In Borges’ story “The Book of Sand” (1975), the narrator acquires a heavy little book that has an infinite number of pages. When he opens it, he can never find the same page twice. The discrepancy between its finite size and its infinite contents begins to prey on his mind. He decides the book is a monstrous thing and wants to get rid of it: “I considered fire, but I feared that the burning of an infinite book might be similarly infinite, and suffocate the planet in smoke.”
It’s a good story, but the central idea doesn’t work, unless you assume magic is at work. A book with an infinite number of pages would be infinitely heavy. In fact, it would instantly become a black hole and start swallowing the universe.
So I assume, anyway. I’m interested in physics but I don’t know much about it. This book is aimed at people like me. It reminded me of Borges’ Book of Sand, partly because it’s small but heavy, partly because of the density of its ideas and the weight of history behind those ideas. Each page of explanation could easily become a hundred or a thousand: physics is daunting in its scope and complexity. Some of the greatest minds in history have put centuries of effort into understanding the behaviour of matter and energy.
That’s how we got astonishing things like electronics, X-rays and the atom bomb. Physics is an intellectual over-achiever, the super-star of the sciences, the most spectacular, powerful and difficult of all. But it’s the most difficult science because it’s also the simplest. Stars and steam-engines are much less complex than societies or brains, which is why you can’t get away with talking nonsense in physics. And although mathematics governs everything, it’s the simpler things – pendulums, light-rays, atoms, stars – that we can mathematize first.
Or some of us can, at least: the highly intelligent and obsessive men, like Galileo and Isaac Newton, who began modern physics by finding ways to extract abstract mathematics from concrete realities. If they’d tried to find maths in psychology or culture, they would have failed, because those things are too complex. They had to look at much simpler things like falling objects, planetary motion and light-rays. Galileo and Newton laid the foundations and later physicists have built on them, so that physics now towers into the scientific skies, the envy and awe of those working with more complex and intractable aspects of existence.
Giles Sparrow takes his readers on a tour of the tower. I suppose you could say he’s operating an express elevator, stopping briefly on the floors and offering a brief explanation of what it contains: elastic and inelastic collisions on one floor, fluid mechanics on another, mass spectrometry, electromagnetic induction and quantum electrodynamics on more. Then the doors snap shut and the elevator shoots up another floor. But one thing is found everywhere: mathematics. Sparrow quotes a lot of equations and uses a lot of numbers. If you want to understand physics, you have to know the maths. If you don’t, there’s no way to disguise your ignorance.
The maths is beyond me, so until brain-modification arrives I won’t be able to understand physics properly. Until then, this book is a good way of glimpsing the glories of the science. It’s also the closest you’ll get to handling Borges’ Book of Sand in real life.