Renowned physicist Professor Stephen Hawking, who was born in Oxford, has died at the age of 76.
Paying tribute to him, his family said they were "deeply saddened". Many scientists, politicians and celebrities have also offered words of condolence and respect.
He died peacefully at his home in Cambridge in the early hours of Wednesday morning.
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."
Astrophysicist Neil de Grasse Tyson paid tribute to him on social media.
Sharing a photo of himself and Prof Hawking on Twitter, he said: "His passing has left an intellectual vacuum in his wake. But it's not empty. Think of it as a kind of vacuum energy permeating the fabric of spacetime that defies measure. Stephen Hawking, RIP 1942-2018."