From cube-lovers-errors@mc.lcs.mit.edu Fri Mar 19 19:31:58 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 TAA18275 for ; Fri, 19 Mar 1999 19:31:57 -0500 (EST) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Date: Fri, 19 Mar 1999 16:21:33 -0500 (Eastern Standard Time) From: Jerry Bryan Subject: Re : RE: parity pairs In-Reply-To: <009D558A.B96AC759.280@ice.sbu.ac.uk> To: Cube Lovers Message-Id: On Fri, 19 Mar 1999 12:16:04 +0000 David Singmaster wrote: > Conway noted the two mirror-image orientations of the standard colour > pattern (W/Y, B/G, R/O). W/Y, B/G, R/O is the "differ by yellow" standard, which I prefer as "the" standard. However, there are also references in Cube-Lovers archives to W/B, R/O, and Y/G as a standard or as the tournament standard. I have no idea who gets to be the standards body to select "the" standard. But as one example of why I like the W/Y, B/G, R/O standard, many of the local maxima at 12q from Start are only "somewhat symmetric", but the eye's sense of symmetry in looking at them can be much stronger. The reason is that the eye (or my eye, at least) can easily identify W/Y as the "same" color, B/G as the "same" color, and R/O as the "same" color. And when such identifications are made, the symmetry of many of the 12q local maxima is much stronger than it would be otherwise. I really haven't looked at them with any other color scheme, but I can't imagine that the apparent symmetry would look as strong otherwise. Also, in all the various discussions about stickers, falling off and otherwise, there have been comments about cubes where it is hard to tell the colors apart, depending on the exact colors which are used, how faded the colors are with age, etc. I guess my experience has been pretty positive in that my stickers have not fallen off and with one notable exception, the colors seem easy to distinguish. The exception is that with my 2x2x2 Pocket Cube, it is very difficult to distinguish the orange from the red stickers unless I have very, very good lighting conditions. This particular cube has always been this way. I can think of no reason that a 2x2x2 should be this way as compared to a 3x3x3 or a 4x4x4, but it does seem to be the case. ---------------------------------------- Jerry Bryan