A new 50 pence piece featuring a black hole in commemoration of Stephen Hawking is proving so popular the Royal Mint was temporarily forced to make people queue to visit its website on Tuesday morning.
Limited editions versions of the coin in silver and gold, priced at £95 and £795 respectively, have already sold out and those trying to get their hands on one this morning were met with a screen informing them they would have to wait.
A £10 presentation version of the coin that will go into circulation is still in stock.
The online auction site, eBay, is already filled with limited edition versions of the coin going for well above the recommended retail price.
The coin features an optical illusion design of concentric rings that give the appearance of a hole disappearing into it.
Prof Hawking died last year aged 76, having become one of the most renowned scientists in his field, despite his long battle with motor neurone disease.
The design of the coin is influenced by Prof Hawking’s pioneering work on black holes and his ability to make science accessible and engaging, the Press Association reports.
The Mint said: “This work, which used a tentative unification of Einstein’s theory of general relativity with quantum mechanics, reported that black holes should not be completely black, instead emitting radiation, meaning they evaporate and eventually disappear.”
“Hawking Radiation” was an influential development, leading to the conclusion that information is lost as a black hole forms and subsequently evaporates.
Prof Hawking explained black holes in his best-selling book ‘A Brief History Of Time’.
Edwina Ellis, who designed the coin said: “Stephen Hawking made difficult subjects accessible, engaging and relatable and this is what I wanted to portray in my design, which is inspired by a lecture he gave in Chile in 2008.
“Hawking, at his playful best, invites the audience to contemplate peering into a black hole before diving in. I wanted to fit a big black hole on the tiny coin and wish he was still here chortling at the thought.”
In recent years he has been the subject of a film starring Eddie Redmayne, who won an Oscar for the role, and has had a recording of his voice beamed into a black hole.
Prof Hawking once said in an interview with the BBC: “I think my greatest achievement will be my discovery that black holes are not entirely black.”
He is one of an elite group of scientists to have been honoured on UK coinage, alongside the likes of Sir Isaac Newton in 2017 and Charles Darwin in 2009.
Tim and Lucy Hawking, son and daughter of Stephen, visited the Royal Mint.
Lucy said: “It is a great privilege to be featured on a coin and I hope my father would be pleased to be alongside Sir Isaac Newton and Charles Darwin as scientists who have made it onto money!”
Nicola Howell, director of consumer at the Royal Mint, said: “We are very pleased to honour Stephen Hawking on his own coin.
“As one of the world’s most brilliant physicists he was a great ambassador for science.
“His popularisation of science and breakthrough work on black holes stand as great achievements and significant contributions to humanity.”
Prof Hawking is also among a large number of scientists whose names have been suggested for a new £50 banknote.
The Bank of England has previously asked for nominations for the face of the new banknote, which will be someone from the world of science.
It will announce who will appear on the note in the summer.