The best known theoretical physicist of his time, Stephen Hawking passed away at the age of 76 in the early hours of Wednesday. The cosmologist and author of the best-selling book A Brief History of Time was one of science’s biggest celebrities since Albert Einstein.
Professor Hawking was born on January 9, 1942, the 300th death anniversary of Galileo, and died on Wednesday, the 139th birthday of Einstein.
As news of his death broke, his fans and well-wishers took to Twitter and other social media to pay tributes to one of the greatest minds of our time.
Professor Hawking visited India in 2001 to deliver the Albert Einstein Memorial Lecture titled ‘Predicting the Future: From Astrology to Black Holes.’ He met then President K.R. Narayanan, who later described the meeting as "an unforgettable experience."
Astrophysicist Neil deGrasse Tyson said Professor Hawking's passing has left "an intellectual vacuum".
"But it's not empty," he wrote on Twitter. "Think of it as a kind of vacuum energy permeating the fabric of spacetime that defies measure. Stephen Hawking, RIP 1942-2018."
Google CEO Sundar Pichai kept his tribute short and to the point. "The world has lost a beautiful mind and a brilliant scientist. RIP Stephen Hawking," he wrote.
America's space agency National Aeronautics and Space Administration (NASA) shared a video of Professor Hawking speaking with the Space Station in 2014. "Remembering Stephen Hawking, a renowned physicist and ambassador of science. His theories unlocked a universe of possibilities that we & the world are exploring. May you keep flying like superman in microgravity, as you said to astronauts on @Space_Station in 2014," it wrote.
Sir Tim Berners-Lee, founder of the World Wide Web, wrote: "We have lost a colossal mind and a wonderful spirit. Rest in peace, Stephen Hawking."
Errol Morris, who directed the biographical documentary film A Brief History of Time, took to Twitter to share a heartfelt message: "It had to happen, eventually," he wrote. "We were lucky to have him for so long, and I was lucky to be able to work with him. A truly fabulous human being. Stephen Hawking. Funny, perverse, and, of course, brilliant."
Astrophysicist Dr. Karan Jani wrote: "Thank you for the infinite inspiration to explore our cosmos. The courage for a career in astrophysics happened due to Brief History of Time- a used copy that I got from a street vendor in my small town of [India] 12yrs ago."
CEO of Microsoft Corporation Satya Nadella said in a statement: "We lost a great one today. 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. May he rest peacefully as his legacy and brilliance live on."
American astronaut Scott Kelly wrote: "A loss for all humanity. RIP Stephen Hawking."
"A star just went out in the cosmos," wrote American-Canadian theoretical physicist and cosmologist Lawrence M. Krauss on Twitter. "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. I will miss him."
President Ram Nath Kovind said, "Sad to hear of the passing of scientist Stephen Hawking. His brilliant mind made our world and our universe a less mysterious place. And his courage and resilience will remain an inspiration for generations."
Prime Minister Narendra Modi hailed Professor Hawking as an "outstanding scientist and academic."
He said on Twitter, "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."
Professor Hawking had been mentioned in many popular movies and series. He appeared as himself in the American sitcom The Big Bang Theory.
"In loving memory of Stephen Hawking. It was an honor to have him on The #BigBangTheory. Thank you for inspiring us and the world," the series tweeted with a photograph.
Simpsons producer Matt Selman wrote, "Farewell to Stephen Hawking, the most intelligent guest star in the brief history of The Simpsons," along with a photograph of Professor Hawking's appearance on the beloved show.