Twitter pays tribute to renowned scientist Stephen Hawking

Stephen Hawking's "theories unlocked a universe of possibilities that we & the world are exploring," tweeted NASA in a tribute to the late physicist. "He'll be remembered for his...pursuit to gain a complete understanding of the universe, despite the obstacles he faced," said Microsoft CEO Satya Nadella. "We have lost a colossal mind," said World Wide Web creator Tim Berners-Lee.