Quotes from David Boyle

Alan Turing appears to be becoming a symbol of the shift towards computing, not least because of his attitude of open-minded defiance of convention and conventional thinking. Not only did he conceptualise the modern computer – imagining a simple machine that could use different programmes – but he put his thinking into practice in the great code breaking struggle with the Nazis in World War II, and followed it up with pioneering early work in the mathematics of biology and chaos.

He was briefly a member of the Home Guard, but got bored of it in 1942 and stopped turning up. The commander tried to frighten him with military law, only to find that on his application form under the question: 'do you understand that by enrolling in the Home Guard you place yourself liable to military law?' Turing had written 'No'.

and the refusal of the Roosevelt administration to recognise the Japanese government imposed on Manchuria.

The Turing Test never claimed to be able to verify anything metaphysical, but that is where the debate is going. It is a debate about authenticity, which asserts or denies that there are attributes which are uniquely human, not so much conventional intelligence, but love, care and generosity. Turing believed that intuition was computable. Even if a computer passes his test, we won't know if he was right or not.

While Hall was taking it upon himself to re-arrange the leadership of the navy, and shuffle the cabinet, he was also perfecting the art of the intelligence dirty trick. He created his own fake code book, to be used only at a time of national crisis – called the Secret Emergency War Code – and had it sold to the Germans by a representative in Rotterdam for £500.

In fact, when Admiral Godfrey took up the same job in 1939, he asked Hall for his advice, and good quality assistants with links to other areas of public life was high on his list. It was the main reason why Godfrey recruited Ian Fleming, the creator of the fictional spy James Bond. Hall's influence is clear, though indirect, on the creation of Bond's world.

It was Churchill himself who described Sir John Jellicoe, the commander-in-chief, as "the only man who could lose the war in an afternoon".

the fans interfered with the radar so they were turned off

With great difficulty, Hall managed to extract Commander William James, who had been his second-in-command on Queen Mary. James had the nickname 'Bubbles', because it was well known in the navy that he had been, as a curly-haired child, the original for the famous Millais painting of the boy blowing soap bubbles, which was used eventually for advertising Pears Soap.

But we do know more about the fleet action that so nearly took place a few days after the battle of the Falkland Isles in December 1914, because it was the first naval action of any kind where one side was able, and with some clarity, to listen in to the thoughts, preparations and orders of the other.

To understand the background to the most momentous telegram ever sent, we have to go back to July 1916. Jutland has just been fought, the British and their allies are dying in unprecedented numbers on the Somme, and the American general John Pershing is fighting in Mexico in pursuit of Pancho Villa. It isn't going well for him.

vaporised thousands of people in the centre of Hiroshima, leaving their shadows scorched into the walls behind them

The British signal system was archaic. In battle, British ships hoisted enormous 'battle ensigns' to prevent them from being mistaken for the other side, but the signal flags remained as small as ever, and easy to misinterpret in the heat of battle.

It reveals both the failures and the huge successes of the navy at the end of a brutal and brutalising war.

Turing had important things to say on all of these, and he is probably best known for his wartime code-cracking, but he ought perhaps to be remembered more for his pioneering contribution to the very beginning of information technology.

One of the controversies about the history of Room 40 was how much the British authorities had thought about codes before 1914. They had certainly not prepared for the sheer flood of coded, intercepted signals that would pour into the Admiralty or War Office. But recent scholarship suggests that they had in fact been making preparations to intercept and, in a quiet way, attempt code-breaking, whereas before, the whole story had been reduced to an amateur series of lucky coincidences.

We can't just accept it – we must doubt it. For by doubting we come to inquiry, and from inquiry we come to the truth.