Cambridge physicist Stephen Hawking has died at the age of 76, reports Dennis Overbye at The New York Times. Hawking was one of the most well-known scientists of the late 20th and early 21st centuries, recognized for his work on black holes, his efforts to communicate complex cosmology to the general public and a sense of humor said to be "as vast as the universe."
Despite a grim diagnosis of amyotrophic lateral sclerosis—also known as Lou Gehrig’s disease—at the age of 21 that gave him just a few years to live, Hawking survived another 55 years, cruising around the world in an electric wheelchair and speaking through his iconic speech synthesizer during the last 30 years of his life.
Condolences have poured in from mourners from around the world, including U.K. prime minister Theresa May, astrophysicist Neil deGrasse Tyson and theoretical physicist Michio Kaku who told Overbye, “Not since Albert Einstein has a scientist so captured the public imagination and endeared himself to tens of millions of people around the world.”
According to his family, Hawking passed away peacefully at his home early on Wednesday morning. “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 write in a statement. “His courage and persistence with his brilliance and humour 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.”
After a childhood spent in Oxford and St. Albans, Hawking attended university at Oxford before moving to Cambridge for his PhD work. There he began work on singularities, or points in space where the gravity of a collapsing star would warps space-time into an infinitely dense point, creating a black hole.
According to his friend and collaborator Roger Penrose, who penned an obituary in The Guardian, the pair worked together to show that if there was a big bang that started the universe, it originated from a singularity. In 1974, Hawking released his most famous academic paper detailing what became known as Hawking radiation. Contrary to previous theories about black holes, he showed that they radiate energy, gradually losing mass in the process. Ian Sample at The Guardian reports that for very small black holes, that radiation would eventually lead to a massive explosion, releasing 1 million megatons of energy.
The BBC reports that discovery pushed Hawking into one of the great physics debates of recent decades, the information paradox. Hawking argued that any information—in particular things like the spin, mass and temperature of particles entering a black hole—would be destroyed when the black hole evaporated away or exploded. Others argued that the information would be preserved and released eventually released by the black hole. In 2004, while in a pub with some of his students, Sample reports, Hawking cranked up the mic on his synthesizer and made a public declaration that he relented and agreed that information would be preserved by black holes, though exactly how that information escapes when the black hole dissipates is up for debate.
While his academic achievements earned him countless honors, including the Lucasian Professor of Mathematics at Cambridge, the chair held by Sir Isaac Newton and other luminaries in math and physics, and election to the Royal Society at the very young age of 32, Hawking is arguably best known to the general public as a science communicator. In 1988, he published A Brief History of Time, a synthesis of cosmology and his own work on black holes for layman scientists that has sold 10 million copies. The book spawned a documentary and illustrated edition that made Hawking one of the most recognized scientists in the world.
In a follow-up book, 1993’s Black Holes and Baby Universes and Other Essays, he explained his motivation for taking his work directly to the public. “If we do discover a complete theory [of the universe], it should in time be understandable in broad principle by everyone, not just a few scientists,” he wrote. “Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason — for then we would know the mind of God.” (Hawking was using the term "God" loosely. He was a vocal atheist and was not a fan of organized religion.)
In other popular books, Hawking continued to bring cosmology to the mainstream, and became a popular figure himself. He appeared on television shows including “The Simpsons,” “Big Bang Theory” and “Star Trek: The Next Generation,” and his voice was also included on the 1994 Pink Floyd album The Division Bell. He was portrayed by Benedict Cumberbatch in the 2004 dramatization of his early life Hawking and by Eddie Redmayne, who won an Oscar in 2014 for his portrayal of the physicist in The Theory of Everything, which told the story of his first marriage and how he dealt with his diagnosis of ALS.
Overbye opines that the most incredible part of Hawking’s life is the fact that he had a life and career at all. While ALS, a motor neuron disease, often kills people who have it relatively quickly, Hawking’s disease progressed slowly. In the 1970s, he slowly lost the ability to walk and his speech weakened. After a bought of pneumonia in 1984, he lost his speech. A colleague outfitted him with his iconic speech synthesizer that allowed him to select letters and words via a small joystick and later by moving his eyes and twitching his cheek. (He complained, however, that the synthesizer gave him an American accent.)
Hawking continued traveling the globe, giving lectures and visiting new places, such as Antarctica, where he celebrated his 60th birthday with a hot-air balloon ride. Among his many adventures, the British cosmologist once experienced floating weightlessly in a zero-gravity on a Boeing 727. He was also known to zoom around Cambridge in his electric wheelchair at unsafe speeds. He was never able to make a trip into space, something he had planned with Richard Branson, who in 2017 offered him a seat on a future Virgin Galactic flight. “I want to show that people need not be limited by physical handicaps as long as they are not disabled in spirit,” as he told Overbye in an interview a decade earlier, back in 2007.
In recent years, Hawking has become something of a public intellectual with reporters asking his opinions on many subjects. Most famously, in 2010, Hawking suggested that making contact with aliens would be a bad idea, and that the outcome would be similar to when Columbus made contact with Native Americans. He offered similar warnings about the development of unregulated artificial intelligence in 2014.
Just last week, he was in the news for discussing what the universe might have been like before the Big Bang—a complex topic that required physics, astronomy, and an outsized human imagination to distill down for the public. A topic, in other words, that was perfectly suited to Hawking.