PREFACE

T

his book celebrates the many facets of Alan Turing, the British mathematician and com-

puting pioneer who is widely considered to be the father of computer science. The book

is written for general readers, and Turing’s scientific and mathematical concepts are

explained in an accessible way.

Each of the book’s eight parts covers a different aspect of Turing’s life and work. Part I is

biographical: Chapter 1 contains a timeline of Turing’s short but brilliant life, Chapter 2 is an

appraisal by family member Dermot Turing, and Chapter 3, by Turing’s close colleague and

friend Peter Hilton, describes what it was like to work with a genius like Alan Turing, while

Chapter 4 focuses on his trial—for being gay—and his shocking punishment. Part II deals with

the early origins of the computer, and focuses in particular on Turing’s ‘universal computing

machine’, now known as the universal Turing machine. Part III explains exactly what Turing

did as a codebreaker at Bletchley Park during the Second World War. The war was a disastrous

interlude for many, but for Turing it provided an internationally important outlet for his crea-

tive genius. It is no overstatement to say that, without Turing, the war would probably have

lasted longer, and might even have been won by the Nazis. The ultrasecret nature of Turing’s

wartime work meant that much of what he did was kept secret until recent times. Some remains

classified to this day.

When the war was over, Turing left Bletchley Park and joined London’s National Physical

Laboratory. Part IV is about his post-war work on computing, first in London and then in

Manchester: Turing had his own quirky but highly effective approach to designing hardware

and software. Part V discusses artificial intelligence (AI), called ‘machine intelligence’ by Turing.

He was AI’s first major prophet and contributed a slew of brilliant concepts to the field that he

founded. Part VI goes on to explain Turing’s theory of morphogenesis, his final scientific con-

tribution. This theory tries to unlock the secret of how shapes—such as the shape of a starfish or

a daisy—are formed during biological growth. Turing’s brilliant 1952 paper on morphogenesis

made his reputation as a mathematical biologist, and was also the starting point of the modern

field called ‘artificial life’. Part VII describes some of Turing’s contributions to pure and applied

mathematics, including his ‘Banburismus’ method, used against the German Enigma code, and

his work on the Entscheidungsproblem or ‘decision problem’, which gave rise to his universal

computing machine. Part VIII is, as its title says, a finale: its topics range from speculations

about the nature of the universe to a discussion of recent plays, novels, and music about Turing.