Stephen Hawking, physicist who came to symbolize the power of the human ...

Stephen Hawking, physicist who came to symbolize the power of the human mind, dies at 76

Stephen W. Hawking, the British theoretical physicist who overcame a devastating neurological disease to probe the greatest mysteries of the cosmos and become a globally celebrated symbol of the power of the human mind, has died at his home in Cambridge, England. He was 76.

His family announced the death but did not provide any further details.

Unable to move a muscle, speechless but for a computer-synthesized voice, Dr. Hawking had suffered since the age of 21 from a degenerative motor neuron disease similar to amyotrophic lateral sclerosis, or Lou Gehrig’s disease.

Initially given two years to live, a diagnosis that threw him into a profound depression, he found the strength to complete his doctorate and rise to the position of Lucasian professor of mathematics at the University of Cambridge, the same post held by Isaac Newton 300 years earlier.

Dr. Hawking eventually became one of the planet’s most renowned science popularizers, and he embraced the attention, traveling the world, meeting with presidents, visiting Antarctica and Easter Island, and flying on special “zero-gravity” jet whose parabolic flight let Dr. Hawking float through the cabin as if he were in outer space.

“My goal is simple,” he once said. “It is complete understanding of the universe, why it is as it is and why it exists at all.” He spent much of his career searching for a way to reconcile Einstein’s theory of relativity with quantum physics and produce a “Theory of Everything.”

He wrote an international best seller, “A Brief History of Time” (1988), which delved into the origin and ultimate fate of the universe. He deliberately set out to write a mass-market primer on an often incomprehensible subject.

Although the book was sometimes derided as being dense, and had a reputation for being owned more than read, it sold millions of copies, was translated into more than 20 languages, and inspired a mini-empire of similar books from Dr. Hawking, including “The Universe in a Nutshell” and “A Briefer History of Time.”

With his daughter, Lucy, he wrote a series of children’s books about a young intergalactic traveler named George. His blunt 2013 memoir, “My Brief History,” explored his development in science as well as his turbulent marriages. In addition, Dr. Hawking was the subject of a 1991 documentary, “A Brief History of Time,” directed by Errol Morris, and countless newspaper and magazine articles.

With the aid of a voice synthesizer, controlled by his fingers on a keyboard, he gave speeches around the world, from Chile to China. He played himself on such TV programs as “Star Trek: The Next Generation” and “The Simpsons,” the latter featuring Dr. Hawking telling the show’s lazy animated patriarch, “Your theory of a doughnut-shaped universe is interesting, Homer. I may have to steal it.”

He insisted that his reputation as the second coming of Albert Einstein had gotten out of control through “media hype.”

“I fit the part of a disabled genius,” he told the Los Angeles Times in 1990. “At least, I’m disabled — even though I’m not a genius like Einstein. ... The public wants heroes. They made Einstein a hero, and now they’re making me a hero, though with much less justification.”

His scientific achievements included breakthroughs in understanding the extreme conditions of black holes, objects so dense that not even light can escape their gravity.

His most famous theoretical breakthrough was to find an exception to this seemingly unforgiving law of physics: black holes are not really black, he realized, but rather can emanate thermal radiation from subatomic processes at their boundary, and can potentially evaporate. Scientists refer to such theoretical emanations as “Hawking radiation.”

This revelation impressed other scientists with the way it took Einstein’s general theory of relativity, which is essential for understanding the gravity of black holes, and connected it to newer theories of quantum mechanics, which cover subatomic processes.

Plus, he threw in a dash of old-fashioned thermodynamics — achieving a kind of physics trifecta.

“Black holes ain’t as black as they are painted,” Dr. Hawking once said in a lecture, characteristically describing complicated physics in ordinary language. “They are not the eternal prisons they were once thought. Things can get out of a black hole, both to the outside, and possibly, to another universe. So, if you feel you are in a black hole, don’t give up. There’s a way out.”

He also hypothesized that miniature black holes, remnants of the big bang, may be strewn through space, though he noted that so far they haven’t be discovered. “This is a pity, because if they had, I would have got a Nobel prize,” he joked.

Early life