Book review: ‘The Spinning Magnet’ by Alanna Mitchell

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How a natural phenomenon that helped create the modern world could one day contribute to its destruction.

Every engineer out there knows that the planet we inhabit is essentially an enormous spherical magnet. As with all magnets it has two poles, but unlike most, these ones wander around while roughly speaking corresponding to the locations of the geographical north and south poles that, being artificial concepts, never move at all. But what many of us might not realise – largely because it’s never happened since humans have been on Earth – is that there have been times when these poles have inverted. And when our big magnet switches polarity, chaos ensues. It’s unlikely that as a race we could survive the next big inversion.

So says Alanna Mitchell in her latest volume, ‘The Spinning Magnet: The Force that Created the Modern World – and Could Destroy It’ (OneWorld, £16.99, ISBN 9781786074249), a compelling yarn describing our historical efforts to understand the force that created the world, and as the subtitle warns, could bring about its end.

The Earth’s magnetic (more correctly ‘electromagnetic’) field plays a crucial role in our existence and our ability to continue to exist. It’s what stops us spinning off the planet and it’s what protects us from being fried by the sun. Apart from one glorious exception, in the form of the aurora seen in the polar regions, we can’t see it, and despite being one of the four fundamental physical forces that govern the physical universe, when it comes to understanding it, we’ve only just begun to scratch the surface.

In attempting to describe his mental image of an electromagnetic field, no less a mind than that of the mighty theoretical physicist Richard Feynman said: “Is it any different from trying to imagine a room full of invisible angels? No, it’s not like imagining invisible angels. It requires a much higher degree of imagination to understand the electromagnetic field than to understand invisible angels.” Feynman’s choice of image is apt because, as Mitchell says, the study of magnetism was once covered within the fields of religion, magic and natural philosophy. Indeed, had she written this wonderful book only a few hundred years ago, she’d have run the risk of being burned at the stake for such heresy.

But as anyone who knows the eminent Canadian science writer’s books – including ‘Invisible Plastic’ and ‘Malignant Metaphor’ – will attest, she’s prepared to take on such a risk in pursuit of a good story. In clear and concise journalism (at one point she suspects an eminent scientist is patronising her with ‘gobbledygook’) she traces the timeline of the human understanding of magnetism from ancient times, through the Age of Enlightenment and to the Victorian era, when there was a frenzied outburst of scientists trying to define the phenomenon, up until today.

We may not know much about this fundamental force, she says, but we know enough to realise that what awaits the planet is a future where solar radiation storms could wipe out power grids and electronic communications. The latter, of course, for many would be the end of the world in itself.

Destined to become a classic of popular science.

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