Professor Stephen Toope, vice chancellor of the University of Cambridge, paid tribute, saying: "Professor Hawking was a unique individual who will be remembered with warmth and affection not only in Cambridge but all over the world".

Piers Morgan, a British journalist and television personality, said Hawking's life and defiance in the face a seemingly insurmountable encumbrance was a testament to the fact that "self pity is a pathetic waste of life". His death is sad of course, but the immediate reaction is what a life he had.

Hawking attended the University of Cambridge, where he obtained his Ph.D.in 1965.

The couple were married for 30 years from 1965, after they met while studying at Cambridge.

"Have fun out there among the stars", Obama tweeted along with a photo from when he awarded Hawking with the Presidential Medal of Freedom in 2012. "Events before the Big Bang, are simply not defined, because there's no way one could measure what happened at them". So he set up a "simple experiment" to uncover whether human time travel through a wormhole is possible now... or in the future.

"He also noted that we hadn't quite got his electronic voice right and wondered whether we would care to use his actual voice.

And he made many more such appearances. We would need a lot of energy, though. For Hawking, the early diagnosis of his terminal disease ignited a fresh sense of purpose. "I have so much I want to do first", he said at the time. "And his courage and resilience will remain an inspiration for generations", Kovind said in a tweet. Stephen was a towering figure intellectually in terms of scientific achievement, major contributions in cosmology and gravitation. He was so moved that he used Hawking's words and his electronic voice for the track Keep talking that was a part of the band's album, Division Bell.

In 1971, Hawking's essay titled "Black Holes" won the Gravity Research Foundation Award. This theory states that rather than having just one initial state, the universe could have actually had a series of original positions that all lent a helping hand in creating what we know as our modern universe.

Theoretical physicist Stephen Hawking has died at the age of 76.

A 2014 film, The Theory of Everything, with Eddie Redmayne playing Hawking, charted the onset of his illness and his early life as a brilliant student. Hawking is believed to be the disease's longest-living survivor.

For reasons not yet understood, military veterans are twice as likely to be diagnosed with ALS as the general public, according to the ALS Association.

"We lost a great one today". Humanity's deepest desire for knowledge is justification enough for our continuing quest.

His death even drew mourning from celebrities not normally associated with the intricacies of astrophysics.

The physicist's disease spurred him to work harder but also contributed to the collapse of his two marriages, he wrote in a 2013 memoir My Brief History.

Forever pushing the bounds of his fascination with the nature of space and time, relativity and quantum theory, Hawking's groundbreaking work aimed to give the world new insights into the creation of the universe.