Stephen Hawking, the physicist whose insights shaped modern cosmology and whose struggle with ALS became an inspiration for a worldwide audience, has died at age 76.

His family released a statement in the early hours of Wednesday morning confirming his death at his home in Cambridge, UK.

Hawking became a celebrity thanks to his A Brief History of Time best-seller and his striking struggle against the ravages of ALS, portrayed in the film The Theory of Everything.

A statement from Hawking’s children delivered the grim news. “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 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.”

Even though he was a deep scientist, Hawking had a playful side. He appeared on numerous television shows, most memorably Star Trek: The Next Generation, playing a card game with Sir Isaac Newton, Albert Einstein and Data, the android. He also appeared on The Big Bang Theory and The Simpsons. The CBS comedy paid tribute to the renowned physicist tonight.

In loving memory of Stephen Hawking. It was an honor to have him on The #BigBangTheory. Thank you for inspiring us and the world. pic.twitter.com/9rWoYqIToy — The Big Bang Theory (@bigbangtheory) March 14, 2018

Hawking was diagnosed with motor neurone disease in 1963 at the age of 21. He was expected to live for just two more years, but he had a form of the disease that progressed far more slowly. He survived for more than half a century beyond that prognosis. He began to use crutches in the 1960s, then finally a motorized wheelchair, wherein he popularized a unique method of synthesized computer vocalizations when that technology developed.

Hawking’s work focused on black holes, which he initially contended should emit heat and eventually go out of existence. Miniature black holes dot the universe, Hawking claimed, each as heavy as a billion tons, but no larger than a proton. When they collapsed, he claimed all their information would be lost, contradicting one of the most basic laws of quantum mechanics. Many physicists disagreed, and even Hawking eventually changed some of the theory, positing that information was stored at the black hole’s event horizon and encoded back into radiation.

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Hawking was elected in 1974 to the Royal Society at the exceptionally young age of 32. Five years later, he became the Lucasian professor of mathematics at Cambridge, arguably Britain’s most distinguished chair, and one formerly held by Isaac Newton, Charles Babbage and Paul Dirac, the latter one of the founding fathers of quantum mechanics. Hawking held the post for 30 years, then moved to become director of research at the Centre for Theoretical Cosmology.

His career took on a public aspect when A Brief History of Time was published in 1988. It stayed on the Sunday Times of London’s best-sellers list for an unprecedented 237 weeks, selling 10 million copies worldwide and translated into 40 different languages. It made Hawking into pop science’s most visible physicist.

Hawking lectured at the White House during the Clinton administration and returned in 2009 to get the presidential medal of freedom from Barack Obama.

In his later days, Hawking joined the chorus of scientists who warned against artificial intelligence’s dangers, and also called for a ban on autonomous weapons.

He also offended the religious when he declared that God was not needed to set the universe going, although he made some statements that caused a belief that he had changed his mind at one point.

“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,” he said.

Survivors include three children, Robert, Lucy and Timothy, from his first marriage to Jane Wilde, and three grandchildren.