Stephen Hawking's PhD thesis goes online, crashes website

Cambridge University has put Stephen Hawking's doctoral thesis online, triggering such interest that it crashed the university's website.

Completed in 1966 when Hawking was 24, "Properties of Expanding Universes" explores ideas about the origins of the universe that have resonated through the scientist's career.

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The university says the thesis was already the most-requested item in its online repository. It was free to download Monday to mark Open Access Week. The website was intermittently inaccessible during the day as it struggled to handle to the interest.

Hawking said he hoped making his thesis available to all would "inspire people around the world to look up at the stars and not down at their feet; to wonder about our place in the universe and to try and make sense of the cosmos."

After the release on Monday, Hawking wrote on his Facebook page: "After so many requests over time from people wanting to read this thesis, I also hope it doesn't disappoint. If it does, please address any questions or complaints to my younger self. You will only have to invent time travel to do so."

Hawking is most notable for his theory on black holes and cosmology, with 12 honorary degrees. He was propelled into the public eye with the release of his 1988 book,A Brief History of Time.

Most recently, he has expressed concern over the advancement of artificial intelligence, telling the BBC in 2014 that"the development of full artificial intelligence could spell the end of the human race."

Hawking is also a distinguished visiting research chair at the Perimeter Institute in Waterloo, Ont.