From cube-lovers-errors@mc.lcs.mit.edu Mon Feb 1 15:08:06 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 PAA14298 for ; Mon, 1 Feb 1999 15:08:05 -0500 (EST) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Mail-from: From cube-lovers-request@life.ai.mit.edu Sun Jan 24 13:57:32 1999 Message-Id: <19990124185842.5788.rocketmail@send103.yahoomail.com> Date: Sun, 24 Jan 1999 10:58:42 -0800 (PST) From: Han Wen Subject: Query on Octagon Cube Edge Parity Problem To: Cube Lovers Hi, I ran into an unusual scenario with the Octagon cube recently where only ONE edge piece was flipped and all the other pieces were positioned and oriented properly. This is bizarre of course, because with a Rubik's cube, this is an impossible scenario; there must be a minimum of TWO edge pieces flipped. Does anyone understand the redundancy that allows this strange edge parity problem? And I guess, how to solve it. I lamely mixed the cube up again, resolved until the problem "went away". For those who may not be familiar, the Octagon cube is a variant of the Rubik's Cube. The cube is organized by color into 8 columns of three cublets: corner, edge, corner. If you look at the top face you see that the half of the corner cublets have been cut away so the the face forms an octagon instead of a square. This octagon shape is extended down through the middle and bottom layer, so that the puzzle looks like an octagon "tube". There are a total of 10 colors, two for the top and bottom faces, and 8 for the eight columns of (top-middle-bottom) cublets. == _________________________________________________________ Han Wen Applied Materials 3050 Bowers Ave, MS 1145 Santa Clara, CA 95054 e-mail: Han_Wen@amat.com / hansker@yahoo.com