From cube-lovers-errors@mc.lcs.mit.edu Fri May 22 19:06:21 1998 Return-Path: Received: from sun28.aic.nrl.navy.mil by mc.lcs.mit.edu (8.8.1/mc) with SMTP id TAA17343; Fri, 22 May 1998 19:06:21 -0400 (EDT) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Mail-from: From cube-lovers-request@life.ai.mit.edu Fri May 22 19:02:24 1998 Date: Fri, 22 May 1998 18:59:24 -0400 (EDT) From: Nicholas Bodley To: Cube Mailing List Subject: Magic Jack Message-Id: Sorry if my memory's faulty, but I don't recall any recent mention of the Magic Jack. This is a 3-cubed, 3-D array of 26 small cubes constrained by an outer cage to slide past their neighbors. At first glance, it looks like a Rubik's Cube, but immediately one realizes it's quite different. It's about the same size. Disassembly looks impossible unless the outer "cage" is cut. As you'd expect, it's a 3^3 array, but with one position empty. It's a 3-D analog of the 15 Puzzle. The individual cubes are not connected in any sense to their neighbors. While the moves in a 15 Puzzle are in one plane and easily defined by amateur mathematicians, in the Magic Jack, there are many more possible ways of moving a given cube to another position. Also, not surprisingly, cube moves are strictly translational. The fun begins when one attempts to create patterns. Each cube has specific surface markings. The simplest configuration creates an exterior in which all cubes have a random, fine-grained, glittery diffraction-grating-like surface. More complicated, and difficult, are the colored patterns, which when solved, create (iirc) a continuous path around the whole puzzle. There are three, I'm fairly sure; one creates a message. Solving is made more difficult by the fact that most cube faces are obscured by their neighbors. As to its intrinsic mathematical difficulty, I'm not close to being well informed/educated enough to judge. The practical problem of hidden faces does add to the practical difficulty, and the number of "degrees" of freedom for a given cube (from 3 to 6, depending on position) certainly increases the available choices. I saw this puzzle at Games People Play in Cambridge; it's a German import. Quality of construction was good, although there was no detenting, and it could be easier to move the cubes. It might actually be easier to constrain potential interferers, and let gravity do the work. The difficulty was essentially caused by other cubes' getting out of position, not poor quality. Price in the store is $25. Not sure whether they're interested in mail orders, but it might be worth a try. While I have no connections with G.P.P., perhaps it wouldn't be out of order to give some info.: The Games People Play 1100 Massachusetts Ave. (Abbreviation = Mass. is OK!) Cambridge, Mass. 02138 (617) 492-0711 Afaik, they had possibly as many as a dozen in stock. G.P.P. also periodically imports 5^3s from Germany, perhaps not from Dr. Bandelow. They have a nice collection of movable-piece puzzles. |* Nicholas Bodley *|* Electronic Technician {*} Autodidact & Polymath |* Waltham, Mass. *|* ----------------------------------------------- |* nbodley@tiac.net *|* Are you designing an icon for a GUI? |* Amateur musician *|* China has been doing it for millennia. --------------------------------------------------------------------------