Ravi Vakil sent around the mail below about a mechanical realization of the Mathieu group, looking for other people who might be interested in owning one. I can think of a few funster candidates... if so, contact Ravi directly. --Michael ---------- Forwarded message ---------- From: Ravi Vakil <vakil@math.stanford.edu> Date: Sat, Aug 15, 2009 at 10:04 AM Subject: Mathieu group puzzle Dear everyone, At Mathfest, before Persi Diaconis' related talk, Ron Graham told me that a very clever Dutch inventor Oskar van Deventer made a permutation puzzle called "Topsy Turvy" centered on the Mathieu group M_12, based on the Scientific American article by Igor Kris. You can see it at http://www.youtube.com/watch?v=H8ZcYvU0sLY It is quite attractive, so of course I was curious about getting one. I contacted van Deventer, and he said that it would be possible to get these made by a professional laser company, but that it would necessarily be expensive. He would check, but he'd expect a single one to perhaps cost more than $500. I asked if it might be cheaper if the company could make more than one (still a small number), he said that he thought the answer would be yes. So I thought I'd e-mail some people (you!) who might have some small chance of being interested. If you are potentially interested (depending of course on the price), and wanted to hear more, please let me know. Please respond just to me, not just the whole list. It might be neat if there are a small number of these in a select few offices/homes around the country and around the planet. Please pass this on to anyone else who you think might be interested. In any case, I hope you are all well! best, Ravi p.s. A few more details: this should be robust enough to have on an office or home wall, and have guests use, but wouldn't be suitable for a public place, as it is easily broken/abused. He also has another puzzle that is more Rubik like involving Mathieu groups, but it is much less robust, and also less attractive, less unique, and not much less expensive. Yes, it's true that these puzzles are expensive, but I'm convinced that this reflects the actual fair cost --- despite van Deventer's expertise in these things (he has lots of neat things that he's made), he has a day job. I am hoping that if a few of us are potentially interested, the price will drop below $500, although well in the triple digits, and then I'd be motivated to dig deep and buy one. -- Forewarned is worth an octopus in the bush.