of dealing with it forces humanity not to look away in embarrassment but to peer into our selves and try to explain why so many handicapped people are ignored, undervalued and discriminated against. HAWKING WAS born in Oxford on January 8, 1942 to research biologist Frank Hawking, and his wife Isobel, who is still alive. The family, which eventually included two younger sisters and an adopted brother, originally lived in London, but during World War II relocated because the city was under attack at the time by the Luftwaffe. After Stephen's birth, they moved back to London, where his father was head of the National Institute for Medical Research's parasitology division. At 11, Stephen was a good but not exceptional pupil when the family moved to Hertfordshire and he attended St Albans School. Inspired by his father, he was always interested in science, but thought biology was "too inexact," and went to Oxford to major in mathematics. A year later, he switched to physics. His teachers recalled later that he had never read many books or even taken notes in class. As the grade on his final examination was on the borderline between first- and second-class honors, Hawking recalled in a speech last week before high school pupils at Jerusalem's Bloomfield Science Museum, he said that if he had received the higher honors, he would go to Cambridge, but if only the second-class honors, he would go to Oxford. "They gave me a first. I arrived at Cambridge as a graduate student in October 1962." He has been there ever since. But studying sunspots in the observatory bored him, and he switched to theoretical astronomy and cosmology, which required imaginative thinking and calculation, without the need for labs or even necessarily jotting numbers down. This career choice, soon after his horrendous ALS diagnosis, was serendipitous, as even today he is freely able to sit and contemplate theories of how the universe began, black holes in space, quantum gravity and other intangibles without his disability infringing on his genius. In the late 1960s, Hawking and his Cambridge friend and colleague Roger Penrose applied a complex new mathematical model they had created using Albert Einstein's general theory of relativity. This led, in 1971, to Hawking proving the first of many singularity theorems - a set of sufficient conditions for the existence of a singularity in spacetime (a singularity is a point or region in which gravitational forces cause matter to have infinite density and zero volume). In 1974, he calculated that black holes should create and emit sub-atomic particles, known as Hawking radiation, until they exhaust their energy and evaporate. That year he was elected as one of the youngest Fellows of the Royal Society; he was named a Commander of the Order of the British Empire in 1982; and in 1988 shared with Penrose Israel's "Nobel" - the Wolf Foundation Prize; he became a Companion of Honor in 1989, and two weeks ago was awarded Britain's highest scientific award, the Copley Medal, which had first been launched by the Royal Society in 1731, for his work in theoretical physics and cosmology. Hawking had initially speculated that the singularity at the center of a black hole could form a bridge to a "baby universe" into which the lost information could pass. But two years ago, Hawking reversed his views, saying at the 17th International Conference on General Relativity and Gravitation in Dublin that black holes eventually transmit - albeit in a garbled form - information about all the matter they swallow: This demonstrated that singularities are not mathematical curiosities that appear only under special conditions. He has written some of his books in popular language to explain cosmology to the general public, said Prof. Jacob Ziv, Technion electrical engineer and former president of the Israel Academy of Sciences. "Hawking is a symbol. His books sell; people don't understand the concepts, but they read them." ALS, WHICH has stricken 500 Israelis, was first described 140 years ago by French neurologist Jean-Martin Charcot, but little has been learned since then. The causes and mechanism of ALS are unknown, yet neurologists do know that misfolded and damaged proteins clump together in cells to form aggregates. This triggers the death of motor neurones (nerve cells along which the brain sends instructions), causing a loss of muscle control. Only cognition, digestion and the five senses continue to function normally. So the disease gradually robbed Hawking of the use of his arms, legs and voice, and he is now almost completely paralyzed. When motor neurones degenerate, muscles gradually become weak and waste away. In the advanced stages, a patient may become almost totally immobile, but the rate of progression varies from patient to patient. On average, ALS takes three to four years to run its course, with about half of its victims surviving three years after diagnosis, 10% dying after 10 years and a minority living more than 20 years. Hawking is in his 43rd year of coping. He was diagnosed shortly after arriving in Cambridge and before he married his first wife Jane. In the first incident, he lost his balance and fell downstairs, hitting his head. Asked why she went through with the wedding, Jane said that during the early part of the Cold War, "these were the days of atomic gloom and doom; we all had rather a short life expectancy." Hawking doesn't talk much about the disease, but has described himself as "lucky" because the relatively slow progress of his disease gave him time to make influential discoveries. It also gave him time to have what he called "a very attractive family." Daughter Lucy Hawking is a novelist living in the UK, while son Robert moved to the US, married and produced Hawking's first grandchild. Lucy and Robert were both present at the Copley Prize ceremony in early December. Jane took care of him until 1991, when they divorced, reportedly under pressure from fame. He then married his personal nurse, Elaine Mason, in 1995 (Mason's first husband, David, had designed the first version of Hawking's talking computer). But just two months ago, Stephen and Elaine filed for divorce. Contrary to conventional wisdom, most ALS patients are not depressed or more likely to become so as the end nears, according to a University of California study published in Neurology. "The resiliency of people with ALS is inspiring, and helps remind us daily of our own mortality," the authors wrote. But because ALS is an "orphan disease" suffered by relatively few people and that life expectancy is usually short, pharmaceutical companies are reluctant to invest huge sums in research, according to Israel ALS Society head and fellow sufferer Avichai Kremer. The computer system attached to Hawking's wheelchair is operated via an infrared "blink switch" attached to his glasses. By contracting his right cheek, he is able to talk, compose speeches, research papers, browse the Internet and write e-mail. Radio transmissions give him control over doors in his home and office. ABOUT 20 years ago, during a visit to the CERN nuclear research center in Geneva, Hawking contracted life-threatening pneumonia. His severe breathing difficulties could be relieved only with a tracheostomy (a hole in his windpipe), which caused him to permanently lose the ability to speak. Since then he has used an electronic voice synthesizer, its hardware developed by Intel. Cambridge computer engineer Sam Blackburn, who was hired by Hawking a month ago as a graduate assistant to ensure the proper workings of his computer system, was one of the seven-member team that accompanied the scientist to Israel. "He gets a new laptop every year and has two as backup," Blackburn told The Jerusalem Post at an intimate Israel Academy of Sciences dinner in Hawking's honor at the King David Hotel. "He likes the system and identifies with the synthetic voice. It is one of the most famous artificial voices in the world, so he refuses to let us change the system to a more modern one." The graduate assistant noted that he has his hands full, as the constant bumps and vibrations of the wheelchair cause the computer to break down all the time. Thousands of English words are stored in the laptop's memory, with the ones he most commonly uses on the bottom row of the home screen. He contracts a muscle in his cheek when the phrase, word or letter he wants is lit up on the screen. A bleep is sounded as feedback to Hawking, who can produce two to five words a minute. The standard six-page lecture he gave in Jerusalem took him many months to produce, but is delivered during his tours around the world. "He is abroad about a quarter of the time. He can't easily be spontaneous in his communications; it takes too long," noted Blackburn. "Most of his books have been co-authored, but Stephen provides the basic ideas and goes over texts. His next major trip is to the US in the spring, when he will visit the California Institute of Technology and other major American universities." After Hawking told the BBC at the Copley Prize ceremony that the long-term survival of the human race is at risk on a single planet, and that "sooner or later, disasters such as an asteroid collision or nuclear war could wipe us all out," British airlines entrepreneur Richard Branson offered to send him to space. Hawking would go at the drop of a hat if his doctors allowed him, but at least he has experienced flight in a jet fighter some years ago. He works from 11 a.m. to 7 p.m., driven there by aides in a specially adapted Chrysler van whose license plate is "SWH4." Hawking does not complain about his disability and rarely expresses anger. "He sees complaining as a waste of valuable speech," said Blackburn, who disclosed that the scientist regularly listens to music by Beethoven, Brahms and Rachmaninoff, as well as Puccini operas. He must follow a strict diet of liquids and pulverized solids. His personal nurse Nicky O'Brien was seen feeding him patiently with a spoon at the Jerusalem dinner. The eight-day visit, which brought him before Israeli and Palestinian audiences, was organized by the British Embassy and its British Council to promote appreciation and understanding of science and Britain's contributions to many fields. Hawking has been asked many times whether he believes in God. "If there is a God, He is not involved and does not interfere in the universe," is his standard answer. But during one visit to Israel, he asked to be taken to the baptismal site on the Jordan River near the Kinneret. "He has a good sense of humor," notes Prof. Tsvi Piran, a Hebrew University physicist who has known Hawking since they met in Cambridge 30 years ago. "Then, in 1983, he was able to speak somewhat with help from an interpreter. He asked to have his shoes removed and to put his wheelchair into very shallow water. A woman who didn't know who he was said out loud: 'Poor soul. God is watching over you!' He whispered to me: 'I hope God is watching over her!' " Last Monday, when photographers endlessly clicked their digital cameras at him in the King David's dining room, Hawking - who is today a wealthy man - batted his eyelids at his console and a few minutes later, his synthesized voice declared: "If I had a dollar for every picture they take..."