Was Stephen Hawking really the greatest scientist of our time?

Ask the average person to name a scientist, and there's a pretty good chance they'll say Stephen Hawking.

If you narrow that down to physicist, if they have an answer at all, it's even more likely they'll namedrop the late Cambridge professor, who appeared in The Simpsons, Star Trek and The Big Bang Theory.

"When we think of a scientist, many people think of Stephen Hawking," University of Auckland physicist Shaun Hendy told The AM Show on Thursday.

But was he truly one of the all-time greats?

Prof Hawking's achievements shouldn't be underestimated, especially considering the obstacles he had to overcome. But there's a strong argument to be made that others' achievements were even greater, without bringing them household-name status.

Asked in 1993 by Time magazine if he was the greatest physicist since Albert Einstein, Prof Hawking himself replied: "Rubbish. It's mere media hype."

And his peers seem to agree. In 1999, magazine Physics World asked hundreds of them to rank the world's greatest physicists. Perhaps predictably, Prof Einstein topped the list - but Prof Hawking didn't even make the top 15.

In fact, even though each of the 130 physicists who contributed to the rankings were asked to vote for their top five, out of a possible 650 votes Prof Hawking only got a single one.

New Zealander Ernest Rutherford came in 10th. Even some of Prof Hawking's peers were ranked higher - including Richard Feynman, who received the Nobel Physics Prize for his work on quantum mechanics, and Paul Dirac, who preceded Prof Hawking as Lucasian Professor of Mathematics at Cambridge University.

Ernest Rutherford.
Ernest Rutherford. Photo credit: File

Physics World notes that Prof Hawking's most famous discovery - that black holes can shrink thanks to what's now called 'Hawking radiation' - has never actually been proven true. It only exists, so far, in mathematics - and may remain that way for a long time yet.

"We don't know. And if we could go and have a look, we couldn't get out," Prof Hendry told The AM Show, when asked what's inside a black hole.

"We can try and do some mathematics to try and predict what might be in there, but we can't actually go and have a look."

Prof Hawking's calculations suggest a black hole the size of a mountain would give off enough radiation to power the world's electricity supply.

"People have searched for mini black holes of this mass, but have so far not found any. This is a pity because if they had I would have got a Nobel Prize," he once said.

That's right - the world's most famous scientist never won a Nobel Prize.

Hawking's true genius

Paul Hardaker, president of the Institute of Physics which publishes Physics World, said Prof Hawking "made several fundamental and lasting contributions to cosmology but is probably best known by the public for his passion and enthusiasm in sharing his knowledge of how the universe works".

In other words, Prof Hawking's true genius perhaps lay in his connection to the public. Prof Hawking's book A Brief History of Time came out in 1988, and sold more than 10 million copies.

"One of his important legacies was sending people into science. He was one of the reasons I went into science," said Prof Hendry.

"I was in my teens when he wrote A Brief History of Time, so that was something that sent me there."

The UK Motor Neurone Disease Association praised Prof Hawking as an inspiration.

"Throughout his inspirational life Professor Hawking played a vital role in raising awareness of motor neurone disease around the world," it tweeted.

Hawking's big bets

Prof Hawking also liked to make bets on big scientific questions - not only for his own amusement, but to raise awareness.

And considering he almost always lost - sometimes thanks to his own research - it was never about satisfying his ego.

Despite making his name for revealing the secrets of black holes, he infamously once bet an anomaly detected in the constellation of Cygnus wouldn't turn out to be one - despite the fact if he was right, it would have proven his life's work to be a gigantic mistake.

His explanation? If he was right, he'd be able to console himself with his prize - a four-year subscription to Private Eye magazine. He lost the bet, and bought his opponent Kip Thorne a year's subscription to Penthouse, much to the annoyance of Prof Thorne's wife.

Prof Hawking also bet against the Higgs boson being found, angering Peter Higgs, the physicist who'd long argued for its existence. When the team behind the Large Hadron Collider found it, Prof Hawking not only paid up the $100 wager, he graciously called for his opponent to be awarded the Nobel Prize.

Antics like this, and his unique public image, were arguable just as key to his fame as his work.