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." -- .
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"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." -- .
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"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." -- .
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"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." -- .
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"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." -- .
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"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."
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"He was a true genius who had a great admiration of and connection to the public. ... He simplified and explained, but without gimmicks. His assumption that people are curious about the universe and black holes was true. He inspired us all to wonder." -- Katherine Mathieson, chief executive of the British Science Association.
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"He inspired generations to look beyond our own blue planet and expand our understanding of the universe. His personality and genius will be sorely missed." -- .
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"A star just went out in the cosmos. We have lost an amazing human being. Stephen Hawking fought and tamed the cosmos bravely for 76 years and taught us all something important about what it truly means to celebrate about being human." -- .
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"Along with groundbreaking and inspiring work came another attribute that made Stephen a hero not just to younger generations, but also to his peers. A longtime friend to NASA, Stephen was a passionate communicator who wanted to share the excitement of discovery with all." -- acting NASA Administrator Robert Lightfoot.
