The Wavewatcher’s Companion

Gavin Pretor-Pinney (http://en.wikipedia.org/wiki/Gavin_Pretor-Pinney) achieved unexpected success with his previous book, The Cloudspotter’s Guide, an appreciation of the different types of water vapour masses that fill our skies. Now the author has produced what he claims is a natural follow-up. ‘A mere cloud-spotter is, in fact, without even realising it, a wave-watcher, since clouds are often borne on waves of air,’ he tells us.

The end result is a witty, discursive and entertaining guide to entities that control our lives in ways we rarely appreciate: microwaves that heat our food; polarised light used in glasses for watching 3D films; sound-wave interference that musicians use to tune guitars and other instruments; and sonar devices that allow submarines to ‘see’ with sound under the surface of the sea.

Waves rule our lives, it would seem – right down to our heartbeats, which turn out to be exquisitely coordinated muscular waves. Similarly, the movement of food through our digestive systems and the tiny electrical signals that constantly flit across our brains are controlled by waves. Everything that we see and hear reaches us through the medium of a wave. As the American poet Oliver Wendell Holmes put it: ‘A word, whatever tone it wear, is but a trembling wave of air.’ Thus an examination of the subject offers us an unusual way to look at our lives and the world about us, though given the nature of the subject, such an approach is fraught with complexities – including quantum mechanics, general relativity and other weighty notions. Fortunately, Pretor-Pinney is a gentle writer and his narrative rarely gets bogged down in these areas. Consider the Mexican wave, much loved by crowds at football and Test cricket matches. Not much to say about them, you might think. However, it turns out they are influenced by unsuspected planetary forces, says Pretor-Pinney. After studying video footage of Mexican waves in stadiums in the northern hemisphere and those in the southern hemisphere, he has found a rather surprising phenomenon: that ‘stadium waves are more likely to go clockwise in the north and anti-clockwise in the south.’ Just why this should be the case is not revealed.

And then there are electromagnetic waves that range from radio waves to light to gamma radiation. ‘The amazing thing is that they are all the same waves, just at different scales,’ says Pretor-Pinney. ‘And though we don’t ever think about it, they are all around us, passing through us everywhere we go –  incessant messages, signals and information overlapping, intersecting, combining and passing on their way.’ The great US physicist Richard Feynman summed up the subject thus: ‘These things are going through the room at the same time. You’ve got to stop and think about it to really get the pleasure … the complexity, the inconceivable nature of Nature.’ In short, waves have a lot to tell us about our lives and our world. Pretor-Pinney is entertaining and informative in the telling.

Incidentally, Pretor-Pinney co-founded The Idler magazine (http://idler.co.uk/) which admirably entertains the person with time on their hands.