Skip to main content

Magical Mathematics – Persi Diaconis & Ron Graham ***

This is an oddity of a popular maths book in that the approachable bits of the book aren’t, on the whole, about maths but about magic. Magic is a strange topic – for me, certainly, it has a fascination. When I was at school I briefly flirted with the school’s magical society, but in the end I hadn’t the patience to practice the tricks over and over again until they were slick enough to be worth watching. I wanted instant magic that didn’t require sleight of hand ability. The other interesting thing about magic as a topic is that we seem, mostly, to have lost patience with the traditional forms. On the TV show Britain’s Got Talent, magicians mostly don’t fare well as the audience and judges don’t have the patience to sit through the build. We love Derren Brown’s dramatic showmanship, but not traditional tricks. This means that Persi Diaconis and Ron Graham have a potentially difficult audience.
Magical Mathematics really has three different threads interwoven. There’s biographical information about magicians (this is the smallest part). There are details of how to do tricks. And there’s the maths behind the tricks. These are actual tricks which at first sight should have appealed to my young self because they are worked by mathematics – the magician need have no physical dexterity. This sounds horribly like the kind of recreational maths (you know, magic squares and the like) that mathematicians get all excited about but for most people cause big yawns. However, when you look at some of these tricks in terms of the effect, they are very impressive. I particularly like one where five spectators each cut a pack of cards in turn, then take a card each. They are asked to do a simple thing (everyone with a red card stands up), and the magician then tells each of them which card they are holding. That really is impressive.
Of course there’s no gain without pain, and in the case of this trick, though there is no dexterity required, you do have to remember (or otherwise access) quite a lot of information. Even so it’s a great trick, and the maths behind it, on de Bruijn sequences (don’t ask) is also really interesting, including some real world applications of the mathematical structure that’s used. This is by far the most engaging bit of the book – but even here, the maths isn’t particularly well explained. I didn’t really get the first explanation and it was only because there’s a second chapter dedicated to the applications that I grasped what was going on. It’s not complicated, it’s just that the explanation isn’t particularly well written.
Other sections of the book proved less interesting. The tricks were not so impressive or the maths was obscure, hard to follow and, frankly, more than a little dull. It got even worse when juggling was brought into the mix, something that, along with mimes, should have been banished from the world many years ago. Only jugglers appreciate juggling.
The underlying thesis, that you can do real, entertaining magic driven by maths was interesting (though I wish it hadn’t concentrated so much on card magic, which is one of the less appealing aspects of the business). The idea of combining explanations of tricks with info on the maths was good too. But overall the book (and I’ve no idea why it’s in a near-coffee table format) didn’t really work for me.

Hardback:  

Kindle:  
Review by Brian Clegg

Comments

Popular posts from this blog

The Antigravity Enigma - Andrew May ****

Antigravity - the ability to overcome the pull of gravity - has been a fantasy for thousands of years and subject to more scientific (if impractical) fictional representation since H. G. Wells came up with cavorite in The First Men in the Moon . But is it plausible scientifically?  Andrew May does a good job of pulling together three ways of looking at our love affair with antigravity (and the related concept of cancelling inertia) - in science fiction, in physics and in pseudoscience and crankery. As May points out, science fiction is an important starting point as the concept was deployed there well before we had a good enough understanding of gravity to make any sensible scientific stabs at the idea (even though, for instance, Michael Faraday did unsuccessfully experiment with a possible interaction between gravity and electromagnetism). We then get onto the science itself, noting the potential impact on any ideas of antigravity that come from the move from a Newtonian view of a...

The World as We Know It - Peter Dear ***

History professor Peter Dear gives us a detailed and reasoned coverage of the development of science as a concept from its origins as natural philosophy, covering the years from the eighteenth to the twentieth century. inclusive If that sounds a little dry, frankly, it is. But if you don't mind a very academic approach, it is certainly interesting. Obviously a major theme running through is the move from largely gentleman natural philosophers (with both implications of that word 'gentleman') to professional academic scientists. What started with clubs for relatively well off men with an interest, when universities did not stray far beyond what was included in mathematics (astronomy, for instance), would become a very different beast. The main scientific subjects that Dear covers are physics and biology - we get, for instance, a lot on the gradual move away from a purely mechanical views of physics - the reason Newton's 'action at a distance' gravity caused such ...

It's On You - Nick Chater and George Loewenstein *****

Going on the cover you might think this was a political polemic - and admittedly there's an element of that - but the reason it's so good is quite different. It shows how behavioural economics and social psychology have led us astray by putting the focus way too much on individuals. A particular target is the concept of nudges which (as described in Brainjacking ) have been hugely over-rated. But overall the key problem ties to another psychological concept: framing. Huge kudos to both Nick Chater and George Loewenstein - a behavioural scientist and an economics and psychology professor - for having the guts to take on the flaws in their own earlier work and that of colleagues, because they make clear just how limited and potentially dangerous is the belief that individuals changing their behaviour can solve large-scale problems. The main thesis of the book is that there are two ways to approach the major problems we face - an 'i-frame' where we focus on the individual ...