From anandrao@hk.super.net Wed Dec 15 20:27:19 1993 Return-Path: Received: from hk.super.net by life.ai.mit.edu (4.1/AI-4.10) for /com/archive/cube-lovers id AA18806; Wed, 15 Dec 93 20:27:19 EST Received: by hk.super.net id AA23068 (5.65c/IDA-1.4.4 for cube-lovers@ai.mit.edu); Thu, 16 Dec 1993 09:26:47 +0800 Date: Thu, 16 Dec 1993 09:17:27 +0800 (HKT) From: Mr Anand Rao Subject: Re: Description of Tangle, Part 2 To: "Dale I. Newfield" Cc: cube-lovers@ai.mit.edu, don.woods@eng.sun.com, acw@riverside.scrc.symbolics.com In-Reply-To: Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Just because no non-brute-force method has been found, does not make this puzzle any less intersting. As we have been told that there is a solution, it is exciting to search for one, even by brute force methods. The real challenge is to find a brute-force method with sufficient insight to solve the problem within a reasonable time-frame. All the algorithms so far are exponential. We may never find a linear algorithm for this problem. The idea is to find one algorithm that can be used in actual practice. We can then bury this puzzle into the archives, for the next generation to pick up! > > (Thanks for the pointers to the Apr 92 discussion) > I agree with the concensus expressed in the archives that this puzzle is > inherently "not that great" because no non-brute-force method has been > found/seems to exist. > > -Dale > Is this the reason why Rubik has gone into hiding? I haven't seen any puzzle from him after this set of 4 released in 1990/1991. I tried to contact the Hong Kong office of Matchbox which gets Rubik's puzzles in China, but they have closed shop. Matchbox UK said that they have discontinued this line. If anyone has found another source for Rubik's puzzles, or discovered anyone else who has taken the responsibility of giving us sleepless nights, please let me know!