It was not without reason that he was compared to Albert Einstein. Rarely do scientists become as famous as he did, even though his work, just like Einstein’s, was largely incomprehensible to most people outside the domain of his expertise. What added to his aura was the fact that he triumphed in science despite his debilitating physical disability. For the last three decades, Stephen Hawking, a British theoretical physicist and cosmologist, who died today aged 76, was the best identified, and possibly the most admired, scientist in the world.
Confined to a wheelchair because of his near complete paralysis, and able to speak only through a computerised speech generator, Hawking regularly appeared in public for lectures and talks that were hugely popular, especially among students and youngsters who used to feel transported to the fascinating world of black holes and other remarkable heavenly bodies in outer space that could only be imagined in science fiction.
Hawking’s talks, however, were anything but fiction. He spoke of amazing discoveries made by physics and cosmology in the 20th century and the possibilities that these pointed to, and inspired people to think and imagine the universe beyond the obvious. “Stephen Hawking was a larger than life figure. People may not remember him so much for his work on black holes but on how he brought science in the public gaze. The man on the street might not be aware of his scientific theories and research, but admired him for the way he overcame his afflictions,” said Somak Raychaudhury, director of the Pune-based Inter-University Centre for Astronomy and Astrophysics.
Raychaudhury did his PhD at the University of Cambridge where Hawking has worked for most of his career. “I was a 22-year-old student at Cambridge when I first met Hawking in the 1980s. He was in a wheelchair but had not undergone the operation that took away his ability to speak. In fact, I had attended a series of lectures that eventually became part of his best-selling book ‘A Brief History of Time’,” Raychaudhury said. Pune’s own Jayant Narlikar happened to be a contemporary of Hawking at Cambridge in the early 1960s. In fact, Hawking had arrived at Cambridge hoping to do his PhD under noted astronomer Fred Hoyle, who Narlikar was working with at that time. Hawking eventually worked with someone else for his PhD.
“Though we interacted only occasionally, we were both students at the same department at the Cambridge University. I guess he was a couple of years junior to me. I still remember him being an extremely hardworking and dedicated person on the campus who set out to achieve something big,” said Narlikar.
In fact, in his PhD dissertation, Hawking had pointed to problems in a theory of gravity proposed by Narlikar and Hoyle. Hawking’s subsequent work eventually made the ‘Big Bang’ the most accepted theory of the origin of the universe. Narlikar, on the other hand, has not been entirely convinced of the Big Bang. But he acknowledged Hawking’s achievements nonetheless. “He had a very sharp power to think and reason. His finding that black holes radiated energy was a milestone in black hole physics, as it went completely against the prevailing wisdom then… His works on Big Bang theory and space-time-singularity will be something he will always be remembered for,” Narlikar said.
Hawking was best known for his work on black holes, those unimaginably dense structures in the universe that remain one of the most puzzling subjects in cosmology. In 1974, he showed that rotating black holes emit radiation — later named Hawking radiation — that leads to a loss of energy and the ultimate evaporation of the black hole. This was contrary to the then prevailing understanding of black holes which were known not to let anything escape from them. A few years later, Hawking proposed that during this evaporation process, the ‘information’ contained in the black hole vanishes permanently. This set off a major debate — unsettled till date — because its consequences were seen as violating the quantum theory that describes the behaviour of sub-atomic particles.
“The work that he did along with his colleagues like Roger Penrose and Jacob Beckenstein would have made him famous anyway. I think he would have been a household name even if he did not get into public outreach of science so much. He had already earned fame through his scientific achievements. It was ground-breaking research and added, in very fundamental ways, new information to our understanding of the universe,” Gautam Mandal, a senior professor at the Mumbai-based Tata Institute of Fundamental Research, who works in the related fields of quantum field theory, string theory and gravity, said. Mandal said besides being an outstanding scientist, Hawking had a very jovial and pleasing personality which endeared him to his audience. “He had a very British sense of humour. You could sense a wicked smile on his face when he was about to crack a joke. And that was quite often,” he said.
Sandip Trivedi, director of TIFR, recalled how he had found Hawking wearing a kurta in his hotel room during his 2001 India visit and had complimented him for it. “He immediately replied (through his machine) ‘But where is your kurta? He had a great sense of repartee and always had a comeback,” said Trivedi. “He was an inspiring figure, not just for scientists but the general public as well. People were just in awe of him. I remember when he had given this public talk at TIFR in 2001, a massive crowd had gathered, and he started by telling the audience ‘You must be wondering how I think about myself’, and then proceeded to say that he thought of himself as a scientist with some qualities or traits that are peculiar to them, to any other scientist’. This was his way of conveying that he had indeed overcome all the odds, even in his mind. There was immediate response from the crowd in the form of a thunderous applause,” Trivedi said.
“He had this amazing ability to connect to people. He was a great communicator. And of course, the subjects he used to deal with, black holes, outer universe, are very fascinating topics. People loved listening to him,” he said.
Raychaudhury of IUCAA said one of his greatest regrets was being unable to get Hawking to Pune. “Much as we tried we could not get Hawking for a conference on general relativity that was organised in 1997. He was extremely ill at that time and couldn’t come… After Einstein, he was probably the most iconic scientific figure. Science needs ambassadors like Hawking,” said Raychaudhury.