Bletchley Park Turing Special - United Kingdom Mathematics Trust

TI
ES
The Alan Turing Year around the world
W
elcome to this
special edition of the
Bletchley Park
Times that celebrates 100
years since the birth of the
man who is considered to be
the father of computing, Alan
Mathison Turing, the person
who influenced theories in
many scientific studies in his
short 42 year life.
Depending on your
background, you may know of
his influence in one of several
scientific fields. However the
recent growth in popularity of
the Bletchley Park museum
has helped propel Alan Turing
into the public limelight due to
his codebreaking work during
WW2. Several plays and TV
documentaries written about
his life and work have been
produced. Whilst not the sole
codebreaker at Bletchley
Park, for there were many
brilliant minds who worked on
breaking messages from
several countries, he is the
one whose charismatic and
quirky persona has entered
the British psyche and been
adopted as the focal point of
many groups.
Before the Alan Turing Year
(ATY) started, his life and
works were generally
shrouded in mystery and
almost legendary. His life
through his work has more
recently come under greater
scrutiny for public
consumption. As the publicity
of this centenary has ramped
up, more stories and artefacts
have come to light to help us
understand a little more about
this influential life.
This publication provides a
very brief introduction to the
centenary celebrations. There
is of course plenty of other
information available and we
hope that you feel inspired to
seek it out. The back cover
lists a few links to further
information. The black and
white patterns are QR codes
that most smart phones can
use to navigate to the listed
website 2
Alan Turing Centenary
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A
lan Turing and Bletchley Park were
made for each other. Where else
would your average gay geekish
genius, with an interest in running and all
things computable, have been sufficiently
challenged and appreciated for the
phenomenon he was? It is said that
Britain survived in WW2 because
individuality, even the oddest of
eccentricity, was part and parcel of the
Bletchley Park community of
codebreakers; very different from life
under the Third Reich.
So the 2012 Alan Turing Year is not just
an opportunity to celebrate the 100th
birthday of one of Britainʼs greatest
scientists. It is also a chance to focus on
the diversity of those touched by Turing,
personally and through the richness of his
scientific legacy. At the same time, it is a
chance to find out more about the
amazing synergetic coming together of a
confusion of ideas and creative quantum
leaps within the mind of this strangely
complex figure.
It is not easy to explain to the uninitiated
what was so special about Turing. He
pops up in so many different research
communities, each not very aware of the
Turing beyond their own horizons. The
logic, the number theory, the computable
analysis, the cryptography, the statistics,
programming and software, computer
science, developmental biology, the
artificial intelligence - and the gay martyr.
The Alan Turing Year will see a multitude
of conferences celebrating the Turing
legacy.
Some - such as the big Turing Centenary
conferences in Cambridge and
Manchester - will try to capture some of
the breadth and coherence of this legacy,
as will the Isaac Newton Institute 6- month
Turing centenary programme in
Cambridge. Others, scattered all around
the world, will collectively draw together
the strands of ideas - philosophy in
Manila, the Philippines and in Zurich in
Switzerland, mathematics in Kent,
Washington DC and Boston,
computational economics in Taipei,
computer science in Beijing (ATY in
China), Princeton, San Francisco (for the
ACM Annual Meeting and 2011 Turing
Award presentation), Buenos Aires,
Dubrovnik, Poland, Newcastle on Tyne
and a host of other centres. Also there
will, of course be, artificial intelligence and
the Turing Test at Bletchley Park (in fact
twice, for the Loebner Prize in May and
for the special Turing100in2012 event on
23rd June) and a major AI world congress
in Birmingham in July. Moreover, there
will be lots of logic, including January in
Florida, February in Portugal, July in
Manchester and September in Paderborn.
As well as cryptography at Bletchley Park,
there will be a huge EuroCrypt meeting in
Cambridge and Pattern Formation in
Biology at Oxford. The list and variety is
quite remarkable. You need to visit the
ATY webpage at:
www.turingcentenary.eu
to appreciate the full extent. There is even
cognitive sciences in Montreal and
complexity and human experience in
North Carolina and meetings in Stanford,
Chicheley Hall and Orléans.
exploring incomputability and computing
beyond the so-called ʻTuring barrierʼ. Also,
the Mathematica conference in London
next June has Turingʼs biographer
Andrew Hodges giving a special lecture.
To end this list - already too long! - we
must just mention that the IET/BCS 2012
Turing Lecturer, Professor Ray Dolan will
talk on links between Turingʼs original
ideas in biology and cutting edge work
going on today in cognition and neuroimaging. He will be speaking in London,
Cardiff, Manchester and Edinburgh. Best
to get tickets early, the lectures will soon
fill up. Itʼs not all conferences and other
academic events - although Turingʼs big
ideas are harder to explain in laypersonʼs
terms than those of Darwin or Einstein.
They are more abstract; even the
explanation of how cows get their spots or
how the stripes on tropical fish vary,
needs some grasp of differential
equations to properly appreciate.
Furthermore, the link between the
Universal Turing Machine and the familiar
stored program computer inhabiting every
aspect of our daily lives is not properly
understood by many who should know
better. Even harder to explain is Turingʼs
unifying vision and its influence across
disciplines. As Andrew Miller MP put it,
when explaining why the Government's
new Technology and Innovation Centres
(TICs) would be named after Alan Turing:
“There isn't a discipline in science that
Turing has not had an impact upon.”
Anyway, there are a host of exhibitions
and meetings dealing with the life of
Turing and the history of the computer.
Bletchley Park (with its recently acquired
Max Newman collection of Turingʼs
papers and working Turing Bombe
rebuild) and the National Museum of
Computing will be an essential venue to
visit. However, there are lots more,
including a major Science Museum exhibit
in London and interesting exhibitions
sprouting up at the Heinz Nixdorf Museum
in Paderborn (“Eminent and Enigmatic: 10
Aspects of Alan Turing”), Kansas, Brazil
and France. Meetings include Jack
Copelandʼs ACE 2012 in Cambridge and
an interesting two-part conference on
“Turing In Context”, Part 1 at Kingʼs
College, Cambridge and Part 2 at the
University of Ghent - the idea being to
give attention to some of the other major
figures in the history of the computer.
Also, there are cultural events. There are
planned major new stagingʼs of Hugh
Whitemoreʼs “Breaking The Code”, in
London and New York. Additionally, there
are films: The pre-2012 Channel 4 film of
“Britainʼs Greatest Codebreaker” was truly
remarkable, very moving and good on the
science. Those lucky enough to be at the
Google sponsored preview in November
at BAFTA will have been been struck by
the positive way the film was received memorably Captain Jerry Roberts starting
with “Iʼm a Tunny man myself” and going
on to pay tribute to the genius of Turing
and to the overdue recognition the film
represents. Also, there were Alan's
nephew Dermot Turing (who will be much
in demand in 2012) and his mother Mrs
Beryl Turing, both eager to see the Turing
brothers, Alan and John, properly
remembered. Of course, there are more
films in prospect, including a Turing Test
themed Hollywood feature film called “The
Imitation Game”, maybe even starring
(controversially) Leonardo DiCaprio as
Alan Turing. Other cultural events are
centred around Turingʼs influence on the
arts - computer art, music etc. - and there
are interesting events planned by the
Turing Centenary Arts and Culture
Committee in Brighton and London.
Literary events include a reissue by
Cambridge University Press of Sara
Turingʼs biography of her son - original
copies seen going on Ebay for thousands
- with a previously unpublished memoir
written soon after Alanʼs death by his
brother Sir John Turing. Expect something
typically Turingesque and completely
engrossing. There are too many other
excellent Turing-themed books in
prospect to mention, though a reissue of
Andrew Hodgesʼ classic biography of
Turing is no surprise.
So it will be a richly various year of great
excitement for very many people, both old
and with memories, for researchers
seeing the science and its history get
more attention and for the young coming
to Turing for the first time. And there will
be competitions directed at students and
young researchers. The John Templeton
Foundation is funding a Turing Fellowship
competition with more than a half-million
pounds, for young researchers to
investigate ʻbig problemsʼ arising from
Turingʼs scientific legacy. And Computing
At School is joining with Animation12 in
Manchester to organise a ʻCodebreakerʼ
competition for school students.
Like Turing, the year will arouse different
emotions. It will be impossible to forget
that Britain treated one of its greatest
scientists in history outrageously and that
Bletchley Park and Alan Turing are only
just starting to get the recognition at
national level that they should. On the
other hand, the achievements of Turing
and of those who worked with him—at
Bletchley Park, Hanslope Park,
Manchester, Cambridge, the National
Physical Laboratory and Princeton - will
be remembered like never before during
2012. It may even be a time for a real
celebration. From Israel's Turing Year
organisers comes a suggestion for a
‘Night for Alan’ on his actual 100th
birthday on 23rd June 2012. A date to fill
with special events all round the world and maybe even the occasional party, to
celebrate a remarkable, if too short life Professor S Barry Cooper is currently Professor of
Mathematical Logic at the University of Leeds. He has
had several papers published within the field of
computability and unsolvability—a subject that was the
focus of one of with its application to the real world.
Amongst his many interests and memberships, he edits
the Alan Turing Year newsletter which informs its
readers of the many world-wide events and
celebrations of Alan Turing’s life.
A time to remember
I
n this year of 2012, the UK
will be celebrating the 60th
anniversary of Her Majesty
The Queen Elizabeth’s
accession as head of the
United Kingdom and
Commonwealth and hosting
the global phenomena of the
Olympics and Paralympics in
London for the first time since
1948. In addition, another key
anniversary is being
remembered and celebrated
throughout the world of
mathematics and computing.
It will be 100 years since the
‘Father of Computing’, Alan
Mathison Turing was born on
23rd June 1912.
You may have come across
Alan Turing for a number of
different reasons: perhaps
you are interested in
mathematics and statistics or
biological systems and how
they develop. Maybe you
have been involved with
computer science and
followed the development of
computers for several years.
Possibly, due to the more
recent interest and publicity of
Bletchley Park and his efforts
in helping to break the Nazi
WW2 encrypted messages
that were so important for
communicating operationally.
Alan Turing had a broad
range of scientific interests
and influences, publishing
unique ideas that spanned the
scientific corners of
Chemistry, Physics, Biology,
Mathematics and Computer
science. At the heart of this
was possibly a desire to
understand more clearly how
nature generally worked and
Humans specifically
functioned in terms of
consciousness, reasoning and
adaptability. To Turing these
subjects held a fascination
that allowed him to
intellectually explore each
area. However, his legacy is
that he helped create new
ideas and spin-off research in
each of these areas that we
Alan Turing Centenary
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The Life and Works of Alan Turing
are still researching and
developing today.
Probably the biggest impact of
his work was through the
investigation of thought and
how to develop machines that
could think or at least provide
a very strong illusion of
thinking. His theories of
thinking and artificial
intelligence led to basic ideas
that we would find familiar
today – digital storage of
instructions, decisions based
on stored information leading
to clearly defined actions.
Today we recognise these as
the basis of the modern digital
world where computers help
control and run everything
from washing machines and
telephones through to satellite
communications global
positioning systems,
aeroplane and ship navigation
and running a myriad of online
services. We take many of
these products and
technologies for granted these
days, but pre-WW2, these
ideas were completely
revolutionary, not evolutionary
– very few scientists were
even dreaming of such ideas
in a world run by mechanical
and sometimes highly
unreliable machines.
Turing was able to advance
his ideas of machine
intelligence and control faster
than would probably have
been possible due a twist of
fate that threw the UK into the
second major war of the 20th
century. The rise of the Nazis
and Hitler’s determination for
world domination meant that
all corners of the Nazi
operations needed to maintain
contact with central military
guidance and feedback
information on progress in a
secure way. The fastest way
to do this was using radio
communications. However,
due to the insecure nature of
this communications medium
(i.e. anyone with a cheap
radio set was able to listen in
to the same broadcast
messages) a second
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just eleven days via the Justgiving
website. Then, search engine giant
Google, stepped up and generously
pledged $100,000 and a further significant
sum was received from a private donor.
T
he Bletchley Park Trust is proud
and delighted to have been
nominated for the Art Fund Prize
2012 for its exhibition, “The Life and
Works of Alan Turing”, in the centenary
year of his birth. Alan Turing, one of the
pre-eminent Bletchley Park codebreakers,
was a visionary mathematician and
genius whose work contributed
enormously both to the outcome of WW2
and the computer age that was to follow.
In 2011, after an extraordinarily highprofile, four month campaign, an
exceptionally rare and valuable cache of
the works of genius of the WW2
codebreaker arrived at their final resting
place and rightful home on public display
at Bletchley Park. How a seriously underfunded organisation, the Bletchley Park
Trust, came to acquire this expensive
collection is an uplifting and inspirational
story. The story of a determined nation
mobilised and united in action for a cause
in which they believed. A campaign that
sparked the imagination of the public, the
media and both the private and public
sectors, causing them to collaborate to
achieve what seemed unachievable.
It started with a tweet – The
Acquisition of the Turing-Newman
Collaboration Collection
The Director of Museum Operations at
Bletchley Park, Kelsey Griffin, had spotted
the collection due to be auctioned just
eleven days later on the Christie’s
website. The guideline price of between
£300,000 and £500,000 completely
prohibited the Bletchley Park Trust from
bidding for them and Kelsey sent out a
longing tweet, “If only the Trust could
afford to buy these for the museum and its
visitors”. This single tweet was spotted by
passionate Bletchley Park supporter
Gareth Halfacree who promptly launched
the hugely ambitious campaign to secure
the funds needed to purchase the
collection for the Trust. The campaign
attracted colossal public and media
backing and the story went viral across
social media sites and the internet
triggering hundreds of members of the
public to donate a total of £28,500 within
The day of the auction came on 23rd
November. The Bletchley Park Trust
placed its bid of the accumulated
donations totalling £100,000.
Disappointingly bidding began at
£200,000 and the collection remained
unsold at £240,000 having failed to reach
its reserve price. Despite the tremendous
support, the future of the collection was
uncertain and still at risk of being bought
by an overseas collector. Simon
Greenish, the then CEO of the Bletchley
Park Trust, entered into vital talks with the
auction house, Christie's, and with the
National Heritage Memorial Fund
(NHMF).
In December during Prime Minister's
Questions, Iain Stewart, MP for Milton
Keynes South, asked David Cameron to
support Bletchley Park in acquiring the
collection. He informed the Prime Minister
that the Trust was confident of raising
funds to buy the papers but stood a risk of
losing out as the collection could be sold
before its fundraising target was achieved.
He asked if the PM would "do all he can
to give Bletchley Park a fair chance to
secure those important documents for the
nation". Cameron replied by praising
Turing as a remarkable man and saying
that he hoped that private donors would
generously support the fundraising
campaign. He said: "I am very happy to
work with my honourable friend and do
anything I can to make that happen".
On the 25th February 2011, the Bletchley
Park Trust announced that the collection
had been saved for the nation as the
NHMF had stepped in quickly to provide
£213,437, the final piece of funding
required. The collection was personally
delivered by Christie’s manuscript and
book specialist, Julian Wilson.
Interpretation of the Turing-Newman
Collaboration Collection
The next challenge was the interpretation
of the Collection which primarily consisted
of high-level academic papers. Professor
Jack Copeland, Director of the Turing
Archive for the History of Computing,
wrote the captions for each of the papers
making the complex mathematical
subjects more easily understood. He also
developed a timeline around the life and
work of Alan Turing along with a
description of his importance to the
Part of the new Turing
exhibition in Block B.
evolution of computing.
Display of the Turing-Newman
Collaboration Collection
The NHMF also generously made
provision for the conservation and display
of the collection. Each item was sent
away for conservation. The Trust’s
Curator, Gillian Mason, procured secure
and environmentally-controlled display
cases from Bletchley-based company,
‘Armour Systems’. The cases present the
artefacts on raspberry coloured mountings
and ivory plinths. The Hampshire-based
company, ‘The Exhibition Factory’ was
selected to produce the interpretative
panels due to their proven creative skills
in bringing projects to life. The exhibition
extends into an alcove that was filled with
display cases and visually-striking panels.
The Turing-Newman Collaboration
Collection
This collection is particularly rare,
important and valuable, as very few
physical traces of Turing’s work or
personal belongings still exist. Most of the
wartime records at Bletchley Park were
destroyed after the war, while Turing
himself kept little of his work and very few
personal belongings.
The collection of articles belonged to
Professor Max Newman, Turing’s friend
and fellow Bletchley Park codebreaking
genius. It includes offprints of fifteen of
Turing’s eighteen published works
including his momentous paper ‘On
Computable Numbers’. A limited number
of the off-prints would have been
produced at the time and Turing’s gifting
them to Newman bears testimony to their
unique relationship. The set includes
articles annotated by Newman, along with
his name inscribed in pencil in Turing's
hand. Accompanying the set of offprints is
the Newman household visitors’ book with
several signatures of Turing, one shortly
before his death, a signature of Turing’s
mother, poignantly a few days after his
death, and signatures of other wartime
codebreakers.
The Turing-Newman Relationship
As mathematician, logician, cryptanalyst
and computer scientist, Turing is best
known for being the father of modern
computer science and his work at
Bletchley Park conceiving the TuringWelchman Bombe to mechanise the
process of breaking the Enigma cipher.
He is considered to be one of the most
influential thinkers of our time. His work
was fundamental to the Allied victory of
WW2 and freedom in the West.
Turing's close relationship with Newman
was crucial to the historic contribution
Turing made, starting with Newman's
encouragement to investigate 'mechanical
processes' and his help in securing Turing
a fellowship at Princeton to continue his
research. In 1952 at a time when
homosexuality was illegal in the UK,
Turing was convicted of having a sexual
relationship with another man. He was
sentenced to a hormone treatment that
amounted to chemical castration. Having
made one of the most outstanding
contributions of the 20th century, he died
from cyanide poisoning in 1954 aged 41.
The coroner recorded a verdict of suicide.
William Newman, son of Max Newman,
explaining the special relationship
between Turing and Newman, said, “Max
Newman supported Alan Turing and
collaborated with him for nearly twenty
years, starting in 1935 when Turing was
inspired by one of Newman’s lectures to
innovation was employed: the
process of encrypting data
with machines such as the
Enigma and Lorenz series of
devices. These effectively
masked the data to such an
extent that they seemed to be
a garbled mess of data that
made no sense to the casual
observer. The encryption was
considered by many to be unbreakable. Several tried and
failed so efforts were
abandoned. However, as the
popular saying goes,
‘Necessity is the mother of
invention’. A number of key
events triggered new hope.
The Poles were afraid of a
German invasion and set a
number of top mathematicians
Marian Rejewski, Henryk
Zygalski and Jerzy Różycki
onto working on ways to
decode the Nazi
communications. They made
several breakthroughs and
managed to create a machine
(Bomba) to help with the
process. However, with the
imminent German invasion
and increased security
changes made to the Enigma
machines by the Nazis, the
Poles were forced to confide
their work to a party of allies
in the hope of continuing the
work and finding a way of
breaking the more secure
codes.
A meeting in 1939 in Pyry
forest between the Polish
mathematicians and G.C. &
C.S. staff saw a number of
key documents and machines
handed over to the British
who took the material away to
work on. From around 1938,
the GC&CS were looking to
expand their operations since
they had grown out of Room
40 in the Admiralty from WW1
and settled on an empty
mansion in Buckinghamshire,
well served by road and rail
links to London, Oxford and
Cambridge (key for accessing
the brilliant minds of the day).
Here Alan Turing was
recruited to help in the effort
to break the Enigma codes.
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As an eminent mathematician
with also a keen interest in
mechanised processes, he
was able to use his theories to
improve on the Polish
mathematicians' work to
develop mechanical tools to
help in the decoding process.
This effort had the backing of
Winston Churchill, the Prime
Minister at the time. This no
doubt helped accelerate the
development of Turing’s ideas
into reality through the
invention of the Bombe, a
copy of which can often be
seen being demonstrated at
the Bletchley Park museum
today.
Around 1942, a machine
produced code was regularly
being picked up by listening
stations. This was an
advanced, high speed
automated code produced by
the Lorenz system used by
the German High Command
to communicate with their
senior officers in the field. A
break into these messages
would be like eavesdropping
on Hitler’s thoughts. An attack
on these messages would
require a much more
sophisticated approach
compared to the Enigma
break. Another brilliant
mathematician, Bill Tutte, who
worked in the Testery (named
after Major Tester who
headed up the section) finally
worked out a way to decode
the messages. Moreover, the
complexity of the code, and
the fact that it was produced
in a highly repeatable and
mechanised way, led to a
mechanised solution. Turing’s
previous work and theories of
statistics and machine
intelligence, coupled with the
repetitive processes required
to break the codes, seemed
like a suitable solution to a
real world problem; however
the mechanical technology so
well employed in the Bombe
needed to be much more
sophisticated, reliable and
faster.
The other piece of the
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write his ‘On Computable Numbers’
paper. It was a huge blow to Turing, and
also to Newman, when Turing was
arrested and prosecuted for gross
indecency. Newman gave evidence at
Turing’s trial and may have helped the
court decide on probation rather than
imprisonment.”
Additions to the Turing-Newman
Collaboration Collection: Turing
In September 2009, following a public
campaign with a petition attracting more
than 30,000 signatures, the Prime
Minister Gordon Brown issued an
unequivocal and powerful apology for the
way in which Turing had been inhumanely
treated, saying “on behalf of the British
government and all those who live freely
thanks to Alan's work I am very proud to
say: we're sorry, you deserved so much
better”. In the summer of 2011, Gordon
Brown, having heard about the recent
acquisition of the collection, provided a
personally signed copy of the apology for
incorporation into the display.
Reports of the acquisition and impressive
display of the collection inspired others to
come forward with rare artefacts of Alan
Turing’s life. In the summer of 2011,
Government Communications
Headquarters provided the Trust with a
rare copy of ‘Prof’s Book’, a guide written
by Turing to help those at wartime
Bletchley Park who were embarking on
breaking Enigma ciphers.
In the autumn of 2011, impressed by the
way in which the Bletchley Park Trust had
displayed the Turing-Newman
Collaboration collection, the Turing family
placed some incredibly rare personal
artefacts on loan with Bletchley Park.
These included Porgy, the teddy bear
Alan Turing had bought for himself as an
adult having not owned one as a child.
Along with the teddy bear was Turing’s
wristwatch and several beautifully bound
books awarded to Turing as prizes during
his time at Sherborne School as well as
two tankards awarded to him for rowing at
Cambridge. Also provided by the family
for the Trust to display is an eloquent
biography of Turing written by his mother,
Sara and featuring rare photographs of
him as a child and a young adult.
Max Newman’s son, William, also came
forward and provided a hand-drawn
Monopoly board he had made as a young
boy and on which he had played and
beaten, Alan Turing. A hand-painted set
James May inspecting Porgy. Photo
courtesy Shaun Armstrong
of oars, commemorating Turing’s position
in the King’s College rowing team at
Cambridge University and already owned
by the Trust, is also in the exhibition.
Jason Gorman, a Patron of the Bletchley
Park Trust, generously offered the support
of his annual conference, Software
Craftsmanship 2012, in order to fund the
display case needed to exhibit these
compelling artefacts within the exhibition.
Delilah – a very first Rebuild
Unveiled for the very first time in 2012 is
the world’s only Delilah Rebuild. Delilah
was the portable speech scrambler
machine designed and constructed in
1943 by Alan Turing when he had moved
to work for the Secret Service's Radio
Security Service at Hanslope Park.
Though Turing demonstrated it to officials
by encrypting and decrypting a recording
of a Winston Churchill speech, Delilah
was not adopted for wartime use. Delilah
has now been rebuilt by the Bombe
Rebuild Team led by John Harper and, for
the first time since WW2 can be seen
demonstrated as part of the exhibition.
The Largest and Most Comprehensive
Exhibition of the Life and Work of Alan
Turing in the World
As Professor Jack Copeland stated, “this
is the first permanent public exhibition of
Turing's work and is of major international
importance". However, more than that,
these unique and very personal artefacts
complement beautifully the highly
academic nature of Turing’s work making
the exhibition visually compelling and
providing a deeply touching human
dimension. It depicts a man who was not
only a brilliant and visionary
mathematician and codebreaker but also
a beloved son, an accomplished
sportsman and a man of sensitivity. The
exhibition makes a complex subject
accessible to all, inspiring mathematicians
of the future and giving long-awaited
• Riverside Museum, Scotland's
Museum of Transport and Travel,
Glasgow
• Royal Albert Memorial Museum & Art
Gallery, Exeter, Devon
• Turner Contemporary, Margate, Kent
• Watts Gallery, Guildford, Surrey
The opening of the Turing exhibition by
James May. Photo courtesy Shaun
Armstrong
recognition to the legacy of Alan Turing,
the father of computing. It is fitting,
therefore that the exhibition came to
fruition by the use of modern social
media.
Maybe the most incredible feature of this
world-class exhibition officially-unveiled by
BBC presenter, James May, in March
2012, is that its creation has been the self
-fulfilling prophecy of a determined nation.
Now, inside the historic Block B
codebreaking building, set against the
background of the exquisite, life sized
slate statue of Alan Turing, which was
created by world-renowned sculptor,
Stephen Kettle, and the remarkable
example of precision engineering, the
Turing Bombe Rebuild, the exhibition has
an inherent sense of belonging.
The Art Fund Prize
Bletchley Park’s Alan Turing exhibition
has been nominated as one of the
contenders for the Art Fund Prize, which
is awarded to museums and galleries for
projects completed or mainly undertaken
in the previous calendar year in order to
recognise and stimulate originality and
excellence in museums and galleries in
the UK and also to increase public
appreciation of all they have to offer.
Bletchley Park is competing against the
following sites all of which are hoping to
win the £100,000 prize:
• The Hepworth Wakefield, Wakefield,
West Yorkshire
• The Holburne Museum, Bath,
Somerset
• M Shed, Bristol
• The National Galleries of Scotland,
Edinburgh
• National Museum of Scotland,
Edinburgh
Judging for the title of Museum of the
Year will be undertaken by a panel
consisting:
• Chris Smith, Lord Smith of Finsbury
(chair of judges), former Member of
Parliament for Islington South and
Finsbury and who was Secretary of
State for Culture, Media and Sport from
1997 to 2001.
• Professor Jim Al-Khalili OBE, a
theoretical physicist born in Baghdad,
author and broadcaster whose work has
explored black holes, quantum
mechanics and the history of Arabic
science.
• Charlotte Higgins, author and chief
arts writer for the Guardian and prior to
that was the paper’s classical music
editor.
• Lucy Worsley, Chief Curator at
Historic Royal Palaces, the organisation
responsible for Kensington Palace and
Kew Palace, author and television
presenter of historic programmes about
the King James Bible and the British
home.
• Sir Mark Jones, Art historian who has
overseen the creation of the National
Museum of Scotland and a ten-year
tenure as Director of the Victoria and
Albert Museum.
• Rick Mather, an American-born
architect, whose architectural style is
notable for its extensive use of structural
glass and natural lighting.
• Lisa Milroy, a Canadian painter,
whose art is characterised by an interest
in depicting collections of everyday
items.
The competition asked for comments from
the public as to why their favourite
museum should win. Of course, we all
have our fingers crossed for Bletchley
Park! You can see more information about
the Art Fund Prize online at:
http://www.artfundprize.org.uk/ computing puzzle came in the
form of the Post Office
engineer Tommy Flowers,
who used his engineering
expertise and knowledge of
new electronic circuits, being
employed by the Post Office,
to create the machine that
processed the mechanical
codes. This work eventually
lead to the Colossus being
developed, a dedicated
machine for breaking part of
the Lorenz keys and set the
foundations for the computer
age as we know it today. The
Colossus was operated by the
Newmanry (headed by
William Newman, a great
friend and mentor of Alan
Turing). No doubt this work
helped Turing to further
develop his ideas for
computing machines.
Many of the principles of that
machine, i.e. stored program,
separate digital
representations of data, and
electronic circuitry, are still
being used and evolved
today, albeit now fitting into
circuits that can be easily held
in the hand instead of the
room filling giants they were
when they were first created.
Without the necessity of
solving the wartime problems
and the opportunity to put
theories into practice, the
computer age would probably
have taken longer to get off
the ground as most
revolutionary ideas do when
the visionaries are trying to
get their ideas across to those
who can effect change.
However, the necessity to
retain secrecy around what
had been developed and how
it had been used during the
war meant that it wasn’t until
much later that the world
accepted that Turing had
invented the computer and
that he was the driving force
for providing arguably one of
the biggest revolutions in
Human industrial
mechanisation which has had
such a global effect. After the
war, Turing further developed
Alan Turing Centenary
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7
The people’s choice
his ideas on computers,
taking significant leads in
developing ideas of
intelligence and information
processing. However, this did
not prevent his continued
interest and research into
other aspects of seemingly
unrelated corners of science
such as his paper on the The
chemical basis of
morphogenesis which
looked at how patterns
evolved in animals. In all
probability this was not
completely unrelated to his
computing work as it was an
extension of his interests in
the development of creatures
through influences of
chemicals and electrical
changes in organisms leading
to the rich variety of creatures
in the world. He achieved so
much in his relatively short
life. We can only wonder at
what continued legacy this
world missed out on due to
his untimely death.
I
n 2010 the British Computer Society
(BCS) launched a film campaign to
illustrate the lives and
accomplishments of five shortlisted
candidates from a list of 150 and allowed
the public to vote for the person they felt
was the most influential IT pioneer.
Lewis Georgeson, Emmy nominated and
multi-award winning director of short form
digital programmes, directed the films,
starring British celebrities. BBC
Television’s ‘Click’ reporter, Kate Russell
(pictured below), presented the winning
film about Alan Turing — the man who
taught computers to think - with over 32%
of the votes.
The other shortlisted members were:
• Sir Clive Sinclair, serial entrepreneur,
who envisaged a small, affordable
computer that could be used in the
home to learn, organise, and play on
and which the general public could
programme themselves.
So, in 1979, he gave us the ZX80 - a
home computer with a 1KB memory,
So what was the background
of events that lead to Turing
developing his groundbreaking ideas and research?
This timeline outlines a
number of events and
influences in his life that can
help us understand the
enigma that was Alan Turing:
1912—Born on 23rd June in a
nursing home at 2 Warrington
Crescent, Paddington,
London W9 to Julius Mathison
Turing, a Civil Servant
stationed in India, and Ethel
Sara Stoney whom he met
and married while serving in
the Madras Presidency in
India.
1922—Attended Hazelhurst
Preparatory School. There
was little in the Turing family
background to suggest that
Turing would be so strongly
attracted to scientific studies.
Both he and his brother were
raised in the UK while his
parents continued their work
in India, until his father retired
from there in 1926. Turing
developed his initial interests
8
Alan Turing Centenary
Special Edition
no sound and a monochrome display.
This machine helped launch the
industry that surrounds us today.
• Tim Berners-Lee, who, while working
at CERN in Switzerland and suffering
from information overload, developed
the idea of linking one piece of
infomation to another, which lead to
the way information is stored and
linked on the World Wide Web.
• Hedy Lamarr, Hollywood actress, also
developed with George Antheil, her
pianist neighbour, a system called
frequency hopping for controlling
torpedos; this system allowed
torpedoes to be controlled without
being intercepted. The patent she held
is the basis for today's Wi-Fi, GPS and
mobile communications.
• Ada Lovelace, 19-year-old daughter
of Lord Byron and Annabella Millbank,
is introduced to an eccentric genius,
Charles Babbage; he showed her a
prototype calculating machine which
he invented which he called the
Difference Engine.
Kate Russell presented the case for Alan
Turing:
“Cambridge, 1936. While the world was
being shaped by events in Europe - the
Spanish Civil War, the Nazis retaking the
Rhineland - Alan Turing, a young
mathematician, worked on an imaginary
machine to crunch imaginary numbers.
This went on to be the origin of Artificial
Intelligence as we now know it. Turing
was the first to understand that computers
could learn and adapt to new stimuli, just
as we humans can; it was just a matter of
having the right tools in place.
Much like teaching a child to cross the
road, Turing set about creating Artificial
Intelligence in his machines. Today, selfparking cars, self-flying planes, even the
Mars rover are all descendants of Turing's
Machine”.
In 1952, Turing was arrested and tried for
homosexuality, which at that time was a
criminal offence. He died on 7th June
1954 in an apparent suicide. In 2009
Turing was pardoned by Gordon Brown
due to a campaign initiated by computer
scientist John Graham-Cumming who
posted a petition with more than 5,500
signatures on Number 10’s website. The
campaign had the backing of author Ian
McEwan, Peter Tatchell, gay-rights
campaigner and scientist Richard
Dawkins, amongst others.
Dr Sue Black, founder of the BCS
Women’s Group, said: “Not only did
Turing play a key role in codebreaking at
Bletchley Park he also made fundamental
and insightful contributions to computer
science and elsewhere. The government
apology highlighted his lasting
contribution and acknowledged his
persecution and abhorrent treatment”.
“Honouring Turing as an information
pioneer provides a chance to celebrate
his life and legacy as a role model for
information pioneers of the future” Turing in the modern world
S
ince the 60 or more years that have
passed since Turing first proposed
and published his theories, the
world of science and technology has
made significant advances in
understanding how the world works.
Some might ask ‘What relevance does his
work have on our lives in the 21st
century?’ In short a lot! Some of the
advancements that we take for granted
today include:
Computer controls
Back in the early 1940’s computers were
humans working with paper and pencils,
possibly with mechanical calculators.
Today we have added electronic
computers to all areas of life in the home,
workplace and leisure. It seems that there
is nothing that can’t be adapted to use a
processing device—truly a universal
machine! Washing machine, radios, TV’s,
telephones, music systems, cars,
aeroplanes, navigation aids, satellites,
even shopping and banking have all
changed due to this truly revolutionary
technology. Many homes now have at
least one personal computer to help with
banking, shopping, homework,
researching information, games playing
and communicating. We have become
highly reliant on these devices that stem
from the basic ideas of the Turing
Machine.
Secure communications
Certainly the work carried out by G.C. &
C.S at Bletchley Park during WW2 and
afterwards were responsible for increased
understanding of how to secure
transactions and communications; after
all, we were reading the enemy’s
messages regularly! The work has directly
lead to the ability to communicate
securely in the web enabled world.
Physiological development
Simple changes in chemical reactions
lead to complex natural shapes, functional
segmentation and markings, leading to a
lot of interest in this area of science
focussing on its application to medical
advancement for growing skin and other
organs in the future.
‘Intelligent’ help systems
Such systems offer interaction able to
recognise handwriting and spoken words
for dictation or accessing bank accounts
around the clock. In fact the latest version
of the iPhone from Apple supports a
program called Siri that attempts to
‘understand’ speech requests and
respond with ‘sensible’ responses,
sometimes with comical results!
Response validation
Sometimes websites need to ensure that
data being entered onto online forms is
coming from a human and not another
automated system (called bots) trying to
maliciously break in. Website creators
have turned to a new technique termed
CAPTCHAs (Completely Automated
Public Turing Test to Tell Computers and
Humans Apart) which requires users to
recognise obscured words or pictures and
to type in what they see. These are very
difficult for other machines to recognise
and process but something that humans
find quite easy to do such as the following
example:
And one that may not be so easy!:
Of course Turing was not the only brilliant
codebreaker / mathematician working at
Bletchley Park; there were others such as
Bill Tutte and Dilly Knox. The work of
several other people has gone into
shaping the technological world we take
for granted today; however Alan Turing
has captured the imagination of the public
and become the focal point of interest of
all the codebreakers, rightly or wrongly
depending on your point of view, due to
his revolutionary work, observations and
his approach to life. To him, the mundane
items in life were not of great interest and
the complex seemed normal. He strived to
make sense of the natural world and to
explain the complexity that grew out of
simple structures and processes he
observed around him. Scientists are still
growing his ideas and learning from them,
probably continuing for many years to
come in chemistry after reading a
book popular at the time,
‘Natural Wonders Every Child
Should Know’. He continued
his private extracurricular
interest in science; however
his mother worried that he
would not be acceptable to an
English Public School.
Despite this he was offered a
place at Sherborne School.
1926—Education began at
Sherborne School in Dorset –
his first day coincided with the
1926 General Strike so Turing
cycled over 60 miles to get to
the school, stopping briefly
over night at an Inn. Turing
continued his interest in all
matters of science and
struggled with classical
studies, to the consternation
of his Headmaster who stated
in a report “If he is to be solely
a scientific specialist, he is
wasting his time at a Public
School”.
While at Sherborne, Turing
developed an intellectual
companionship with a boy in
the year above him,
Christopher Morcom. They
challenged each other on
scientific studies, experiments
and other intellectual matters.
Turing had found a soul mate
to bounce ideas around with.
This friendship was
terminated suddenly by
Morcom’s death in February
1930. Fortunately Turing was
spurred on to continue the
ideas they had developed and
try to achieve something in life
that could not now be
completed by Morcom. His
scientific interests were now
heading deeply into Physics
on matters such as Quantum
Mechanics.
1931—Turing entered King’s
College, Cambridge to read
Mathematics and found that
the freedom to think, that this
opportunity brought him, was
stimulating, particularly after
reading the 1932 work of von
Neumann on the logical
foundations of quantum
mechanics. This period
Alan Turing Centenary
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9
Alan Turing’s school days
helped him develop a rigorous
and intellectual approach to
his work now. He was also a
keen sportsman developing
his prowess in running, rowing
and sailing.
1935—Elected a Fellow of
King’s after a distinguished
degree and picking up a
Smith’s prize for his work on
probability theory in 1935. By
now his mind was firmly
entrenched in mathematics on
subjects such as
mathematical logic and Gödel
showing the incompleteness
of mathematics with the
existence of true statements
about numbers that could not
be proved by formal set rules
of deduction. After attending a
lecture course by topologist
M. H. A. Newman, he learnt
that a question posed by
Hilbert lay unanswered, in
relation to the question of
Decidability, the
Entscheidungsproblem. Could
there exist, at least in
principle, a definite method or
process that could show
whether any given
mathematical assertion was
provable?
Turing recognised that a
precise definition of ‘method’
was required to answer such
a question needed a definition
of 'method'. Turing analysed
what could be achieved by a
person performing a
methodical process seizing on
the idea of something
performed 'mechanically' and
expressed the analysis in
terms of a theoretical machine
able to perform precisely
defined elementary operations
on symbols on paper tape. He
presented convincing
arguments that the scope of
such a machine was sufficient
to encompass everything that
would count as a 'definite
method' including 'states of
mind' of a human being
performing a mental process.
1936— The drawing together
of the principles of logical
instructions, the workings of
Turing Centenary
10 Alan
Special Edition
spending the night at the best hotel duly
reported the following morning.
The School had not awarded a
scholarship to the best brain it had had
since Prof. A.N. Whitehead, for he was no
great shakes at the necessary Latin and
was the despair of W.J. Bensly (Reverend
W.J. Bensly was Alan Turing’s form
Master in 1928).
Photo: Alan Turing at School – Image
provided courtesy of Sherborne School
Archives
A
t Bletchley Park we are privileged
to meet many people with
memories of the war-time workings
of Bletchley Park. When we sit down and
talk to these people their stories never
cease to amaze us and even seasoned
researchers are often unprepared for the
little gems that are revealed.
It was during a chance meeting with a
lady who had worked in Hut 6, that one
such gem was uncovered. Having been
evacuated to Canada with her school,
Sherborne Girls, she returned to England
in 1943 aged seventeen and was
promptly introduced to the BLETCHLEY
PARK by her cousin, who worked in Hut
3. This is a fascinating story of war-time
Atlantic crossings, convoys, evacuation,
return to England and her ‘recruitment’ to
work on the modified Typex machines in
Hut 6. Yet it would be research into the
evacuation of Sherborne Girls School
which would give us insight into the
school days of one of the pupils of
Sherborne Boys School.
Alan Turing’s School Days
The
Shirburnian, vol.44, no.2, Summer 1954,
pp.54-55.
A.M. Turing (1926-1931)
Alan Turing came to Sherborne at the
time of a railway strike. Landing from
France at Southampton, he bought a
map, bicycled to Blandford and after
His contemporaries, boys and masters,
probably did not realise his originality was
of a sort that any school is lucky to have
once in a century, if ever. They knew him
as clever, odd, unpredictable and perhaps
tiresome. His record is in part in the
Register, but it stops short of his work on
“Ace” and “Madam”, the calculating
machines and of his latest adventure into
a mathematical theory of the chemistry of
living tissues. An appreciation of his work
by one who understands it can be found
elsewhere.
For those who knew him here the memory
is of an even-tempered, lovable character
with an impish sense of humour and a
modesty proof against all achievements.
You would not take him for a Wrangler,
the youngest Fellow of King’s and the
youngest F.R.S. or as a Marathon runner
or that behind a negligé appearance he
was intensely practical. Rather you
recollected him as one who buttered his
porridge, brewed scientific concoctions in
his study, suspended a weighted string
from the staircase wall and set it swinging
before Chapel to demonstrate the rotation
of the Earth by its change of direction by
noon, produced proofs of the postulates of
Euclid or brought bottles of imprisoned
flies to study their “decadence” by
inbreeding.
On holidays in Cornwall or Sark he was a
lively companion even to the extent of
mixed bathing at midnight. During the war
he was engaged in breaking down enemy
codes and had under him a regiment of
girls, supervised to his amusement by a
dragon of a female. His work was hushhush, not to be divulged even to his
mother. For it he was awarded O.B.E. He
also adopted a young Jewish refugee and
saw him through his education.
Besides long distance running, his
hobbies were gardening and chess; and
occasionally realistic water-colour
painting.
In all his preoccupation with logic,
mathematics and science he never lost
his common touch; in a short life he
accomplished much and to the roll of
great names in the history of his particular
studies added his own.
By G. O’Hanlon, Housemaster of
Westcott House, 1920-1936 With thanks to Mr Michael Hanson for use
of this article.
Photo below of one of Turing’s school
reports from Sherborne.
Philomena Liggins is a volunteer tour guide. A qualified
designer and tutor she taught Interior Design and has
authored a number of Open College Network courses. As
a member of the London Feng Shui Society she helped
develop the bench marks for teaching that subject in the
UK. Her interest in social history, the effect that war has on
the development of society and in particular the part
played by women during both world wars, have prompted
her ongoing research into the ladies of Bletchley Park.
the human mind and the
possibility of a practical
machine were significant
concepts that lead to his
concluding paper, "On
computable numbers, with
an application to the
Entscheidungsproblem",
although he had to refer to
work by Alonzo Church, an
American logician, whose
work paralleled Turing’s but
became public first, although
it was later recognised as
different and original. Thus
the starting step of modern
computer science was
founded. He moved to
Princeton University in the
U.S. to continue his research
into theoretical logic. It would
be another nine years before
electronic circuits could be
created to make the ground
breaking ideas a reality. Also
around this time he dabbled in
the study of ciphers as the
prospect of war with Germany
loomed.
1938—Completed his Ph.D.
thesis Systems of logic
based on ordinals and
returned to his Fellowship at
King’s in Cambridge. He also
worked part time for the
Government Code and
Cypher School bringing a
scientific approach to
breaking the German Enigma
cipher. Little progress was
made until the meeting in Pyry
forest between Commander
Denniston and Dilly Knox from
G.C.& C.S and the Polish
mathematicians Marian
Rejewski, Henryk Zygalski
and Jerzy Różycki in July
1939 who shared their
knowledge and successes in
breaking the codes. As a
result of German
enhancements to the Enigma,
and concern over the
impending invasion of Poland,
they felt they had to share
their knowledge with allies to
take over the work to stop the
advancement of the Nazi
machine.
At Bletchley, Turing worked
on the ideas, handed to them
Alan Turing Centenary
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11
The Bombe Rebuild
M
by the Poles, to develop a
more generic process for
breaking the Enigma; this
work resulted in the machines
called "Bombes". These were
later enhanced by W.G.
Welchman with the Diagonal
Board modification. The
Bombes helped make
significant progress with
breaks into the Luftwaffe
messages. However the
German Navy added further
modifications to their Enigma
design by adding a fourth
rotor which locked Bletchley
out of reading the messages.
Turing worked tirelessly, often
by himself for days, until he
had cracked the system.
Breaks were not regular
occurrences until further
material was captured from
the Navy and advanced
statistical methods were
developed.
any visitors to Bletchley Park’s
Block B are fascinated by the
Bombe rebuild. Standing over six
feet tall, seven feet wide and weighing in
at around one ton, it is often
demonstrated by volunteers. When it is
switched on, the noise fills the exhibition
space, but it is the operation of the
precision built mechanics of the device
that is mesmerising to many.
During 1941 there were
shortages of typists,
equipment and unskilled staff,
which was hindering the
process of breaking the
increasing number of
messages being intercepted.
This prompted a number of
the codebreakers to write a
letter directly to the Prime
Minister, Winston Churchill,
explaining the limits to the
work and impact to the war
effort. The letter was signed
by A Turing, W G Welchman,
C H O’D Alexander and P S
Milner-Barry. The letter was
produced without the
knowledge of the heads of the
G.C. & C.S and delivered to
10 Downing Street. On
receiving the letter, Winston
Churchill immediately ordered
his Chief of Staff, General
Ismay, to make sure they had
all they want on extreme
priority and to report back that
it had been done and marked
it ‘ACTION THIS DAY’. From
this period on, G.C. & C.S
would be able to access as
many staff and materials as
was necessary for the top
secret work.
There were perhaps two reasons for
embarking on rebuilding a Bombe. The
first is that I joined the Computer
Conservation Society and this led to the
suggestion by Tony Sale and others that a
Bombe Rebuild should be considered.
Secondly, the gentlemen, who had
worked in the British Tabulating Machine
Company in either Bombe production or
maintenance, also came up with the same
suggestion. They had told me, before the
Bletchley Park secret started to come out,
that Letchworth had done more for the
war effort than was generally known.
When the secret came out they were able
to tell me what had gone on. It was their
judgment of what would be involved in a
Rebuild that really got me started.
The discovery of a much more
Turing Centenary
12 Alan
Special Edition
John Harper describes how and why his
team decided to rebuild one of the
Bombes that proved to be so important in
helping to break into the Enigma codes
during WW2:
"Most of my working life was spent with
ICL where the most satisfying part was
running a large development team
designing and developing the small end of
the ICL mainframe range. Leading the
Rebuild Project was not much different,
except that leading volunteers, raising
funds and seeking out benevolent
suppliers was an interesting new venture.
Like any other project, one needs to study
the task and produce objectives,
timescales, budgets, resources etc. We
managed to keep close to the original
timetable and the expenditure came out
very close to prediction. One approach
that paid dividends, was to produce a full
set of assembly drawings before we
started ‘cutting metal’. For the first two
years we were regularly asked “when are
we to see anything?”
There was never any major recruitment
drive for the team. The majority of the
team found us. They heard about the
Project and asked if they could contribute.
Most were retired professional engineers
who not only brought with them their own
particular skills and often tools but also
set their own quality standards. In total
about 60 volunteers helped us in one way
or another over the 12 year period.
Although we never thought of giving up
we did have times when we thought that
we had run up against an insurmountable
problem. Looking back at previous
hurdles gave us the confidence to move
on.
Throughout the project we strove to be as
correct to the original design as was
possible. That is not to say that all the
information was readily to hand and all in
one place. Often a lot of time had to be
spent in researching a particular part of
the machine. Snippets of information
were found in many unlikely locations but
when all were brought together it was
clear that we had a true picture. It is a bit
like putting the last piece into a jigsaw
puzzle where there is no doubt that this
piece is correct.
The majority of the value of our Rebuild is
in free labour or donations from generous
companies. We spent about £65,000 in
cash having parts made that were beyond
our own capability, either in technical
terms or just sheer numbers. However the
time spent over the years by around 60
volunteers must be at least ten times the
above figure. In fact I suspect that if we
took a set of drawings to a company for a
quotation to build and deliver the same
machine there would not be much change
out of £1 million.
If I started the project again with
hindsight, I would have tried to get more
information from those who had worked
on the Bombe during WW2 much more
quickly than I did. Initially I did not realise
how many people were still around to
advise us. What I should have known was
that these people might not have been
with us much longer. We gathered vital
information just in time.
It was a great surprise when we had so
much publicity on national television and
in the press. I am sure that the whole
team had a great feeling of satisfaction
with what we had achieved. Further
recognition of our success came when on
17th July 2008 His Royal Highness the
Duke of Kent officially switched the
Bombe rebuild on.
Even when complete, there was still
plenty to be achieved. The Bletchley Park
Pictured above are John Harper, far right, with HRH Duke of Kent. In the middle are
Ruth Bourne and Jean Valentine, two Bombe operators during the war and now guides
at Bletchley Park.
archives has a considerable number of
messages and decrypts that need to be
worked through and sometimes we
decode messages that had not previously
been broken. I realise that we could do all
this on a PC simulator but it is not the
same. We are re-learning methods and
techniques used during WW2 that were
not written down anywhere and this gives
us an intriguing insight into what went on
at Bletchley Park during the war. Also
there were many adaptations and non
standard uses that the Bombes were put
to that we would like to re-discover."
For his work John was made an Honorary
Fellow of the British computer Society and
on 4th June 2011 was awarded an
honorary doctorate from the Open
University at Ely cathedral.
On receiving the award, John Harper said
“I particularly wish to thank the Open
University, Dr Anthony Lucas-Smith for
his Eulogy, and all those who suggested
this honour and, in particular, members of
the Bletchley Park Trust who supported
this award. Many people have found
themselves in the same situation where a
team leader is awarded an honour but
where it is the team members who really
deserve the praise.”
Dr Anthony Lucas-Smith, a colleague of
John at ICL, said “we are proud to honour
John Harper, distinguished engineer and
cryptology expert, a man of vision yet
extremely modest about his
achievements. His ground-breaking work
on the origins of electronic computing,
particularly in the context of code
breaking at Bletchley Park has, after
many years, become widely appreciated.”
For readers who would like more
information on the rebuild project, there is
a 3D film about the rebuild in Block B and
a considerable amount of information at:
www.jharper.demon.co.uk/bombe1.htm
Or use the following QR code to tgo
directly to this website:
complex machine-generated
code, produced by the Lorenz
system used by the German
High Command, offered a
significant challenge to the
codebreakers at Bletchley
Park, with messages being
encoded with a far more
complex encoding algorithm
than had been seen in the
Enigma messages. The
received messages (codenamed Tunny by the
codebreakers) seemed
impenetrable. Another brilliant
mathematician at the site, Bill
Tutte, worked on the code day
and night for around two and
a half months until eventually
breaking a message. This
process required advanced
statistical methods and was
painstakingly slow. At this
stage, a reliable mechanical
solution was required to help
break the codes. This is when
telephone engineers,
including Tommy Flowers,
were enlisted by Max
Newman, whose section must
have employed several of
Turing’s ideas to mechanically
process the messages and
must have drawn on his logic
and universal computing
ideas leading to the
introduction of Colossus just
before D-Day.
Turing had been working in
Hut 8 during 1941 with
several colleagues, one of
whom had been recruited
from Cambridge by Gordon
Welchman – Joan Clark.
Turing soon developed a
friendship with Joan, often
spending their free time
together going to the cinema,
playing chess or cycling in the
country side. They shared
many interests and soon
Turing proposed to Joan. A
few days later he told her of
his ‘homosexual tendencies’
which he thought would finish
the relationship. Joan was
unperturbed and they
continued their friendship,
even getting an engagement
ring. Eventually Turing ended
the engagement, deciding
that he could not go through
Alan Turing Centenary
Special Edition
13
The Bletchley Park Turing Trail
Map of the Bletchley Park site where you can discover items and places
relating to Alan Turing’s life and work.
Block H
Blo
1
Photos:
2
3
1. The
bungalows
where Alan
Turing worked
initially to break
the Enigma
codes.
The
Bungalows
2. Hut 8 with its
bike racks,
where Alan
Turing had an
office
4
3. Inside Hut 8:
Alan Turing
used to chain
his mug to the
radiator to
prevent it being
used by other
people.
4. Stories
abound that he
used to wear his
gas mask while
cycling to help
prevent hay
fever (Hut 8).
5
5. Porgy, the toy
bear that Alan
Turing owned
(Block B).
6. Slate status of
Alan Turing
(Block B).
7. Part of the
Turing exhibition
(Block B).
Turing Centenary
14 Alan
Special Edition
Ma
Hut 4
6
A
sion
7
Block B
8
Hut 8
8. Display of several Enigma
variants on display in Block B.
9
9. The Bombe rebuild that can
often be seen running in Block B.
10. Hand painted oars featuring
the names of the team involved in
the races, including Alan Turing’s.
They are now on display in the
Turing exhibition in Block B.
10
Alan Turing Centenary
Special Edition
15
Turing in art
with the marriage.
By 1942, Turing was turning
his attention to the further
possibilities of electronic
circuits, learning all about
them, and also working on
speech secrecy systems for
use between Churchill and
Roosevelt. His assistant in
this research was Donald
Bayley, who worked at
Hanslope Park about eight
miles north of central Milton
Keynes; however, Turing
focussed on developing his
Universal Turing Machine
using the new electronic
components which provided
both high speed processing
and reliability, the
cornerstones of development
of a universal machine
capable of handling different
logical processes instead of
separate, purpose built,
devices. (Note Colossus was
built to only perform one task
– but very efficiently!). Turing
even theorised with Donald
Bayley that computers could
one day be able to think like a
human brain – true artificial
intelligence.
Following the war, Turing was
awarded an OBE for his
services to the war effort and
he joined the National
Physical Laboratory following
the announcement that the
EDVAC computer had been
developed by the Americans.
There was a decision within
the UK to catch up and push
the boundaries in the new
technology. This work lead to
the design of the Automatic
Computing Engine (ACE) in
1946 which utilised the
cumbersome acoustic delay
lines of the time to act as a
memory data store. Turing
strived to continue technical
development in the quest for
more speed to develop further
his Universal Computing
Machine. His vision was for a
machine that could switch
between all manner of
processes such as playing
chess, working on algebra, file
handling and codebreaking.
Turing Centenary
16 Alan
Special Edition
The Sidney E. Frank
Foundation, set up by the
late Sidney Frank, an
American Philanthropist
who set out to
commemorate people
whose contribution to the
WW2 effort was not
properly recognised,
funded the statue. Alan
Turing was clearly one of
the prime contenders. In
the near future we hope
to secure a substantial
donation from this
Foundation to support the
project to develop Huts 3
and 6.
Stephen Kettle (pictured
below holding a miniature
bust of Alan Turing, also
in slate) is based in
London and specialises
with working in this
unique art form. It took 18
months of continuous
work to create the statue.
L
ocated in the Alan Turing exhibition
in Block B is a life size statue of him
made by Stephen Kettle from
around half a million pieces of Welsh slate
depicting Alan Turing in deep thought
looking at an Enigma machine on his
desk. The desk, the setting and his
clothes all reflect Alan Turing’s rather
scruffy dress style and his wartime place
of work, the wooden hut. The accuracy
and likeness of the head to photographs
of him at the time is extraordinary.
Visitors to Manchester
can find another statue of Alan Turing in
Sackville Gardens lying between
Manchester’s thriving gay village on Canal
Street and Manchester University’s iconic
red brick buildings (UMIST) on Whitworth
Street. David Darwent continues the story.
Central within the gardens is a bronze
park bench with a seated figure upon it:
Alan Turing is immortalised in bronze,
complete with pencils in his top pocket
and a poignant apple in his right hand.
Nearby, an information board summarises
his life and laments his death.
At his feet a Rainbow Flag plaque
indicates his inclusion in Manchester’s
Gay Heritage Trail. Tourists and ‘boyz’
from The Village pose with Alan for
photographs. In August, at Pride, he is
often decorated with Pride balloons and
rainbow ribbons around his neck. In
winter, he sometimes wears a scarf
against the cold. Periodically the City
Council give him a quick wash.
The statue of Turing was created by
sculptor Glyn Hughes and unveiled in
2001 on his birthday, 23rd June. The
funding came from Manchester City
Council, the British Society for the History
of Mathematics and private donations.
In 1947 Turing described his
vision of a national computer
centre with remote terminals
and the machine performing
more of its own programming.
He even invented Abbreviated
Code Instructions signalling
the start of programming
languages – truly the core
ideas of current day computer
technology. However,
frustrated at the lack of
progress within the NPL to
build the ACE, he left in
October 1947 and re-joined
Cambridge University.
The plaque at the feet of the statue reads
“Father of computer science,
mathematician, logician, wartime code
breaker, victim of prejudice”. It also has a
quote from Bertrand Russell
“Mathematics, rightly viewed, possesses
not only truth, but supreme beauty — a
beauty cold and austere, like that of
sculpture”. Embossed on the bench on
which the statue is seated is the following
text ‘Alan Mathison Turing 1912-1954
IEKYF RQMSI ADXUO KVKZC GUBJ (an
artists interpretation of an Enigma
encoding?) The sculptor also buried his
old computer under the plinth, as a tribute
to "the godfather of all modern
computers".
The following video recently appeared on
Youtube of a dog trying to coax ’Alan’ to
throw a stick and is worth watching: http://
www.youtube.com/watch?
v=q8DiOthAKek (this URL also features in
the QR code in the lower right corner of
this page)
Steve Williams is an artist who has
produced several paintings in support of
the Park. A recent picture, at the base of
this page, focuses on two veterans,
looking at Bletchley Park, imagining and
remembering. There are several aspects
of Bletchley Park montaged into the vista.
From the left, two veterans, who could be
anybody's mother, father, grandparents,
etc, can see the ghosts of the (Churchill’s)
golden eggs. The roundels signify: the
GCHQ medal awarded to veterans; a
Bombe wheel; 6XY signifies MI6, which
was housed on Bletchley Park's upper
floor during WW2 at station X with input
fed from ‘Y’ stations; a Colossus wheel
with tape; finally, an Enigma rotor.
The ghosted figures represent the
thousands of Bletchley Park workers who
passed through Bletchley Park during the
war years.
The veteran lady is pointing at the figure
on the bicycle: this is Alan Turing, who
had a habit of riding his bike wearing a
gas mask, and cycling in front of Hut 8
where he had an office. Also featured are:
It was during this period that
he turned his attention to
neurology and physiology,
writing his pioneering paper
on a subject, now known as
neural nets, which built on his
ideas that a large and
complex enough system could
develop a ‘learning’ potential’.
The NPL never published this
paper in his lifetime. However
Cambridge and Manchester
started to take the lead on this
research and development.
Supported by Max Newman
and with the aid of
F.C.Williams, Manchester
University had constructed the
world's first practical
demonstration of Turing's
computing ideas.
Apart from his mental feats iin
the scientific world, Turing
was also an accomplished
athlete. He rowed for
Cambridge University,
preferred cycling to taking
cars and buses and took part
in several cross country
running competitions. The
Block B exhibition on Turing
has on display a part of a pair
Alan Turing Centenary
Special Edition
17
of oars from Turing’s
university rowing days.
Post war he achieved a high
rate of success in amateur
athletics. Stories abound
where Turing would even run
to meetings and arrive ahead
of colleagues who travelled by
public transport! His prowess
in sport was such that he only
narrowly missed consideration
to be entered in the 1948
Olympic Games in London
due to an injury.
During the period from 1948
to 1950, Turing turned his
attention to a number of
subjects, some old and some
new. He revisited his
Riemann zeta-function
calculations of 1939 to pursue
computability within group
theory algebra. This period
culminated in the release of
his paper on the philosophy of
machine and mind,
Computing Machinery and
Intelligence which appeared
in the journal Mind in 1950.
One of the key legacies from
this paper is the Turing Test
that has had many artificial
intelligence experts trying to
develop machines that could
convince humans
communicating via terminals
that they are conversing with
another human and not a
computer. There is a
competition which goes under
the title of the Loebner
competition, and a prize of
$100,000 and a gold medal
are up for grabs for the first
computer whose responses
were indistinguishable from a
human's. So far, there have
been several close attempts
but no out right winner. In
2012, the Loebner
competition will be held at
Bletchley Park on 15th May
2012.
During 1950 and settling in
Manchester, he turned his
thought processes to the way
complex asymmetric shapes
could be derived from simple
symmetric ones through
nonlinear chemical equations
Turing Centenary
18 Alan
Special Edition
the radio room in the tower of Station X
connected to the tall tree to the left by a
full length dipole aerial; the Mansion; the
lake nearby.
Under the Mansion, the sea blends into
sky and depicts the German U-boat from
which an Enigma machine and code book
were captured Pictured on the right is Steve Williams.
Memories of Alan Turing
M
y earliest memories of Alan
Turing date back to 1948, when I
was nine years old. This was the
year in which Alan moved to the
Manchester area, to take up the
readership in mathematics that my father
had offered him. He bought a house in
Wilmslow, six miles from our house in
Bowdon, and soon became a regular
visitor.
Pictured with William Newman above at
the Google garden party in 2011, is Mrs
Inagh Jean Payne (left), Alan Turing's
eldest niece - daughter of Alan Turing's
older brother John Ferrier Turing and Mrs
Janet Ferrier Robinson (right), Inagh’s
youngest sister.
At this time I was already accustomed to
visits by mathematicians. My father was
determined that his department should
acquire a high profile and therefore laid on
a monthly lecture by a distinguished
visitor, who would usually stay with us in
Bowdon to keep costs down. None of
them left an impression on me, other than
cybernetics pioneer Norbert Wiener,
whom I recall walking around the house
with our kitten on his shoulder, licking his
bald head.
Alan’s visits were quite different. He and
my father had known each other since
1935 and had kept closely in touch during
the war when both were working at
Bletchley Park. They were both now
involved in Manchester University’s
computer project, which they often
discussed when Alan visited. Usually Alan
would also spend time with me and my
brother, playing games with us or
accompanying us on walks. Occasionally
he would invite us all to supper at his
house; I well remember the occasion
when he turned up at our house at 6 a.m.,
having run all the way from Wilmslow, and
I awoke to find him at our front door.
Lacking pen and paper, he had scratched
his invitation on a rhododendron leaf with
a twig.
On my birthday I always looked forward to
the present that arrived from Alan. It was
usually something that could serve a
practical purpose, such as a slide rule or a
woodworking tool. More than once he
gave me things that at first seemed
useless; one of them – a small bench vice
– I actually took back to the shop and got
a refund. Almost at once I discovered that
it was just what I needed; I returned to the
shop and bought it back.
In 1952 we moved back to the house near
Cambridge where I was born and Alan’s
visits became less frequent. His last entry
in our visitors’ book was dated April 9th to
14th, 1954. Seven weeks later he was
dead William Newman
More intelligent than a chicken?
sets of traffic lights. Wow! Much faster
and now my regular route. One up for the
SatNav - and more intelligent than a
chicken?
T
he National Museum of Computing
(TNMoC) volunteer Pete Chilvers
recalls how he gave his new
SatNav an unusual test and wondered
how intelligent it really was^
With meetings now taking place to plan
the celebrations of Turing's Centenary in
2012 and getting a new SatNav boasting
Intelligent Routes (iQR), my mind
wandered onto how it would fare in a
Turing Test! (The Turing Test is a test of a
machine's ability to exhibit intelligent
behaviour.) That is: how does the SatNav
compare to a navigator (mate / wife / self /
chicken)?
And anyway, what is intelligence in the
context of navigation?
Well, I'm reminded of someone's
observation of how to show that a dog is
more intelligent than a chicken. I was told
to imagine a 3-sided cage. Put the
chicken 'inside' and its food outside: the
chicken will go hungry as it tries and fails
to break out. Do similar with a dog and it
will, after a while, realise the futility of the
direct route and go out the back and
round.
On my way to TNMoC at Bletchley Park I
naturally turn off the A5 dual carriageway,
going right and south-ish and on to the
double roundabouts on the old A5 Watling
Street. But trying out my new SatNav it
sent me off to the left, north and the
wrong way. What?! But then at the next
roundabout, sharp-right and on to that
double roundabout, but without the three
Later I visited the Cold War exhibition at
RAF Museum Cosford travelling to it via
motorway. But a nice feature of the
SatNav is to be able to ask for an
alternative route and this I requested for a
pretty way back to the south. Travelling
into a town I was told 'Turn Right' which I
did obediently at the traffic lights and a
moment later 'Turn Right' (now going
north!). Hmm. Perhaps OK, but a look on
the map display showed I was about to
'Turn Left' and be taken round a green in
the centre of a little estate and back out to
the traffic lights where I would turn right to
continue along the original road
southward! I found myself crossing a river
bridge and on the other side I was again
told to turn right. Ahh! The original
instruction meant turn at the second set of
lights south of the river. Oh Well. I reckon
a person would have told me more
clearly, but at least the SatNav found a
safe way to turn round rather than a 3point turn in the middle of a busy main
road. Score here - one each?
But the clincher came while driving in a
familiar area of a city with traffic getting
congested and personal knowledge of
danger spots. As the SatNav gave
instructions clearly taking me to suicidal
right turns I repeatedly ignored its
instructions. At each moment of
disobedience it gave 'Recalculating
Route...', impressively quickly, over and
over to keep up. And then I realised - in
spite of all this, it had failed the Turing
Test. Unlike a human navigator getting
exasperated at being ignored, it had just
got on with it - no huffing; no puffing, no
comment!
Technology does not always work in your
favour... The Museum's postcode actually
takes you to an old Bletchley Park
entrance which is closed. To find the new
entrance you should use the postcode for
the local railway station MK3 6DS Pete Chilvers is a long standing volunteer at The National
Museum of Computing and is often found wondering the
corridors passing on his wealth of historical knowledge to visitors
and other volunteers alike. He also gives guided tours of
Bletchley Park.
This article first appeared in the Computer Weekly blog from The
National Museum of Computing: http://
www.computerweekly.com/blogs/computing-museum/
of reaction and diffusion. The
repetitive calculations
required for testing the ideas
were ideal fodder for the new
computers. This work on The
Chemical Basis of
Morphogenesis formed the
founding work on non-linear
dynamical theory and was
published in 1952 after he’d
been elected as Fellow of the
Royal Society in July 1951.
He continued this work even
through the turbulent period
during which he was arrested
for his relationship with a
young man in Manchester and
tried in March 1952.
Turing was quite open about
his relationship and saw
nothing wrong with his
actions. When he reported a
break-in at his house to the
Police, he admitted that he
had had a sexual relationship
with someone whom he later
found to be an accomplice of
the burglar. As a result, he
was tried and found guilty of
gross indecency. As
punishment, he was offered a
choice of imprisonment, or
probation on condition that he
underwent a course of
hormone treatment to reduce
his libido. He accepted the
latter and underwent chemical
castration with oestrogen
hormone injections for a year.
It has been suggested that
that course which he chose
affected his ability of logical
thought, upsetting him when
he had difficulty in
concentrating on his research
areas. However, he did
continue with his
morphogenetic theory in
areas such as the
development of patterns from
unstable objects such as
spheres to form cylinders for
plant stems, and the
appearance of Fibonacci
numbers in the leaf patterns
of plants, in sunflower heads
and in fir cones.
The chemical castration didn’t
work and his continued
homosexual relationships
were viewed as a security
Alan Turing Centenary
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19
Little pieces of Art
risk. His security clearance
was revoked and he was
barred from continuing further
cryptographic work for GCHQ.
This was at a time of
heightened suspicion during
the Cold War and coincided
with the discovery of the
Cambridge Five (in particular
Guy Burgess and Donald
Mclean) as double agents
working for the KGB.
Turing continued his research
as best he could. It was one
fateful morning on 8th June
1954, just after performing
home experiments with
cyanide, that he was found
dead by his cleaner. There
was a half-eaten apple by his
bed. The post-mortem found
that Turing had died from
cyanide poisoning and the
inquest decided that he had
taken his own life. It has been
speculated that he was reenacting a scene from his
favourite fairy tale, Snow
White, where the apple was
coated in cyanide. However,
the apple found with Turing’s
body was never tested for the
poison so it could not be
confirmed that his death was
suicide. Turing was cremated
at Woking cemetery on 12th
June 1954.
Mavis Batey, one of the
Codebreakers who worked
with Dilly Knox at Bletchley
Park and who was married to
another codebreaker, Keith,
supports the accidental death
theory as follows: “I was there
when Keith told Jack
Copeland (author of The
Essential Turing) that Alan’s
mother’s account of the event
was correct and why we knew
this to be so. Keith was a
good friend and close
colleague of Professor James
Lighthill, when they worked
together in the Royal Aircraft
Establishment at Farnborough
in the late 1950s after James
had retired from being
Professor of Applied
Mathematics at Manchester.
While there, he worked
closely with Alan Turing and
Turing Centenary
20 Alan
Special Edition
T
he world of
miniature art also
known as philately
has encompassed many
themes in the years since
stamps stopped depicting
only the head of state for
the issuing country. Since
around 1845 stamps have
started to depict themes
such as maps, animals,
birds, ships, major events,
space exploration,
presidents and historic
people to name a few.
However, the subject of
codebreaking, and, in
particular, Bletchley Park,
has rarely made it onto
stamps until relatively
recently.
Mark Baldwin who
specialises in selling
WW2 Intelligence and
codebreaking publications
has researched potential
candidates from around
the world and provide
some of the background
information to this article.
Apart from brief forays
into acknowledging the
codebreaking work in
1983 with the issue by the Poles of a
cover and stamps celebrating the work in
1933 of the Polish mathematicians Marian
Rejewski, Jerzy Różycki and Henryk
Zygalski in breaking into Enigma
messages and the US Postal Service
issued stamp set of 1991 that featured a
codebreaker's work sheet, headphones
and a pencil, all under a desk light, there
have been no other stamps depicting this
work. That is, until recently.
St Vincent & the Grenadines, 2000
On 13th March 2000, St Vincent & The
Grenadines published a set of stamps
(photo top right) to commemorate the
opening of the new millennium by
celebrating the greatest achievements of
the twentieth century. The first group was
issued as a large pane, 23 x 16 cm (9 x
6.3 ins), which included 18 different 20cent stamps, each depicting an event
between 1900 and 1950. Down the left
hand side of the pane is a series of notes,
each of which gives a short explanation
and date for each event depicted on the
stamps. In the notes we read: '1937: In a
paper called "On Computable Numbers"
Alan Turing established the theoretical
possibility for the digital computer, a
machine that uses "0" and "1",
representing yes or no answers to coded
questions.'
The stamp itself (row four, column three in
the picture) carries a recognisable portrait
of Turing against a background of
repeated 0’s and 1’s and is captioned
'1937: Alan Turing's theory of digital
computing'.
We might take issue with this description
of the digital computer and we might point
out that the paper was actually delivered
in 1936, not 1937, but we must salute the
perception displayed by the stamp
designers of St Vincent. Alone amongst
the world's stamp designers they
recognised the stature of Turing and
appreciated that his seminal paper is
undoubtedly one of the 18 definitive
events of the first half of the twentieth
century.
You might argue that I am stretching a
point to include this stamp in a series
devoted to WW2 codebreaking. I readily
agree, but in mitigation would plead that
Turing was Bletchley's leading Enigma
codebreaker and that the
ideas in his famous
paper led directly to the
creation of Colossus, the
world's first computer,
designed specifically to
help break the high-level
Schlüsselzusatz codes.
So, even if the stamp
mentions neither
Bletchley nor
codebreaking, it has a
double resonance with WW2
codebreaking. If I were aware of lots of
other relevant stamps, I might put this
third one to one side, but I know of no
further examples (although there are quite
a number depicting computers,
information technology, etc).
The Bletchley Park Post Office (BPPO)
Bringing the story of Bletchley Park more
into the focus of the public and collectors
is the Park’s own Post Office run by Terry
Mitchell and John Chapman. During the
war this building was a post room serving
the thousands of people involved in the
WW2 codebreaking activities. To maintain
its secret cover it was often referred to as
simply PO Box 111, Bletchley in
addresses.
In 1947 the British General Post Office
(GPO) opened a sub post office in the
building to provide a small shop serving
the GPO engineers attending training
courses. Then in 1994 the Park was
saved from demolition and John and Terry
opened a gift shop, eventually selling
stamps and covers which lead to them
producing their own popular cover
artwork. Proceeds from sales are used to
help support the Park.
They have employed the skills of many
artists to produce limited edition covers
over the years. Subjects depicted have
Rebecca Peacock pictured with the Alan
Turing statue in Sackville Gardens,
Manchester. Photo supplied by courtesy
of the Manchester Evening News.
was with him the night before
he died. In fact he said Alan
had never seemed more
normal and had just bought
two new pairs of socks which
is the last thing he would have
done if he intended to commit
suicide.
included the Royal Family, sports cars,
historic aircraft, cricket and of course,
Bletchley Park, Station X and activities
related to the WW2 codebreaking
operations.
With 2012 being the centenary of Alan
Turing’s birth, a special cover was
commissioned to celebrate this event.
Rebecca Peacock was the artist chosen
to create the Alan Turing cover (shown
above) that would carry the special issue
stamp depicting a Turing Bombe.
Rebecca Peacock has been fascinated by
the computer pioneer and Bletchley Park
codebreaker ever since growing up near
Alan Turing Way in east Manchester.
And the illustrator was ‘amazed’ to be
picked by Bletchley Park to create the
artwork for the first day covers to
accompany the Royal Mail’s ‘Turing
Bombe’ stamp. Turing is one of ten
prominent people chosen for the Britons
of Distinction stamps.
She said: “I’ve been really excited to work
on this project, especially being from
Manchester, a place where Turing was so
influential and being interested in his life
and work for such a long time.”
Rebecca added: “I hope my work goes
some way to raise awareness for Alan
Turing’s amazing contribution.”
The BPPO have produced several
popular covers on the Bletchley Park,
codebreaking and Station X themes which
have sold very
well. Take a
look at their
website for
more
information:
http://stnx.at/
bwyk “Alan described the
experiment he had been
doing with cyanide just as
Sarah Turing describes it, as
it is quoted by Andrew
Hodges in his biography. She
had warned him not to get
cyanide on his hands when
last she saw him. ‘Wash your
hands Alan and keep your
nails clean and do not put
your fingers in your mouth’
she had warned in vain.
Those who worked with Alan
at Bletchley Park knew that
cleanliness was not on the top
of his list of priorities. Why
should one go to the trouble
of putting cyanide on an apple
when it would have been
much easier just to drink it?”
In August 2009 a petition for
the Government to apologise
for prosecuting him and the
way he was treated was
raised by John GrahamCumming. On 10th
September, the Prime
Minister, Gordon Brown,
issued a public apology for
the way the country had
treated someone who had
given so much to help his
country in its time of great
need. This apology can be
seen as part of the Turing
Exhibition in Block B.
Then in December 2011
William Jones raised an epetition to press the
government for a pardon for
convicting Turing of grossindecency. Although this
request was declined by Lord
McNally, there are several
people still continuing to call
for a pardon.
There have been several calls
to promote Alan Turing and
his work by raising public
awareness of him Alan Turing Centenary
Special Edition
21
Delilah
he original Delilah Project
came to the attention of the
Bletchley Park Volunteers
when one of our team, who regularly
visits the National Archive in Kew,
discovered a very large report. It
consisted of 80 pages of text and
formulae plus circuit diagram
blueprints and oscilloscope images.
We arranged to make copies of
these using a camera. This was a
start but later the GCHQ Archives
department made available a full
copy in much better quality than
ours.
T
would have run until the end of
1944.
We became quite excited about this
project because it was a major piece
of work carried out by Alan Turing
during 1943 and 1944 about which
few people had heard.
Although Turing was considered to
still be based at Bletchley Park, he
spent many months at Hanslope
Park presumably because they had
good workshop facilities away from
the hurly-burly of Bletchley Park
The first record official record that
has come to light appears to have
been a report dated 6th June 1944
where Alan Turing is writing that
research began in May 1943. A
Combining Unit appears to be in
existence at this time but the ideas
about the Key Stream are just
coming together. The main report
appears to be undated but it must
have taken many more months to
build a Key Unit and carry out the
reported tests and measurements.
One might speculate that the project
Turing Centenary
22 Alan
Special Edition
To be fair, Andrew Hodges had
already ‘discovered’ the Delilah
Project some years ago (Alan
Turing – The Enigma – pages 273 276 inclusive). In this he writes
about Don Bayley , Turing’s
colleague and co-author of the
report. Also there is a picture and a
brief reference by Dr. Robin Gandy
in a BBC TV Horizon documentary
directed and produced by
Christopher Sykes some years ago.
With the help of retired Hanslope
Park Foreign Office staff we were
able to track down Don Bayley who
now lives quietly in Yorkshire. I
have visited him there and since
corresponded.
What is common to many voice
encipherment systems is a key
stream that is unique for a given
transmission. This is ideally in a
‘one time pad’ form. It is believed
that Alan Turing was shown under
strict security the workings of an
American Voice Secrecy system
called SIGSALY when visiting the
States (see http://en.wikipedia.org/
wiki/SIGSALY etc.). These systems
were extremely large, about the size
of a 1950s mainframe computer and
extremely expensive. Even more
expensive were the ‘gramophone
records’ that held the unique key
stream. These had to be distributed
very securely to each end of the
voice link and once used, destroyed.
It is speculation, but assumed, that
Turing thought that he could improve
dramatically on this at a fraction of
the cost. In Delilah, his ‘one time
pad’ comprised the setting of five
letter-transposition wheels similar to
those in an Enigma Machine, plus a
seven way patch panel. This
modified the key stream. Not quite a
‘one time pad’, but, as this key
stream changed with every send and
receive change, breaking an
enciphered voice message that
would change in minutes was
considered at that time to be very
secure. To add to this, wheels could
be reversed or alternatives fitted. As
with Enigma, the weak spot would be
the ‘Setting Sheet’.
The system is labelled MK 1 with the
report detailing the need for further
development. No doubt this work
could have continued but the war
was being won and people were
looking forward to a civilian career.
From what we read about Alan
Turing he was also very keen to get
back to computing.
No doubt the authorities were no
longer keen to fund further, war
related, developments. Whatever the
reason no further work was done on
Delilah and it never went into
production.
Delilah Hardware
This consists of three separate units
at each end of a link. These are
connected together by power and
signal cables with an external
connection to a landline or other link
such as a VHF radio link.
Power Supply
This works off the mains and
supplies power to the Combiner and
Key Unit
Combiner
The voice signal is combined with
the key stream to produce a signal to
line that is no longer intelligible and
highly secure. The unit also works in
reverse when set to ‘receive’ with the
key unit again providing the key.
This, when processed with the
incoming signal, recovers voice.
Key Unit
The purpose of this unit is to provide
a key stream at one end of the link.
At the other end an identical key
stream has to be produced that is
precisely synchronised with the
sending end.
A set of multi-vibrators all producing
different frequency square wave
signals are mixed in a unique way
depending on the settings of a
cypher unit and a seven way
plugboard
The 2011 project
Having studied the report,
photographs and circuit diagrams it
was decided that to reproduce what
Turing and Bayley had achieved was
possible. As with the previous
Bombe Rebuild Project it was
necessary to identify things that
would stop us succeeding.
Manufacture of chassis etc.,
assembly, premises, testing
facilities, where to demonstrate and
funding etc. whilst not being solved
at the onset were deemed to be
solvable. The major issues were
details of the Cypher Unit, detailed
manufacturing drawings and
obsolete 1940s radio components.
Most components are obsolete and
no longer available but good, used
parts can still be found by
enthusiasts. We have been able to
find most of what we need from
donations made by such
organisations as the RAF Signals
Museum at Henlow and various
branches of the Radio Society of
Great Britain. As I write this in
September 2011 we have over 95%
of all the 1940s components
collected and over 90% of the valves
(tubes). All together we need nearly
100 valves.
Manufacturing drawings for the
chassis and covers were not in the
report so they had to be recreated.
This activity is almost complete
using Computer Aided Design
techniques. Recreation of accurate
drawings is perhaps more easy that
one might at first think. The report
gives overall dimensions for the
three units. One photo has a ruler
showing but most importantly it is
possible to identify the 1940s
components and with these
available and measured it is possible
to reasonably accurately draw the
area where they are mounted.
Our most difficult problem is the
Cypher Unit. Don Bayley said that
this was an American CCM unit.
Comparing our photos with WWII
American cryptography equipment it
was possible to verify this up to a
point. What we have discovered is
that what Delilah used was similar to
the CCM but as the CCM is of
modular construction one can see
that this has been modified to be
‘double ended’ as is necessary in
the Delilah application. We have
borrowed a CCM wheel from a kind
gentleman in the States; other
Americans who have access to the
National Security Agency Museum in
Washington DC are making detailed
measurements that we will use to
check our ‘speculative’ drawings.
Construction is under way in
September 2011 with the Power
Supply being used as a pilot. This is
to prove our drawing methods that
involve laser cutting of the chassis
parts before bending and painting.
This has proved successful and one
Power Supply is assembled with its
components fitted.
The remaining pairs of Key Unit and
Combiner cabinets will be heading
towards the sheet metal people
shortly. The current activity is to
decide the best way to make the
complex Cypher Unit components
One has to ask the question why
embark on such a reconstruction?
Having completed the Bombe
Rebuild Project that is now working
well and regularly demonstrated, the
team became fascinated with the
way that Alan Turing approached
problems such as how to break
Enigma. To see an Enigma
technique being used in voice
encipherment was intriguing. When
the discussion started about the
Turing Centenary we thought, what
additional attraction could we display
at Bletchley Park to add to existing
items including the Bombe Rebuild
and Checking Machine, the slate
statue and the Turing Papers?
Delilah seemed appropriate but I
must add that success is not
guaranteed because time is short.
To be honest though, the Bombe
Rebuild team needed a new
challenge because we had worked
so well together before and had
obtained such satisfaction and
recognition of what we had
achieved. John Harper
Alan Turing Centenary
Special Edition
23
Turing and the cow
eventually becomes the skin — in
effect, the embryo’s surface — these
morphogens react together to create
other chemical molecules. These
reactions can be modelled by
ordinary differential equations.
However, the skin also has a spatial
structure and that is where diffusion
comes into play. The chemicals and
their reaction products can also
diffuse, moving across the skin in
any direction.
Friesian cow with
dappled hide.
Photo by Keith
Weller
T
he name of Alan Turing brings
many things to mind, among
which are: his wartime work
on Colossus at Bletchley Park, the
Turing test for artificial intelligence
and the undecidability of the halting
problem for Turing machines. From
these activities it might appear that
Turing was a pioneer in computer
science and cryptography; this is
true. It might appear that he
specialised in these areas; this is
false. His collected scientific works
also include deep and difficult
research in analytic number theory,
where he made significant progress
in connection with the Riemann
Hypothesis, arguably the most
significant open question in
mathematics.
Another topic, the focus of this
article, is the form of markings on
animals. Spots, stripes, dappled
patterns... for half a century
mathematical biologists have built on
Turing’s ideas. Much of our
understanding of these questions,
along with related ones about the
shapes of living organisms, can be
traced back to Turing’s pioneering
work in biomathematics, a subject
that did not exist when he introduced
his now-famous equations. Turing’s
equations, and the biological theory
of pattern-formation that motivated
them, turn out to be too simple to
explain many details of animal
markings, but they captured many
important features in a simple
context and pointed the way to what
is now a vast field: pattern formation
in nonlinear partial differential
equations.
Turing Centenary
24 Alan
Special Edition
In the early 1950s, Turing became
puzzled about the geometry of
animal form and markings. Everyone
is familiar with the stripes on tigers
and zebras, the spots on leopards
and the dappled patches on Friesian
cows. Although these patterns do
not display the exact regularity that
people often expect from
mathematics, they have a distinct
mathematical ‘feel’. By the start of
the 21st Century—thanks in large
measure to Turing’s pioneering
work—it has become clear that the
mathematics of pattern formation
can produce irregular patterns as
well as regular ones. Even though
the patches on a cow are not circles,
squares or other familiar objects of
Euclidean geometry, they can be
generated by simple mathematical
processes. So this early intuition
turns out to be closer to reality than
the irregularity of real animals might
appear to indicate.
In a celebrated paper ‘The Chemical
Basis of Morphogenesis’, published
in 1952, Turing presented his theory
of pattern formation. He modelled
the formation of animal markings as
a process that laid down a ‘prepattern’ in the developing embryo.
As the embryo grew, this pre-pattern
became expressed as a pattern of
protein pigments. He therefore
concentrated on modelling the prepattern. His model has two main
ingredients: reaction and diffusion.
Turing imagined some system of
chemicals, which he called
morphogens. At any given point on
the part of the embryo that
Diffusion is typically much slower
than reaction, but its mathematical
description is simpler. Chemical
reactions require so-called nonlinear
differential equations, in which, for
example, twice the input does not
give twice the output. Diffusion can
sensibly be modelled by linear
equations: twice as much of some
molecule, starting from a given
location, diffuses to give twice as
much everywhere. This distinction
may not seem terribly vital, but linear
equations behave in fairly
straightforward ways, whereas
nonlinear ones are far richer and (as
Regular Turing patterns: spots
(above) and stripes (below). Photos
courtesy of Harry Swinney,
University of Texas at Austin)
Irregular Turing patterns. Photos courtesy of Erik Rauch & Mark Millonas, MIT.
we have learned over the past 50
years) can be very surprising.
patterns with those found on real
shells.
The most important result to emerge
from Turing’s ‘reaction-diffusion’
equations is that local nonlinearity
plus global diffusion creates striking
and often complex patterns. It turns
out that many different equations
can produce such patterns, not just
the specific ones proposed by
Turing. So the occurrence of the
patterns does not confirm Turing’s
proposed mechanism for animal
markings; on the other hand, it
doesn’t disprove the mechanism
either. Mathematically, there is a
large class of equations which have
the same general catalogue of
possible patterns. What
distinguishes them are the details:
which patterns occur in which
circumstances.
Use of the word ‘pattern’ does not
imply regularity. Many striking
patterns on seashells are complex
and irregular. Some cone shells
have what seem to be random
collections of triangles of various
sizes. Mathematically, patterns of
this kind can occur in Turing-like
equations; they are fractals, a
complex kind of geometric structure
popularised by Benoit Mandelbrot in
the 1960s. Fractals are closely
associated with dynamical chaos,
irregular behaviour in a deterministic
mathematical system. So the cone
shell combines mathematical
features of order and chaos in one
pattern.
Turing patterns in a chemical
medium arise spontaneously from
competition between a localized
autocatalytic (self-amplifying)
chemical reaction and the longranged diffusion of a substance that
inhibits the reaction. The colours
(which are real) correspond to
regions of different chemical
composition. The patterns are static,
but a switch from stripes to spots
can be induced by changing the
ratios of ingredients in the mixture.
Hans Meinhardt has made extensive
studies of many variants of Turing’s
equations, with particular emphasis
on the markings on seashells. His
elegant book The Algorithmic Beauty
of Seashells studies many different
kinds of chemical mechanism,
showing that particular types of
reaction lead to particular kinds of
pattern. For example, some of the
reactants inhibit the production of
others, some activate the production
of others. Combinations of inhibitors
and activators can cause chemical
oscillations, resulting in regular
patterns of stripes or spots.
Meinhardt compares his theoretical
James Murray has applied Turing’s
ideas, suitably modified and
extended, to the markings on big
cats, giraffes, zebras and related
animals. Here the two classic
patterns are stripes (tiger, zebra)
and spots (cheetah, leopard). Both
patterns are created by wavelike
structures in the chemistry. Long,
parallel waves, like waves breaking
a seashore, produce stripes. A
second system of waves, at an
angle to the first, can cause the
stripes to break up into series of
spots. Mathematically, stripes turn
into spots when the pattern of
parallel waves becomes unstable.
Pursuing this led Murray to an
interesting ‘theorem’: a spotted
animal can have a striped tail, but a
striped animal cannot have a spotted
Photo Conus textile, Copyright ©
2005 Richard Ling
tail. The idea is that the smaller
diameter of the tail leaves less room
for stripes to become unstable,
whereas this instability is more likely
on the larger-diameter body. So, if
the tail has spots, the body is almost
certain to have spots too. But if the
tail has stripes, these may or may
not become spots on the body.
There is a deeper and more general
explanation of the range of patterns
found in Turing’s equations. It is
called symmetry-breaking. In
mathematics, symmetry is not a
thing but a transformation: a system
or shape is symmetric if, when
suitably transformed, it looks exactly
the same as it was to begin with. If I
rotate a square through a right
angle, no one could tell the
difference. So ‘rotate through a right
angle’ is a symmetry of the square.
Turing’s equations are very
symmetric. Typically they are posed
on a plane and a featureless plane
has a lot of symmetry: any rotation
through any angle with any centre
and reflection in any line, and any
‘translation’: sliding the whole plane
sideways. However, solutions of the
equations need not be as symmetric
as the equations themselves; if they
were, every solution would be just as
featureless as the plane.
To see how this can be and why it
can lead to patterns, let’s think of a
more familiar physical system: sand
dunes. Imagine a perfectly flat
desert, over which a steady wind
blows, at the same speed and in the
same direction everywhere. In this
idealised desert, the only departure
from the symmetry of a
mathematical plane is the existence
of a preferred direction, that of the
wind. So the system has no
rotational symmetries. The only
reflectional symmetries occur for
mirrors aligned with the wind
direction or at right angles to it. But I
can slide the entire desert north,
south, east or west and the system
— therefore also its mathematical
representation — will look exactly
the same.
If the behaviour of the sand in
response to the wind were as
symmetric as the system itself, there
would be no patterns. The state of
the sand, in particular the height of
Alan Turing Centenary
Special Edition
25
the desert surface, would be
identical at every point. So the sand
would stay flat and the symmetry of
the system would not break.
If we inject just one element of
realism, however, this picture
changes dramatically. Sand is not
smooth; it comes in tiny grains.
Those grains can poke above the
surface, with gaps between. The
surface departs from perfect
planarity by a very tiny amount, but
those departures are pretty much
random. Such a system has no
symmetry at all; however you
transform the desert, the sand grains
will not repeat the exact same
pattern.
What actually happens in a (fairly)
flat desert subjected to (fairly)
constant winds is quite different. The
sand forms dunes, which are great
mounds of sand, thousands of times
the size of the sand grains that
cause the departure from exact
symmetry. Also, very commonly, the
dunes have large-scale patterns.
The most typical pattern, for a
constant wind in a fixed direction, is
linear dunes, arranged in regularly
spaced parallel stripes, like waves
on a beach. Parallel rows of dunes
have quite a lot of symmetry, but not
as much as the original flat desert.
The pattern of dunes can be slid
sideways, along the direction of the
stripes. It can also be slid
perpendicular to the stripes, through
a distance that is any multiple of the
distance between adjacent stripes.
This is remarkable. The symmetry of
the typical pattern of behaviour
resembles neither that of the perfect
idealised model, with complete
translational symmetry, nor the small
but total asymmetry of real sand
grains. Instead, it lies somewhere in
between. It arises because the
uniform pattern is unstable. Any tiny
imperfection, however small, grows.
If a grain of sand pokes up slightly
more than its neighbours, the wind
picks it up and blows it somewhere
else. The resulting hole creates a
bigger difference in height and the
grains on either side become more
exposed and also get blown away.
The hole grows and the displaced
sand piles up.
Once the uniformity is lost, largerscale processes take over.
Feedback between the shape of the
desert surface and the movement of
the wind tends to lead to a stable
pattern: waves of sand and waves of
wind. In the right range of wind
speeds, that pattern is linear dunes.
A similar instability gives rise to
stripes or spots in Turing’s
equations. Any small disturbance to
the uniform state will grow and
spread. Diffusion organises such
disturbances into large-scale
patterns that have some, but not all,
of the symmetries of the plane.
Many of nature’s most striking
patterns can arise through this same
mechanism. If the fully symmetric
state becomes unstable, we expect
to observe a broken-symmetry
alternative.
To my mind, this general
consequence of Turing’s key
example, reaction-diffusion
equations, is even more important
than any specific theory of animal
markings. It is a mark of his genius
that he came up with such an
elegant example of such a farreaching phenomenon Professor Ian Stewart gained an MA at Cambridge
and PhD at Warwick and is Emeritus Professor of
Mathematics at Warwick University. He is an active
research mathematician with over 170 published
papers and works on pattern formation, chaos and
network dynamics. His many awards include the
Royal Society's Faraday Medal and was elected a
Fellow of the Royal Society in 2001. He presented
the 1997 Royal Institution Christmas Lectures.
He has published over 70 books including Does
God Play Dice?, What Shape is a Snowflake? and
the bestselling series The Science of Discworld I, II and III (with Terry
Pratchett and Jack Cohen).
Turing Centenary
26 Alan
Special Edition
A
part from Alan
Turing’s theoretical
agility, he was also
an accomplished athlete,
having rowed for
Cambridge University; he
also developed an
enthusiasm for running,
rowing and sailing. During
WW2 he could often be
seen cycling to and from
Bletchley Park and nearby
Hanslope Park. To the
amazement of his
colleagues, he would often
run to scientific meetings,
beating those who took
public transport!
After WW2 he took up
cross-country running
competitively, reaching the
top levels as an amateur
in the sport. He had a
personal best in the marathon of two
hours, forty six minutes and three
seconds. The 1948 Olympic
marathon winner, held in London,
beat this by 11 minutes. In another
cross country race he finished before
Tom Richards who won a silver
medal in the Olympics that year.
Turing narrowly missed
consideration for the 1948 Olympics
due to an injury.
It is fitting that in 2012, the centenary
of Turing’s birth and the return of the
Olympics to London that the Olympic
torch will pass two locations
significant during Turing’s lifetime.
On 23rd June (Turing’s birthday) it
will pass his statue in Sackville
gardens, Manchester and on 9th
July pass through Bletchley Park on
its way to the Olympic stadium for
27th July Photos: above 2012 Olympic torch,
below a sporting second in a three
mile race, possibly the event of 26th
December 1946, courtesy of Kings
College Cambridge.
The Turing Papers
A
significant set of historic
artefacts was acquired by
Bletchley Park on 25th
February 2011. There are few
remains from the life of Alan
Turing, so when a set of rare
offprints came up for auction at
Christies late last year,
passionate supporter Gareth
Halfacree started a campaign to
prevent the papers going abroad
and secure them for Bletchley
Park where they will be available
for the public. Despite an online
fundraising campaign that raised
£28,500 and a generous
donation of $100,000 from
Google, it wasn’t enough to
reach the reserve price at the
auction and they remained
unsold. A campaign to find
further support to help buy the
papers privately, began.
The collection of articles
belonged to Professor Max
Newman, Turing’s friend and
fellow Bletchley Park code
breaking genius. It includes
offprints of sixteen of Turing’s
eighteen published works,
including his momentous paper
‘On Computable Numbers’. A
limited number of the offprints
would have been produced at
the time and Turing’s gifting
them to Newman bears
testimony to their unique
relationship. The set includes
articles which have been
annotated by Newman, along
with Max Newman's name
inscribed in pencil in Turing's
hand. Accompanying the set of
offprints is the Newman
household visitors’ book with
several signatures of Turing, that
of Turing’s mother and, of
special significance to Bletchley
Park, signatures of other wartime
code breaking giants.
On the 25th February, the Trust
announced that the National
Heritage Memorial Fund (NHMF)
had stepped in with the remaining
£213,437 to finally secure the
papers for the Park. After minor
restoration, the papers were put
on display.
Speaking about the acquisition,
Dame Jenny Abramsky, Chair of
the NHMF, said: “Alan Turing was
a true war hero and played an
absolutely crucial role during
WW2. The National Heritage
Memorial Fund was set up in
memory of those who have given
their lives for the UK and this
grant will now ensure that this
extremely rare collection of his
work stands as a permanent
memorial to the man and to all
those who paid the ultimate price
in service to this nation.”
Above: Gareth Halfacree and Simon Greenish
with the Turing papers. Below, pictures of the
Turing exhibition in Block B including Porgy,
Turing’s bear.
Peter Barron, Director of External
Relations for Google, said,
“Turing is a hero to many of us at
Google for his pioneering work on
algorithms and the development
of computer science. We're
delighted that this important
collection will now be accessible
to everyone visiting Bletchley
Park.”
Simon Greenish, CEO of the
Bletchley Park Trust, added, “The
acquisition of this hugely
important collection has been
made possible only by the
astonishing support
demonstrated by the public, the
media, Google, the NHMF and
Christies the auctioneers whose
help in brokering the purchase is
gratefully acknowledged. We are
delighted to have the collection,
which is surely its most fitting
home Alan Turing Centenary
Special Edition
27
For further Information….
Books
Alan Turing: The
Enigma by
Andrew Hodges
ISBN-10:
0099116413
ISBN-13: 9780099116417
RRP £10.99
Andrew Hodges
has researched
and presented
through this book
an immense amount of information
about Alan Turing’s life, the
influences on him and his ground
breaking work that has added so
much to our understanding of the
world. His work is still very valid to
today’s research. There is a lot of
information contained within this
book but is worth the read to gain a
much greater understanding of the
man who was ahead of his time and
gave so much to the world.
The Essential
Turing by B.
Jack. Copeland
ISBN-10:
0198250800
ISBN-13: 9780198250807
RRP £22.00
Within this book,
Jack Copeland
has collected
together and
explains the best of Turing’s papers.
These include the fundamentals of
the Turing machine, artificial
intelligence and morphogenesis.
Interspersed with this are detail of
Turings life with a strong emphasis
of his wartime work at Bletchley
Park.
Alan M Turing by
Sara Turing
ISBN-10:
1107020581
ISBN-13: 9781107020580
RRP 17.99
After Turing’s
death, his
mother, Sara
Turing, penned a
biography of her
son. The manuscript has been
republished for the centenary of
Turing’s birth with a new foreword by
Martin Davis and a brand new
memoir by Alan's brother. This
biography reveals the relationship
between Turing and his family.
There are many other publications in
the Bletchley Park bookshop that
cover Alan Turing’s life and works
including the Bletchley Park Reports
providing greater detail on several
aspects of his achievements while
working at the Park during WW2.
Websites
Useful sites to visit for more
information:
Alan Turing Year official website:
http://www.mathcomp.leeds.ac.uk/
turing2012/
Events
15th May 2012 The Loebner Prize
in Artificial Intelligence
Bletchley Park Trust is delighted to
be hosting the annual Loebner Prize
competition to find the world’s best
conversational computer program
(chatbot). Competitors will be
competing for a coveted bronze
medal and a prize fund of $7,000
sponsored by Dr Hugh Loebner who
founded the competition 20 years
ago.
The Loebner Prize competition is
based on the Turing Test, proposed
by Alan Turing in his famous 1950
paper entitled Computing Machinery
and Intelligence, as a way of
determining whether a computer
program could be said to be
intelligent. The chatbot with the
highest overall ranking wins the
prize.
Conversations will be shown on
screens in the Mansion for the Public
and streamed live on the internet for
the first time this year.
30th June 2012 TED 2012 Turing
Educational Day.
The Turing Education Day (TED)
incorporating the Alan Turing
Memorial Lecture 2012. A team of 10
speakers will explain key aspects of
Turing's many-faceted work. Topics
include codebreaking, the birth and
early development of the computer
and computer programming, artificial
intelligence, artificial life and the
foundations and philosophy of
mathematics. The final lecture will be
delivered by ex-codebreaker Jerry
Roberts who has campaigned for 10
years for greater recognition of the
Testery, Turing, Tutte and Tommy
Flowers (the 4 T’s).
Jack Copeland’s Turing archive :
http://www.alanturing.net/
Andrew Hodges’ website on the life
of Alan Turing:
http://www.turing.org.uk/
Loebner competition:
http://www.loebner.net/Prizef/loebner
-prize.html
Bletchley Park website:
www.bletchleypark.org.uk