Skip to main content

The Secret World of Flexagons - Scott Sherman, Yossi Elran and Ann Schwartz ***

A great book for the right audience. When I was a teenager I loved Martin Gardner's Mathematical Puzzles and Diversions books. They combined mathematical oddities, such as there being more than one size of infinity, with numerical tricks and some physical maths-based objects, most notably flexagons. As someone who is physically inept, I never got much beyond a basic hexaflexagon, but these paper-based three dimensional structures that could change shape when manipulated, a bit like more sophisticated versions of paper fortune tellers, were fascinating.

Now we have a chunky, large format title exploring flexagons in far more depth. The first part of the book takes us into different flexagon structures and the range of possibilities enabling flexing. Some of these require quite sophisticated manipulation of the paper structure (which I did struggle with somewhat, being clumsy). Each flexagon type comes with a flat template to reproduce. These are sometimes quite small and for me benefited from blowing up a bit to make them more practical to manipulate, though many are reproduced larger later in the book.

Having got past the basics, the authors introduce more and more complex flexes (who is for a Möbius flip flex?), before exploring the culture that has built up around flexagons, such as naming conventions and 'pinch state diagrams', which use network diagrams to show how the different transformations are linked. We also get an exploration of the relationship between flexagons and group theory, some maths theory specifically built around flexagons, and the links between flexagons and topology. The final section, 'fun with flexagons' looks at combining flexagon structures with art work to give a more impressive visual impact.

This book will be hugely appealing if this is your thing. I'm giving it three stars, which my rating system describes as 'good solid book, worth reading if you are interested in the topic', not to say that it's a mid-ranking book, but rather that I suspect there are many popular science/maths readers it won't appeal to. I confess I did lose my interest in much of recreational maths as I got older, but if you find the concepts here get you excited, you absolutely need this book.

Paperback:   
Kindle 
Using these links earns us commission at no cost to you
These articles will always be free - but if you'd like to support our online work, consider buying a virtual coffee or taking out a membership:
Review by Brian Clegg - See all reviews and Brian's online articles or subscribe free here

Comments

Popular posts from this blog

Mathematics with Love – Mary Stopes-Roe *****

Admittedly it’s early days (this review is written in January), but this, for me, is the surprise hit of the year so far! I approached this book with trepidation, but found it absolutely delightful. It is described on the cover as the “courtship correspondence of Barnes Wallis, inventor of the bouncing bomb”, and contains a series of letters between Wallis and his cousin and eventual wife Molly Bloxham, along with some useful annotation by their daughter, Mary. The courtship itself is not without difficulties, as Wallis was 18 years older than the 17-year-old Molly at the start of the correspondence, and her father, not surprisingly, wasn’t too pleased about the interest of such an elderly suitor, but that isn’t the only reason the letters are interesting – it’s also because of maths, and Wallis’s position in the UK as the engineering hero of the Second World War. (Incidentally, it seemed very strange to see letters addressed to “Barnes” – I had always assumed Barnes Wallis was a ...

Why Nobody Understands Quantum Physics - Frank Verstraete and Céline Broeckaert **

It's with a heavy heart that I have to say that I could not get on with this book. The structure is all over the place, while the content veers from childish remarks to unexplained jargon. Frank Versraete is a highly regarded physicist and knows what he’s talking about - but unfortunately, physics professors are not always the best people to explain physics to a general audience and, possibly contributed to by this being a translation, I thought this book simply doesn’t work. A small issue is that there are few historical inaccuracies, but that’s often the case when scientists write history of science, and that’s not the main part of the book so I would have overlooked it. As an example, we are told that Newton's apple story originated with Voltaire. Yet Newton himself mentioned the apple story to William Stukeley in 1726. He may have made it up - but he certainly originated it, not Voltaire. We are also told that ‘Galileo discovered the counterintuitive law behind a swinging o...

On Time - Jim Al-Khalili *****

By a small margin Jim Al-Khalili's The World According to Physics is my favourite of his books, both because the 'three pillars' concept at its heart works so well - but also because it's short. On Time is somewhat heavier, but thankfully not a wrist-buster. It might seem at first sight odd that a book on a subset of physics is considerably longer than one covering the whole thing, but time is one of those subjects that inevitably involves considerable complexities and needs depth. As Al-Khalili establishes, it's hard to think of any other scientific concept where our perception of it - what he refers to as manifest time or psychological time - is so different from the view from physics. Some physicists go so far as to suggest that time doesn't exist at all. In the book, Al-Khalili sets out (to my mind quite successfully) both to explain why they think this is the case, but also why it's not the best interpretation of time. I'd certainly note that I...