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CodeBreaker
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Codebreaker
Alan Turning’s Life & legacy
Contents: 36. Can machines think?
Introduction: Prologue
8.
Introduction: About CodeBreaker
10. Introduction:
40. A matter of life & death
46. Programming computing today
About Alan Turing
16. Computing before computing
52. Eniac 19,000
20. Alan Turning’s War
54. Index
28.
ACE
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7.
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Codebreaker
Alan Turning’s Life & legacy
Contents: 36. Can machines think?
Introduction: Prologue
8.
Introduction: About CodeBreaker
10. Introduction:
40. A matter of life & death
46. Programming computing today
About Alan Turing
16. Computing before computing
52. Eniac 19,000
20. Alan Turning’s War
54. Index
28.
ACE
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7.
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Alan Turning
About
Into
Alan turing’s life and legacy. The second world war was not just fought with bombs and shells. it was a war of electronic whispers
and
secret
radio
signals
snatched
from the ether. At bletchley park, buckinghamshire, thousands of men and women laboured night and day to crack these coded radio messages which held germany’s most secret plans. one
of
these
codebreakers
was
alan
turing.
but turing was not just a codebreaker. born 100 years ago, this british mathematician was also a philosopher and computing pioneer who grappled with some of the fundamental problems of life itself. yet his own life was cut tragically short. in 1954 he was found dead, poisoned
by
cyanide.
he
was
41.
throughout
his life, turing broke the codes of science and society. his ideas helped shape the modern world – but it was a world he did not live
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to see. this is his story.
The exhibition: Codebreaker is an exhibition developed by the Science Museum to celebrate the centenary of the birth of this pioneering British figure. Alan Turing is most widely known for his critical involvement
in
the
codebreaking
at
Bletchley
Park
during the Second World War. But Alan Turing was not just a codebreaker. This British mathematician was also a philosopher and computing pioneer who grappled with the fundamental problems of life itself. His ideas have helped shape the modern world, including early computer programming and even the seeds of artificial intelligence. This exhibition tells the story of Turing and his most important ideas. At the heart of the exhibition is the Pilot ACE computer, built to Turing’s ground-breaking design. Alongside this remarkable machine is a sequence of exhibits showcasing Turing’s breadth of talent. Together with interactive exhibits, personal recollections and a wealth of historic imagery, the exhibition offers an absorbing retrospective view of one of
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Britain’s greatest twentieth-century thinkers.
About
Exhibition
The exhibition is arranged in six sections:
4
5
ENTRANCE
2 6
3 1
ENTRANCE
ENTRANCE
1. Computing before computers 2. Alan Turing’s war 3. ACE – the Automatic Computing Engine 4. Can machines think? 5. A matter of life and death 6. Programming computers today
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Lift
About Alan Turning: Alan
Mathison
Turing
was
a
British
mathematician,
logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, giving a formalisation of the concepts of “algorithm”
and
“computation”
with
the
Turing
ma-
chine, which can be considered a model of a general purpose computer. Turing is widely considered to be the father of computer science and artificial intelligence. During World War II, Turing worked for the Government Code and Cypher School (GC&CS) at Bletchley Park, Britain’s codebreaking centre. For a time he was head of Hut 8, the section responsible for German naval cryptanalysis. He devised a number of techniques for breaking German ciphers, including the method of the bombe, an electromechanical machine that could find settings for the Enigma machine. After the war, he worked at the National Physical Laboratory, where he designed the ACE, one of the first designs for a stored-program computer. In 1948 Turing joined Max Newman’s Computing Laboratory at Manchester University, where he assisted in the development of the Manchester computers and became interested in mathematical biology. He wrote a paper on the chemical basis of morphogenesis, and predicted oscillating chemical reactions such as the Belousov– Zhabotinsky reaction, which were first observed in the 1960s.
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Turing’s homosexuality resulted in a criminal prosecution
in
1952,
when
homosexual
acts
were
still
illegal in the United Kingdom. He accepted treatment with female hormones (chemical castration) as an alternative to prison. Turing died in 1954, just
About
Alan Turning
over two weeks before his 42nd birthday, from cyanide poisoning. An inquest determined that his death was suicide; his mother and some others believed his death was accidental. On 10 September 2009, following an Internet campaign, British Prime Minister Gordon Brown made an official public apology on behalf of the British government for “the appalling way he was treated.” As of May 2012, a private member’s bill was put before the House of Lords which would grant Tu-
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ring a statutory pardon if enacted.
Aboout Alan Turning: Turing was born in London while his father was on leave from his position with the Indian Civil Service (ICS) at Chhatrapur, Odisha, in British India. Turing’s fathevr, Julius Mathison Turing (1873–1947), was the son of a clergyman from a Scottish family of merchants which had been based in the Netherlands and included a baronet. Julius’s wife, Alan’s mother, was Ethel Sara (née Stoney; 1881–1976), daughter of Edward Waller Stoney, chief engineer of the Madras Railways. The Stoneys were a Protestant Anglo-Irish gentry family from both County Tipperary and County Longford, while Ethel herself had spent much of her childhood in County Clare. Julius’ 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 England, so they moved to Maida Vale, London, where Turing was born on 23 June 1912, as recorded by a blue plaque on the outside of the house of his birth, later the Colonnade Hotel. His father’s civil service commission was still active, and during Turing’s childhood years his parents travelled between Hastings in England and India, leaving their two sons to stay with a retired Army couple. Very early in life, Turing showed signs of the genius he was later to display prominently. His
parents
enrolled
him
at
St
Michael’s,
a
day
school at 20 Charles Road, St Leonards-on-Sea, at the age of six. The headmistress recognised his talent
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early on, as did many of his subsequent educators. In 1926, at the age of 13, he went on to Sherborne School, a well known independent school in the market town of Sherborne in Dorset. The first day of term coincided with the 1926 General Strike in Britain,
About
Alan Turning
but so determined was he to attend that he rode his bicycle unaccompanied more than 60 miles (97 km) from Southampton to Sherborne, stopping overnight at an inn. King’s College, Cambridge, where the computer room is named after Turing, who became a student there in 1931 and a Fellow in 1935 Turing’s natural inclination toward 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. In 1928, aged 16, Turing encountered Al-
King’s College, Cambridge
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bert Einstein’s work; not only did he grasp it, but
he extrapolated Einstein’s questioning of Newton’s laws of motion from a text in which this was never made explicit. At Sherborne, Turing formed an important friendship with fellow pupil Christopher Morcom, which provided inspiration in Turing’s future endeavours. However, the friendship 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. This event shattered Turing’s religious faith. He became an atheist and adopted the conviction that all phenomena, including the workings of the human brain, must be materialistic, but he still believed in the survival of the spirit after
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death.
Alan Turning
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About
Computers before computing. When we talk about computers today, we usually mean electronic devices that can be programmed to carry out many different tasks – socalled universal stored-program computers. The first were built in the 1940s. But there were ‘computers’ before this. In some cases, the word simply meant ‘person who computes’, and many were women working with simple aids on repetitive calculations. In other cases, one-off devWices computed specific problems, such as aiming aircraft bombs or solving certain mathematical equations. Alan Turing wrote a seminal mathematics paper in 1936 which came to be seen as a theoretical basis for today’s computers. In it he imagined a single machine that could compute any problem, effectively uniting all these early problem-specific ‘computers’ into one universal device.
When we talk about computers today, we usually mean electronic devices that can be programmed to carry out many different tasks – socalled universal stored-program computers. The first were built in the 1940s. But there were ‘computers’ before this. In some cases, the word simply meant ‘person who computes’, and many were women working with simple aids on repetitive calculations. In other cases, one-off devWices computed specific problems, such as aiming aircraft bombs or solving certain mathematical equations.
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We usually mean electronic devices that can be programmed to carry out many different tasks – so-called universal stored-program computers.
Computers before computing
Calculating machine used at the Scientific Computing Service, c. 1939 -Â
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This calculating machine was used at the Scientific Computing Service (SCS) from about 1939 to 1965, when it was transferred to the physics and astronomy department of University College London. It was given to the Science Museum in 1981 by Beryl Waters, a computer at the SCS. The production of mechanical calculators came to a stop in the middle of the 1970s closing an industry that had lasted for 120 years. There for it is highly established as being one of the most influencial pieces of machinery to shape our modern world.
Aircraft bomb-aiming mechanical computer, c. 1942 -
bomb-aiming computer
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This ‘bombsight’ mechanical computer was used on board Lancaster and other aircraft in the Second World War. It was used to aim the bombs, taking factors such as aircraft height and speed and weather conditions into account. Unlike electronic computers, which are programmed using software, mechanical computers carried out their computations according to the physical shape and design of the mechanism, which can be seen at the back of the machine. The gears, linkages and cams literally embodied the equations that needed to be solved.
Computers before computing
Meccano differential analyser by Douglas Hartree, rebuilt c. 1947 -
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Meccano analyser
This is a reconstructed machine for solving complex mathematical equations, originally made in 1934 by mathematician Douglas Hartree and his student Arthur Porter from the construction toy Meccano. It was one of the first electromechanical computers. It used the movement of shafts and gears as the physical analogue of the mathematical relationships. Later digital computers electronically manipulated the numerical values themselves.
Alan Turning’s War In the Second World War armed forces communicated using encrypted radio messages. Britain was desperate to understand the German messages, so a codebreaking institution was set up at Bletchley Park to crack them. It was a race against the clock. Alan Turing worked at Bletchley on a type of encryption known as ‘Enigma’ after the machines used to create it. He developed sophisticated decryption processes and, with colleague Gordon Welchman, devised machines called ‘bombes’ that could break the code on an industrial scale. Some 200 bombes were built at a secret facility nearby. They operated around the clock at several sites including Bletchley Park itself, tended by the Women’s Royal Naval Service. The intelligence gained from the Enigma messages was vital to Britain’s success in the war.
Early military Enigma machine, 1937 The secret Enigma codebreaking work carried out at Bletchley Park during the Second World War became public knowledge in the 1970s, following publication of some of the details. Interest in the story grew rapidly. In the late 1970s the Science Museum began to negotiate with the Government Communications Headquarters (GCHQ), the successor to Bletchley Park, on acquiring an Enigma machine for public display. Following much consideration, this German military machine was donated to the Museum in 1980. It is believed to have been the first shown to the public.
Captured German U-boat Enigma machine, 1944
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In 1942 the German navy introduced more complex Enigma machines for use by its submarine U-boats. Radio messages between command stations and the submarines contained vital intelligence about attacks
Alan Turning’s War
on British and Allied supply ships, which carried food, armaments and fuel vital for Britain to continue the war. Germany considered this new Enigma unbreakable. For ten months the British codebreakers seemed defeated. But Enigma material seized from a German U-boat gave Turing and his team the breakthrough they needed, and soon the U-boat messages could again be read.
Enigma machine from the 2001 film ‘Enigma’, 1930s -
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Public interest in the Enigma story grew rapidly after details started to emerge in the 1970s. Several literary, theatrical and film adaptations of the story were made. In 2001 musician and film producer Sir Michael Jagger co-produced ‘Enigma’, a fictionalised account of the warwinning work at Bletchley Park starring Kate Winslet and Dougray Scott. It was a critical and popular success, sharing the inspirational story with a wide audience. This Enigma machine featured in the film, and was lent by Jagger to the project. Alan Turing worked at Bletchley on a type of encryption known as ‘Enigma’ after the machines used to create it. He developed sophisticated decryption processes and, with colleague Gordon Welchman, devised machines called ‘bombes’ that could break the code on an industrial scale. Some 200 bombes were built at a secret facility nearby.
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Enigma roller
Enigma machine
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Alan Turning’s War
Bletchley Park Enigma working aids, 1939–45 These devices were amongst many made by codebreakers working at Bletchley Park on the Enigma system. Their work was highly mathematical, searching for patterns and other ways to crack the coded messages. To speed up their work they devised all sorts of homemade working aids such as these. One may well have been a teaching aid for other codebreakers working on the Enigma problem. By 1944 some 10,000 people worked at the site. Julius’ 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 England, so they moved to Maida Vale, London, where Turing was born on 23 June 1912, as recorded by a blue plaque on the outside of the house of his birth, later the Colonnade Hotel. His father’s civil service commission was still active, and during Turing’s childhood years his parents travelled between Hastings in England and India, leaving their two sons to stay with a retired Army couple. Very early in life, Turing showed signs of the genius he was later to display prominently.
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After the war, he worked at the National Physical Laboratory, where he designed the ACE, one of the first designs for a stored-program computer. In 1948 Turing joined Max Newman’s Computing Laboratory at Manchester University, where he assisted in the development of the Manchester computers and became interested in mathematical biology. He wrote a paper on the chemical basis of morphogenesis, and predicted oscillating chemical reactions such as the Belousov–Zhabotinsky reaction, which were first observed in the 1960s. The secret Enigma codebreaking work carried out at Bletchley Park during the Second World War became public knowledge in the 1970s, following publication of some of the details. Interest in the story grew rapidly. In the late 1970s the Science Museum began to negotiate with
Alan Turning’s War
the Government Communications Headquarters (GCHQ), the successor to Bletchley Park, on acquiring an Enigma machine for public display. Following much consideration, this German military machine was donated to the Museum in 1980. It is believed to have been the first shown to the public. Public interest in the Enigma story grew rapidly after details started to emerge in the 1970s. Several literary, theatrical and film adaptations of the story were made. In 2001 musician and film producer Sir Michael Jagger co-produced ‘Enigma’, a fictionalised account of the warwinning work at Bletchley Park starring Kate Winslet and Dougray Scott. It was a critical and popular success, sharing the inspirational story with a wide audience. This Enigma machine featured in the film, and was lent by Jagger to the project. Alan Turing worked at Bletchley on a type of encryption known as ‘Enigma’ after the machines used to create it. He developed sophisticated decryption processes and, with colleague Gordon Welchman, devised machines called ‘bombes’ that could break the code on an industrial scale. Some 200 bombes were built at a secret facility nearby. In 1936, Turing went to Princeton University in America, returning to England in 1938. He began to work secretly part-time for the British cryptanalytic department, the Government Code and Cypher School. On the outbreak of war he took up full-time work at its headquarters, Bletchley Park.
After the war, Turing turned his thoughts to the development of a machine that would logically process information. He worked first for the National Physical Laboratory (1945-1948). His plans were dismissed by his colleagues and the lab lost out on being the first to design a digital computer. It is thought that Turing’s blueprint would have secured them the honour, as his machine was capable of computation speeds higher
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Here he played a vital role in deciphering the messages encrypted by the German Enigma machine, which provided vital intelligence for the Allies. He took the lead in a team that designed a machine known as a bombe that successfully decoded German messages. He became a well-known and rather eccentric figure at Bletchley.
than the others. In 1949, he went to Manchester University where he directed the computing laboratory and developed a body of work that helped to form the basis for the field of artificial intelligence. In 1951 he was elected a fellow of the Royal Society.
Wheels from a bombe checking machine, 1940s The bombes were manufactured on a secret production line at the British Tabulating Machines factory in Letchworth, near Bletchley. Each one contained dozens of wheels similar to these. Different wiring configurations were tested by the bombes at high speed until a possible match to that day’s Enigma settings had been found. The device would then stop, and the settings were checked on a smaller ‘checking machine’. After the war ended the bombes were broken up and destroyed. However, these wheels from a checking machine survived, leaving us a tangible reminder of Turing’s wartime achievements.
Punched-card machine by British Tabulating Machines, c. 1930 -
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Bletchley Park’s work also involved industrialscale information-handling to manage the huge number of intercepted German messages. In the 1930s commercial data-processing was the preserve of punched-card machines. Many British Tabulating Machines (BTM) devices, branded ‘Hollerith’ after their inventor, were installed at Bletchley Park. This identical machine was given to the Science Museum by BTM in 1932.
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Alan Turning’s War
ACE – the Automatic Computing Engine After the Second World War, Alan Turing was asked to put his theories and experience into action by developing a ground-breaking computer at the government’s National Physical Laboratory. His first specifications were written in 1945. Following administrative delays, Turing left the project in 1948, but a trial version (known as Pilot ACE) was completed in 1950. It is now the most significant Turing artefact in existence. Yet the Pilot ACE computer was more than just a trial. It was used for several years by a variety of external customers desperate to employ its computing power. It also became a public celebrity, referred to as Turing’s ‘electronic brain.
The Pilot ACE computer, 1950 This was one of the first electronic ‘universal’ computers. Its fundamental design was by Alan Turing, who wrote the specification in 1945 while working at the government’s National Physical Laboratory. It was completed in 1950. Turing’s idea was to build a large computer, to be known as the Automatic Computing Engine or ACE. But slow progress, coupled with changes in project direction imposed on Turing, left him deeply frustrated, and he quit in 1948. This small-scale trial version, called Pilot ACE, was completed in his absence
Demonstrating the ‘electronic brain’, 1950
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The Pilot ACE computer, conceived by Alan Turing in 1945, was both fast and complicated. But this caused a problem. How could its operation be demonstrated to non-specialists? The answer lay in this specially made simulator, which showed how binary digits were manipulated by the computer – but at much slower speed. In January 1950 it was shown at the Royal Society’s library in central London.
Automatic Computing Engine
Wreckage from a Comet jet aircraft, 1954 Alan Turing’s pioneering electronic computer immediately proved its power in a life-saving race against time, following a series of fatal air crashes. Known as Comets, the world’s first jet airliners entered passenger service in 1952 to huge public acclaim. Two years later, a Comet crashed into the Mediterranean near Italy, killing all 35 on board. This is part of its fuselage. Wreckage was recovered from the seabed and sent to the Royal Aircraft Establishment in Farnborough where, along with an undamaged Comet, it was subjected to exhaustive testing. The investigation relied on a huge amount of high-speed computation provided by the Pilot ACE computer.
Model of vitamin B12 by Dorothy Hodgkin, c. 1957 -
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By the 1950s electronic computers, including Alan Turing’s Pilot ACE, were being pressed into service by scientists struggling to unlock the patterns of the body’s own chemistry. Dorothy Hodgkin was a chemist who developed pioneering methods for understanding the structure of complex molecules such as vitamins and insulin, which are crucial in the functioning of the human body. This model of vitamin B12 was presented by her to the Science Museum in 1959. It represented the culmination of years of study, supported by computation carried out by the Pilot ACE and several other computers.
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The Pilot ACE computer
Automatic Computing Engine
Wreckage from aircraft
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Demonstrating the ‘electronic brain’
Dorothy Hodgkin (1910 - 1994) [Et Al]. XRay Crystallographic Evidence On The Structure Of Vitamin B12. (Nature 1954, 174, 1169-1171.)
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First Edition, Journal Issue Of Dorothy Hodgkin’s 1954 Initial Determination Of The Structure Of Vitamin B12, A Dietary Component Important To Human Health. For Her Contributions To The X-Ray Analysis Of Natural Products Such As Steroids, Antibiotics, And Proteins, Hodgkin Was Awarded The Nobel Prize In Chemistry For 1964. William L. Bragg Described The B12 Study As The Crystallographic Equivalent To “Breaking The Sound Barrier.”
Model of vitamin -
Dorothy Hodgkin’s Theorem
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Automatic Computing Engine
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Model of vitamin -
Dorothy Hodgkin’s Theorem
Page 35.
Automatic Computing Engine
Can machines think? In 1927, aged 14, Alan Turing began a close friendship with a boy at his school, Christopher Morcom. Three years later, Morcom died, aged 18, from tuberculosis. While grieving, Turing wrote a short essay expressing his belief that the human spirit can live outside the body. Throughout the rest of his life, Turing grappled with ideas about human thought. As he developed electronic computers in the 1940s and 1950s, he debated whether machines could be made to think like people, and published a seminal paper on the subject. Games such as chess formed a crucial part of this early work, with Turing and others writing computer versions. One of Turing’s protégés, Dietrich Prinz, also built an electrical ‘logic machine’, inspired by a Victorian device made 80 years before. Others also attempted to simulate thought processes in machines resembling animals. These ‘thinking machines’ quickly captured public interest.
Letter from Alan Turing to Mrs Morcom, 1930 Christopher Morcom, Alan Turing’s teenage friend, died in February 1930 from tuberculosis. Turing was heartbroken, as he was devoted to Morcom. Shortly after, Turing wrote this letter to Morcom’s mother to express his condolences. He made clear the intensity of his feelings for Morcom, and explained, ‘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.’
Letter from Alan Turing to Mrs Morcom, 1930
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Christopher Morcom, Alan Turing’s teenage friend, died in February 1930 from tuberculosis. Turing was heartbroken, as he was devoted to Morcom. Shortly after, Turing wrote this letter to Morcom’s mother to
Can machines think?
express his condolences. He made clear the intensity of his feelings for Morcom, and explained, ‘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.’
‘Impressions of Chris’, by Alan Turing, 1930 Four months after Christopher Morcom’s death in 1930, Turing sent Mrs Morcom this set of recollections about their friendship, entitled ‘Impressions of Chris’. In it he admitted, ‘Of course I simply worshipped the ground he trod on – a thing which I did not make much attempt to disguise, I am sorry to say.’ He also revealed that he had experienced dark premonitions before Morcom died. ‘Some time before Chris’s death’, he explained, ‘I had presentiments about him that were surprising in their accuracy ... That Chris would soon die kept coming to me.’
‘The Nature of Spirit’, by Alan Turing, 1932
Alan Turing wrote this short essay for Mrs Morcom in 1932. In it he expressed complex ideas about the human mind and his belief that it could survive after the death of the body. Certain passages offer a foretaste of the work he published some 20 years later on machine intelligence. ‘Personally’, he wrote, ‘I think that spirit is really eternally connected with matter, but certainly not always by the same kind of body ... 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.’
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-
Electrical logic machine by Dietrich Prinz and Wolfe Mays, 1949 This machine was made at Manchester University by physicist Dietrich Prinz, one of Alan Turing’s protégés, and Wolfe Mays, a 36-year-old philosophy lecturer. It is an electrical device for testing logical propositions, built mostly from RAF spare parts left over from the Second World War, and was unique in Britain at the time. Turing grappled with ideas about human thought. As he developed electronic computers in the 1940s and 1950s, he debated whether machines could be made to think like people, and published a seminal paper on the subject. Games such as chess formed a crucial part of this early work, with Turing and others writing computer versions. One of Turing’s protégés, Dietrich Prinz, also built an electrical ‘logic machine’, inspired by a Victorian device made 80 years before. Others also attempted to simulate thought processes in machines resembling animals. These ‘thinking machines’ quickly captured public interest.
Mechanical logic machine by William Stanley Jevons, 1869
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This Victorian machine profoundly influenced Dietrich Prinz and Wolfe Mays in their construction of the electrical logic machine displayed alongside. It was made in 1869 by William Stanley Jevons, professor of logic at Manchester University, and it performed logical operations mechanically. Turing was heartbroken, as he was devoted to Morcom. Shortly after, Turing wrote this letter to Morcom’s mother to express his condolences. The device would then stop, and the settings were checked on a smaller ‘checking machine’. After the war ended the bombes were broken up and destroyed. However, these wheels from a checking machine survived, leaving us a tangible reminder of Turing’s wartime achievements.
Can machines think?
Cybernetic tortoise by William Grey Walter, c. 1950 -
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Young Alan Turning
This ‘tortoise’ was made by neurologist William Grey Walter as an ‘artificial animal’ to investigate brain function. It travelled around floors, avoiding obstacles, and was attracted to light. Alan Turing knew Grey Walter well, being a fellow member of the influential ‘Ratio Club’ for cybernetics researchers. Four months after Christopher Morcom’s death in 1930, Turing sent Mrs Morcom this set of recollections about their friendship, entitled ‘Impressions of Chris’. In it he admitted, ‘Of course I simply worshipped the ground he trod on – a thing which I did not make much attempt to disguise, I am sorry to say.’ He also revealed that he had experienced dark premonitions before Morcom died. ‘Some time before Chris’s death’, he explained, ‘I had presentiments about him that were surprising in their accuracy ... That Chris would soon die kept coming to me.’
A matter of life & death In 1948, Turing moved to Manchester University to work on a groundbreaking stored-program computer. He used subsequent versions of it to develop mathematical theories of morphogenesis – growth and patterns in plants and animals. His ideas are only today being fully appreciated. Four years later, following a relationship with a local man, Arnold Murray, Turing was arrested under anti-homosexuality legislation and convicted of ‘gross indecency’. At this time doctors were experimenting with ways to ‘treat’ gay people. Given a choice of imprisonment or a one-year course of female hormones, Turing opted for the latter. Nevertheless, during his sentence and for several months afterwards Turing continued to work on his morphogenesis research. Indeed, on the day after his arrest he delivered an important lecture on the subject. Yet, in unexplained circumstances, he was found dead in his bed in 1954. The official verdict was suicide.
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On 8 June 1954, Turing’s cleaner found him dead. He had died the previous day. A post-mortem examination established that the cause of death was cyanide poisoning. 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 a fatal dose was consumed. This suspicion was strengthened when his fascination with Snow White and the Seven Dwarfs was revealed, especially the transformation of the Queen into the Witch and the ambiguity of the poisoned apple.An inquest determined that he had committed suicide, and he was cremated at Woking Crematorium on 12 June 1954. Turing’s ashes were scattered there, just as his father’s had been. Hodges and David Leavitt have suggested that Turing was re-enacting a scene from the 1937 Walt Disney film Snow White, his favourite fairy tale, both noting 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”.This interpretation was supported in an article in The Guardian written by Turing’s friend, the author Alan Garner, in 2011. Professor of Philosophy Jack Copeland has questioned various aspects of the coroner’s historical verdict, suggesting the alternative explanation
A matter of life & death
of the accidental inhalation of cyanide fumes from an apparatus for gold electroplating spoons, using potassium cyanide to dissolve the gold, which Turing had set up in his tiny spare room. Copeland notes that the autopsy findings were more consistent with inhalation than with ingestion of the poison. Turing also habitually ate an apple before bed, and it was not unusual for it to be discarded half-eaten.] In addition, 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 prior to his death, in fact, setting down a list of tasks he intended to complete upon return to his office after the holiday weekend. At the time, Turing’s mother believed that the ingestion was accidental, caused by her son’s careless storage of laboratory chemicals. Biographer Andrew Hodges suggests that Turing may have arranged the cyanide experiment deliberately, to give his mother some plausible deniability.
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Statue of Alan Turning
Some felt suicide was the only option. In parallel, scientists and doctors were experimenting with ways to ‘cure’ gay people or remove their sexual urges. In 1952, Turing was arrested for a sexual relationship with a man, and sentenced to a oneyear course of female hormone treatment. At the time he had been advising the government on secret codebreaking projects, but his security clearance was revoked and he was later placed under surveillance.
Programming the Turing machine In 1948, Alan Turing moved to Manchester University to lead software development for pioneering computers being developed there. He also wrote a programmers’ handbook. Turing had designed his own computer in 1945 at the National Physical Laboratory (NPL), but delays to the project, combined with changes in its management, led him to resign in 1948. In his absence, a cut-down version was only completed in 1950. With these delays, the NPL had lost out on building the world’s first stored-program computer. Manchester beat the NPL to it with their first machine, completed in June 1948, followed quickly by the two larger versions that Turing worked on.
‘His mind had become unbalanced’
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Until the late 1960s, most homosexual acts were illegal. Many people lived in constant fear of being caught by police, prosecuted and either imprisoned or fined. Lives were routinely destroyed in the aftermath of such humiliating events. People were often sacked from their jobs and ostracised by families, friends and the wider community. Some felt suicide was the only option. In parallel, scientists and doctors were experimenting with ways to ‘cure’ gay people or remove their sexual urges. In 1952, Turing was arrested for a sexual relationship with a man, and sentenced to a oneyear course of female hormone treatment. At the time he had been advising the government on secret codebreaking projects, but his security clearance was revoked and he was later placed under surveillance. Two years after his arrest, in 1954, Turing was found dead at his Wilmslow home. The official verdict was suicide from cyanide poisoning, the coroner believing ‘his mind had become unbalanced’.
A matter of life & death
Decoding the patterns of life In February 1952, Alan Turing gave a lecture to the influential ‘Ratio Club’ of academics studying cybernetics, of which he was a member. The subject of his lecture was morphogenesis – the study of pattern formation and growth in nature. The link between mathematics, chemistry and life had long interested Turing, but his access to the powerful new electronic computer at Manchester University gave him the opportunity to explore his ideas in much greater depth.
Bottle of oestrogen female hormone pills, c. 1950 In 1949 neuroscientist Frederick Golla published the first British results of experiments on the use of the female hormone oestrogen to reduce the libido of sexual offenders. Three years later, Alan Turing was sentenced to oestrogen treatment as an alternative to imprisonment for ‘gross indecency’, following a sexual relationship. He had to fight to keep his job at Manchester University.
Reproduction of Alan Turing’s postmortem examination report, 1954
On 7 June 1954, Alan Turing died. The pathologist carried out an examination two days later, finding fluid in Turing’s stomach he believed to be cyanide solution. A pan of the solution had been found bubbling on a stove, and by Turing’s bed was a half-eaten apple. The pathologist concluded that Turing had died from cyanide poisoning, the apple being used to take away some of the taste. The coroner recorded a verdict of suicide.
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A matter of life & death
Programming computers today Alan Turing was fundamental in shaping the practice we now call ‘programming’. In his day, there existed just a handful of computers in the world. Today there are billions, embedded into every aspect of our daily lives, and each one needs to be programmed.A culture of computer programming now exists which involves more people than ever before. It is a rewarding activity open to anyone. This series of interactive exhibits distils down the basic principles of programming. They help reveal how computer programs work.
Looping Programs are sets of instructions for a computer to carry out. But sometimes the same type of instruction can be repeated several times within a program. For instance, a program might need to read information or ‘data’ from input devices such as punched cards a certain number of times. The same section of program might be used to look at each card in turn to see what information it holds. This is one example of ‘looping’. You can explore how looping works at this exhibit.
Variables
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Computer programs are all about handling information and data. The programs contain instructions on what to do with the data. The data can change but the programs will always use them in the same way. For instance, a program might be used to control the movement of a mechanical device such as a robot arm, using motors to set the arm at certain angles. The angles will vary depending on what the user wants the arm to do. The program needs a way to handle these changing quantities. It does so using ‘variables’. You can explore how variables work at this exhibit.
Programming computers today
Conditionals Computers have to make decisions at certain points in the program. For instance, a program might be operating lights in a building. It would have to decide whether to turn each individual light on or off according to rules set by the user. A simple rule might be, ‘if the room is dark, then the light should be switched on’. Or it might be more complicated than that, with lighting being conditional on the room being occupied. These decisions are known as ‘conditionals’. You can explore how conditionals work at this exhibit. A biography published by the Royal Society shortly after Turing’s death, while his wartime work was still subject to the Official Secrets Act, recorded;
Since 1966, the Turing Award has been given annually by the Association for Computing Machinery for technical or theoretical contributions to the computing community. It is widely considered to be the computing world’s highest honour, equivalent to the Nobel Prize. Breaking the Code is a 1986 play by Hugh Whitemore about Alan Turing. The play ran in London’s West End beginning in November 1986 and on Broadway from 15 November 1987 to 10 April 1988. There was also a 1996 BBC television production (broadcast in the United States by PBS). In all three performances Turing was played by Derek Jacobi. The Broadway production was nominated for three Tony Awards including Best Actor in a Play, Best Featured Actor in a Play, and Best Direction of a Play, and for two Drama Desk Awards, for Best Actor and Best Featured Actor.
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Three remarkable papers written just before the war, on three diverse mathematical subjects, show the quality of the work that might have been produced if he had settled down to work on some big problem at that critical time. For his work at the Foreign Office he was awarded the OBE.
On 23 June 1998, on what would have been Turing’s 86th birthday, his biographer, Andrew Hodges, unveiled an official English Heritage blue plaque at his birthplace and childhood home in Warrington Crescent, London, later the Colonnade Hotel. To mark the 50th anniversary of his death, a memorial plaque was unveiled on 7 June 2004 at his former residence, Hollymeade, in Wilmslow, Cheshire. On 13 March 2000, Saint Vincent and the Grenadines issued a set of postage stamps to celebrate the greatest achievements of the 20th century, one of which carries a portrait of Turing against a background of repeated 0s and 1s, and is captioned: “1937: Alan Turing’s theory of digital computing”. On 1 April 2003, Turing’s work at Bletchley Park was named an IEEE Milestone. On 28 October 2004, a bronze statue of Alan Turing sculpted by John W. Mills was unveiled at the University of Surrey in Guildford, marking the 50th anniversary of Turing’s death; it portrays him carrying his books across the campus. In 2006, Boston Pride named Turing their Honorary Grand Marshal.
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Turing was one of four mathematicians examined in the 2008 BBC documentary entitled “Dangerous Knowledge”. The Princeton Alumni Weekly named Turing the second most significant alumnus in the history of Princeton University, second only to President James Madison. A 1.5-ton, life-size statue of Turing was unveiled on 19 June 2007 at Bletchley Park. Built from approximately half a million pieces of Welsh slate, it was sculpted by Stephen Kettle, having been commissioned by the late American billionaire Sidney Frank. Turing has been honoured in various ways in Manchester, the city where he worked towards the end of his life. In 1994, a stretch of the A6010 road (the Manchester city intermediate ring road) was named “Alan Turing Way”. A bridge carrying this road was widened, and carries the name Alan Turing Bridge. A statue of Turing was unveiled in Manchester on 23 June 2001 in Sackville Park, between the University of Manchester building on Whitworth Street and the Canal Street gay village. The memorial statue, depicts the “father of Computer Science” sitting on a bench at a central position in the park.
Programming computers today
Turing memorial statue plaque in Sackville Park, Manchester Turing is shown holding an apple—a symbol classically used to represent forbidden love, the object that inspired Isaac Newton’s theory of gravitation, and the assumed means of Turing’s own death. The cast bronze bench carries in relief the text ‘Alan Mathison Turing 1912–1954’, and the motto ‘Founder of Computer Science’ as it would appear if encoded by an Enigma machine: ‘IEKYF ROMSI ADXUO KVKZC GUBJ’. A plinth at the statue’s feet says ‘Father of computer science, mathematician, logician, wartime codebreaker, victim of prejudice’. There is also a Bertrand Russell quotation saying ‘Mathematics, rightly viewed, possesses not only truth, but supreme beauty—a beauty cold and austere, like that of sculpture.’ The sculptor buried his old Amstrad computer, which was an early popular home computer, under the plinth, as a tribute to “the godfather of all modern computers”. In 1999, Time Magazine named Turing as one of the 100 Most Important People of the 20th century and stated: “The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine.”[3] Turing is featured in the 1999 Neal Stephenson novel Cryptonomicon.
In February 2011, Turing’s papers from the Second World War were bought for the nation with an 11th-hour bid by the National Heritage Memorial Fund, allowing them to stay at Bletchley Park.
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In 2002, Turing was ranked twenty-first on the BBC nationwide poll of the 100 Greatest Britons. In 2006 British writer and mathematician Ioan James chose Turing as one of twenty people to feature in his book about famous historical figures who may have had some of the traits of Asperger syndrome. In 2010, actor/playwright Jade Esteban Estrada portrayed Turing in the solo musical, ICONS: The Lesbian and Gay History of the World, Vol. 4. In 2011, in The Guardian’s “My hero” series, writer Alan Garner chose Turing as his hero and described how they had met whilst out jogging in the early 1950s. Garner remembered Turing as “funny and witty” and said that he “talked endlessly”.
In November 2011, Channel 4 aired the docudrama Britain’s Greatest Codebreaker about the life of Turing. The logo of Apple Computer is often erroneously referred to as a tribute to Alan Turing, with the bite mark a reference to his method of suicide. Both the designer of the logo and the company deny that there is any homage to Turing in the design of the logo. Stephen Fry has recounted asking Steve Jobs whether the design was intentional, saying that Jobs’ response was, “God, we wish it were.” The Turing Rainbow Festival, held in Madurai, India in 2012 to celebrating the LGBT cause, was named in honour of Alan Turing. -
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Thank you.
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Programming computers today
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Eniac 19,000 Taking the rapid adoption of ebooks and ebook readers into account, I believe that the clearest analogies between fifteenth century developments in book history and current developments may be obtained, if rather than attempting to compare the fifteenth century printing developments.
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With the Internet and the World Wide Web, we narrow our focus to studying analogies between the fifteenth century transition from manuscript copying to print with the transition in our time from printed books to ebooks or digital books. Limiting the approach is useful because with respect to electronic books.
Science
Index
The Science Museum thanks the following people and organisations for their invaluable advice and support in the development of this exhibition:
Age UK Camden’s ‘Opening Doors London’ project Bletchley Park Trust
GCHQ
Daniela Derbyshire
Professor Simon Lavington and the Computer Conservation Society National Physical Laboratory Sir John Dermot Turing
This exhibition was made possible with the support of Google.
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The Museum is also most grateful to all those who have lent objects, taken part in interviews and provided historic images for display in the exhibition