The Bank of England has released new polymer £50 banknotes featuring Alan Turing. The release of the bills completes the Bank’s transition from paper to polymer banknotes and is a fitting tribute to a brilliant mind.
A famous mathematical mind
Alan Turing may be best known for his codebreaking work for the Allies at Bletchley Park during WWII, but he’s also credited with formulating the foundations of computer science. His 1936 paper, On Computable Numbers, with an Application to the Entscheidungsproblem, presented his theory regarding whether a theorem could be assessed using a machine and introduced the concept of the Turing machine.
Turing was a homosexual and was persecuted because of his sexual orientation. In 1952, he was arrested after having a sexual relationship with a 19-year-old man from Manchester. Such relations between men were illegal in Britain at the time.
In lieu of prison time, he was forced to take female hormones as a form of chemical castration, and just two years later died by suicide after ingesting cyanide. In 2013, Queen Elizabeth II posthumously pardoned Turing.
The banknote is officially released
The new £50 banknote was released on June 23, 2021, Turing’s birthday. The decision to feature him was announced in July 2019, after a 2018 campaign, which allowed the public to submit nominations for who they thought should be pictured on the denomination.
Bank of England Governor Andrew Bailey ultimately made the decision to feature Turing, saying, “Our banknotes celebrate some of our country’s most important historical figures. That’s why I’m delighted that Alan Turing features on the new polymer £50 note. Having undertaken remarkable codebreaking work here at Bletchley Park during the Second World War, he went on to pioneer work on early computers, as well as making some ground-breaking discoveries in the field of developmental biology.
“He was also gay and was treated appallingly as a result. Placing him on this new banknote is a recognition of his contributions to our society, and a celebration of his remarkable life,” he concluded.
To coincide with the bill’s release, the Bank of England launched an online exhibit about how Turing’s work inspired the design.
A celebratory design
The banknote’s design features an array of images dedicated to Alan Turing’s accomplishments. The image of him was taken by Elliott & Fry in 1951 and is part of the Photographs Collection at the National Photography Gallery. As with other British currency, a portrait of the Queen is on the opposite side.
His signature is from the visitor’s book at Max Newman’s House in 1947, and there’s a 1949 Times quote, which reads: “This is only a foretaste of what is to come and only the shadow of what is going to be.” There is also a small see-through window toward the banknote’s lower corner in the shape of Bletchley Park.
There are various images representing his life’s work, among a host of security features. These include his technical drawings for the British Bombe, tables and mathematical formulae from his 1936 paper, a sunflower head to represent his morphogenetic work, and the Automatic Computer Engine (ACE) Pilot Machine.
Future of paper money
According to the Bank of England, the paper £50 banknotes currently in circulation will no longer be considered legal tender as of September 30, 2022. Their production has already ceased, and after the September 2022 deadline, only post offices will accept them.
The release of the £50 banknote is the last in a set of polymer banknotes the Bank has released to replace paper money. The £5, £10, and £20 paper banknotes have been replaced by polymer ones featuring images of Winston Churchill, Jane Austen, and J.M.W. Turner, respectively.
The polymer ones are believed to last two-and-a-half times longer than their paper predecessors and feature advanced security systems aimed at making them harder to forge. “The polymer £50 note is the most secure Bank of England banknote yet, and the features of the note make it very difficult to counterfeit,” says Sarah John, Chief Cashier with the Bank of England.”
“All of our polymer banknotes can be checked by looking for two key security features: a hologram which changes image; and see-though windows. So if you can check one denomination of banknote, you can check them all,” she continued.
The rollout of the new banknotes at banks and ATM machines will occur over the coming days and weeks.