World-famous physicist who theorised about black holes

“If science could find ‘a theory of everything’, then, he said, we would finally ‘know the mind of God’”

He may not have been the world’s greatest scientist, but Stephen Hawking was certainly its most famous. Roaming “the cosmos from a wheelchair, pondering the nature of gravity and the origin of the universe”, he captured the world’s imagination like no scientist since Einstein, said The New York Times – and became a striking emblem of human “determination and curiosity”. His 1988 book, A Brief History of Time, has sold more than ten million copies, and he became not only acclaimed in his field, for his work exploring the properties of those mysterious entities known as black holes, but also something of a pop cultural icon. An Oscar-winning film was made of his life; he mingled with presidents and rock stars; and he popped up in numerous TV shows, including Star Trek and The Simpsons. In the latter, the great theoretical physicist and Lucasian Professor of Mathematics, who has died aged 76, was seen sharing a beer with Homer Simpson in Moe’s Tavern and congratulating him, in his instantly recognisable synthesised voice, for his theory that the universe is shaped like a doughnut.

Stephen Hawking was born on 8 January 1942 – 300 years to the day after the death of Galileo, as he liked to point out – and brought up in an academic and bohemian household in St Albans, the eldest of four children. His father, Frank, was a prominent medical researcher; his mother, Isobel, had studied PPE at Oxford. As a child, he and his mother would sit in the garden and gaze at the evening sky. “Stephen always had a strong sense of wonder and I could see that the stars would draw him,” she once said. At St Albans School, he was considered something of a boffin, said The Daily Telegraph – skinny, bespectacled and uncoordinated, and bad at games, except cross-country running. Although some of his peers noted his extraordinary ability to grasp any given mathematical problem, he didn’t excel academically: in one year, he finished third from the bottom of his class. But studying physics and then natural science at University College, Oxford, he found it all so easy, he barely had to do any work – he reckoned about an hour a day. A sociable student, he coxed a college eight, and graduated with a first in 1962.

From Oxford he moved to Cambridge, to study cosmology under Dennis Sciama. He’d always preferred theory to observation; he said he found cosmology exciting because it asks “the big question: Where did the universe come from?” But by then, he’d already noticed that something was awry: his speech was slurred, he had trouble tying his shoelaces. Then, in 1963, came the shattering diagnosis: a rare form of motor neurone disease called amyotrophic lateral sclerosis. He was told he had two years to live. He was 21.

For the next few months, he shut himself away in his room, listening to Wagner at full volume. But then the disease seemed to stabilise; he fell in love with a language student, Jane Wilde, and thanks largely to her, found the strength to carry on. Later, he would say that after receiving his diagnosis, he reset his expectations of life to zero – everything that came after was a bonus. In 1965, he and Jane married (earlier than they might have, because he thought he hadn’t long to live), and he identified, after reading a paper by Roger Penrose, his academic speciality: black holes. Predicted by Einstein’s theory of relativity (though Einstein himself did not believe in them), black holes are infinitely dense remnants of dead stars where gravity is so strong nothing can escape, not even light. For his PHD, Hawking – with help from Penrose and others – used his understanding of black holes to show that Einstein’s general relativity implied the Big Bang, this at a time when many leading scientists were still championing the rival Steady State model. Later, he showed that black holes “ain’t so black”, as he put it: instead, owing to quantum mechanical effects, they “glow” as some particles escape. Known as Hawking radiation, this phenomenon has yet to be observed, but is widely believed to exist. The realisation that quantum mechanics, which affect the smallest things in the universe, could also affect the biggest was “doubly significant”, said The Times. “Like Einstein before him, he was desperate to find a way of linking the subatomic world with the cosmological: to find a ‘theory of everything’.” If only science could do this, he said, we would finally “know the mind of God”.

He began work on A Brief History of Time in the mid-1980s. He had just lost his voice box and his condition had so deteriorated that he could only type with one finger on an electronic voice synthesizer, producing at most 15 words per minute. Anxious that he might not have long to live, he hoped the book would make a bit of extra money for his family once he was gone. Instead, it changed his own life beyond all measure. It topped the bestseller lists for four years and Hawking became a global celebrity. It’s not clear how many people who bought the book actually read it, but even those who struggled to understand his theories were inspired by his courage, and moved by the thought of a “great mind trapped in a weak and fallible body”. Hawking, a man with an acerbic sense of humour and a (necessarily) pithy turn of phrase, was fully aware of the nature of his appeal. “No one can resist the idea of a crippled genius,” he said.

Hawking and Wilde had three children. Bringing up a family with a husband who not only required 24-hour care, but who was also passionately dedicated to his work had often put Wilde under huge strain. His new-found celebrity status made her life yet more difficult. They drifted apart. Then in 1990 he left her and went on to marry his nurse, Elaine Mason, in 1995. That marriage was rocked by controversy: there were claims, which he denied, that she was abusing him, and they divorced in 2006. Although initially hurt and angry, Wilde was subsequently able to make her peace with her ex-husband: it was her candid but affectionate book about their relationship, Travelling to Infinity (2007), that formed the basis of the film The Theory of Everything (2014), starring Eddie Redmayne. In his final years, Hawking could communicate only through a twitch of a muscle in one of his cheeks, yet he kept working: two weeks before his death (on the 139th anniversary of Einstein’s birth) he’d completed a new paper, which reportedly provides mathematical evidence for the theory that there were multiple Big Bangs, each creating its own universe – the “multiverse” theory.