The Postcard
A postcard that was published on behalf of the Royal Academy. The photography was by Anderson of Rome. On the back of the card is printed:
'Exhibition of Italian Art
Royal Academy London
1930.
Titian - Salome - Rome,
Collection of Prince
Doria Pamphili.'
The card was posted in South Kensington using stamps to the value of 2d. The postmark states 'Postage on Letters to Europe 4d.'
The card was sent on Monday the 7th. June 1954 to:
Mrs. Chanter,
Fort Hill,
Barnstaple,
North Devon.
The message on the divided back of the card was as follows:
"10, Courtfield Road,
SW7.
Whit Monday.
Dear Aunt Ann,
Thank you for your card.
I have been delayed in
London.
Nigel is leaving for the
Continent & it has been
necessary for me to stay
behind to help him with
his things.
I intend if I can to come
down tomorrow.
Please keep the parcel -
I wonder what it can be.
Love to you and Uncle
Edward.
Rob."
Salome With the Head of John the Baptist
90 x 73 cm; oil on canvas.
This early masterpiece shows that Titian’s personal style had already evolved , with a “sense of physical proximity and involvement of the viewer” (David Jaffé).
Salome was a Jewish princess, the daughter of Herod II and princess Herodias. In the New Testament, Salome demands and receives the head of John the Baptist.
The scene is scattered with refined lyricism, and represents Salome, given the presence of the maidservant and the silver platter on which John the Baptist’s head is laid.
Some scholars suggest that the head of the Baptist might be a self-portrait of the artist. It is usually dated about 1515. The picture’s early fame is demonstrated by the various copies that were made of it.
Iowa Class Battleships
So what else happened on the day that Rob posted the card to his aunt?
Well, on the 7th. June 1954, all four Iowa class battleships were together in one place for the only time in their history.
Alan Turing
The day also marked the death by suicide of Alan Turing.
Alan Mathison Turing, who was born on the 23rd. June 1912, was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist.
He was highly influential in the development of computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer.
Turing is widely considered to be the father of theoretical computer science.
Born in London, Turing was raised in southern England. He graduated from King's College, Cambridge, and in 1938, earned a doctorate from Princeton University. During World War II, Turing worked for the Government Code and Cypher School at Bletchley Park, Great Britain's codebreaking centre that produced Ultra intelligence.
Alan led Hut 8, the section responsible for German naval cryptanalysis. Turing devised techniques for speeding the breaking of German ciphers, including improvements to the pre-war Polish bomba method, an electromechanical machine that could find settings for the Enigma machine.
He played a crucial role in cracking intercepted messages that enabled the Allies to defeat the Axis powers in many engagements, including the Battle of the Atlantic.
After the war, Turing worked at the National Physical Laboratory, where he designed the Automatic Computing Engine, one of the first designs for a stored-program computer.
In 1948, Turing joined Max Newman's Computing Machine Laboratory at the Victoria University of Manchester, where he helped develop the Manchester computers and became interested in mathematical biology.
Turing wrote on the chemical basis of morphogenesis, and predicted oscillating chemical reactions such as the Belousov–Zhabotinsky reaction, first observed in the 1960's.
However despite these accomplishments, Alan was never fully recognised during his lifetime, because much of his work was covered by the Official Secrets Act.
In 1952, Turing was prosecuted for homosexual acts. He accepted hormone treatment, a procedure commonly referred to as chemical castration, as an alternative to prison.
Turing died on the 7th. June 1954, aged 41, from cyanide poisoning. An inquest determined his death to be suicide, but the evidence is also consistent with accidental poisoning.
Following a campaign in 2009, British prime minister Gordon Brown made an official public apology for "the appalling way Turing was treated".
Queen Elizabeth II granted a pardon in 2013. The term "Alan Turing law" is used informally to refer to a 2017 law in the UK that retroactively pardoned men cautioned or convicted under historical legislation that outlawed homosexual acts.
Turing left an extensive legacy in mathematics and computing which today is recognised more widely, with statues and many things named after him, including an annual award for computing innovation.
Alan's portrait appears on the Bank of England £50 note, first released on the 23rd. June 2021 in order to coincide with his birthday. The audience vote in a 2019 BBC series named Turing the greatest person of the 20th century.
-- Alan Turing - The Early Years
Turing was born in Maida Vale, London, while his father, Julius Mathison Turing, was on leave from his position with the Indian Civil Service (ICS) of the British Raj government at Chatrapur.
Turing's father was the son of a clergyman, the Rev. John Robert Turing, from a Scottish family of merchants that had been based in the Netherlands and included a baronet.
Turing's mother was Ethel Sara Turing (née Stoney), daughter of Edward Waller Stoney, chief engineer of the Madras Railways. Julius and Ethel married on the 1st. October 1907 at St. Bartholomew's Church in Dublin.
Julius's work with the ICS brought the family to British India, where his grandfather had been a general in the Bengal Army. However, both Julius and Ethel wanted their children to be brought up in Britain, so they moved to Maida Vale, London, where Alan Turing was born.
His birth is recorded by a blue plaque on the outside of the house, later the Colonnade Hotel.
Turing had an elder brother, John Ferrier Turing, father of Sir John Dermot Turing, 12th. Baronet of the Turing baronets.
Turing's father's civil service commission was still active during Turing's childhood years, and his parents travelled between Hastings and India, leaving their two sons to stay with a retired Army couple.
At Hastings, Turing stayed at Baston Lodge, Upper Maze Hill, St. Leonards-on-Sea, now marked with a blue plaque.
Turing's parents purchased a house in Guildford in 1927, and Turing lived there during school holidays. The location is also marked with a blue plaque.
-- Alan Turing's Schooldays
Turing attended St. Michael's, a primary school at 20 Charles Road, St. Leonards-on-Sea, from the age of six to nine. The headmistress recognised his talent, noting that:
"We have had clever boys and
hardworking boys, but Alan is
a genius".
Between January 1922 and 1926, Turing was educated at Hazelhurst Preparatory School, an independent school in the village of Frant in Sussex.
In 1926, at the age of 13, Alan went on to Sherborne School, an independent boarding school in Sherborne in Dorset.
The first day of term coincided with the 1926 General Strike, but Turing was so determined to attend that he rode his bicycle unaccompanied 60 miles (97 km) from Southampton to Sherborne, stopping overnight at an inn.
Turing's natural inclination towards mathematics and science did not earn him respect from some of the teachers at Sherborne, whose definition of education placed more emphasis on the classics. His headmaster wrote to his parents:
"I hope he will not fall between two stools.
If he is to stay at public school, he must
aim at becoming educated.
If he is to be solely a Scientific Specialist,
he is wasting his time at a public school".
Despite this, Turing continued to show remarkable ability in the studies he loved, solving advanced problems in 1927 without having studied even elementary calculus.
In 1928, aged 16, Turing encountered Albert Einstein's work; not only did he grasp it, but it is possible that he managed to deduce Einstein's questioning of Newton's laws of motion from a text in which this was never made explicit.
-- Christopher Morcom
At Sherborne, Turing formed a significant friendship with fellow pupil Christopher Collan Morcom (1911 – 1930), who has been described as Turing's first love.
Their relationship provided inspiration in Turing's future endeavours, but it was cut short by Morcom's death, in February 1930, from complications of bovine tuberculosis, contracted after drinking infected cow's milk some years previously.
The event caused Turing great sorrow. He coped with his grief by working that much harder on the topics of science and mathematics that he had shared with Morcom. In a letter to Morcom's mother Turing wrote:
"I am sure I could not have found anywhere
another companion so brilliant and yet so
charming and unconceited. I regarded my
interest in my work, and in such things as
astronomy (to which he introduced me) as
something to be shared with him, and I think
he felt a little the same about me ...
I know I must put as much energy if not as
much interest into my work as if he were
alive, because that is what he would like
me to do."
Turing's relationship with Morcom's mother continued long after Morcom's death, with her sending gifts to Turing, and him sending letters, typically on Morcom's birthday. A day before the third anniversary of Morcom's death (13th. February 1933), he wrote to Mrs. Morcom:
"I expect you will be thinking of Chris when
this reaches you. I shall too, and this letter
is just to tell you that I shall be thinking of
Chris and of you tomorrow.
I am sure that he is as happy now as he
was when he was here.
Your affectionate Alan."
Some writers have speculated that Morcom's death was the cause of Turing's atheism and materialism. Apparently, at this point in his life he still believed in such concepts as a spirit, independent of the body and surviving death. In a later letter, also written to Morcom's mother, Turing wrote:
"Personally, I believe that spirit is really eternally
connected with matter, but certainly not by the
same kind of body ... as regards the actual
connection between spirit and body, I consider
that the body can hold on to a 'spirit', whilst the
body is alive and awake the two are firmly
connected.
When the body is asleep I cannot guess what
happens but when the body dies, the 'mechanism'
of the body, holding the spirit is gone and the
spirit finds a new body sooner or later, perhaps
immediately."
-- Alan Turing at University and his Work on Computability
After graduating from Sherborne, Turing applied for several Cambridge scholarships, including Trinity and King's, eventually earning an £80 per annum scholarship (equivalent to about £4,300 as of 2023) in order to study at the latter.
There, Turing studied the undergraduate course in a three-year Parts I and II of the Mathematical Tripos, with extra courses at the end of the third year from February 1931 to November 1934, at King's College, Cambridge, where he was awarded a first-class honours degree in mathematics.
His dissertation, On the Gaussian error function, written during his senior year and delivered in November 1934 (with a deadline date of the 6th. December) proved a version of the central limit theorem. It was finally accepted on the 16th. March 1935.
By the spring of 1935, Turing had started his master's course (Part III)—which he completed in 1937—and, at the same time, he published his first paper, a one-page article called Equivalence of Left and Right Almost Periodicity, featured in the tenth volume of the Journal of the London Mathematical Society.
Later that year, Turing was elected a Fellow of King's College on the strength of his dissertation where he served as a lecturer. However, and, unknown to Turing, this version of the theorem that he proved in his paper, had already been proven, in 1922, by Jarl Waldemar Lindeberg.
Despite this, the college committee found Turing's methods original and so regarded the work worthy of consideration for the fellowship. Abram Besicovitch's report for the committee went so far as to say that:
"If Turing's work had been published
before Lindeberg's, it would have
been an important event in the
mathematical literature of that year".
Between the springs of 1935 and 1936, at the same time as Alonzo Church, Turing worked on the decidability of problems, starting from Gödel's incompleteness theorems.
In mid-April 1936, Turing sent Max Newman the first draft typescript of his investigations. That same month, Church published his An Unsolvable Problem of Elementary Number Theory, with similar conclusions to Turing's then-yet unpublished work.
Finally, on the 28th. May of 1936, Alan finished and delivered his 36-page paper for publication called "On Computable Numbers, with an Application to the Entscheidungsproblem".
The paper was published in the Proceedings of the London Mathematical Society journal in two parts, the first on the 30th. November, and the second on the 23rd. December 1936.
In this paper, Turing reformulated Kurt Gödel's 1931 results on the limits of proof and computation, replacing Gödel's universal arithmetic-based formal language with the formal and simple hypothetical devices that became known as Turing machines.
The Entscheidungsproblem (Decision Problem) was originally posed by German mathematician David Hilbert in 1928. Turing proved that his "universal computing machine" would be capable of performing any conceivable mathematical computation if it were representable as an algorithm.
Alan went on to prove that there was no solution to the decision problem by first showing that the halting problem for Turing machines is undecidable: it is not possible to decide algorithmically whether a Turing machine will ever halt.
This paper has been called:
"Easily the most influential
math paper in history".
Although Turing's proof was published shortly after Church's equivalent proof using his lambda calculus, Turing's approach is considerably more accessible and intuitive than Church's.
It also included a notion of a 'Universal Machine' (now known as a Universal Turing Machine), with the idea that such a machine could perform the tasks of any other computation machine (as indeed could Church's lambda calculus).
According to the Church–Turing thesis, Turing machines and the lambda calculus are capable of computing anything that is computable. John von Neumann acknowledged that the central concept of the modern computer was due to Turing's paper.
To this day, Turing machines are a central object of study in the theory of computation.
From September 1936 to July 1938, Turing spent most of his time studying under Church at Princeton University. In addition to his purely mathematical work, Alan studied cryptology, and also built three of four stages of an electro-mechanical binary multiplier.
In June 1938, Alan obtained his PhD from the Department of Mathematics at Princeton; his dissertation, Systems of Logic Based on Ordinals, introduced the concept of ordinal logic and the notion of relative computing, in which Turing machines are augmented with so-called oracles, allowing the study of problems that cannot be solved solely by Turing machines.
John von Neumann wanted to hire Alan as his postdoctoral assistant, but he went back to the United Kingdom.
-- Turing's Return to Cambridge
When Turing returned to Cambridge, he attended lectures given in 1939 by Ludwig Wittgenstein about the foundations of mathematics. The lectures have been reconstructed verbatim, including interjections from Turing and other students, from students' notes.
Turing and Wittgenstein argued and disagreed, with Turing defending formalism and Wittgenstein propounding his view that mathematics does not discover any absolute truths, but rather invents them.
-- Alan Turing and Cryptanalysis
During the Second World War, Turing was a leading participant in the breaking of German ciphers at Bletchley Park. The historian and wartime codebreaker Asa Briggs has said:
"You needed exceptional talent,
you needed genius at Bletchley,
and Turing's was that genius."
From September 1938, Turing worked part-time with the Government Code and Cypher School (GC&CS), the British codebreaking organisation. He concentrated on cryptanalysis of the Enigma cipher machine used by Nazi Germany, together with Dilly Knox, a senior GC&CS codebreaker.
Soon after the July 1939 meeting near Warsaw at which the Polish Cipher Bureau gave the British and French details of the wiring of Enigma machine's rotors and their method of decrypting Enigma machine's messages, Turing and Knox developed a broader solution.
The Polish method relied on an insecure indicator procedure that the Germans were likely to change, which they in fact did in May 1940. Turing's approach was more general, using crib-based decryption for which he produced the functional specification of the bombe (an improvement on the Polish Bomba).
On the 4th. September 1939, the day after the UK declared war on Germany, Turing reported to Bletchley Park, the wartime station of GC&CS. Like all others who came to Bletchley, he was required to sign the Official Secrets Act, in which he agreed not to disclose anything about his work at Bletchley, with severe legal penalties for violating the Act.
Specifying the bombe was the first of five major cryptanalytical advances that Turing made during the war. The others were:
-- Deducing the indicator procedure used by the German navy.
-- Developing a statistical procedure dubbed Banburismus for making much more efficient use of the bombes.
-- Developing a procedure dubbed Turingery for working out the cam settings of the wheels of the Lorenz SZ 40/42 (Tunny) cipher machine.
-- Towards the end of the war, the development of a portable secure voice scrambler at Hanslope Park that was codenamed Delilah.
By using statistical techniques to optimise the trial of different possibilities in the code breaking process, Turing made an innovative contribution to the subject.
He wrote two papers discussing mathematical approaches, titled The Applications of Probability to Cryptography and Paper on Statistics of Repetitions, which were of such value to GC&CS and its successor GCHQ that they were not released to the UK National Archives until April 2012, shortly before the centenary of Alan's birth.
A GCHQ mathematician, who identified himself only as "Richard," said at the time that the fact that the contents had been restricted under the Official Secrets Act for some 70 years demonstrated their importance, and their relevance to post-war cryptanalysis.
Richard said:
"The fact that the contents has been restricted
shows what a tremendous importance it has in
the foundations of our subject.
The papers detailed using mathematical analysis
to try and determine which are the more likely
settings, so that they can be tried as quickly as
possible.
GCHQ has now "squeezed the juice" out of the
two papers, and is now happy for them to be
released into the public domain".
Turing had a reputation for eccentricity at Bletchley Park. He was known to his colleagues as "Prof," and his treatise on Enigma was known as the "Prof's Book". Jack Good, a cryptanalyst who worked with Turing, said of his colleague:
"In the first week of June each year he would
get a bad attack of hay fever, and he would
cycle to the office wearing a service gas mask
to keep the pollen off.
His bicycle had a fault: the chain would come
off at regular intervals. Instead of having it
mended, he would count the number of times
the pedals went round and would get off the
bicycle in time to adjust the chain by hand.
Another of his eccentricities is that he chained
his mug to the radiator pipes to prevent it
being stolen."
Peter Hilton recounted his experience working with Turing in Hut 8 in his "Reminiscences of Bletchley Park" from A Century of Mathematics in America:
"It is a rare experience to meet an authentic genius.
Those of us privileged to inhabit the world of
scholarship are familiar with the intellectual
stimulation furnished by talented colleagues.
We can admire the ideas they share with us, and are
usually able to understand their source; we may even
often believe that we ourselves could have created
such concepts and originated such thoughts.
However, the experience of sharing the intellectual
life of a genius is entirely different; one realizes that
one is in the presence of an intelligence, a sensibility
of such profundity and originality that one is filled with
wonder and excitement.
Alan Turing was such a genius, and those, like myself,
who had the astonishing and unexpected opportunity,
created by the strange exigencies of the Second World
War, to be able to count Turing as colleague and friend
will never forget that experience, nor can we ever lose
its immense benefit to us."
Hilton reported on the athletic side of Alan's life in the Nova PBS documentary Decoding Nazi Secrets:
"While working at Bletchley, Turing, who was a talented
long-distance runner, occasionally ran the 40 miles
(64 km) to London when he was needed for meetings,
and he was capable of world-class marathon standards.
Turing tried out for the 1948 British Olympic team, but
he was hampered by an injury. His tryout time for the
marathon was only 11 minutes slower than British silver
medallist Thomas Richards' Olympic race time of 2 hours
35 minutes.
He was Walton Athletic Club's best runner, a fact
discovered when he passed the group while running
alone. When asked why he ran so hard in training,
he replied:
'I have such a stressful job that the
only way I can get it out of my mind
is by running hard; it's the only way
I can get some release.'"
Due to the problems of counterfactual history, it is hard to estimate the precise effect that Ultra intelligence had on the war. However, official war historian Harry Hinsley estimated that this work shortened the war in Europe by more than two years, and saved over 14 million lives.
At the end of the war, a memo was sent to all those who had worked at Bletchley Park, reminding them that the code of silence dictated by the Official Secrets Act did not end with the war, but would continue indefinitely.
Thus, even though Turing was appointed an Officer of the Order of the British Empire (OBE) in 1946 by King George VI for his wartime services, his work remained secret for many years.
-- Bombe
Within weeks of arriving at Bletchley Park, Turing had specified an electromechanical machine called the bombe, which could break Enigma more effectively than the Polish bomba kryptologiczna, from which its name was derived.
The bombe, with an enhancement suggested by mathematician Gordon Welchman, became one of the primary tools, and the major automated one, used to attack Enigma-enciphered messages.
The first bombe was installed on the 18th. March 1940.
The bombe searched for possible correct settings used for an Enigma message (i.e., rotor order, rotor settings and plugboard settings) using a suitable crib: a fragment of probable plaintext.
For each possible setting of the rotors, which had on the order of 1019 states, the bombe performed a chain of logical deductions based on the crib, implemented electromechanically.
The bombe detected when a contradiction had occurred and ruled out that setting, moving on to the next. Most of the possible settings would cause contradictions and be discarded, leaving only a few to be investigated in detail.
A contradiction occured when an enciphered letter was turned back into the same plaintext letter, which was impossible with the Enigma.
-- The 'Action This Day' Memo
By late 1941, Turing and his fellow cryptanalysts Gordon Welchman, Hugh Alexander and Stuart Milner-Barry were frustrated.
Building on the work of the Poles, they had set up a good working system for decrypting Enigma signals, but their limited staff and bombes meant that they could not translate all the signals.
In the summer, they had considerable success, and shipping losses had fallen to under 100,000 tons a month; however, they badly needed more resources in order to keep abreast of German adjustments. They had tried to get more people and fund more bombes through the proper channels, but had failed.
On the 28th. October they wrote directly to Winston Churchill explaining their difficulties, with Turing as the first named. They emphasised how small their need was compared with the vast expenditure of men and money by the forces, and compared with the level of assistance they could offer to the forces.
As Andrew Hodges, biographer of Turing, later wrote:
"This letter had an electric effect."
Churchill wrote a memo to General Ismay, which read:
"ACTION THIS DAY. Make sure they
have all they want on extreme priority
and report to me that this has been
done."
On the 18th. November 1941, the chief of the secret service reported that every possible measure was being taken. The cryptographers at Bletchley Park did not know of the Prime Minister's response, but as Milner-Barry recalled:
"All that we did notice was that almost
from that day, the rough ways began
miraculously to be made smooth."
More than two hundred bombes were in operation by the end of the war.
-- Hut 8 and the Naval Enigma
Turing decided to tackle the particularly difficult problem of cracking the German naval use of Enigma:
"... because no one else was doing
anything about it, and I could have
it to myself".
In December 1939, Turing solved the essential part of the naval indicator system, which was more complex than the indicator systems used by the other services.
That same night, he also conceived of the idea of Banburismus, a sequential statistical technique to assist in breaking the naval Enigma. Alan noted:
"I was not sure that it would work
in practice, and was not, in fact,
sure until some days had actually
broken".
For this, he invented a measure of weight of evidence that he called the ban. Banburismus could rule out certain sequences of the Enigma rotors, substantially reducing the time needed to test settings on the bombes.
Later this sequential process of accumulating sufficient weight of evidence using decibans (one tenth of a ban) was used in cryptanalysis of the Lorenz cipher.
Turing travelled to the United States in November 1942 and worked with US Navy cryptanalysts on the naval Enigma and bombe construction in Washington. He also visited their Computing Machine Laboratory in Dayton, Ohio.
Turing's reaction to the American bombe design was far from enthusiastic:
"The American Bombe programme was to produce
336 Bombes, one for each wheel order. I used to
smile inwardly at the conception of Bombe hut
routine implied by this programme, but thought
that no particular purpose would be served by
pointing out that we would not really use them
in that way.
Their test (of commutators) can hardly be
considered conclusive as they were not testing
for the bounce with electronic stop finding devices.
Nobody seems to be told about rods or offiziers or
banburismus unless they are really going to do
something about it."
During this trip, Alan also assisted at Bell Labs with the development of secure speech devices. He returned to Bletchley Park in March 1943.
During his absence, Hugh Alexander had officially assumed the position of head of Hut 8, although Alexander had been de facto head for some time (Turing having little interest in the day-to-day running of the section). Turing became a general consultant for cryptanalysis at Bletchley Park.
Alexander wrote of Turing's contribution:
"There should be no question in anyone's mind that
Turing's work was the biggest factor in Hut 8's success.
In the early days, he was the only cryptographer who
thought the problem worth tackling, and not only was
he primarily responsible for the main theoretical work
within the Hut, but he also shared with Welchman and
Keen the chief credit for the invention of the bombe.
It is always difficult to say that anyone is 'absolutely
indispensable', but if anyone was indispensable to
Hut 8, it was Turing.
The pioneer's work always tends to be forgotten
when experience and routine later make everything
seem easy, and many of us in Hut 8 felt that the
magnitude of Turing's contribution was never fully
realised by the outside world."
-- Turingery
In July 1942, Turing devised a technique termed Turingery (or jokingly Turingismus) for use against the Lorenz cipher messages produced by the Germans' new Geheimschreiber (Secret Writer) machine.
This was a teleprinter rotor cipher attachment codenamed Tunny at Bletchley Park. Turingery was a method of wheel-breaking, i.e., a procedure for working out the cam settings of Tunny's wheels.
Alan also introduced the Tunny team to Tommy Flowers who, under the guidance of Max Newman, went on to build the Colossus computer, the world's first programmable digital electronic computer.
This replaced a simpler prior machine (the Heath Robinson), and its superior speed allowed the statistical decryption techniques to be applied usefully to the messages.
Some have mistakenly said that Turing was a key figure in the design of the Colossus computer. Turingery and the statistical approach of Banburismus undoubtedly fed into the thinking about cryptanalysis of the Lorenz cipher, but Alan was not directly involved in the Colossus development.
-- Delilah
Following his work at Bell Labs in the US, Turing pursued the idea of electronic enciphering of speech in the telephone system. In the latter part of the war, he moved to work for the Secret Service's Radio Security Service (later HMGCC) at Hanslope Park.
At the park, he further developed his knowledge of electronics with the assistance of REME officer Donald Bayley. Together they undertook the design and construction of a portable secure voice communications machine codenamed Delilah.
The machine was intended for different applications, but it lacked the capability for use with long-distance radio transmissions. In any case, Delilah was completed too late to be used during the war.
Though the system worked fully, with Turing demonstrating it to officials by encrypting and decrypting a recording of a Winston Churchill speech, Delilah was not adopted for use.
Turing also consulted with Bell Labs on the development of SIGSALY, a secure voice system that was used in the later years of the war.
-- Early Computers
Between 1945 and 1947, Turing lived in Hampton, London, while he worked on the design of the ACE (Automatic Computing Engine) at the National Physical Laboratory (NPL).
He presented a paper on the 19th. February 1946, which was the first detailed design of a stored-program computer.
Von Neumann's incomplete first draft of a report on the EDVAC had pre-dated Turing's paper, but it was much less detailed and, according to John R. Womersley, Superintendent of the NPL Mathematics Division:
"It contains a number of ideas
which are Dr. Turing's own".
Although ACE was a feasible design, the effect of the Official Secrets Act surrounding the wartime work at Bletchley Park made it impossible for Turing to explain the basis of his analysis of how a computer installation involving human operators would work.
This led to delays in starting the project, and he became disillusioned. In late 1947 he returned to Cambridge for a sabbatical year during which he produced a seminal work on Intelligent Machinery that was not published during his lifetime.
While he was at Cambridge, the Pilot ACE was being built in his absence. It executed its first program on the 10th. May 1950, and a number of later computers around the world owe much to it, including the English Electric DEUCE and the American Bendix G-15.
The full version of Turing's ACE was not built until after his death.
In 1948, Turing was appointed reader in Mathematics at the Victoria University of Manchester. A year later, he became deputy director of the Computing Machine Laboratory, where he worked on software for one of the earliest stored-program computers—the Manchester Mark 1.
Turing wrote the first version of the Programmer's Manual for this machine, and was recruited by Ferranti as a consultant in the development of their commercialised machine, the Ferranti Mark 1. He continued to be paid consultancy fees by Ferranti until his death.
-- The Turing Test
During this time, Alan continued to do more abstract work in mathematics, and in "Computing Machinery and Intelligence" (Mind, October 1950), Turing addressed the problem of artificial intelligence, and proposed an experiment that became known as the Turing Test.
The Turing Test was an attempt to define a standard for a machine to be called "intelligent". The idea was that a computer could be said to "think" if a human interrogator could not tell it apart, through conversation, from a human being.
In the paper, Turing suggested that rather than building a program to simulate the adult mind, it would be better to produce a simpler one to simulate a child's mind, and then to subject it to a course of education.
A reversed form of the Turing test is widely used on the Internet; the CAPTCHA test is intended to determine whether the user is a human or a computer.
In 1948, Turing, working with his former undergraduate colleague, D. G. Champernowne, began writing a chess program for a computer that did not yet exist. By 1950, the program was completed and dubbed the Turochamp.
In 1952, he tried to implement it on a Ferranti Mark 1, but lacking enough power, the computer was unable to execute the program. Instead, Turing "ran" the program by flipping through the pages of the algorithm and carrying out its instructions on a chessboard, taking about half an hour per move. The game was recorded.
According to Garry Kasparov, Turing's program "played a recognizable game of chess". The program lost to Turing's colleague Alick Glennie, although it is said that it won a game against Champernowne's wife, Isabel.
The Turing Test was a significant, characteristically provocative, and lasting contribution to the debate regarding artificial intelligence, which continues after more than half a century.
-- Pattern Formation and Mathematical Biology
When Turing was 39 years old in 1951, he turned to mathematical biology, finally publishing his masterpiece "The Chemical Basis of Morphogenesis" in January 1952.
Alan was interested in morphogenesis, the development of patterns and shapes in biological organisms. He suggested that a system of chemicals reacting with each other and diffusing across space, termed a reaction–diffusion system, could account for the main phenomena of morphogenesis.
He used systems of partial differential equations to model catalytic chemical reactions. For example, if a catalyst A is required for a certain chemical reaction to take place, and if the reaction produced more of the catalyst A, then we say that the reaction is autocatalytic, and there is positive feedback that can be modelled by nonlinear differential equations.
Turing discovered that patterns could be created if the chemical reaction not only produced catalyst A, but also produced an inhibitor B that slowed down the production of A.
If A and B then diffused through the container at different rates, then you could have some regions where A dominated, and some where B did.
In order to calculate the extent of this, Turing would have needed a powerful computer, but these were not freely available in 1951, so he had to use linear approximations to solve the equations by hand.
These calculations gave the right qualitative results, and produced, for example, a uniform mixture that oddly enough had regularly spaced fixed red spots.
The Russian biochemist Boris Belousov had performed experiments with similar results, but could not get his papers published because of the contemporary prejudice that any such thing violated the second law of thermodynamics.
Belousov was not aware of Turing's paper in the Philosophical Transactions of the Royal Society.
Although published before the structure and role of DNA was understood, Turing's work on morphogenesis remains relevant today, and is considered a seminal piece of work in mathematical biology.
-- Stripey Cats and Spotty Cats
One of the early applications of Turing's paper was the work by James Murray explaining spots and stripes on the fur of cats, large and small.
Further research in the area suggests that:
"Turing's work can partially explain the
growth of feathers, hair follicles, the
branching pattern of lungs, and even the
left-right asymmetry that puts the heart
on the left side of the chest".
In 2012, Sheth et al. found that in mice, removal of Hox genes causes an increase in the number of digits without an increase in the overall size of the limb, suggesting that Hox genes control digit formation by tuning the wavelength of a Turing-type mechanism.
Later papers were not available until the Collected Works of A. M. Turing was published in 1992.
A study conducted in 2023 confirmed Turing's mathematical model hypothesis. Presented by the American Physical Society, the experiment involved growing chia seeds in even layers within trays, later adjusting the available moisture.
Researchers experimentally tweaked the factors which appear in the Turing equations, and, as a result, patterns resembling those seen in natural environments emerged.
This is believed to be the first time that experiments with living vegetation have verified Turing's mathematical insight.
-- Alan Turing's Personal Life
-- Lost Treasure
In the 1940's, Turing became worried about losing his savings in the event of a German invasion. In order to protect them, he bought two silver bars weighing 3,200 oz (90 kg) and worth £250 (in 2022, £48,000) and buried them in a wood near Bletchley Park.
Upon returning to dig them up, Turing found that he was unable to break his own code describing where exactly he had hidden them. This, along with the fact that the area had been renovated, meant that he never regained the silver.
-- The Engagement of Alan Turing
In 1941, Turing proposed marriage to Hut 8 colleague Joan Clarke, a fellow mathematician and cryptanalyst, but their engagement was short-lived.
After admitting his homosexuality to his fiancée, who was reportedly "unfazed" by the revelation, Turing decided that he could not go through with the marriage.
-- Alan Turing's Homosexuality and Indecency Conviction
In December 1951, Turing met Arnold Murray, a 19-year-old unemployed man. Turing was walking along Manchester's Oxford Road when he met Murray just outside the Regal Cinema and invited him to lunch.
The two agreed to meet again, and in January 1952 began an intimate relationship. On the 23rd. January, Turing's house was burgled. Murray told Turing that he and the burglar were acquainted, and Turing reported the crime to the police.
During the investigation, he acknowledged a sexual relationship with Murray. Homosexual acts were criminal offences in the United Kingdom at that time, and both men were charged with "gross indecency" under the Criminal Law Amendment Act of 1885.
Initial committal proceedings for the trial were held on the 27th. February 1952 during which Turing's solicitor reserved his defence, i.e., did not argue or provide evidence against the allegations. The proceedings were held at the Sessions House in Knutsford.
Turing was later convinced by his brother and solicitor to enter a plea of guilty. The case, Regina v. Turing and Murray, was brought to trial on the 31st. March 1952.
Turing was convicted, and given a choice between imprisonment and probation. His probation would be conditional on his agreement to undergo hormonal physical changes designed to reduce libido, known as "chemical castration".
He accepted the option of injections of what was then called stilboestrol (now known as diethylstilbestrol or DES), a synthetic oestrogen; this feminization of his body was continued for the course of one year.
The treatment rendered Turing impotent and caused breast tissue to form. In a letter, Turing wrote that:
"No doubt I shall emerge from it all
a different man, but quite who I've
not found out".
Murray was given a conditional discharge.
-- Consequences of Alan Turing's Conviction
Turing's conviction led to the removal of his security clearance and barred him from continuing with his cryptographic consultancy for the Government Communications Headquarters (GCHQ), though he kept his academic job.
Alan's trial took place only months after the defection to the Soviet Union of Guy Burgess and Donald Maclean in summer 1951, after which the Foreign Office started to consider anyone known to be homosexual as a potential security risk.
Turing was denied entry into the United States after his conviction in 1952, but was free to visit other European countries.
In the summer of 1952 he visited Norway which was more tolerant of homosexuals. Among the various men he met there was one named Kjell Carlson. Kjell intended to visit Turing in the UK, but the authorities intercepted Kjell's postcard detailing his travel arrangements, and were able to intercept and deport him before the two could meet.
It was also during this time that Turing started consulting a psychiatrist, Dr Franz Greenbaum, with whom he got on well and who subsequently became a family friend.
-- The Death of Alan Turing
On the 8th. June 1954, Turing's housekeeper found him dead at his house at 43 Adlington Road, Wilmslow. A post mortem was held that evening; this determined that he had died the previous day at the age of 41, with cyanide poisoning cited as the cause of death.
When his body was discovered, an apple lay half-eaten beside his bed, and although the apple was not tested for cyanide, it was speculated that this was the means by which Turing had consumed a fatal dose.
Turing's brother, John, identified the body the following day and took the advice given by Dr. Greenbaum to accept the verdict of the inquest, as there was little prospect of establishing that the death was accidental.
The inquest was held the following day, which determined the cause of death to be suicide. Turing's remains were cremated at Woking Crematorium just two days later on the 12th. June 1954, with just his mother, brother, and Lyn Newman attending, and his ashes were scattered in the gardens of the crematorium, just as his father's had been.
Turing's mother was on holiday in Italy at the time of his death and returned home after the inquest. She never accepted the verdict of suicide.
Philosopher Jack Copeland has questioned various aspects of the coroner's historical verdict. He suggested an alternative explanation for the cause of Turing's death: the accidental inhalation of cyanide fumes from an apparatus used to electroplate gold onto spoons.
The potassium cyanide was used to dissolve the gold. Turing had such an apparatus set up in his tiny spare room. Copeland noted that the autopsy findings were more consistent with inhalation than with ingestion of the poison.
Turing's mother believed that the ingestion was accidental, resulting from her son's careless storage of laboratory chemicals.
Turing also habitually ate an apple before going to bed, and it was not unusual for the apple to be discarded half-eaten.
Furthermore, Turing had reportedly borne his legal setbacks and hormone treatment (which had been discontinued a year previously) "with good humour," and had shown no sign of despondency before his death.
He had even set down a list of tasks that he intended to complete upon returning to his office after the holiday weekend.
Turing's biographer Andrew Hodges theorised that Turing deliberately left the nature of his death ambiguous in order to shield his mother from the knowledge that he had killed himself.
Doubts on the suicide thesis have been also cast by John W. Dawson Jr. who, in his review of Hodges' book, recalls "Turing's vulnerable position in the Cold War political climate," and points out that:
"Turing was found dead by a maid, who
discovered him 'lying neatly in his bed'—
hardly what one would expect of a man
fighting for life against the suffocation
induced by cyanide poisoning."
Turing had given no hint of suicidal inclinations to his friends, and had made no effort to put his affairs in order.
Hodges and a later biographer, David Leavitt, have both speculated that Turing was re-enacting a scene from the Walt Disney film Snow White and the Seven Dwarfs (1937), his favourite fairy tale.
Both men noted that (in Leavitt's words):
"He took an especially keen pleasure
in the scene where the Wicked Queen
immerses her apple in the poisonous
brew".
It has also been suggested that Turing's belief in fortune-telling may have caused his depressed mood. As a youth, Turing had been told by a fortune-teller that he would be a genius.
In mid-May 1954, shortly before his death, Turing again decided to consult a fortune-teller during a day-trip to St. Annes-on-Sea with the Greenbaum family. According to the Greenbaums' daughter, Barbara:
"It was a lovely sunny day and Alan was in a
cheerful mood and off we went ... Then he
thought it would be a good idea to go to the
Pleasure Beach at Blackpool.
We found a fortune-teller's tent, and Alan
said he'd like to go in, so we waited around
for him to come back ...
And this sunny, cheerful visage had shrunk
into a pale, shaking, horror-stricken face.
Something had happened. We don't know
what the fortune-teller said, but he obviously
was deeply unhappy.
I think that was probably the last time we
saw him before we heard of his suicide."
-- Government Apology and Pardon
In August 2009, British programmer John Graham-Cumming started a petition urging the British government to apologise for Turing's prosecution as a homosexual. The petition received more than 30,000 signatures.
The prime minister, Gordon Brown, acknowledged the petition, releasing a statement on the 10th. September 2009 apologising, and describing the treatment of Turing as "appalling":
"Thousands of people have come together to
demand justice for Alan Turing and recognition
of the appalling way he was treated.
While Turing was dealt with under the law of the
time and we can't put the clock back, his treatment
was of course utterly unfair, and I am pleased to
have the chance to say how deeply sorry I and we
all are for what happened to him ...
So 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 December 2011, William Jones and his member of Parliament, John Leech, created an e-petition requesting that the British government pardon Turing for his conviction of gross indecency:
"We ask the HM Government to grant a pardon
to Alan Turing for the conviction of gross
indecency. In 1952, he was convicted of gross
indecency with another man, and was forced to
undergo so-called "organo-therapy"—chemical
castration.
Two years later, he killed himself with cyanide,
aged just 41.
Alan Turing was driven to a terrible despair and
early death by the nation he'd done so much to
save.
This remains a shame on the British government
and British history. A pardon can go some way to
healing this damage. It may act as an apology to
many of the other gay men, not as well-known as
Alan Turing, who were subjected to these laws."
The petition gathered over 37,000 signatures, and was submitted to Parliament by the Manchester MP John Leech, but the request was discouraged by Justice Minister Lord McNally, who said:
"A posthumous pardon was not considered
appropriate as Alan Turing was properly convicted
of what at the time was a criminal offence.
He would have known that his offence was against
the law, and that he would be prosecuted. It is tragic
that Alan Turing was convicted of an offence that
now seems both cruel and absurd—particularly
poignant given his outstanding contribution to the
war effort.
However, the law at the time required a prosecution
and, as such, long-standing policy has been to accept
that such convictions took place and, rather than trying to
alter the historical context and to put right what cannot
be put right, ensure instead that we never again return
to those times."
Nevertheless, John Leech, the MP for Manchester Withington (2005–15), submitted several bills to Parliament, and led a high-profile campaign to secure the pardon.
Leech made the case in the House of Commons that Turing's contribution to the war made him a national hero, and that it was "ultimately just embarrassing" that the conviction still stood. Leech continued to take the bill through Parliament and campaigned for several years, gaining the public support of numerous leading scientists, including Stephen Hawking.
At the British premiere of a film based on Turing's life, The Imitation Game, the producers thanked Leech for bringing the topic to public attention and securing Turing's pardon.
Leech is now regularly described as the "architect" of Turing's pardon, and subsequently the Alan Turing Law, which went on to secure pardons for 75,000 other men and women convicted of similar crimes.
On the 26th. July 2012, a bill was introduced in the House of Lords to grant a statutory pardon to Turing.
Late in the year in a letter to The Daily Telegraph, the physicist Stephen Hawking and 10 other signatories including the Astronomer Royal Lord Rees, President of the Royal Society Sir Paul Nurse, Lady Trumpington (who worked for Turing during the war) and Lord Sharkey (the bill's sponsor) called on Prime Minister David Cameron to act on the pardon request.
The government indicated that it would support the bill, and it passed its third reading in the House of Lords in October 2012.
However at the bill's second reading in the House of Commons on the 29th. November 2013, Conservative MP Christopher Chope objected to the bill, delaying its passage. The bill was due to return to the House of Commons on the 28th. February 2014, but before the bill could be debated in the House of Commons, the government elected to proceed under the royal prerogative of mercy.
On the 24th. December 2013, Queen Elizabeth II signed a pardon for Turing's conviction for gross indecency, with immediate effect. Announcing the pardon, Lord Chancellor Chris Grayling said:
"Turing deserves to be remembered and
recognised for his fantastic contribution
to the war effort, and not for his later
criminal conviction."
The Queen pronounced Turing to be pardoned in August 2014. It was only the fourth royal pardon granted since the conclusion of the Second World War. Pardons are normally granted only when the person is technically innocent, and a request has been made by the family or other interested party; neither condition was met in regard to Turing's conviction.
In September 2016, the government announced its intention to expand this retroactive exoneration to other men convicted of similar historical indecency offences, in what was described as an "Alan Turing law".
The Alan Turing law is now an informal term for the law in the United Kingdom, contained in the Policing and Crime Act 2017, which serves as an amnesty law to retroactively pardon men who were cautioned or convicted under historical legislation that outlawed homosexual acts.
On the 19th. July 2023, following an apology to LGBT veterans from the UK Government, Defence Secretary Ben Wallace suggested that Turing should be honoured with a permanent statue on the fourth plinth of Trafalgar Square, describing Turing as:
"Probably the greatest war hero, in my book,
of the Second World War, whose achievements
shortened the war, saved thousands of lives,
helped defeat the Nazis.
And his story is a sad story of a society and
how it treated him."
Gordon Welchman
For more interesting information relating to Gordon Welchman, please search for the tag 68HST77
Tommy Flowers
For more interesting information relating to Tommy Flowers, please search for the tag 89TBR42
