Arguably it was the point where science and technology started to clearly dominate in importance the traditional military virtues. There is nothing heroic in the traditional sense about scientists in a laboratory evaluating the possibility of a nuclear bomb or working on codebreaking algorithms but the results or lack of them become critical to the outcome of a conventional war.

The idea is interesting and Johnson has covered all the main scientific/technical areas in the conflict showing how technology (more than science) is forced into a rapid rate of evolution and testing. He looks at most developments in the "secret" conflict but is particularly good on radar and the breaking of the German "Enigma" code.

He makes the point clearly when for example he talks about the "Oboe" blind bombing system that was quickly put together for use by British aircraft over Germany. It consisted of two transmitters on the English coast connected by a land line and sending out synchronized pulses that were returned by the aircraft to the same ground stations. The idea was to know exactly the aircraft's speed and height and plot the distance from the target. Then knowing the ballistic properties of the bombs the ground station could transmit a bomb release signal to the navigator.

As he summarizes it, "Before the advent of Oboe ....only some 23% of bombs dropped on the actual target: with Oboe , the figure rose to 70% which meant that Bomber Command's force had been effectively trebled." This was a not greatly understood victory of the two scientists, A.H.Jones and F.E.Reeves who developed the idea in 1941-42.

The Germans were also successful in the war of measure and (top)

The picture that starts to appear is of war more as a technical puzzle where the life of a submariner, pilot or resident of a bombed city starts to depend a great deal on technological change - or rather whether their scientists can compete with the scientists of the people that they are fighting against.

Johnson doesn't go into the consequences of the idea but after reading the book it's clear that the strength of a country's scientific base can be a matter of survival.

It seems that war is the greatest spur to innovation and the book also tells the story of the invention of the magnetron (short wave radar) and the building of the first non-mechanical computer, "Colossus", that was installed at Bletchley Park in December 1943. As the Post Office engineer T.H.Flowers who was working on it said," It occurred to me that electronic equipment, including valves, could be made to do the same function as mechanical switches very much faster and more reliably, and that this would solve our problems."

He was right and it was found that the machine could read at the then incredible rate of 5000 characters per second- the text in question being German cipher text from their "Enigma" machines and the deciphering algorithms applied being those principally devised by the mathematicians Alan Turing and Gordon Welchman

This is a fascinating book about science and technology in the making.