Stephen Hawking, the most famous modern-day scientist, has died aged 76.
The British physicist died peacefully at his home in Cambridge in the early hours of Wednesday morning, his family said.
Hawking was world renowned for his groundbreaking research and theories into relativity and black holes.
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Aged 21, Hawking was diagnosed with a rare form of motor neurone disease and told he only had a few years to live. He had to use a wheelchair and was unable to speak except through a voice synthesiser.
In a statement, his children Lucy, Robert and Tim said, "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 1988 book, A Brief History of Time, sold more than 10 million copies and inspired a documentary film by Errol Morris.
A movie was made about his life in 2014, The Theory of Everything. Eddie Redmayne won the Best Actor Oscar for the role.
Hawking also appeared in several TV shows including The Simpsons, Red Dwarf and The Big Bang Theory.
On Twitter, Nasa described Hawking as an “ambassador of science” and said he “unlocked a universe of possibilities”.
Professor Brian Cox said, "He spoke about the value and fragility of human life and civilisation and greatly enhanced both."
Astrophysicist Neil deGrasse Tyson said that "his passing has left an intellectual vacuum in his wake".
And many celebrities and people who worked with Hawking honoured the genius…