"Everyone can enjoy a life of luxurious leisure if the machine-produced wealth is shared, or most people can end up miserably poor if the machine-owners successfully lobby against wealth redistribution". This is an unparalleled contribution for anyone, but especially for someone whose communication was severely limited by ALS or Amyotrophic Lateral Sclerosis.

Prof Hawking was diagnosed with a rare form of motor neurone disease when he was 22. It was a proponent of steady state who coined the term Big Bang, almost as a slur on the theory. "He wanted to live".

Hawking's scientific achievements are too obscure for most people, even though he was outstanding at popularizing his work.

Renowned, Hawking was best known as the author of A Brief History of Time, the best-selling 1988 book that first brought modern astrophysics into popular understanding for many and made him into an icon. He made us laugh and we made him laugh.

In the first leg of the tour in Mumbai, Hawking addressed an international physics seminar at the Tata Institute of Fundamental Research (TIFR).

"Professor Stephen Hawking was a brilliant man and a mediocre student", then-President Barack Obama said to a round of laughter, "when he lost his balance and tumbled down a flight of stairs". All he had to do was sit and wait for a visitor from the future, but sadly, no one showed up.

"What did he overcome?"

"I have experimental evidence that time travel is not possible", Hawking told reporters at the Seattle Science Festival in 2012.

More: How did Stephen Hawking live so long with ALS?

Professor Hawking turned into a Transformer in the UK sketch show Little Britain and killed carer Lou, played by David Walliams. I have been lucky, that my condition has progressed more slowly than is often the case.

Such a theory would resolve the contradictions between Einstein's General Theory of Relativity, which describes the laws of gravity that govern the motion of large objects like planets, and the Theory of Quantum Mechanics, which deals with the world of subatomic particles.

In the United States, one out of every five adults has a disability, according to a 2015 study published by the Centers for Disease Control and Prevention.

"Name a scientist in another field of science who's had the same kind of impact - it's really difficult".

She suggests journalists use "simple language" when writing about people with disabilities and pay attention to subtleties.

"With Hawking, you can't deny the impact of the book, you can't deny the impact of the man. There were so many things about him that set him apart from most scientists". Instead, use "able-bodied". "RIP Stephen Hawking", tweeted American astronaut Scott Kelly. His theories unlocked a universe of possibilities that we & the world are exploring. "But they are mostly things I don't particularly want to do anyway".