Acclaimed professor and cosmological theorist Stephen Hawking turned 70 on Sunday.
For the past 40 years Hawking has captured the public's imagination by exploring the boundaries of scientific knowledge.
Current media scientist du jour Professor Brian Cox told the Press Association that Stephen Hawking is a "genius of Nobel Prize calibre" who has done more to popularise physics than anybody else.
However, he added that Hawking himself would not agree that his fame corresponds to his ability: "If you spoke to Stephen himself he would say that he considered himself a fairly average scientist whose condition provided an opportunity to focus on his work," Cox said.
"One thing he told me was that he spends a great amount of time theorising as he gets in and out of the bath, simply because it takes so long."
Through his characteristic computer generated voice, Hawking has spoken some memorable pearls of wisdom.
Huffington Post UK celebrates one of the world's most celebrated scientists with some of Stephen Hawking's best quotes:
- On the reason why the universe exists: "If we find the answer to that, it would be the ultimate triumph of human reason - for then we would know the mind of God" - A Brief History Of Time, published 1988.
- On being diagnosed with motor neurone disease: "My expectations were reduced to zero when I was 21. Everything since then has been a bonus" - Interview in The New York Times, December 2004.
- On black holes: "Einstein was wrong when he said, 'God does not play dice'. Consideration of black holes suggests, not only that God does play dice, but that he sometimes confuses us by throwing them where they can't be seen" - The Nature Of Space And Time, published 1996.
- On UFOs: "I am discounting reports of UFOs. Why would they appear only to cranks and weirdos? - As quoted in a TED talk, "Asking big questions about the universe"
- On commercial success: "I want my books sold on airport bookstalls" - Interview in The New York Times, December 2004.
- On fame: "The downside of my celebrity is that I cannot go anywhere in the world without being recognised. It is not enough for me to wear dark sunglasses and a wig. The wheelchair gives me away" - Interview on Israeli TV, December 2006.
- On humanity: We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special. - Der Spiegel October 1988
- On his IQ: I have no idea. People who boast about their IQ are losers". - Interview with Deborah Solomon "The Science of Second-Guessing", The New York Times December 2004
- On Euthanasia: The victim should have the right to end his life, if he wants. But I think it would be a great mistake. However bad life may seem, there is always something you can do, and succeed at. While there's life, there is hope." - Quoted in People's Daily Online June 2006