Bletchley Park:
How new computing machinery
helped to win WWII
18 March 2021 Selected topics in history of science 1
Bletchley Park:
Location
North-East of London
(50 minutes by train)
Close cities and towns:
London
Birmingham
Cambridge
Oxford
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Bletchley Park: the estate
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Bletchley Park:
government crockery losses
„The breakage and loss of tea cups,
tumblers, knives and forks and other mess
traps is taking place on fantastic scale.
The rate of loss is no less than five times
that normally experienced in a man-of-war.
Tumblers, cups and plates have been found
pushed away into the shrubberies and left
about in offices, many of them broken.“
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Bletchley Park:
measures
„This state of affairs cannot be allowed to
go on and it has become necessary to
prohibit the removal of any Government
property whatsoever from the dining rooms
except by members of the kitchen and
dining room staff. The watchmen have
orders to stop anyone carrying
Government Crockery, etc. away from the
dining room and to také their names.
Those who wish to have milk in their
offices must provide their own gear.“
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Bletchley Park:
Afternoon Tea
- Tea served each day from 3:15 to 4:15
pm in the Recreation Hut
- Breaks taking too long – urns with 70
cups delivered to the Heads of Larger
Section
- Milk distributed daily at 2pm, tea once a
week (on a Monday)
- Allowance: 1 pound of tea per 200
people, 1 pint of milk per 10 people
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Film The Enigma (2001)
⚫ Story of the film
⚫ Weird things:
− Why would one fight for a
copy of their own paper?
− Turing was gay
− Based on a book – but for
the sake of simplicity, two
characters are merged
into a single one
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Alan Mathison Turing (1912-1954):
Mathematician.
Codebreaker.
Marathon-runner.
Machine-designer.
Secret service.
Programmer.
Thinker.
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Alan Turing‘s family
⚫ Born 1912
⚫ Father: in India
(government service)
⚫ Mother – Sarah Turing
⚫ Elder brother John
⚫ photo: Alan, ca. 5 years
old, his brother John
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Christopher Morcom
⚫ Secondary school
⚫ Common interests:
astronomy, mathematics
⚫ “won over Turing”
⚫ Ch. M. died 1930
⚫ A.T.‘s friendship with
Christopher‘s family
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Turing‘s mathematical career
⚫ Sherborne (1926-1931)
⚫ Cambridge, King's College
(mathematics, 1931-1934)
⚫ 1935: King's College member
⚫ Interest in quantum
mechanics, probability, logic,
and also the foundations of
mathematics
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“On Computable Numbers”
(a mathematical intermezzo)
⚫ Turing, A. M., 1936, On computable numbers, with
an application to Entscheidungsproblem. Proceedings
of the London Mathematical Society 2(43): 544-546.
⚫Priority issue: dealt with by his senior colleague, who
wrote a recommendation and explanation
⚫Publishing then: peer review – plagiarism – etc.
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Turing machine
⚫ The 1936 article does NOT state HOW the machine
should be made
⚫ Image: infinite tape, divided into square fields
⚫ States and transition between them: on the basis of
the sign read, the tape would
− move right
− move left
− delete / overwrite a sign
− stop the machine („halting problem“)
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Return to pre-WWII England
1936-38: Ph.D. in Logic,
algebra, number theory,
Princeton University
1938-39: return to
Cambridge.
Learning about the
German encryption
machine Enigma
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Enigma
https://www.cryptomuseum.com/crypto/enigma/hist.htm
⚫ Photo of Enigma: looks
like a typewriter
⚫ an encryption machine,
complicated inside
⚫ Role of Polish
mathematicians
⚫ Interception of messages
⚫ The importance of time
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Bletchley Park
“Bombe”
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The Bombe and Alan Turing
⚫ Paper-and-pencil solving: too slow
⚫ A setting of the Enigma lasted for a day
⚫ 1939-40: constructing the Bombe, a machine for
cracking the code of Enigma in time
⚫ 1942: Decrypting the message about U-boat
attacks, key turn in the battle of the Atlantic
⚫ 1943-45: Turing named key Anglo-American
consultant in cryptology.
(For Turing, an opportunity to work with electronics.)
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World War II
⚫ A letter to Churchill
⚫ Sent to the US
⚫ AT&T Bell Laboratories
⚫ Anecdote:
“I do not want to
construct a brain of a
genius, bud only an
average brain, like the
brain of the AT&T CEO”
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The Colossus Computer
⚫ Colossus Mark I
− February 1944
⚫ Colossus Mark II
− June 1944
(D-Day - Normandy)
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Turing‘s activities after WWII
⚫ 1945: National Laboratory of Physics, London
⚫ 1948: University of Manchester
⚫ 1949: First use of computers for mathematics
⚫ 1952: sued for a homosexual relationaship (crime)
⚫ Punishment: hormonal treatment
⚫ Loss of security clearance
⚫ 1954, 7 June: died – cyanide poisoning, probably
suicide, in Wilmslow, Cheshire.
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Hugh Whitemore:
Breaking the Code
(1986)−
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National Physics Laboratory: ACE
⚫ Turing‘s practical experience from the war
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Pilot ACE
⚫ Turing in NPL since
1945
⚫ 1946: design of
computers and
programmes
⚫ 1947-48: programming
neural networks,
artificial intelligence
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Turing test
⚫ Article in Mind, 1950
⚫ Turing‘s thoughts on intelligence
⚫ Again: computer and brain
⚫ Turing tried to show what machines can do
⚫ “machies do not think, and Turing said so”
⚫ Defence of human intelligence
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Manchester
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Ferranti and Manchester University
⚫ The Ferrranti company and
the University of Manchester
co-operated in producing the
computer
⚫ Hence the name:
Ferranti Mark I
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Programming: Manchester
(A programmer‘s sheet
used by Turing in
Manchester)
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