Invisible: the Dangerous Allure of the Unseen

By Philip Ball, Bodley Head, 336 pages, £25

How could you make yourself invisible? Some of the recipes from early magic books make for eye-popping reading. One suggests burying the severed head of a fresh suicide victim before sunrise, along with seven black beans, and carefully watering everything with brandy. Another advises the reader to scoop out a living owl’s eyes and bury them in a secret place.

In fact many of the proposals are so nasty we might be tempted to follow the example set by young children, who think they can make things vanish simply by closing their eyes. But as Philip Ball observes, that has not stopped people trying to fill the world with extra blanks and blind spots, from the magician David Copperfield’s claim that he had made the Statue of Liberty disappear, to plans for a 450-metre skyscraper in Seoul that uses technical wizardry to blend into the background.

Invisibility is a dream as common as flight. Ball argues that it is where “myth collides with reality”, and many of his examples show that it is also where magic overlaps with technology.

Harry Potter’s cloak of invisibility, for example, is something that could actually be manufactured in the future, either by making light bend around the wearer or by applying a coating of tiny LEDs on which images of his surroundings would be projected. Even an idea as ancient as the magic ring Plato describes in The Republic has been reproduced through the medium of film. Put on Plato’s ring and you become invisible; take it off and you become visible again.

But what is film, other than a series of bodies appearing and disappearing, frame by frame, as images on a screen? In fact the closer one approaches the subject of invisibility, the more it starts to reveal itself in the cracks of ordinary life. We find ourselves in an increasingly invisible world, where buried power cables ripple with energy under our feet and radio waves are woven into intricate patterns above our heads.

And while it may be convenient to distinguish between two main types of invisibility, namely what lies beyond our senses and what we take for granted, much of modern life straddles both. Every time we use Wi-Fi, or download data from the cloud, we are relying upon a world that is pulsing with unseen forces. In just a few decades we have created a real version of Prospero’s magic island, where life’s steady hum is overlaid by the chirrup of mobile phones and the tinny beat of headphones. “Be not afeared,” Caliban tells his shipwrecked sailors, “the isle is full of noises/ Sounds and sweet airs, that give delight and hurt not.”

Today he would feel perfectly at home. So would many of Shakespeare’s contemporaries, because the inventions that surround us are increasingly hard to distinguish from old magical theories that insisted everything was bound together by a network of hidden correspondences. Technology is simply magic that works.

Few people who use a mobile phone know how it works, and the line between knowledge and ignorance is one that invisibility patrols with vigour. The first microscopes revealed that a drop of water was squirming with miniature monsters in the form of germs. In 1895 the use of X-rays allowed people to peer at the body’s secrets through its ghostly envelope of flesh. More recently, DNA has revealed the code that makes each of us unique. In each case science took something that has always been present and introduced it to the naked eye. These examples suggest that invisibility is not just a matter of hiding things or making them dissolve into the air. It is also a matter of perception.

Like beauty, invisibility is in the eye of the beholder. In the case of Ralph Ellison’s 1947 novel, “Invisible Man”, it is the result of prejudice, as the hero discovers that an educated black man in post-war America can only make himself noticed through violence. At the end of the 18th century, at a time when gender roles were being put under pressure, one popular illusion was the “Invisible Woman”, which seemed to show a voice coming out of an empty box, allowing audiences to entertain the fantasy of a woman who could be heard but not seen.

The idea that this invisible woman could only be detected if she blew her cover by speaking is typical. Invisibility thrives on paradox. “You can do what you want” if you are invisible, Ball points out, “but no one knows that it is you who has done it.”

Indeed, one of the reasons the invisible man in H.G Wells’s story goes on a murderous rampage is that for everyone else he is not a genius but simply an annoyance. The only time they know he is around is when they bump into him; “Far from being a god amongst men,” Ball neatly observes, “he is literally nothing to them.”

Internet trolls who post vicious comments under pseudonyms offer a modern version of the same problem. They can say anything, but could be anyone. That is why swathing themselves in a modern version of the cloak of invisibility is never likely to satisfy them. It makes their power over other lives seem as anonymous as the weather. Interestingly, the same people who are drawn to invisibility are often hungry for publicity. Ball includes an excellent rogue’s gallery of eccentrics. They include the legendary actor David Garrick, who achieved one of his finest effects as Hamlet by means of a hydraulic wig, which made his hair stand on end when he saw the invisible ghost of his father. There was also a Spanish assassin who, in 1582, tried to slip naked past a set of guards, convinced that he was invisible (he wasn’t). Then there was the stage magician and relentless self-promoter John Nevil Maskelyne, who claimed after the Second World War that he had advised the Army on camouflage techniques and had made entire cities disappear.

Actually, as Ball points out, some of the best camouflage involves hiding things in plain sight. Zebras, for example, don’t disappear against a grassy background, but their markings do confuse predators. Seen through a lion’s eyes, the zebra’s body effectively dissolves into a set of slashing verticals, and it becomes hard to tell whether stalking it is likely to be any more profitable than attacking a fence. The parts don’t seem to add up to a coherent whole.

Some readers might feel the same about this book. Ball sees invisibility everywhere, and as a result it teems with a dizzying array of examples: dark matter, microscopic life, Abbott and Costello, ghosts, radiation, “The Blair Witch Project” and much more. Inevitably there are a few occasions when all these local details overwhelm the larger ideas. But as a harvest of fascinating facts delivered with sharp wit and insight, it is hard to fault. And like all good works of cultural history, it reveals how extraordinary the ordinary is when viewed from a different angle.

The Telegraph Group Limited, London 2014