The British Royal Mint has commemorated professor Stephen Hawking in a new 50p coin, which references the late physicist's pioneering work on black holes.
The honorary coin, which is available in three metal finishes, aims to celebrate the life and "ground-breaking" achievements of Hawking, who passed away in 2018.
It features Hawking's name in capital letters above a rippling drawing of concentric circles, intended to represent a black hole. Designer Edwina Ellis, a British engraver and printmaker, wanted to "fit a big black hole on the tiny coin".
Also on the coin is the formula for arguably Hawking's most important scientific contribution. It references his discovery that black holes are not completely black, and instead emit radiation, meaning they eventually evaporate and disappear.
"Termed Hawking Radiation, this was an unexpected but highly influential development," said The Royal Mint when introducing the coin. "Hawking's discovery led physicists to the unavoidable conclusion that information is lost as a black hole forms and subsequently evaporates," explained the organisation.
"This is the black hole information paradox, one of the greatest unsolved problems in theoretical physics," it continued.
Ellis looked to Hawking's "playful" side and his ability to explain complex ideas in a simple way, when designing the coin.
"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," said Ellis.
"Hawking, at his playful best, invites the audience to contemplate peering into a black hole before diving in."
The new 50p coin is the latest in a series of scientist honoured by the UK coinage, including Charles Darwin in 2009 and Isaac Newton in 2017.
"[Hawking's] popularisation of science and breakthrough work on blackholes stand as great achievements and significant contributions to humanity," said The Royal Mint.
The general public can purchase the coins from The Royal Mint website.
Hawking has been a source of inspiration for many designers, including Es Devlin who looked to the physicist's 2015 launch of the Breakthrough Initiative to search for extraterrestrial life, when imagining her Poem Pavilion for Dubai Expo 2020.
The late scientist was also chosen by design agency One Rise East, who created a set of 26 coins to represent an A-to-Z of modern-day Britain.