Stephen Hawking: The famed physicist’s best quotes

The famed physicist Stephen Hawking died on this day five years ago, aged 76. During decades in the public eye – from his work investigating black holes to a cameo on The Simpsons – he amassed a portfolio of witty and memorable quotes.

A few of them appear below, on subjects including artificial intelligence, fame, life, the universe and everything.

In the words of others, Hawking was described on Wednesday as “a colossal mind and a wonderful spirit”; “inspirational”; and an “ambassador of science”.

Hawking did not believe in an afterlife, he saidin 2011. But the threat of one was not necessary to induce people to behave well, he added. When asked how a person should live their only life, he said: “We should seek the greatest value of our action.”

In the same interview with The Guardian, Hawking said having motor neurone disease meant he had lived with the possibility of dying early for several decades. He added: “I’m not afraid of death, but I’m in no hurry to die. I have so much I want to do first.”

The scientist took a pithy line on staying cheerful when he spoke to The New York Times in 2004, saying: “Life would be tragic if it weren’t funny.”

And he was quoted in People’s Daily Online in 2006 as having said about 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.”

“I think the development of full artificial intelligence could spell the end of the human race,” Hawking told the BBC in 2014. “Once humans develop artificial intelligence, it will take off on its own and redesign itself at an ever-increasing rate.

“Humans, who are limited by slow biological evolution, couldn’t compete and would be superseded.”

Despite pushing for humanity to escape Earth and explore space, and in 2016 backing the Breakthrough Starshot interstellar spacecraft project, Hawking felt strongly that first contact with alien species should be avoided.

He told the National Geographic Channelin 2004: “I think it would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on this planet is not very happy, and they were the same species. I think we should keep our heads low.”

“People who boast about their IQ are losers,” he said in the December 2004 interview with The New York Times.

Nonetheless in a 1999 episode of The Simpsons – “They Saved Lisa’s Brain”, in which Lisa joins the Springfield branch of Mensa and eventually takes over the running of the town – Hawking silenced all the show’s brainiest characters by announcing during an argument as to who was smartest: “Big deal. My IQ is 280.”

He further admonished the group with a lecture on how power corrupts, while sending himself up with an Inspector Gadget-style turn from his motorised wheelchair.

Hawking was famously possessed of a sharp wit. Speaking to comedian John Oliver on his programme Last Week Tonight the physicist was asked whether in a reality that contained multiple universes, one existed in which the host was “smarter than you”.

“Yes, and also a universe where you’re funny,” the Cambridge academic shot back.

Stephen Hawking: a life in pictures

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“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,” he said on Israeli TV in December 2006.

However, he told The New York Times two years earlier he wanted his books “sold on airport bookstalls”.

Hawking remains best-known for his work describing the nature of black holes.

Of the phenomenon, he said in a 1996 book: “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.”

In his classic book A Brief History of Time, Hawking famously said of scientists striving to produce a unifying theory explaining the universe’s mechanics: “If we discover a complete theory, it would be the ultimate triumph of reason – for then we should know the mind of God.”

The memorable, metaphorical statement has been often discussed since it was published in 1988, but questions over Hawking’s beliefs about the origins of the universe were answered firmly in his 2010 book, The Grand Design.

In it, he wrote: “Because there is a law such as gravity, the universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.”

Hawking told The New York Times in 2011 that motor neurone disease had taught him “not to pity myself” because others were worse off.

He added: “My advice to other disabled people would be, concentrate on things your disability doesn’t prevent you doing well, and don’t regret the things it interferes with. Don’t be disabled in spirit, as well as physically.”

Additional reporting by PA

This article was originally published in 2018. It has been republished in 2023, to mark the anniversary of Hawking’s death