An intellectual vacuum left in his wake: World mourns Stephen Hawking
Tributes to Professor Stephen Hawking have been made around the world after the celebrated physicist's death at 76 was announced.
Indian prime minister Narendra Modi said Prof Hawking had "made the world a better place" and his death was "anguishing".
"Professor Stephen Hawking was an outstanding scientist and academic. His grit and tenacity inspired people all over the world," a tweet on his page said.
Professor Stephen Hawking was an outstanding scientist and academic. His grit and tenacity inspired people all over the world. His demise is anguishing. Professor Hawking's pioneering work made our world a better place. May his soul rest in peace.
-- Narendra Modi (@narendramodi) March 14, 2018
US astrophysicist Neil deGrasse Tyson was one of the first to pay tribute to Prof Hawking. Sharing a photo of himself and Prof Hawking on Twitter, he said the scientist's death has "left an intellectual vacuum in his wake".
He added: "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."
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. pic.twitter.com/nAanMySqkt
-- Neil deGrasse Tyson (@neiltyson) March 14, 2018
Sean Carroll, a physics professor at US university Caltech, said: "Stephen Hawking was the rare famous scientist who deserved every bit of his fame. A brilliant physicist and an inspirational person. And quite a character."
Greenpeace USA thanked Prof Hawking for helping people understand their place in the universe and for "leaving us in awe and wonder".
Celebrities also paid tribute, with US singer Katy Perry saying his death left a "big black hole in my heart".
Jonathan Ross tweeted: "RIP Stephen Hawking. The world just dropped a lot of IQ points. And, he was a fun person. Very sad news."
RIP Stephen Hawking. The world just dropped a lot of IQ points. And, he was a fun person. Very sad news.
-- Jonathan Ross (@wossy) March 14, 2018
KT Tunstall tweeted: "Wow. What a life. What an extraordinary Human Being. Enjoy the cosmos Stephen Hawking, the biggest and most mysterious adventure that we all get to go on one day... RIP #genius."
The rock band Foo Fighters tweeted: "'Remember to look up at the stars and not down at your feet' - RIP Stephen Hawking you f****** legend."
US actor Macaulay Culkin described Prof Hawking as a "genius", adding that the physicist was also his favourite Simpsons character.
He tweeted: "I just heard about Stephen Hawking's passing. He was both a genius and my favorite Simpsons character. We'll miss you, buddy."
I just heard about Stephen Hawking's passing. He was both a genius and my favorite Simpsons character. We'll miss you, buddy.
-- Macaulay Culkin (@IncredibleCulk) March 14, 2018
Defence Minister Tobias Ellwood said Prof Hawking "epitomised true courage over adversity as you explained the wonders of the universe to the world".
He wrote on Twitter: "Your achievements symbolise the pwr of the human mind. An inspiration to us all, whatever our station in life, to reach for the stars-from where you now shine down on us."