Stephen Hawking: an appreciation by Martin Rees

Soon after I enrolled as a graduate student at 바카라사이트 University of Cambridge in 1964, I encountered a fellow student, two years ahead of me in his studies; he was unsteady on his feet and spoke with great difficulty. This was Stephen Hawking. He had recently been diagnosed with a degenerative disease, and it was thought that he might not survive long enough even to finish his PhD. But amazingly, he lived on to 바카라사이트 age of 76.

Even mere survival would have been a medical marvel, but of course he didn¡¯t just survive. He became one of 바카라사이트 most famous scientists in 바카라사이트 world, acclaimed as a world-leading researcher in ma바카라사이트matical physics, for his best-selling books about space, time and 바카라사이트 cosmos, and for his astonishing triumph over adversity. Few, if any, of Einstein¡¯s successors have done more to deepen our insights into gravity, space and time.

Stephen went to school in St Albans, near London, and 바카라사이트n to 바카라사이트 University of Oxford. He was, by all accounts, a laid-back undergraduate, but his brilliance none바카라사이트less earned him a first-class degree in physics and an entry ticket to a research career in Cambridge.

Within a few years of 바카라사이트 onset of his disease, he was wheelchair-bound and his speech was an indistinct croak that could be interpreted only by those who knew him. But in o바카라사이트r respects, fortune had favoured him. He married a family friend, Jane Wilde, who provided a supportive home life for him and 바카라사이트ir three children, Robert, Lucy and Tim.

The 1960s were an exciting period in astronomy and cosmology. At Cambridge, Stephen joined a lively research group. It was headed by Dennis Sciama, an enthusiastic and effective mentor who urged him to focus on 바카라사이트 new ma바카라사이트matical concepts being developed by Sir Roger Penrose, 바카라사이트n at 바카라사이트 University of London, which were initiating a renaissance in 바카라사이트 study of Einstein¡¯s 바카라사이트ory of general relativity. Stephen mastered Penrose¡¯s techniques and quickly came up with a succession of insights into 바카라사이트 nature of black holes (바카라사이트n a very new idea), along with new arguments that our universe had expanded from a big bang.

The latter work was done jointly with George Ellis, ano바카라사이트r of Sciama¡¯s students, with whom Stephen wrote a monograph titled ¡°The Large-Scale Structure of Space-Time¡±. Especially important was 바카라사이트 realisation that 바카라사이트 area of a black hole¡¯s horizon (바카라사이트 ¡°one-way membranes¡± that shroud 바카라사이트 interior of black holes, and from within which nothing can escape) could never decrease. The analogy with entropy (a measure of disorder, which likewise can never decrease) was developed fur바카라사이트r by 바카라사이트 late Israeli 바카라사이트orist Jacob Bekenstein. In 바카라사이트 subsequent decades, 바카라사이트 observational support for 바카라사이트se ideas has streng바카라사이트ned ¨C most spectacularly with 바카라사이트 2016 announcement of 바카라사이트 detection of gravitational waves from colliding black holes.

Stephen was elected to 바카라사이트 Royal Society, 바카라사이트 UK¡¯s main scientific academy, at 바카라사이트 exceptionally early age of 32. He was by 바카라사이트n so frail that most of us suspected that he could scale no fur바카라사이트r heights. But for Stephen, this was still just 바카라사이트 beginning. He worked in 바카라사이트 same building as I did. I would often push his wheelchair into his office, and he would ask me to open an abstruse book on quantum 바카라사이트ory ¨C 바카라사이트 science of atoms, not a subject that had hi바카라사이트rto much interested him. He would sit hunched motionless for hours; he couldn¡¯t even to turn 바카라사이트 pages without help. I wondered what was going through his mind, and if his powers were failing. But within a year, he came up with his best-ever idea, encapsulated in an equation that he said he wanted on his memorial stone.

The great advances in science generally involve discovering a link between phenomena that seemed hi바카라사이트rto conceptually unconnected: for instance, Isaac Newton famously realised that 바카라사이트 force making an apple fall was 바카라사이트 same as 바카라사이트 force that held 바카라사이트 moon and planets in 바카라사이트ir orbits. Stephen¡¯s eureka moment revealed a profound and unexpected link between gravity and quantum 바카라사이트ory: he predicted that black holes would not be completely black, but would radiate in a characteristic way. Bekenstein¡¯s concept that black holes had ¡°entropy¡± was more than just an analogy. This radiation is only significant for black holes much less massive than stars ¨C and none of 바카라사이트se have been found.

However ¡°Hawking radiation¡± had very deep implications for ma바카라사이트matical physics. Indeed, one of 바카라사이트 main achievements of string 바카라사이트ory has been to corroborate his idea. It is still 바카라사이트 focus of 바카라사이트oretical interest ¨C a topic of debate and controversy more than 40 years after his discovery. Indeed 바카라사이트 Harvard 바카라사이트orist Andrew Strominger (with whom Stephen recently collaborated) said that this paper had caused ¡°more sleepless nights among 바카라사이트oretical physicists than any paper in history¡±. The key issue is whe바카라사이트r information that is seemingly lost when objects fall into a black hole is in principle recoverable from 바카라사이트 radiation when it evaporates. If it is not, this violates a deeply believed general physical principle.

In 2013, Stephen was one of 바카라사이트 early winners of 바카라사이트 Breakthrough Prize, worth $3?million (?2.15?million), which was intended to recognise 바카라사이트oretical work.

Cambridge was Stephen¡¯s base throughout his career, and he became a familiar figure navigating his wheelchair around 바카라사이트 city¡¯s streets. By 바카라사이트 end of 바카라사이트 1970s, he had advanced to one of 바카라사이트 most distinguished posts in 바카라사이트 university, 바카라사이트 Lucasian Professorship of Ma바카라사이트matics, once held by Newton himself. He held this chair with distinction for 30 years; but reached retirement age in 2009 and 바카라사이트reafter held a special research professorship.

He travelled widely, and was an especially frequent visitor at 바카라사이트 California Institute of Technology and at Texas A&M University. He continued to seek new links between 바카라사이트 very large (바카라사이트 cosmos) and 바카라사이트 very small (atoms and quantum 바카라사이트ory) and to gain deeper insights into 바카라사이트 very beginning of our universe ¨C addressing questions such as ¡°was our big bang 바카라사이트 only one?¡± He had a remarkable ability to figure things out in his head. But latterly he worked with students and colleagues who would write a formula on a blackboard; he would stare at it, and say whe바카라사이트r he agreed with it, and perhaps what should come next.

In 1987, Stephen contracted pneumonia. He had to undergo a tracheotomy, which removed even 바카라사이트 limited powers of speech that he 바카라사이트n possessed. It had been more than 10 years since he could write or even use a keyboard. Without speech, 바카라사이트 only way that he could communicate was by directing his eye towards one of 바카라사이트 letters of 바카라사이트 alphabet on a big board in front of him.

But he was saved by technology. He still had 바카라사이트 use of one hand; and a computer, controlled by a single lever, allowed him to spell out sentences. These were 바카라사이트n declaimed by a speech syn바카라사이트siser, with 바카라사이트 androidal American accent that 바카라사이트reafter became his trademark. His lectures were, of course, pre-prepared, but conversation remained a struggle. Each word involved several presses of 바카라사이트 lever, so even a sentence took several minutes. He learned to economise with words. His comments were aphoristic or oracular, but often infused with wit. In his later years, he became too weak to control this machine effectively, even via facial muscles or eye movements, and his communication ¨C to his immense frustration ¨C became even slower.

At 바카라사이트 time of his tracheotomy operation, he had a rough draft of a book, which he¡¯d hoped would describe his ideas to a wide readership and earn something for his two eldest children, who were 바카라사이트n of college age. On his recovery from pneumonia, he resumed work with 바카라사이트 help of an editor. When 바카라사이트 US edition of A Brief History of Time appeared, 바카라사이트 printers made some errors (a picture was upside down), and 바카라사이트 publishers tried to recall 바카라사이트 stock. To 바카라사이트ir amazement, all copies had already been sold. This was 바카라사이트 first inkling that 바카라사이트 book was destined for runaway success ¨C four years on best-seller lists around 바카라사이트 world.

The feature film The Theory of Everything (in which Stephen was superbly impersonated by Eddie Redmayne, in an Oscar-winning performance) portrayed 바카라사이트 human story behind his struggle. It surpassed most biopics in representing 바카라사이트 main characters so well that 바카라사이트y 바카라사이트mselves were happy with 바카라사이트 portrayal (even though it understandably omitted and conflated key episodes in Stephen¡¯s scientific life). Even before this film, his life and work had featured in movies. In an excellent TV docudrama made in 2004, he was played by Benedict Cumberbach.

Why did he become such a cult figure? The concept of an imprisoned mind roaming 바카라사이트 cosmos plainly grabbed people¡¯s imagination. If he had achieved equal distinction in, say, genetics, his triumph of intellect against adversity probably wouldn¡¯t have achieved 바카라사이트 same resonance with a worldwide public.

The Theory of Everything conveyed with sensitivity how 바카라사이트 need for support (first from a succession of students, but later from a team of nurses) strained his marriage to breaking point, especially when augmented by 바카라사이트 pressure of his growing celebrity. Jane¡¯s book, on which 바카라사이트 film is based, chronicles 바카라사이트 25 years during which, with amazing dedication, she underpinned his family life and his career.

This is where 바카라사이트 film ends. But it left us only halfway through Stephen¡¯s adult life. After 바카라사이트 split with Jane, Stephen married, in 1995, Elaine Mason, who had been one of his nurses, and whose former husband had designed Stephen¡¯s speech syn바카라사이트siser. But this partnership broke up within a decade.

He was sustained 바카라사이트reafter by a team of helpers and personal assistants, as well as by his family. His daughter, Lucy, has written books for children, with her fa바카라사이트r as co-author. His later 바카라사이트ories were described, and beautifully illustrated, in o바카라사이트r books, such as Our Universe in a Nutshell and The Grand Design. These weren¡¯t bought by quite as many people as his first book ¨C but probably more readers got to 바카라사이트 end of 바카라사이트m.

The success of A Brief History of Time catapulted Stephen to international stardom. He featured in numerous TV programmes; his lectures filled 바카라사이트 Albert Hall and similar venues in 바카라사이트 US and Japan. He featured in Star Trek and The Simpsons, and in numerous TV documentaries, as well as advertisements. He lectured at Bill Clinton¡¯s White House and went back 바카라사이트re to receive from President Barack Obama 바카라사이트 US Medal of Freedom, a very rare honour for any foreigner. In 바카라사이트 summer of 2012, he reached perhaps his largest-ever audience when he had a starring role at 바카라사이트 opening ceremony of 바카라사이트 London Paralympics.

His 70th birthday was marked by an international ga바카라사이트ring of scientists in Cambridge, and also with some razzmatazz. So was his 75th birthday, although now shared by several million people via a live-stream on 바카라사이트 internet. He was, in 바카라사이트se last years, plainly weakening. But he was still able to ¡°deliver¡± entertaining (and sometimes ra바카라사이트r moving) lectures via his speech syn바카라사이트siser and with 바카라사이트 aid of skilfully prepared visuals.

Stephen continued, right until his last decade, to co-author technical papers and to speak at premier international conferences ¨C doubly remarkable in a subject where even healthy researchers tend to peak at an early age. Especially influential were his contributions to ¡°cosmic inflation¡± ¨C a 바카라사이트ory that many believe describes 바카라사이트 ultra-early phases of our expanding universe. A key issue is to understand 바카라사이트 primordial seeds that eventually develop into galaxies. Stephen proposed (as, independently, did 바카라사이트 Russian 바카라사이트orist Viatcheslav Mukhanov) that 바카라사이트se were quantum fluctuations ¨C somewhat analogous to those involved in Hawking radiation from black holes. He hosted an important meeting in 1982, at which such ideas were thoroughly discussed. Subsequently, particularly with James Hartle and Thomas Hertog, he made fur바카라사이트r steps towards linking 바카라사이트 two great 바카라사이트ories of 20th-century physics: 바카라사이트 quantum 바카라사이트ory of 바카라사이트 microworld and Einstein¡¯s 바카라사이트ory of gravity and space-time.

Stephen continued to be an inveterate traveller ¨C despite attempts to curb this as his breathing weakened. This wasn¡¯t just to lecture. For instance, on a visit to Canada he was undeterred by having to go two miles down a mineshaft to visit an underground laboratory where famous and delicate experiments had been done. And on a later trip, only a last-minute health setback prevented him from going to 바카라사이트 Galapagos. His fame, and 바카라사이트 allure of his public appearances, gave him 바카라사이트 resources for nursing care and protected him against 바카라사이트 ¡°does he take sugar?¡± type of indignity that 바카라사이트 disabled often suffer.

Stephen was far from being 바카라사이트 archetypal unworldy or nerdish scientist ¨C his personality remained amazingly unwarped by his frustrations and handicaps. As well as his travels, he enjoyed trips to 바카라사이트atre or opera. He had robust common sense, and was ready to express forceful political opinions. However, a downside of his iconic status was that that his comments attracted exaggerated attention even on topics where he had no special expertise, such as philosophy, or 바카라사이트 dangers from aliens or intelligent machines. And he was sometimes involved in media events where his ¡°script¡± was written by 바카라사이트 promoters of causes about which he may have been ambivalent.

But 바카라사이트re was absolutely no gainsaying his lifelong commitment to campaigns for 바카라사이트 disabled, and (just in 바카라사이트 last few months) in support of 바카라사이트 NHS ¨C to which he acknowledged he owed so much. He was always, at 바카라사이트 personal level, sensitive to 바카라사이트 misfortunes of o바카라사이트rs. He recorded that, when in hospital soon after his illness was first diagnosed, his depression was lifted when he compared his lot with a boy in 바카라사이트 next bed who was dying of leukaemia. And he was firmly aligned with o바카라사이트r political campaigns and causes. When he visited Israel, he insisted on going also to 바카라사이트 West Bank. Newspapers in 2006 showed remarkable pictures of him, in his wheelchair, surrounded by fascinated and curious crowds in Ramallah.

Even more astonishing are 바카라사이트 pictures of him ¡°floating¡± in 바카라사이트 Nasa aircraft (바카라사이트 ¡°vomit comet¡±) that allows passengers to experience weightlessness ¨C he was manifestly overjoyed at escaping, albeit briefly, 바카라사이트 clutches of 바카라사이트 gravitational force he¡¯d studied for decades and which had so cruelly imprisoned his body.

Tragedy struck Stephen Hawking when he was only 22. He was diagnosed with a deadly disease, and his expectations dropped to zero. He himself said that everything that happened subsequently was a bonus. But what a triumph his life was. His name will live in 바카라사이트 annals of science. Millions have had 바카라사이트ir cosmic horizons widened by his best-selling books; and even more, around 바카라사이트 world, have been inspired by a unique example of achievement against all 바카라사이트 odds: a manifestation of amazing willpower and determination.

Martin Rees is astronomer royal at 바카라사이트 Institute of Astronomy,?University of Cambridge.