£50 note character selection announcement
Speech given by
Mark Carney
Governor of the Bank of England
Science and Industry Museum, Manchester
15 July 2019
I am grateful to Clare Macallan for her assistance in preparing these remarks, and to Matthew Corder,
Toby Davies, Sarah John, Elizabeth Levett, Debbie Marriott and James Oxley for their help with
background research and analysis.
It's a pleasure to be at the Science and Industry Museum in Manchester. These galleries testify to the UK's
rich history of discovery in science, technology and industry.
A little more than eight months ago, the Bank sought to recognise the UK's extraordinary scientific heritage
by asking people across the country to "Think Science"
in order to help us choose the character to feature on
the new £50 note.
We were overwhelmed by the response. In six weeks, almost a quarter of a million nominations were
submitted, from which we distilled a very long list of nearly 1,000 unique characters.1
The hard work of narrowing down these names to a shortlist of twelve options required the incomparable
knowledge and tireless work of the Banknote Character Advisory Committee.2 On behalf of the Bank, I
would like to thank the external members of the Advisory Committee - Dr Maggie Aderin-Pocock, Dr Emily
Grossman, Professor Simon Schaffer, Dr Simon Singh, Professor Sir David Cannadine, Sandy Nairne and
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Baroness Lola Young for their invaluable expert advice and unbridled enthusiasm.
The characters that made it through to the final shortlist were:

Mary Anning

Charles Babbage and Ada Lovelace

Paul Dirac

Rosalind Franklin

Stephen Hawking

Caroline Herschel and William Herschel

Dorothy Hodgkin

James Clerk Maxwell

Srinivasa Ramanujan
 Ernest Rutherford
 Frederick Sanger
 Alan Turing
The shortlist epitomises the breadth and depth of scientific achievement in the UK. Their work covers both
the theoretical and the practical, and spans from the smallest building blocks of the universe to the nature of
life itself.
1
Characters must be non-fictional and deceased. We also need to ensure that a suitable, easy to recognise, portrait of the person is
available.
2
https://www.bankofengland.co.uk/about/people/banknote-character-advisory-committee.
Rosalind Franklin's and Frederik Sanger's
revelations about DNA, for example, furthered our understanding
of the biology of life, and Dorothy Hodgkin's discoveries about the structure of insulin and vitamins better
enabled us to preserve it. Mary Anning's palaeontological discoveries helped us understand the history of
life on earth, while Caroline and William Herschel and Stephen Hawking opened up the heavens.
Srinivasa Ramanujan's
pioneering research transformed modern theoretical mathematics. More practicably,
the ground-breaking work of James Clerk Maxwell, Ernest Rutherford and Paul Dirac on electromagnetism,
radiation and quantum mechanics laid the foundations for telecommunications and nuclear physics.
Likewise, Charles Babbage and Ada Lovelace have contributed to the origins of computing that underpins
virtually every aspect of modern life.
Each of the shortlisted scientists is worthy of celebration, so the Bank is delighted that this Museum is
honouring them with a special exhibition that showcases their many and diverse achievements.
Sadly, there is not adequate space to feature them all on the new £50 note. A choice had to be made.
And it is my pleasure to announce today that the scientist that will feature on the new £50 note is Alan
Turing.
Why Turing?
Alan Turing was an outstanding mathematician whose work has had an enormous impact on how we live
Turing's contributions were far
today. As the father of computer science and artificial intelligence, Alan
ranging and path breaking.
Turing was insatiably curious about the world around him. With his mind ranging widely and freely, he
approached a variety of seemingly intractable problems and found answers that passed others by. His
genius lay in his unique ability to link the philosophical and abstract with the practical and concrete.
All around us, his legacy continues to build. Turing is a giant on whose shoulders so many now stand.
Born in Paddington, London on 23 June 1912, Turing displayed prodigious talent and vibrant interest in the
sciences and mathematics as a schoolboy. This was reinforced by the untimely death of his close friend
Christopher Morcom. Writing to Morcom's mother, he declared,
"I know I must put as much energy if not as
much interest into my work as if he were alive, because that is what he would like me to do."
To many, Turing is renowned for his "indispensable"3
codebreaking contributions at Bletchley Park during the
Second World War.4 The advances Turing made in cryptanalysis then - including co-inventing the Bombe
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computer for solving ciphers and applying statistical techniques to speed up rates of decryption were
work gave the Allies a crucial
pivotal in cracking the hitherto unbreakable German Enigma code. Turing's
advantage in the battle for the Atlantic and is widely credited with hastening the end of the war by at least
two years, potentially saving millions of lives in the process.
lifetime, but Turing's contributions range far more broadly
That alone would be more than enough for one
than those that have been rightly celebrated in print and on screen.
One of Turing's
lesser-known interests was biology. In later life, Turing pioneered morphogenesis by
applying his knowledge of mathematics and computer science to understand how plants and microorganisms
develop their shapes and patterns. Turing used computers to simulate the results of hypothetical chemical
reactions to develop truly original insights in this field. The theoretical foundations he developed have since
been applied to solve puzzles such as why the leaflets on a pinecone follow the Fibonacci sequence and to
explain the pattern of animals' coats from cats to zebras. This work of a lifetime helped lay a cornerstone in
theoretical biology.
It was, however, the workings of the human mind that inspired Turing's greatest contributions to human
knowledge and our lived experience. Turing answered a fundamental question: whether there is a definitive
method that could be applied by machine to solve all mathematical problems. Once again, Turing's genius
lay in his ability to think across boundaries, applying mathematical logic to a problem others had viewed as
- -
one of physics. The answer he supplied captured in his 1936 paper On Computable Numbers5 provides
the very foundations of computer science.
Turing envisaged a machine that could be turned to any well-defined task by supplying it with the appropriate
program. The eponymous Universal Turing Machine, fed instructions through symbols on an infinite piece of
tape, was an abstract concept in his time, but it's something that recognisably embodies the core
principles
of a modern computer and the logic of binary code. Moreover, his insight that only computable functions can
be calculated is vital to software design. In recognition of the importance of this work, Turing was elected a
Fellow of the Royal Society in 1951.
Enough for two lifetimes.
3
by C H O'D Alexander, a colleague of Turing's at Bletchley. See:
Cryptographic History of Work on the German Naval Enigma,
http://www.ellsbury.com/gne/gne-042.htm.
4
In 1946, King George VI appointed Turing an Officer of the Order of the British Empire for his wartime services, although the details of
his work remained secret for many years.
5
Turing, A (1936), 'On Computable Numbers, with an Application to the Entscheidungsproblem', Proceedings of the London
Mathematical Society, Volume 42, Issue 1, pp. 230-265.
Having imagined the concept of a computer, Turing helped turn it into reality. He played a vital role in the
design and development of early electronic computers after the war, continuing to contribute key ideas such
as implementing functions by flexible programing rather than pre-set built-in electronic components. Working
first at the National Physical Laboratory in London and later at the Computing Machine Laboratory at
Manchester University, his insights led to the creation of the Automatic Computing Engine (ACE) in 1950 and
the program for Ferranti Mark 1, the world's first commercially available electronic computer.
A visionary as well as a revolutionary, Turing recognised that
"This is only a foretaste of what is to come and
only the shadow of what is going to be".
True to his nature, Turing himself began to suggest some possible directions.
His interests in neurology and physiology led him to ask whether computing machines could be capable of
mimicking the faculties of the human mind, including the ability to learn. His work prefigured the neural
networks that are used today in applications such as cancer diagnosis and self-driving cars and as yet
undiscovered new technologies of tomorrow. And the Turing Test, a method for determining whether a
computer can exhibit intelligent behaviour indistinguishable from a human being, remains the benchmark for
judging true artificial intelligence.
Turing also leaves a very different, though no less important, legacy. In March 1952, he was convicted of
Gross Indecency for his private relationship with a man, avoiding prison only by submitting to chemical
castration. His security clearance was revoked for no reason other than his homosexuality, bringing to an
end a promising post-war career as a consultant for GCHQ. He died shortly thereafter, on 7 June 1954, from
cyanide poisoning.
In 2009, the then Prime Minister Gordon Brown made an official posthumous apology on behalf of the
"government and all those who live freely thanks to Turing's work" for his "utterly unfair" treatment.6 Turing
in December 2013 and in 2017 the "Alan Turing Law" was passed,
received a royal pardon for his conviction
pardoning the nearly 50,000 men cautioned or convicted under now-rescinded historical legislation that
outlawed homosexual acts.
In the UK today, we are fortunate to live in more inclusive times. Thanks to groups like the Sexual Law
Reform Society and Stonewall, and initiatives like Pride, there has been huge progress towards ending the
unfair treatment of people on the basis of sexual orientation and creating a society in which everyone can be
their true selves without fear or favour.7
6
See https://webarchive.nationalarchives.gov.uk/20091005104048/
http://www.number10.gov.uk/Page20571
7
The Bank of England aims to be an LGBT+ inclusive employer, taking part in the London Pride parade every year and flying the pride
flag atop its Threadneedle Street building. The Bank has a thriving LGBT+ & Allies Network which was launched in 2006 and now has
around 350 members and allies. In 2018, the Bank supported the rollout of rainbow lanyards in the spirit of creating a visibly inclusive
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and supportive environment these are now worn by more than 1,000 colleagues. We complete the Stonewall benchmarking exercise
each year and were pleased to have increased our ranking by over 100 places in 2018.
The Bank of England is committed to ensuring our banknotes are as inclusive as possible. That means
celebrating the breadth of human achievement in this great country from science to the arts to statecraft to
literature. And it means featuring a range of individuals who reflect the vibrant diversity of UK society.
The design of the note
Let me conclude by unveiling the image for the new Turing £50 note.
The design recognises the breadth and variety of Turing's contributions to science. The table taken from his
seminal paper On Computable Numbers in the foreground is a succinct representation of a Turing Machine,
and the ticker tape records Turing's birth date in binary code.
In the background are images of the ACE pilot machine and a section from the technical drawings of the
Bombe.
The portrait is by Elliott and Fry, and the quote is from an interview published in The Times, dated 11 June
1949.
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The characters on our banknotes celebrate those who have advanced British thought, spurred innovation,
shown exceptional leadership, shaped this diverse society and forged our common values. Alan Turing will
join Winston Churchill on the £5 note and Jane Austen on the £10, and JMW Turner who will make his
appearance on the new £20 next year.
Although we look to history when we chose a new character, Turing's work inspires us to look to the future
and imagine what is still to come as a result of his genius.
If anyone can see the future, it's the -
next speaker. It is my pleasure to welcome Demis Hassabis artificial
intelligence researcher, neuroscientist, video game designer, chess champion, co-founder of DeepMind and
one of the 225,000 who submitted a recommendation to this process - to celebrate Turing's past
contributions to science and venture where they might take us tomorrow.