Stephen Hawking, physicist and author of the best-selling book "A Brief History of Time," has died at 76. According to a statement from his spokesperson, he died peacefully in his Cambridge home.
He was diagnosed with Lou Gehrig's disease at age 21 and was one of the world's longest survivors of the disease.
His children Lucy, Robert, and Tim issued a statement about their father's death:
"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 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."
Hawking's cause of death was not immediately released.
He was diagnosed with ALS in 1963 when he was 21 years old. The progression of the illness led to his eventual paralysis. The only way Hawking was able to communicate in his later years was through the help of a device attached to a cheek muscle that used a text-to-speech program that provided a voice for him.
Hawking was best known for his work as a theoretical physicist, cosmologist, author and even sometime actor. He made multiple appearances on "The Big Bang Theory," The Simpsons, Futurama and his life story was portrayed by Eddie Redmayne in the 2014 "The Theory of Everything."
He also held the position as Cambridge University's Lucasian Professorship of Mathematics, a position that has been held by only 17 people in history - including the father of physics, Issac Newton.
His scientific work on gravitational theories and black holes led to a revolution in the field of cosmology. His book "A Brief History of Time" appeared on the best-seller list for a record-breaking 237 weeks.
People were quick to express the loss they were feeling about Hawking's passing online:
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