One of the world's greatest scientists, Professor Stephen Hawking, has died at the age of 76, a spokesman for his family said.
In May last year, Hawking warned that humans should leave earth within 100 years if we wanted to survive.
As part of the documentary Professor Hawking planed to travel around the world to find out how we might exist in outer space.
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Quiet people have the loudest minds.— Vala Afshar (@ValaAfshar) March 13, 2018
—Stephen Hawking pic.twitter.com/hMC2bTYV9c
We were on earth at the same time as Stephen Hawking.— Geraldine (@everywhereist) March 14, 2018
That's kind of a miraculous thing.
We breathed the same air as the man who demystified the stars.
Genius is so fine and rare. Goodbye Professor Hawking. You inspired and taught us all. pic.twitter.com/9Drdnv2eEe— Chris Hadfield (@Cmdr_Hadfield) March 14, 2018