He has grappled with some of the biggest questions about the universe but Professor Stephen Hawking has revealed one mystery still baffles him - women.
Making the comments during a Reddit Ask Me Anything (AMA) session, the eminent physicist said the opposite sex is 'life's most intriguing mystery,' but admitted it is a mystery that should remain unsolved.
Although the questions were posted back in July, the scientist has only just responded, discussing topics as diverse as artificial intelligence to his favourite song.
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During an Ask Me Anything session on Reddit, Professor Stephen Hawking has said that despite unravelling some of the secrets of the universe, women are the biggest mystery he has faced. The eminent theoretical physicist has been married and divorced twice. He is pictured above with this second wife Elaine in 2005
During an Ask Me Anything session on Reddit, Professor Stephen Hawking has said that despite unravelling some of the secrets of the universe, women are the biggest mystery he has faced. The eminent theoretical physicist has been married and divorced twice. He is pictured above with this second wife Elaine in 2005
Asked what the one mystery in life he found most intriguing was, he replied: 'Women. My PA reminds me that although I have a PhD in physics, women should remain a mystery.'
Elsewhere, he reiterated claims he has made previously about the threat of artificial intelligence adding that the greatest risk from AI will be its ability to disregard humans rather than deliberately destroy them.
He said artificial intelligence is unlikely to hold a grudge against mankind, but may ultimately harm us as a result of trying to achieve its goals.
He said: 'The real risk with AI isn't malice but competence. 
'A superintelligent AI will be extremely good at accomplishing its goals and if those goals aren't aligned with ours, we're in trouble.
'You're probably not an evil ant-hater who steps on ants out of malice, but if you're in charge of a hydroelectric green energy project and there's an anthill in the region to be flooded, too bad for the ants.
'Let's not place humanity in the position of those ants.'
Professor Hawking, who is the director of research at the department of applied mathematics and theoretical physics at the University of Cambridge, added an AI computer could eventually evolve to have a desire to survive.
He said: 'An extremely intelligent future AI will probably develop a drive to survive and acquire more resources as a step toward accomplishing whatever goal it has, because surviving and having more resources will increase its chances of accomplishing that other goal.
'This can cause problems for humans whose resources get taken away.'