From cube-lovers-errors@mc.lcs.mit.edu Tue Sep 28 12:32:22 1999 Return-Path: Received: from sun28.aic.nrl.navy.mil (sun28.aic.nrl.navy.mil [132.250.84.38]) by mc.lcs.mit.edu (8.9.1a/8.9.1-mod) with SMTP id MAA21564 for ; Tue, 28 Sep 1999 12:32:22 -0400 (EDT) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Message-Id: <19990923162848.24944.rocketmail@web126.yahoomail.com> Date: Thu, 23 Sep 1999 09:28:48 -0700 (PDT) From: Jaap Scherphuis Reply-To: jaap@org2.com Subject: Square 1, Pyramorphix, Cheap Skewballs To: Cube Lovers Hi all, This is my first post to Cube-Lovers, though I have been reading the archives for a long time now. I'm a 27 year-old mathematician. Re: Square-1 A few years ago I figured out a solution to the Square-1. It was one of the hardest puzzles to solve. Though I did theoretically solved it, the solution was so long and tedious I never actually performed it. In the end I wrote a program that searched for short sequences that go from cube shape to cube shape that do not move the corners. In the list it produced were a few useful sequences moving only a few edges, but all the odd permutations moved a lot of edges. By combining one of them with some other sequences I finally got my own parity fixing sequence that is a nice triple edge swap: Swap FU-BU, LU-RU, FD-BD: /(3,3)/(1,2)/(2,-4)/(-2,4)/(-1,1)/(3,3)/(0,3)/(3,3)/(0,3)/(6,0)/(6,0)/ The notation is fairly obvious: /=half turn of right hand side, (t,b)=move top/bottom the given number of twelfths clockwise, negative for anti-clockwise. I find this much easier to read than any others I've seen, though it is sometimes easy to forget the leading / if there is one. Unfortunately I have since lost any other results I got then except for those I have incorporated into my solution. The square-1 solving program Matt mentioned can be found in the cube-lovers archive in the contrib directory. Re: my webpages I have recently typed up a lot of my notes and put them on the web in a text-only preliminary form. Eventually I hope to make them into proper web-pages with pictures etc. There are solutions there for: Alexander's Star, Pocket Cube (2x2x2), Rubik's Cube (3x3x3), Rubik's Revenge (4x4x4), Profesor's Cube (5x5x5), Dogic, Domino, Impossiball, Megaminx, Octahedron, Pyraminx, Pyramorphix, Skewb, Brain ball, Rubik's Fifteen, Equator, It, Ivory Tower (Babylon Tower), Masterball, Orb, Puck, Roundy, Square One, Topspin, Tower (Whip-It), Rubik's Triamid, Tricky Disky, Rubik's Clock, Lights Out, Rubik's Magic, Spinout, Crazy Tantrix. At the moment there is not yet a links page. You can find it here: http://www.org2.com/jaap/puzzles I'd appreciate any feedback. Re: Pyramorphix. I only have the pocket Pyramorphix, and these are delicate (my first one broke within 5 minutes). The pieces have small feet which slide through grooves in a ball. The grooves are formed between 8 triangular pieces which are screwed onto the ball. By pushing a small screwdriver through at a point where 4 pieces come together you can unscrew it. It may work best if you bring the 4 flat pieces together and use the spot between them to unscrew it. Re: Cheap Skewballs. This week I bought several cheap puzzleballs at the Oxford Toys'r'Us, all of the France '98 type. I bought the last two keychain ones (1 uk pound each), and a couple of normal sized ones (2 uk pounds each). They still have many of those. I plan to paint them with diffent designs, e.g. dodecahedron/icosahedron/octahedron, or rather the spherical projections of these shapes. That's all for now. Bye, Jaap. ===== Jaap Scherphuis Visit the Psion Organiser II CM, XP & LZ Homepage: URL: http://www.org2.com email: jaap@org2.com