Professor Stephen Hawking
The world’s most famous scientist, who wrote A Brief History of Time and unlocked the secrets of the cosmos from his wheelchair
PROFESSOR STEPHEN HAWKING, who has died aged 76, was Lucasian Professor of Mathematics at Cambridge University and was regarded as one of the world’s most brilliant theoretical physicists; he was certainly its most famous.
His life was dominated, positively as well as negatively, by a crippling and incurable form of motor neurone disease, which left him increasingly helpless. He was confined to a wheelchair by the time he was 30, and in 1986, aged 44, his voice was removed to save his life after an attack of pneumonia.
From then on, he spoke through a computer synthesiser on the arm of his wheelchair. It was remarkable that he survived at all. When the disease was diagnosed in 1963 doctors gave him 14 months to live.
Hawking’s most famous insight concerned the arcane physics of black holes. He discovered the phenomenon which has become known as Hawking radiation, where black holes leak energy and fade to nothing. But Hawking radiation was not what he was famous for in a popular context. His illness gave Hawking a preeminence in the public eye that he would never have enjoyed had he been in perfect health.
While most of Hawking’s fellow physicists continued to labour in obscurity, his devastating disability and instantly recognisable synthesised voice brought him cult status with the general public – and wealth. He was feted by Hollywood stars; invited to the White House by President Clinton; appeared in advertisements; and even enjoyed cameo roles in Star Trek and in an episode of The Simpsons, in which his cartoon doppelganger was filmed drinking in a bar with Homer Simpson and announcing: “Your theory of a doughnut-shaped universe is interesting, Homer. I may have to steal it.” His 60th birthday party was attended by the rock star The Edge, guitarist with U2.
Another factor in Hawking’s celebrity was his idea that scientists would one day discover the single “unified theory of everything”. In 1988, he explored this issue in A Brief History of Time, which sold some 10 million copies. It was a bold attempt to explain to the layman current thinking on the origins of the universe, the properties of space-time, and the search for a unified theory of physics.
He concluded the book with the thought that if we do discover a complete theory of physics, we may be able to find the answer to the question of why it is that we and the universe exist. “If we find the answer to that, it would be the ultimate triumph of human reason – for then we would know the mind of God.”
Although Hawking was respected by his fellow physicists, and recognised for his work on black holes, they did not accord him the iconic status which he acquired among the general public and there were some who felt that his presence in a discipline that runs on peer review was not entirely healthy. In 1999, when Physics World conducted a survey among leading physicists of those they thought the greatest living minds in their field, Hawking did not even make it into the top ten.
Stephen William Hawking was born on January 8 1942 in Oxford, the eldest son of Dr Frank Hawking, a prominent research biologist. He was brought up in St Albans, where the routines of middle-class life were tempered by parental Bohemianism. The family car was a London taxi and holidays were spent in a gipsy caravan.
Surprisingly slow to learn to read, Stephen was educated at St Albans School. Skinny and uncoordinated, he was seen by his peers as the boffin type – useless at games except cross-country running, but good at maths and enthusiastic (and chaotic) in chemistry.
He was never top of his class, but a school friend recalled his “incredible instinctive insight”. Faced with a complex mathematical problem, he “just knew the answer – he didn’t have to think about it”.
It was at University College, Oxford, where he arrived in 1959, that he really blossomed. He read mathematics for a year before switching to physics. His mind, according to his tutor, was “completely different from all of his contemporaries”, but he did “positively make an effort to come down to their level and be one of the boys”. He was popular and coxed the college’s second rowing eight. “He did very little work, really,” his physics tutor recalled, “because anything that was doable he could do.”
After graduating in 1962, he decided to go to Cambridge for postgraduate work in cosmology. He was always more interested in theory than in observation, and at Cambridge work was going on in theoretical astronomy and cosmology, which involved abstract thinking about the nature of the universe as well as orthodox scientific reasoning. Hawking said he found cosmology exciting because it concerned “the big question: where did the universe come from?”
Hardly had he arrived in Cambridge, to study under Dennis Sciama, than symptoms which he had first noticed at Oxford – slurred speech and trouble tying shoelaces among them – became worse. (At Oxford he had also seemed to others angry and frustrated at nothing in particular, and his movements had become jerky.)
In 1963 a form of motor neurone disease called amyotrophic lateral sclerosis was diagnosed, a progressive deterioration of the motor nerves which prevents muscle function, affecting speech, swallowing, and limbs, and usually ends in a fatal paralysis of the chest muscles.
For the next two years Hawking did little research work. He spent his time in his room, listening to Wagner, reading science fiction and drinking. Then the disease seemed to stabilise, and his prospects seemed brighter.
He found fresh enthusiasm and returned to work on his doctorate. He also fell in love with a language student named Jane Wilde, and they were married in 1965. Hawking described the marriage as a turning point.
Apart from the disease, an added difficulty in his postgraduate research had been finding problems suitable for someone of his ability. In 1965 Sciama found one in a paper on black holes, by the mathematician Roger Penrose. Black holes, first suggested in the 18th century, are the result of burnt-out stars collapsing under their own weight to a point so dense that nothing, not even light, can escape.
Einstein’s general theory of relativity predicted that a black hole could exist as a singularity of the equations of space-time – a point of zero volume, infinite density and infinite gravity, where the physical laws of nature would break down and time would have no meaning. Most scientists had assumed that such a contraction could not happen in the real universe. But Penrose had shown that, if the collapse was not smooth and symmetrical, a singularity could form.
The following year, in his PHD thesis “Properties of the Expanding Universe”, Hawking suggested running the same process backwards. He showed that the universe could have come out of a singularity without evolving perfectly smoothly. The cosmic clock could be run backwards to the Big Bang, the beginning of the universe, between 10 and 20 billion years ago. He showed that, if general relativity was correct, there did have to be a beginning.
Hawking stayed at Cambridge after receiving his doctorate, as a fellow of Gonville and Caius College and a staff member of the Institute of Theoretical Astronomy and the Department of Applied Mathematics.
He and Penrose refined the new and intricate mathematical method they had devised, and developed their predictions of singularities and the behaviour of matter in the space-time continuum, culminating in a singularity theorem in 1970.
Although he and Penrose had demonstrated that black holes could exist mathematically, Hawking observed that there was still no conclusive evidence for the existence of singularities. He had a bet (which was never settled) with the Californian physicist Kip Thorne that they do not exist. If he had won, he would have wasted much of his life’s work, but he would have received a four-year subscription to Private Eye. If black holes were proved to exist, Thorne would have won a year’s subscription to Penthouse – and Hawking would probably have won the Nobel Prize.
Such wagers were a feature of his scientific life. In 2008 he bet $100 that the Large Hadron Collider, then recently opened outside Geneva, would fail to succeed in its primary goal of finding the elusive Higgs boson, so crucial to the scientific understanding of the universe that it is known as the “God particle”. When he was proved wrong in 2012, he grabbed the headlines with a warning that a cosmic death bubble, caused by changes to the field that the “God particle” is associated with, could wipe out the universe at any time, with no prior warning. Other experts, however, were quick to calm public concerns.
After his work on singularities, Hawking turned to the thermodynamics of black holes. He looked at the theoretical paradox that black holes could never be in equilibrium with thermal radiation at any temperature other than absolute zero, because they would absorb any heat falling on them, but by definition would not be able to emit anything in return. To resolve the paradox, he turned to quantum mechanics.
In 1971, Hawking reasoned that black holes could be created other than by the collapse of massive stars, and that black holes the size of subatomic particles (and the mass of a good-sized mountain) could be left over from the Big Bang.
Applying quantum theory to the region surrounding such a tiny black hole, he found to his surprise that it “seemed to emit particles at a steady rate”. He was reluctant to believe it at first, but became convinced that it was a real physical process, which happens slowly even in large black holes.
Hawking delivered his mathematical evidence for this “Hawking radiation”, as it is now known, at a symposium in Oxford in February 1974, to the consternation and disbelief of most of his colleagues. Although it was later confirmed by others, it still represented one of the greatest challenges ever to confront theoretical physics.
General relativity suggested that black holes could only get bigger and bigger. But by bringing quantum theory into play, Hawking showed that they could “evaporate” and explode. It was a dramatic demonstration that black holes, while severed from the space-time continuum, have important effects on it. The revelation that black holes emit matter and energy also strengthened their link with the Big Bang theory.
Hawking’s paper on the radiation from black holes was also a significant step for another reason – it combined features of quantum physics with classical general relativity, theories which are still widely regarded as almost incompatible, the former dealing with the very small and the latter with the very big.
Hawking now turned to the challenge of uniting them to form a grand unified theory – a new single theory, encompassing gravity at the large scale, and the strong nuclear, weak nuclear and electromagnetic forces at the small scale – which would describe the behaviour of all the matter in the universe. In spite of his efforts, his prediction that the answer would emerge by the end of the 20th century proved wide of the mark.
Hawking had been made a research assistant in the Department of Applied Mathematics and Theoretical Physics in 1973, the year that he and GRF Ellis published The Large Scale Structure of Space-time. He became Reader in gravitational physics in 1975 and professor of gravitational physics in 1977. In 1979 he was appointed to the Lucasian chair of mathematics, a post once held by Sir Isaac Newton; he became emeritus in 2009, having in 2007 established the Centre for Theoretical Cosmology at the university.
For most of his life Hawking managed to escape trappings of fame, such as tabloid fascination with his private life. But this changed in 1990 when he said that he was leaving his wife of 25 years, Jane, to move in with Elaine Mason, one of his nurses, whose former husband, David, had created his voice box. The pair married in 1995.
The end of his first marriage was messy and difficult. Hawking was accused of selfishness and Elaine of marrying him so that she could bask in the reflected glory of his celebrity. In 1999, his former wife published an angry memoir, Music to Move the Stars: My Life with Stephen, in which she described the daily grind of struggling to meet the demands of her three children as well as her increasingly dependent and demanding husband.
Her portrait of Hawking and his new wife was not a flattering one. An “all-powerful emperor”, he “had not liked being treated as but one member of the family when he considered his rightful place to be on a pedestal at the centre”. In Elaine Mason, he had found someone who “was prepared to worship at his feet”.
No sooner had the book appeared than reports began to circulate that all was not well in Hawking’s new household. By 2000 he had become a frequent visitor to Addenbrooke’s hospital, suffering from a series of mysterious injuries – broken bones, gashes and severe bruising.
In 2004, after Hawking had been again been taken into hospital, reports appeared in the press alleging that Elaine Mason had beaten and bullied her husband. Nurses who had worked with Hawking were said to have come forward to allege acts of cruelty.
Hawking, though, consistently refused to say how he came by his injuries or to be interviewed by police. When officers turned up at his house offering to interview him and his wife in separate rooms, he threatened to sue them for harassment. “My wife and I love each other very much,” he maintained. “It is only because of her that I am alive today.” In 2006, however, the couple filed for divorce.
Despite all these problems, Hawking’s mind remained razor sharp and his career flourished. In 2002 he was awarded the Aventis Prize for Science Books for his The Universe in a Nutshell. Some colleagues found in him a self-righteous streak, and he gave few references to the work of others in his field.
Others found him difficult to work with. But he never seemed to lose his sense of fun, and the mischievous glint in his eyes. In 2007 he enjoyed zero gravity on a specially organised flight in America, allowing him to float free of his wheelchair. “It was amazing,” he said. “I could have gone on and on. Space here I come.”
Indeed, in 2009 Hawking was offered a place aboard a proposed commercial space flight operated by Sir Richard Branson. “I would love to go to the Moon,” he said in 2015, “but I fear the doctors won’t allow it.”
He was elected a Fellow of the Royal Society in 1974, was appointed CBE in 1982 and became a Companion of Honour in 1989. He was elected an honorary fellow of University College, Oxford, in 1977, and of Trinity Hall, Cambridge, in 1984.
The Royal Society awarded him its Hughes Medal in 1976, and he was awarded numerous honorary doctorates and medals by universities and academies in Europe and the United States. He was a member of the Vatican’s Pontifical Academy of Sciences from 1986.
With his first wife, Jane, he had two sons and a daughter. After the end of his marriage to Elaine Mason, Hawking resumed closer relationships with his first family and in 2007 Jane revised her 1999 memoir into the less angry Travelling to Infinity: My Life with Stephen, which was subsequently made into a film as The Theory of Everything, starring Eddie Redmayne and Felicity Jones, in 2014.
Professor Stephen Hawking, born January 8 1942, died March 14 2018