two lifetimes. cryptographic history of work on the german naval enigma, by c h o'd alexander, a colleague of turing ’ s at bletchley. see : http : / / www. ellsbury. com / gne / gne - 042. htm. in 1946, king george vi appointed turing an officer of the order of the british empire for his wartime services, although the details of his work remained secret for many years. turing, a ( 1936 ), ‘ on computable numbers, with an application to the entscheidungsproblem ’, proceedings of the london mathematical society, volume 42, issue 1, pp. 230 - 265. all speeches are available online at www. bankofengland. co. uk / news / speeches having imagined the concept of a computer, turing helped turn it into reality. he played a vital role in the design and development of early electronic computers after the war, continuing to contribute key ideas such as implementing functions by flexible programing rather than pre - set built - in electronic components. working first at the national physical laboratory in london and later at the computing machine laboratory at manchester university, his insights led to the creation of the automatic computing engine ( ace ) in 1950 and the program for ferranti mark 1, the world ’ s first commercially available electronic computer. a visionary as well as a revolutionary, turing recognised that “ this is only a foretaste of what is to come and only the shadow of what is going to be ”. true to his nature, turing himself began to suggest some possible directions. his interests in neurology and physiology led him to ask whether computing machines could be capable of mimicking the faculties of the human mind, including the ability to learn. his work prefigured the neural networks that are used today in applications such as cancer diagnosis and self - driving cars and as yet undiscovered new technologies of tomorrow. and the turing test, a method for determining whether a computer can exhibit intelligent behaviour indistinguishable from a human being, remains the benchmark for judging true artificial intelligence. turing also leaves a very different, though no less important, legacy. in march 1952, he was convicted of gross indecency for his private relationship with a man, avoiding prison only by submitting to chemical castration. his security clearance was revoked for no reason other than his homosexuality, bringing to an end a promising post -

renowned for his “ indispensable ” 3 codebreaking contributions at bletchley park during the second world war. 4 the advances turing made in cryptanalysis then – including co - inventing the bombe computer for solving ciphers and applying statistical techniques to speed up rates of decryption – were pivotal in cracking the hitherto unbreakable german enigma code. turing ’ s work gave the allies a crucial advantage in the battle for the atlantic and is widely credited with hastening the end of the war by at least two years, potentially saving millions of lives in the process. that alone would be more than enough for one lifetime, but turing ’ s contributions range far more broadly than those that have been rightly celebrated in print and on screen. one of turing ’ s lesser - known interests was biology. in later life, turing pioneered morphogenesis by applying his knowledge of mathematics and computer science to understand how plants and microorganisms develop their shapes and patterns. turing used computers to simulate the results of hypothetical chemical reactions to develop truly original insights in this field. the theoretical foundations he developed have since been applied to solve puzzles such as why the leaflets on a pinecone follow the fibonacci sequence and to explain the pattern of animals ’ coats from cats to zebras. this work of a lifetime helped lay a cornerstone in theoretical biology. it was, however, the workings of the human mind that inspired turing ’ s greatest contributions to human knowledge and our lived experience. turing answered a fundamental question : whether there is a definitive method that could be applied by machine to solve all mathematical problems. once again, turing ’ s genius lay in his ability to think across boundaries, applying mathematical logic to a problem others had viewed as one of physics. the answer he supplied – captured in his 1936 paper on computable numbers5 – provides the very foundations of computer science. turing envisaged a machine that could be turned to any well - defined task by supplying it with the appropriate program. the eponymous universal turing machine, fed instructions through symbols on an infinite piece of tape, was an abstract concept in his time, but it ’ s something that recognisably embodies the core principles of a modern computer and the logic of binary code. moreover, his insight that only computable functions can be calculated is vital to software design. in recognition of the importance of this work, turing was elected a fellow of the royal society in 1951. enough for