Britons John Bryant and Chris Sangwin have written a book called How Round is Your Circle? that looks incredible. I haven’t read it (yet), but the promotional website by itself has me sold already. Highlights include Reuleaux tetrahedra, square-hole drilling, and self-righting polyhedra.

Sean Michael Ragan

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and makezine.com. My work has also appeared in ReadyMade, c’t – Magazin für Computertechnik, and The Wall Street Journal.

  • Anonymous

    This is a great book. I thoroughly enjoyed reading it.

    Most of the time that I was reading it, I had a netbook next to me running GeoGebra (www.geogebra.org). I was modeled most (maybe all?) of the linkages in the book while I was reading about them. It made it very easy to play and see how things worked – and to see how different changes affected the results.

  • E.Jacob

    This book would make a great textbook. I love the concept of: here is a neat thing… now lets show it mathematically. It will introduce the power of math in a physically motivated way.

  • Adrian Lodge

    This does look fascinating, but the article describing how rounded corners are eliminated doesn’t make sense to me. The ‘corners’ of the cam are over 90 degrees? How can that get into a 90 degree corner of a square, plus watching the video even appears to leave rounded corners despite the square nature of the hole?