British astrophysicist Stephen Hawking, a leading figure in the world of cosmology, died early on March 14 in his sleep at his home in Cambridge, England, at the age of 76.
"We are deeply saddened that our beloved father passed away today. He was a great scientist and an extraordinary man whose work and legacy will live on for many years," his children Lucy, Robert, and Tim said.
"His courage and persistence with his brilliance and humor inspired people across the world. He once said, ‘It would not be much of a universe if it wasn’t home to the people you love.’ We will miss him forever.”
For decades, the theoretical physicist produced theories, resolved problems, gave talks, and participated in documentaries.
Hawking achieved that despite living most of his life with a paralyzing disease and speaking through a computer voice generator.
At a conference in February 2008, he described himself as lucky, as the slow progress of the disease allowed him the time to make discoveries.
"I have been very lucky that my disability has not been a serious handicap," he said. "Indeed, it has probably given me more time than most people to pursue the quest for knowledge."
He told told the BBC last year that he "never expected to reach 75."
Hawking produced a number of first-class research papers during the 1970s, including one of his most important contributions to cosmology.
In 1974, he provided a theoretical argument for the existence of thermal radiation emitted by black holes -- objects in space so massive and dense that even light can’t escape.
Hawking applied his work on black holes to the Big Bang -- the early development of the universe -- and the nature of time.
In 1983, he and Professor Jim Hartle proposed a model of the universe based on the idea that it did not have a boundary.
His discoveries were achieved by bridging the gap between Albert Einstein’s Theory of Relativity, which explains how massive objects like stars and planets cause a distortion in space-time, and quantum physics, which deals with the behavior of atomic and subatomic particles.
In a paper published in January 2014, Hawking presented a "mind-bending" new theory that argued that black holes do not exist in the way we traditionally think of them. Instead of devouring information and energy permanently, he said, black holes release it back into the universe in a garbled, unrecognizable form.
Not content with publishing among his peers, Hawking popularized his ideas in a 1988 best-selling book called A Brief History Of Time, which sold 10 million copies worldwide.
Hawking also examined the relationship between science and religion, writing in his 2010 book Grand Design that evoking God is not necessary to explain the origins of the universe.
In a 2011 interview, he suggested that heaven is a “fairy story for people afraid of the dark.” When we die, the renowned scientist said, our brains switch off like “broken-down computers.”
Hawking repeatedly used his fame to raise alarm over climate change, which he described as one of the greatest threats posed to the future of humankind and the world.
"As we stand at the brink of a second nuclear age and a period of unprecedented climate change, scientists have a special responsibility once again to inform the public and to advise leaders about the perils that humanity faces," he said.
Born on January 8, 1942, Hawking won a scholarship to Oxford University in 1959, and three years later switched to rival Cambridge to conduct research on cosmology.
When he was 21, he received the diagnosis of a debilitating motor-neurone disease, amyotrophic lateral sclerosis (ALS), a condition that has progressed over time.
The disease was expected to kill him within a few years.
At the unusually young age of 32, Hawking was made a fellow of the Royal Society, Britain's most prestigious academic institution.
In a wheelchair since 1970, he relied on a computer and voice synthesizer to speak. But his mind and senses remain unaffected.
For 30 years, Hawking was the Lucasian Professor of Mathematics at the University of Cambridge until he resigned in 2009.
After that, he became director of research at the university’s Centre for Theoretical Cosmology.
He married twice and had three children.
When he was 65, he was given a two-hour ride on a zero-gravity flight that allowed Hawking to experience spurts of weightlessness.
"I have long wanted to go into space, and a zero-gravity flight is the first step toward space travelm," he said at the time. "I also want to demonstrate to the public that everyone can participate in this type of weightless experience."
Hawking became as much a celebrity as a scientist, receiving a number of awards, including the highest U.S. civilian honor: the Presidential Medal of Freedom.
He appeared on the animated sitcom The Simpsons and the science-fiction television series Star Trek, and provided narration for a British Telecom advertisement that was later sampled in a Pink Floyd song.
In August 2012, Hawking had a starring role in the opening ceremony of the London 2012 Paralympic Games.