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:  
Also on Kindle:  
Review by Brian Clegg

Comments

Popular posts from this blog

I, Mammal - Liam Drew *****

It's rare that a straightforward biology book (with a fair amount of palaeontology thrown in) really grabs my attention, but this one did. Liam Drew really piles in the surprising facts (often surprising to him too) and draws us a wonderful picture of the various aspects of mammals that make them different from other animals. 

More on this in a moment, but I ought to mention the introduction, as you have to get past it to get to the rest, and it might put you off. I'm not sure why many books have an introduction - they often just get in the way of the writing, and this one seemed to go on for ever. So bear with it before you get to the good stuff, starting with the strange puzzle of why some mammals have external testes.

It seems bizarre to have such an important thing for passing on the genes so precariously posed - and it's not that they have to be, as it's not the case with all mammals. Drew mixes his own attempts to think through this intriguing issue with the histor…

Foolproof - Brian Hayes *****

The last time I enjoyed a popular maths book as much as this one was reading Martin Gardner’s Mathematical Puzzles and Diversions as a teenager. The trouble with a lot of ‘fun’ maths books is that they cover material that mathematicians consider fascinating, such as pairs of primes that are only two apart, which fail to raise much excitement in normal human beings. 

Here, all the articles have something a little more to them. So, even though Brian Hayes may be dealing with something fairly abstruse-sounding like the ratio of the volume of an n-dimensional hypersphere to the smallest hypercube that contains it, the article always has an interesting edge - in this case that although the ‘volume’ of the hypersphere grows up to the fifth dimension it gets smaller and smaller thereafter, becoming an almost undetectable part of the hypercube.

If that doesn’t grab you, many articles in this collection aren’t as abstruse, covering everything from random walks to a strange betting game. What'…

Karl Drinkwater - Four Way Interview

Karl Drinkwater is originally from Manchester, but has lived in Wales half his life. He is a full-time author, edits fiction for other writers and was a professional librarian for over twenty-five years. He has degrees in English, Classics and Information Science. When he isn't writing, he loves exercise, guitars, computer and board games, the natural environment, animals, social justice, cake and zombies - not necessarily in that order. His latest novel is Lost Solace.

Why science fiction?

My favourite books have always been any form of speculative fiction. As a child I began with ghost stories, which were the first books to make me completely forget I was reading. By my teenage years I was obsessed with fantasy, science fiction, and horror. Although I read literary and contemporary books, non-fiction, historical works, classics and so on, it is speculative fiction that I return to when I want escape and wonder. When I read reviews of my last book, the fast-paced novella Harvest Fe…