Free Turbulence by Giles Foden Page A

black, seemed far less tractable. They regarded me moodily, with a certainty of interspecies difference that reminded me of the way baboons would face up to lions. Where was Vickers when I needed him, to give them a nip?
    By the end of my first full day in the cot-house I had got the HF set playing big-band music from the Home Service and the teleprinter, switched into receive mode, churning out observations and forecasts. Combined with other readings from thelocal area, my own information would be telexed from Dunoon to Met Office operational headquarters and fed into the general weather picture. This, in turn, would be the basis of briefings to the Allied forces all over the world.
    The teleprinter made a chuh-chuh noise as its keys hit the paper, which jerked out off the roll and snaked to the floor. It was heartening to think of all those Met observers and Waafs and Wrens punching in their messages. The meteorological realm presided over by Sir Peter Vaward was very well organised. It had to be. Consider just for a moment how the constant changeability of the weather had to be gauged, now and in the future, against a background of the chaos and upheaval of war.
    But having global weather information is one thing; using it is quite another. If your measurement is even slightly wrong – as we now know it always will be – there’s a danger of the data degrading very rapidly. There’s also a more basic problem of measurements (which are mental artefacts) being taken on certain sizes of eddies (which are physical artefacts) and not others. There are always scales and dimensions that are being ignored. And this is dangerous because the whole point is that all these sizes of turbulence are interconnected; they are both separate and continuous, feeding energy from large to small then back again.
    Each scale must be viewed as information that contributes to understanding the likely pattern of the whole; and they don’t last long anyway, these eddies, even when you do spot them. New information, yes, but now it’s changing, now it’s gone – and what have you understood?
    Ryman’s method did not solve the missing dimensions problem but it went closer to doing so than anything done before. But the Ryman number was clearly not something one could tick off on one’s fingers. So although it was frustrating tohave to wait a week before I could see him, I was grateful for an interval in which to marshal my thoughts and try out his techniques as best I could, using Channel weather as a proving ground.
    I spent the second night in the cot-house, as I would many over the forthcoming four months, doing calculations – sometimes in my head, sometimes with a wooden slide-rule, notched and ink-stained, which I still possess. Squeezing precision out of continuous domains in a mustering tumult of differential calculus – such was my life in that strange time.
    Lying on the bed doing calculus. Sitting on the crapper doing calculus. Shaving doing calculus. Doing calculus while listening to the radio, hearing what was going on in the war or, for preference, some classical music. Doing calculus while eating. Doing calculus while squeezing the toothpaste tube.
    Squeeze, squeeze, squeeze. I am sure I even did it while I was sleeping. Sometimes that can happen. You can go to bed with a problem in your head and wake up with it solved.
    But not this problem: how to supply, on the strategic scale and with enough lead time, a safe weather forecast that would allow thousands of men to land by sea and air on a stretch of the French coast on a single day at the optimum time.

8
    Early on my third day I set off on the motorcycle to Dunoon, in order to report to Whybrow, my notional superior there. I had left it rather late, telling myself the important thing was to ready myself for the encounter with Ryman. Presumably Sir Peter had given Whybrow some indication that I was also doing work other than local