Reaction to the death of theoretical physicist Stephen Hawking:
"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."
— Neil deGrasse Tyson, director of New York's Hayden Planetarium, on Twitter .
"Stephen Hawking will be remembered for his incredible contributions to science — making complex theories and concepts more accessible to the masses. He'll also be remembered for his spirit and unbounded pursuit to gain a complete understanding of the universe, despite the obstacles he faced."
— Satya Nadella, Microsoft CEO, on LinkedIn .
"Professor Stephen Hawking was a brilliant and extraordinary mind - one of the great scientists of his generation. His courage, humour and determination to get the most from life was an inspiration. His legacy will not be forgotten."
— British Prime Minister Theresa May, on Twitter .
"His contributions to science will be used as long as there are scientists, and there are many more scientists because of him. He spoke about the value and fragility of human life and civilisation and greatly enhanced both."
— University of Manchester physicist Brian Cox, on Twitter .
"I join the global community in mourning the loss of the greatest physicist of our era. #StephenHawking is free from the physical constraints of this earthly condition we all exist in and he is soaring above us now marveling at it all."
— actress Mayim Bialik, who appeared with Hawking on the U.S. television show "The Big Bang Theory," on Twitter .
— "We have lost a truly beautiful mind, an astonishing scientist and the funniest man I have ever had the pleasure to meet. My love and thoughts are with his extraordinary family."
— actor Eddie Redmayne, who played Hawking in the 2014 film "The Theory Of Everything."