Obama is the latest high-profile individual to weigh in on the devastating loss of the scientist, a man who forever changed the world with his groundbreaking work across a number of disciplines.

Newton, Einstein, Tesla ... yesterday a new name joined the ranks of past great minds who have through their intellect, curiosity and wisdom bettered humanity and our scientific understanding. "I think they understood most of it". He was elected to Britain's prestigious Royal Society at the early age of 32, despite the fact that he was too frail to turn the pages of a book without help. Hawking eventually concludes: "Is everything determined?". It is time to explore other solar systems. Or the worst. We just don't know. I can check my email... surf the internet... or write lectures.

To conclude the interview, Tyson asked Hawking for any lessons he could offer the rest of us.

Like the mathematics Prof Hawking grappled with from his wheelchair, his domestic life was complicated.

In 1982, I had responsibility for his third academic book for the Press, Superspace And Supergravity.

The physicist, who died early Wednesday, was determined to solve the question of time travel in his 2010 Discovery Channel documentary, Into the Universe.

"The public's view of disability has changed".

Hawking describes these wormholes as very small and hidden throughout space and time in all the crannies and crevices.

He laid out a fairly comprehensive series of benchmarks: nations should send astronauts to the Moon by 2020 (and set up a lunar base in the next 30 years). "Welcome to the party zone".

"The concepts were so unearthly that in a way it was sort of hard to grasp".

Q&A What are the financial pressures on the NHS that have built up over the last decade?

"Life on Earth is at the ever-increasing risk of being wiped out by a disaster, such as sudden global nuclear war, a genetically engineered virus or other dangers we have not yet thought of". Hawking realised that the surface area of the combination would always be at least as big as the areas of the two individual black holes. And he was fairly upbeat about the odds. "I was hoping a future Ms. Universe was going to step through the door".

He was also a vocal champion of the NHS, and until his final months sparred with Health Secretary Jeremy Hunt.

"Life would be tragic", he said, "if it weren't funny".

He was best known for his theories on time, black holes and relativity.

The tweet said: 'In loving memory of Stephen Hawking. He married Mason in the same year, but they also got divorced in 2006. By the mid-1980s, it had been replaced by another candidate for the Theory of Everything, called string theory.

Tim Berners-Lee, inventor of the World Wide Web and professor of Computer Science at Oxford, said: "We have lost a colossal mind and a wonderful spirit".

Here is a selection of his quotes. It necessitates a universe of 11 dimensions, including time.

Stephen Hawking, who sought to explain the origins of the universe, the mysteries of black holes and the nature of time itself, died yesterday aged 76.

"My expectations were reduced to zero when I was 21". In a way, he was like a brand ambassador - a person who made the connection between consumers and products. But the paradox remains unsolved.

"His personality and genius will be sorely missed. No one created the universe and no one directs our fate". We owe much to Professor Hawking's example.

Yonette Joseph is the London weekend editor.

Prof Hawking was a fellow at the university's Gonville and Caius College, where a book of condolence was opened and a flag above the college was flown at half mast.