The new polymer £50 note is coming on 23 June 2021 and features the mathematician Alan Turing.
It will be the last of the Bank’s collection to switch from paper to polymer and in keeping with Alan Turing’s work, the note is said to be its most secure yet.
Alan Turing provided the theoretical underpinnings for the modern computer. While best known for his work devising code-breaking machines during WWII, Turing played a pivotal role in the development of early computers first at the National Physical Laboratory and later at the University of Manchester.
He set the foundations for work on artificial intelligence by considering the question of whether machines could think.
Turing was homosexual and was posthumously pardoned by the Queen having been convicted of gross indecency for his relationship with a man. His legacy continues to have an impact on both science and society today.
Alan Turing’s portrait on the new note is based on a photo taken in 1951 by Elliott & Fry which is part of the Photographs Collection at the National Portrait Gallery.
The design on the reverse of the note celebrates Alan Turing and his pioneering work with computers. It features:
- A mathematical table and formulae from Turing’s seminal 1936 paper “On Computable Numbers, with an application to the Entscheidungsproblem” Proceedings of the London Mathematical Society. This paper is widely recognised as being foundational for computer science.
- The Automatic Computing Engine (ACE) Pilot Machine which was developed at the National Physical Laboratory as the trial model of Turing’s pioneering ACE design. The ACE was one of the first electronic stored-program digital computers.
- Ticker tape depicting Alan Turing’s birth date (23 June 1912) in binary code.
- Technical drawings for the British Bombe, the machine specified by Turing and one of the primary tools used to break Enigma-enciphered messages during WWII.
- The flower-shaped red foil patch on the back of the note is based on the image of a sunflower head linked to Turing’s morphogenetic (study of patterns in nature) work in later life.
- A series of background images, depicting technical drawings from The ACE Progress Report.
- “This is only a foretaste of what is to come and only the shadow of what is going to be” is a quote from Alan Turing, given in an interview to The Times newspaper on 11 June 1949 and also features on the new note. So does Turing’s signature which was taken from the visitor’s signature book on display at Bletchley Park Trust in 1947, where he worked during WWII.
The work of Alan Turing, who was educated in Sherborne, Dorset, helped accelerate Allied efforts to read German Naval messages enciphered with the Enigma machine. His work is said to have been key to shortening World War Two and saving lives.
Less celebrated is the pivotal role he played in the development of early computers, first at the National Physical Laboratory and later at the University of Manchester.
In 2013, he was given a posthumous royal pardon for his 1952 conviction for gross indecency. He had been arrested after having an affair with a 19-year-old Manchester man, and was forced to take female hormones as an alternative to prison. He died at the age of 41. An inquest recorded his death as suicide.
Andrew Bailey, the governor of the Bank of England, said:
“He was a leading mathematician, developmental biologist, and a pioneer in the field of computer science.
“He was also gay, and was treated appallingly as a result. By placing him on our new polymer £50 banknote, we are celebrating his achievements, and the values he symbolises.”
You will still be able to use the paper £50 note until the Bank of England withdraws it from circulation. They will announce the withdrawal date after they have issued the new polymer £50 note in June. They will also give at least six months’ notice of the date you’ll no longer be able to use the paper £50.
Alan Turing is perhaps best known for his code breaking work during World War 2, and in recognition of this the Bank of England have collaborated with GCHQ to design a series of puzzles, based on the Turing £50 note design. Test your code breaking skills where you will have to solve 11 puzzles, each based on one of the features on the note. Solve all 11, and you will have all the clues you need to solve the final puzzle. Good luck!
Photo Credits: Bank of England