Remembering Stephen HAWKING 08.01.1942 – 14.03.2018
One of modern cosmology’s most brilliant minds and sharpest wits passed away in March. Paul Sutherland looks back at the life of Stephen Hawking
Stephen Hawking’s death on 14 March, aged 76, robbed the world of one of its most recognisable scientists. His genius was compared to the likes of Isaac Newton and Albert Einstein, and though a cruel illness confined him to a motorised wheelchair for most of his life, his brilliant mind took him to the farthest reaches of the Universe.
Professor Hawking was born in Oxford on 8 January 1942, the 300th anniversary of Galileo’s death. He was the eldest of four. Father Frank was an expert in tropical diseases and, like mother Isobel, a former student at Oxford. Hawking showed an early interest in astronomy and was encouraged by Isobel to look at the stars from their garden. The family moved to St Albans when Hawking was eight. He was rather laid back at school, but won a place at University College, Oxford, at 17, achieving a First Class Honours degree in Natural Science.
Hawking moved on to the Department of Applied Mathematics and Theoretical Physics at Cambridge in 1962 to pursue a PhD in cosmology. He had hoped to study under the legendary Fred Hoyle, but had to settle for a less well-known supervisor, Dennis Sciama. This was probably fortunate because, whereas Hoyle was rather fixated on the notion of a Universe that had always been around, Sciama enthusiastically supported new ideas in cosmology. A long-running debate over how the Universe began was favouring the concept of a Big Bang – a name coined by Hoyle in an interview as a term of derision – and there was growing interest in the existence of black holes.
Hawking was fascinated by the idea of black holes, known as singularities back then. He saw the Big Bang as being like a singularity in reverse. Whereas anything that fell into a black hole essentially disappeared, the whole of space and time had sprung spontaneously into existence.
Expanding the universe
By this time Hawking had noticed increasing problems with his health, including occasional falls and slurring of speech. In 1963, aged 21, he was diagnosed as suffering from amyotrophic lateral sclerosis, a form of motor neurone disease that removes muscular control.
Fortunately the disease did not diminish the mind. Hawking overcame initial depression and threw himself into his work. And though some had feared he would not live long enough to complete his PhD, he confounded them by surviving a further 55 years.
Hawking achieved his PhD in 1965 with his thesis Properties of Expanding Universes, examining how galaxies and black holes form and evolve. The University of Cambridge made it freely
available to download in 2017. Demand was so great, it brought down the server. Hawking published his first academic book, The
Large Scale Structure of Space-Time, with colleague George Ellis in 1973. One of its major points was that the area of a black hole’s event horizon, beyond which everything was forever lost, could never decrease in size. A year later, aged just 32, he was elected a Fellow of the Royal Society. And in 1979 he became Lucasian Professor of Mathematics at Cambridge, a post held by Newton.
Hawking was showing growing interest in the very small as well as the astronomically large, turning his attention to the science of atomic particles, or quantum theory, and how it related to the Universe. It led to his most famous discovery, that black holes leak energy back into space and will eventually evaporate.
The natural order of the Universe is to become more chaotic, a phenomenon called entropy. If matter falling into a black hole took its entropy with it, that would violate the second law of thermodynamics, which says that the total entropy in the Universe always increases.
A young American scientist, Jacob Bekenstein, suggested that the black hole’s growing event horizon might hold on to the entropy that appeared lost. Hawking set out to prove the idea wrong, but instead, in 1974, showed mathematically how it happens. He realised that as one particle disappeared into a black hole, another must escape from its edge. This became known as Hawking radiation. The force would be so small as to be undetectable in black holes observed across the cosmos. But Hawking believed that the Big Bang itself produced tiny black holes, smaller than atoms, that each exploded with the force of a million hydrogen bombs.
Hawking also changed his opinion on another challenging problem, namely what happens to all the information that falls into a black hole once it evaporates away. In 1976 he argued that the information was forever lost, even though quantum mechanics did not allow for that. But in 2004 he admitted he was wrong.
Following mapping of background radiation from the Big Bang by the Cosmic Background Explorer satellite, COBE, in 1992, Hawking said it showed fluctuations from slight irregularities in the Universe that caused regions to collapse to form stars and galaxies. Other fields of interest included the possibility that black holes might be the seeds of other, baby universes. And in an idea straight out of Doctor Who, he suggested that wormholes in the space-time continuum could provide short cuts across the Universe.
A defining voice
All the while that Hawking was investigating the mysteries of the Universe, he was facing more personal challenges. After contracting pneumonia in 1987, he underwent a tracheotomy and lost his already limited ability to speak. A speech synthesiser gave him the robotic voice that would become synonymous with him. At first he could operate it with his hand, but eventually only with a twitch of his cheek, making it a slow and tedious process.
“He believed the Big Bang created sub-atomic black holes that exploded with the force of a million hydrogen bombs”
Despite advances in speech synthesis, he stuck with the original voice that became his trademark.
Hawking had married family friend Jane Wilde in 1965, and they had three children, Robert, Lucy and Timothy. The couple divorced in 1995 and Hawking married one of his nurses, Elaine Mason. That relationship ended in 2006 after which Hawking grew close to Jane again.
Hawking had a great sense of fun, and those who met him remarked on the twinkle in his eye. By all accounts he loved to party, and his lectures – many viewable online – are laced with jokes.
Hawking was awarded the Presidential Medal of Freedom by Barack Obama in 2009. He used his status to shine a light on wider issues than cosmology, urging humanity to move swiftly to colonise other worlds before catastrophe struck our own. And in 2014, he warned of the rise of the robots, saying artificial intelligence could spell the end of the human race.
The professor also feared that alerting alien races to our presence could end badly for us. But in 2016 he was a leading supporter of Breakthrough Starshot’s plan to send a fleet of tiny spacecraft to Alpha Centauri to search for habitable planets. On more down-to-earth issues, he championed the National Health Service.
Hawking had been a physically active youth, and a rowing coxswain at Oxford. Despite his illness he never lost his sense of adventure. He travelled the world and was offered a sub-orbital flight by Virgin Galactic after he told of his desire to go into space. While he never achieved spaceflight, he did experience weightlessness in 2007 on a parabolic flight with the Zero-G Corporation.
Perhaps Hawking’s greatest proof was that physical disability need not hamper a full and successful life. His achievements will ensure his name lives on.
Hawking married Jane Wilde in St Albans in 1965. “We didn’t know how long Stephen was going to live,” Jane later recalled
Cambridge students claimed Hawking could be a menace on campus with his wheelchair. He even joked himself about being a bad driver
Physicist, wit, author, occasional Transformer and general genius, Stephen Hawking not only rewrote the science books, but also helped break down prejudices about disability Hawking coxed at Oxford, but his daredevil steering led to the boat often...
Barack Obama chats with Hawking and his daughter Lucy before presenting him with his Presidential Medal of Freedom in August 2009
“I could have gone on and on. Space, here I come,” said Hawking after his Zero-G flight in 2007