Stephen Hawking, who has died aged 76, managed to transcend the divide between scientific exoticism and popular culture.
He was a giant among the select band of late-20th-century theoretical physicists contemplating the origins and mysteries of the universe. But he also achieved celebrity status, known more for his motorised wheelchair and computerised voice than his esoteric theories of cosmology.
He will perhaps be remembered best as the man with the brilliant mind trapped in a broken body. Since the age of 21, Hawking had lived under the shadow of motor neurone disease which progressively paralysed his muscles but which, unusually, did not kill him within two years of diagnosis – the usual prognosis.
Neither did his medicinal condition prevent him from accomplishing individual satisfaction and expert brightness. Against all the chances, Hawking encountered the rushes and spills of family life, with the delight of three youngsters and the torment of two separations. What's more, he influenced a progression of imperative disclosures in his handled of hypothetical material science and cosmology.
Despite his encroaching paralysis and the loss of his voice in 1985, Hawking managed to formulate a number of important theories concerning the properties of black holes, the expansion of the universe and what can loosely be described as deep insights into the beginning and end of time.
On top of this, he wrote a best-selling science book, A Brief History of Time, first published in 1988. Although famed for its difficult and challenging subject matter, the book laid the foundations for Hawking’s wider appeal. This extended to cameo appearances on The Simpsons and Star Trek – the only guest to play himself (as a hologram) – as well as several lucrative television commercials.
Hawking later achieved Hollywood star-status when he was portrayed in an Oscar-winning performance by actor Eddie Redmayne in The Theory of Everything (2014), which documented the real-life drama of his life with amyotrophic lateral sclerosis, a form of motor neurone disease also known as Lou Gehrig’s disease. Redmayne was so good, Hawking said: “At times, I thought he was me.”
Stephen William Hawking was born in Oxford on 8 January 1942, exactly 300 years after the death of Galileo, a coincidence he found amusing, although he later calculated that about 200,000 other babies were also born on the same day.
Despite being born in Oxford, his father, a medical researcher, and mother were living in London’s bohemian Highgate, where Hawking was sent to the progressive Byron House School. One of his first memories was complaining to his parents that he wasn’t learning anything – an early indication of his thirst for knowledge, and low boredom threshold.
Another early memory was his boyhood fascination with model trains. “I was always very interested in how things operated and used to take them apart to see how they worked, but I was not so good at putting them back together again. My practical abilities never matched up to my theoretical enquiries”, he later recalled.
His family moved to St Albans in 1950 and, when Hawking was 11, he was sent to the private St Albans School next to the city’s cathedral where he was, by his own reckoning, an unexceptional pupil, although his classmates called him “Einstein”. Towards the end of his schooldays, Hawking had decided he wanted to study physics and mathematics. The reason, he said, was that they offered “the hope of understanding where we came from and why we were here”.
He went up to Oxford University, where he did little work as an undergraduate but still managed to scrape a first after a viva voce interview. Hawking later joked that his examiners had asked him in the interview about his plans. He said he’d stay on at Oxford if he got a second, and go to Cambridge if he got a first. “They gave me a first”, he quipped.
Although he had wanted to do a doctorate under Fred Hoyle, the eminent cosmologist who was working at Cambridge at that time, Hawking had to make do with Dennis Sciama, of whom he had never heard. Hawking later said it turned out to be a lucky break as he would inevitably have had to defend Hoyle’s “steady-state theory” of the universe rather than embrace the concept of the Big Bang – a derogatory term that Hoyle himself had coined to describe a universe that had a definite beginning.
It was around this time, in 1963, that Hawking received the devastating news that he was suffering from motor neurone disease. Towards the end of his undergraduate years, he had noticed that his coordination, which was never brilliant, was getting worse. He could no longer row a sculling boat properly and he fell over several times for no apparent reason.
During the Christmas break of 1962, he tumbled while ice-skating on a lake in St Albans and couldn’t get up again. His mother arranged for him to see a doctor and after several weeks of tests and procedures at St Bartholomew’s Hospital in London he became aware that something very serious was wrong.
“They never actually told me what was wrong, but I guessed enough to know it was pretty bad, so I didn’t want to ask. In fact the doctor who diagnosed me washed his hands of me, and I never saw him again. He felt there was nothing that could be done. In effect, my father became my doctor and it was to him that I turned for advice”, Hawking later recalled on his 70th birthday.
He was only 21, and the thought of dying within a couple of years of a progressive neurological illness filled him with dread. There seemed little point in continuing with his PhD because he was not expected to complete it. Understandably he fell into depression.
Yet something kept him going. On New Year’s Day 1963, at a party in St Albans, he had met a girl, Jane Wilde, who was then in her gap year before going up to university in London. They became engaged in 1964. There was something to live for and he realised that to support himself and his new wife he needed a job. His spirits were lifted, aided by the realisation that his condition was progressing more slowly than expected while his PhD research was actually beginning to bear fruit.
“After my expectations had been reduced to zero, every new day became a bonus and I began to appreciate everything I did have. Where there is life there is hope”, he said. His dreams at the time were about grasping any opportunity that life offered.
Hawking became immersed in one the biggest issues of cosmology in the early 1960s – whether or not the universe had a beginning. Hoyle’s steady-state universe was already in trouble but it was effectively killed off by the discovery in 1964 of microwave background radiation – the “echo” of the Big Bang that permeates all of space.
Hawking set about analysing a rival theory to the Big Bang. Some cosmologists had put forward the idea that the universe was cycling from one state of expansion to another state of contraction. However, working with the Oxford mathematician Roger Penrose, Hawking showed that there was a theoretical point where space and time could indeed have a beginning, or a “singularity” and that this conformed to Einstein’s theory of general relatively rather than contradicting it.
From 1970, Hawking applied the same kind of logic about singularities to black holes. He was particularly interested in the “event horizon” of a black hole, the point when light and all other matter are swallowed up at its edge. Hawking later described this period in the early 1970s as a “golden age” in which he and his colleagues solved most of the major problems in black hole theory.
He later adapted quantum theory – the physics of the very small – to immense cosmological structures such as black holes. In doing so, he discovered the possibility of radiation emissions from near the event horizon of a black hole. Until then, cosmologists had not predicted any loss energy or emissions from black holes. These emissions became known as Hawking radiation and their discovery, he later said, was one of his proudest achievements.
It was while he was writing A Brief History of Time, in 1985, that Hawking developed pneumonia and needed an emergency tracheostomy to save his life, but which also meant that he lost his voice. The only way he was able to communicate now was to build up words letter by letter by raising his eyebrows when someone pointed to the correct letter on a spelling board.
However, a computer engineer in California called Walt Woltosz, heard about his plight and sent him a program he had written that allowed Hawking to write and speak by selecting words from a series of menus on a screen. Once he had built up a sentence or two, he could send them to a speech synthesiser to be spoken. From there on, the mind of Hawking would be heard as a mechanical voice, albeit with a distinctive Americanised accent.
A Brief History of Time proved a publishing phenomenon. It sold more than 10 million copies and was on the Sunday Times best-seller list for more than four years. The first edition, published in 1988, carried an introduction by legendary astronomer and science author Carl Sagan, saying that Hawking was a worthy successor to Isaac Newton. Hawking was the Lucasian Professor of Mathematics at the University of Cambridge until his retirement in 2009, a post held by Newton until 1702.
“I never expected A Brief History of Time to do as well as it did”, Hawking said in 2012. “Not everyone may have finished it, or understood everything they read. But they at least got the idea that we live in a universe governed by rational laws that we can discover and understand.”
In his later career, one of the rational laws that Hawking became deeply associated with was M-theory, which is an extension of string theory and postulates the existence of at least 11 dimensions of space-time. M-theory, named after the idea of multidimensional membranes in the fabric of space-time, is the only unified theory which has all the properties that we think the final theory should have, Hawking explained.
“M-theory predicts that a great many universes were created out of nothing. These multiple universes can arise naturally from physical law. Each universe has many possible histories and many possible states at later times, that is, at times like the present, long after their creation”, he said.
“Most of these states will be quite unlike the universe we observe and quite unsuitable for the existence of any form of life. Only a few would allow creatures like us to exist. Thus our presence selects out from this vast array only those universes that are compatible with our existence”, he added.
“Although we are puny and insignificant on the scale of the cosmos, this makes us, in a sense, lords of creation.”
Although Hawking was an atheist, he was not averse to invoking God. One of the most memorable, and contentious, phrases in A Brief History of Time was the sentence describing what it would be like if physicists could formulate a universal “theory of everything” to unite all that they knew about the universe. If such a theory could be found, Hawking wrote, we would then surely know the mind of God.
For some believers, this smacked of arrogance. For non-believers, it hinted at hypocrisy – if God didn’t exist, then why do we need to know what’s on his mind?
Hawking later explained what he meant when interviewed by John Humphrys on Radio 4’s Today programme. “If we discovered the complete set of laws, and understood why the universe existed, we would be in the position of God. We are making progress towards that goal, but we still have some way to go”, he said.
There were other occasions when Hawking courted controversy. He claimed that humans should travel to other planets because of the environmental problems facing Earth; that extra-terrestrial aliens could be preparing to colonise our planet; and that, after all his ruminations over knowing the mind of God, there was in fact no need for a God in order to jump-start creation.
“Stephen Hawking is a remarkable person whom I’ve known for 40 years and for that reason any oracular statement he makes gets exaggerated publicity”, said his friend and colleague Lord Rees of Ludlow (the Astronomer Royal Martin Rees) in 2010. “I know Stephen Hawking well enough to know that he has read very little philosophy and even less theology, so I don’t think we should attach any weight to his views on this topic”, he added.
Like all scientists who stray into subjects outside of their field, Hawking showed that he is just as susceptible as anyone to exaggeration and hyperbole. But within the esoteric sphere of intellectual endeavour that he made his own, he was, like Isaac Newton before him, a true giant from whose shoulders future generations of scientists will see further.