Renowned Physicist Stephen Hawking Dies At 76
Stephen Hawking possessed one of the greatest minds in history, but he will likely be most remembered for not letting a debilitating disease stop him from contributing to our understanding of the universe.
Stephen Hawking, who was arguably one of the greatest minds in history notwithstanding spending the last several decades of his life confined to a wheelchair and forced to communicate via a computer, has died at the age of 76:
Stephen W. Hawking, the Cambridge University physicist and best-selling author who roamed the cosmos from a wheelchair, pondering the nature of gravity and the origin of the universe and becoming an emblem of human determination and curiosity, died early Wednesday at his home in Cambridge, England. He was 76.
His death was confirmed by a spokesman for Cambridge University.
“Not since Albert Einstein has a scientist so captured the public imagination and endeared himself to tens of millions of people around the world,” Michio Kaku, a professor of theoretical physics at the City University of New York, said in an interview.
Dr. Hawking did that largely through his book “A Brief History of Time: From the Big Bang to Black Holes,” published in 1988. It has sold more than 10 million copies and inspired a documentary film by Errol Morris. The 2014 film about his life, “The Theory of Everything,” was nominated for several Academy Awards and Eddie Redmayne, who played Dr. Hawking, won the Oscar for best actor.
Scientifically, Dr. Hawking will be best remembered for a discovery so strange that it might be expressed in the form of a Zen koan: When is a black hole not black? When it explodes.
What is equally amazing is that he had a career at all. As a graduate student in 1963, he learned he had amyotrophic lateral sclerosis, a neuromuscular wasting disease also known as Lou Gehrig’s disease. He was given only a few years to live.
The disease reduced his bodily control to the flexing of a finger and voluntary eye movements but left his mental faculties untouched.
He went on to become his generation’s leader in exploring gravity and the properties of black holes, the bottomless gravitational pits so deep and dense that not even light can escape them.
That work led to a turning point in modern physics, playing itself out in the closing months of 1973 on the walls of his brain when Dr. Hawking set out to apply quantum theory, the weird laws that govern subatomic reality, to black holes. In a long and daunting calculation, Dr. Hawking discovered to his befuddlement that black holes — those mythological avatars of cosmic doom — were not really black at all. In fact, he found, they would eventually fizzle, leaking radiation and particles, and finally explode and disappear over the eons.
Nobody, including Dr. Hawking, believed it at first — that particles could be coming out of a black hole. “I wasn’t looking for them at all,” he recalled in an interview in 1978. “I merely tripped over them. I was rather annoyed.”
That calculation, in a thesis published in 1974 in the journal Nature under the title “Black Hole Explosions?,” is hailed by scientists as the first great landmark in the struggle to find a single theory of nature — to connect gravity and quantum mechanics, those warring descriptions of the large and the small, to explain a universe that seems stranger than anybody had thought.
The discovery of Hawking radiation, as it is known, turned black holes upside down. It transformed them from destroyers to creators — or at least to recyclers — and wrenched the dream of a final theory in a strange, new direction.
“You can ask what will happen to someone who jumps into a black hole,” Dr. Hawking said in an interview in 1978. “I certainly don’t think he will survive it.
“On the other hand,” he added, “if we send someone off to jump into a black hole, neither he nor his constituent atoms will come back, but his mass energy will come back. Maybe that applies to the whole universe.”
Dennis W. Sciama, a cosmologist and Dr. Hawking’s thesis adviser at Cambridge, called Hawking’s thesis in Nature “the most beautiful paper in the history of physics.”
Edward Witten, a theorist at the Institute for Advanced Study in Princeton, said: “Trying to understand Hawking’s discovery better has been a source of much fresh thinking for almost 40 years now, and we are probably still far from fully coming to grips with it. It still feels new.”
In 2002, Dr. Hawking said he wanted the formula for Hawking radiation to be engraved on his tombstone.
He was a man who pushed the limits — in his intellectual life, to be sure, but also in his professional and personal lives. He traveled the globe to scientific meetings, visiting every continent, including Antarctica; wrote best-selling books about his work; married twice; fathered three children; and was not above appearing on “The Simpsons,”“Star Trek: The Next Generation” or “The Big Bang Theory.”
He celebrated his 60th birthday by going up in a hot-air balloon. The same week, he also crashed his electric-powered wheelchair while speeding around a corner in Cambridge, breaking his leg.
In April 2007, a few months after his 65th birthday, he took part in a zero-gravity flight aboard a specially equipped Boeing 727, a padded aircraft that flies a roller-coaster trajectory to produce fleeting periods of weightlessness. It was a prelude to a hoped-for trip to space with Richard Branson’s Virgin Galactic company aboard SpaceShipTwo.
Asked why he took such risks, Dr. Hawking said, “I want to show that people need not be limited by physical handicaps as long as they are not disabled in spirit.”
Stephen William Hawking was born in Oxford, England, on Jan. 8, 1942 — 300 years to the day, he liked to point out, after the death of Galileo, who had begun the study of gravity. His mother, the former Isobel Walker, had gone to Oxford to avoid the bombs that fell nightly during the Blitz of London. His father, Frank Hawking, was a prominent research biologist.
The oldest of four children, Stephen was a mediocre student at St. Albans School in London, though his innate brilliance was recognized by some classmates and teachers.
Later, at University College, Oxford, he found his studies in mathematics and physics so easy that he rarely consulted a book or took notes. He got by with a thousand hours of work in three years, or one hour a day, he estimated. “Nothing seemed worth making an effort for,” he said.
The only subject he found exciting was cosmology because, he said, it dealt with “the big question: Where did the universe come from?”
Upon graduation, he moved to Cambridge. Before he could begin his research, however, he was stricken by what his research adviser, Dr. Sciama, came to call “that terrible thing.”
The young Hawking had been experiencing occasional weakness and falling spells for several years. Shortly after his 21st birthday, in 1963, doctors told him that he had amyotrophic lateral sclerosis. They gave him less than three years to live.
His first response was severe depression. He dreamed he was going to be executed, he said. Then, against all odds, the disease appeared to stabilize. Though he was slowly losing control of his muscles, he was still able to walk short distances and perform simple tasks, though laboriously, like dressing and undressing. He felt a new sense of purpose.
“When you are faced with the possibility of an early death,” he recalled, “it makes you realize that life is worth living and that there are a lot of things you want to do.”
In 1965, he married Jane Wilde, a student of linguistics. Now, by his own account, he not only had “something to live for”; he also had to find a job, which gave him an incentive to work seriously toward his doctorate.
His illness, however, had robbed him of the ability to write down the long chains of equations that are the tools of the cosmologist’s trade. Characteristically, he turned this handicap into a strength, gathering his energies for daring leaps of thought, which, in his later years, he often left for others to codify in proper mathematical language.
“People have the mistaken impression that mathematics is just equations,” Dr. Hawking said. “In fact, equations are just the boring part of mathematics.”
By necessity, he concentrated on problems that could be attacked through “pictures and diagrams,” adopting geometric techniques that had been devised in the early 1960s by the mathematician Roger Penrose and a fellow Cambridge colleague, Brandon Carter, to study general relativity, Einstein’s theory of gravity.
Black holes are a natural prediction of that theory, which explains how mass and energy “curve” space, the way a sleeping person causes a mattress to sag. Light rays will bend as they traverse a gravitational field, just as a marble rolling on the sagging mattress will follow an arc around the sleeper.
Too much mass or energy in one spot could cause space to sag without end; an object that was dense enough, like a massive collapsing star, could wrap space around itself like a magician’s cloak and disappear, shrinking inside to a point of infinite density called a singularity, a cosmic dead end, where the known laws of physics would break down: a black hole.
Einstein himself thought this was absurd when the possibility was pointed out to him.
Using the Hubble Space Telescope and other sophisticated tools of observation and analysis, however, astronomers have identified hundreds of objects that are too massive and dark to be anything but black holes, including a supermassive one at the center of the Milky Way. According to current theory, the universe should contain billions more.
As part of his Ph.D. thesis in 1966, Dr. Hawking showed that when you ran the film of the expanding universe backward, you would find that such a singularity had to have existed sometime in cosmic history; space and time, that is, must have had a beginning. He, Dr. Penrose and a rotating cast of colleagues went on to publish a series of theorems about the behavior of black holes and the dire fate of anything caught in them.
Dr. Hawking’s signature breakthrough resulted from a feud with the Israeli theoretical physicist Jacob Bekenstein, then a Princeton graduate student, about whether black holes could be said to have entropy, a thermodynamic measure of disorder. Dr. Bekenstein said they could, pointing out a close analogy between the laws that Dr. Hawking and his colleagues had derived for black holes and the laws of thermodynamics.
Dr. Hawking said no. To have entropy, a black hole would have to have a temperature. But warm objects, from a forehead to a star, radiate a mixture of electromagnetic radiation, depending on their exact temperatures. Nothing could escape a black hole, and so its temperature had to be zero. “I was very down on Bekenstein,” Dr. Hawking recalled.
To settle the question, Dr. Hawking decided to investigate the properties of atom-size black holes. This, however, required adding quantum mechanics, the paradoxical rules of the atomic and subatomic world, to gravity, a feat that had never been accomplished. Friends turned the pages of quantum theory textbooks as Dr. Hawking sat motionless staring at them for months. They wondered if he was finally in over his head.
When he eventually succeeded in doing the calculation in his head, it indicated to his surprise that particles and radiation were spewing out of black holes. Dr. Hawking became convinced that his calculation was correct when he realized that the outgoing radiation would have a thermal spectrum characteristic of the heat radiated by any warm body, from a star to a fevered forehead. Dr. Bekenstein had been right.
Dr. Hawking even figured out a way to explain how particles might escape a black hole. According to quantum principles, the space near a black hole would be teeming with “virtual” particles that would flash into existence in matched particle-and-antiparticle pairs — like electrons and their evil twin opposites, positrons — out of energy borrowed from the hole’s intense gravitational field.
In later years, Hawking’s mind had started to focus on the mysteries of the beginning of the universe and what, if anything might have existed before it and, inevitably, religion:
In “A Brief History of Time,” he had referred to the “mind of God,” but in “The Grand Design,” a 2011 book he wrote with Leonard Mlodinow, he was more bleak about religion. “It is not necessary to invoke God to light the blue touch paper,” he wrote, referring to the British term for a firecracker fuse, “and set the universe going.”
He went further in an interview that year in The Guardian, saying: “I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken-down computers; that is a fairy story for people afraid of the dark.”
Having spent the best part of his life grappling with black holes and cosmic doom, Dr. Hawking had no fear of the dark.
“They’re named black holes because they are related to human fears of being destroyed or gobbled up,” he once told an interviewer. “I don’t have fears of being thrown into them. I understand them. I feel in a sense that I am their master.”
There’s much more to the discussion of Hawking’s work in the New York Times obituary I’ve excerpted here, and I recommend reading the whole thing for a fuller understanding of just how remarkable a mind Hawking had. What is remarkable and inspiring about his life, of course, is the fact that he ultimately did not lead a crippling and cruel disease prevent him from contributing to the knowledge of mankind and making breakthroughs in our understanding of the nature of the universe. No doubt, the work he did will be studied, cited, and expanded upon for generations and perhaps take us in directions that even Professor Hawking himself could not anticipate. In that sense, it’s appropriate to note that Hawking was born on the 300th anniversary of the day that Galileo Galilei was born and died on the 139th anniversary of the day that Albert Einstein was born. Like Galileo and Einstein, Hawking will go down in history as one of humanity’s great minds.