Soon after I enrolled as a graduate student at Cambridge University in 1964, I encountered a fellow student, two years ahead of me in his studies, who 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 he lived to the age of 76, passing away on March 14, 2018.
It really was astonishing. Even mere survival would have been a medical marvel, but of course he didn’t just survive. He became one of the most famous scientists in the world “ acclaimed as a world-leading researcher in mathematical physics, for his best-selling books and for his astonishing triumph over adversity.
Early work
The 1960s were an exciting period in astronomy and cosmology. This was the decade when evidence began to emerge for black holes and the Big Bang. In Cambridge, Hawking focused on the new mathematical concepts being developed by the mathematical physicist Roger Penrose, which were initiating a renaissance in the study of Einstein’s theory of general relativity.
He worked out that the universe must have emerged from a “singularity” “ a point in which all laws of physics break down and realised that the area of a black hole’s event horizon “ a point from which nothing can escape “ could never decrease. In subsequent decades, the observational support for these ideas has strengthened “ most spectacularly with the 2016 announcement of the detection of gravitational waves from colliding black holes.
Hawking was elected to the Royal Society, Britain’s main scientific academy, at the exceptionally early age of 32. He was by then so frail that most of us suspected that he could scale no further heights. But, for Hawking, this was still just the beginning.
The great advances in science generally involve discovering a link between phenomena that seemed hitherto conceptually unconnected. Hawking’s “eureka moment” revealed a profound and unexpected link between gravity and quantum theory: he predicted that black holes would not be completely black, but would radiate energy in a characteristic way.
This radiation is only significant for black holes that are much less massive than stars “ and none of these have been found. However, “Hawking radiation” had very deep implications for mathematical physics.
He was specially influential in his contributions to “cosmic inflation” “ a theory that many believe describes the ultra-early phases of our expanding universe. A key issue is to understand the primordial seeds which eventually develop into galaxies. Hawking proposed (as, independently, did the Russian theorist Viatcheslav Mukhanov) that these were “quantum fluctuations” (temporary changes in the amount of energy in a point in space) “ somewhat analogous to those involved in “Hawking radiation” from black holes.
He also made further steps towards linking the two great theories of 20th century physics: the quantum theory of the microworld and Einstein’s theory of gravity and space-time.
In 1987, Hawking contracted pneumonia. He had to undergo a tracheotomy, which removed even the limited powers of speech he then possessed. It had been more than ten years since he could write, or even use a keyboard. Without speech, the only way he could communicate was by directing his eye towards one of the letters of the alphabet on a big board in front of him.
But he was saved by technology. He still had the use of one hand; and a computer, controlled by a single lever, allowed him to spell out sentences. These were then declaimed by a speech synthesiser, with the androidal American accent that thereafter became his trademark.
His lectures were pre-prepared, but conversation remained a struggle. Each word involved several presses of the lever, so even a sentence took several minutes to construct. He learnt to economise. His comments were aphoristic or oracular, often infused with wit. In his later years, he became too weak to control this machine even via facial muscles or eye movements, and his communication “ to his immense frustration “ became even slower.
He also became somewhat of a cult figure, featuring on popular TV shows from the Simpsons to The Big Bang Theory. As shown in the feature film The Theory of Everything, which tells the human story behind his struggle, Hawking was far from being the archetype unworldy or nerdish scientist. His personality remained amazingly unwarped by his frustrations and handicaps. 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 “ for instance, philosophy, or the dangers from aliens or from intelligent machines. And he was sometimes involved in media events where his “script” was written by the promoters of causes about which he may have been ambivalent.
Ultimately, Hawking’s life was shaped by the tragedy that struck him when he was only 22. His name will live in the annals of science and millions have had their cosmic horizons widened by his best-selling books. He has also inspired millions by a unique example of achievement against all the odds “ a manifestation of amazing willpower and determination.
