http://downlode.org/Wiki/pics/rubik.gif A cube-shaped puzzle designed by Ernő Rubik in the 1970s, which became a worldwide fad in the early 1980s. To aficionados, it is known simply as TheCube. The six faces of the cube have different colors, and each face is divided into a 3-by-3 grid by cuts through the puzzle. Pick any face of the puzzle, and you can rotate (twist) the face around its center. The goal is to restore solid colors on all six faces at the same time. Quite challenging. http://trucsmaths.free.fr/images/Ernorubik_tr.gif Rubik's Cube is an excellent tool for teaching basic GroupTheory. * http://www.rubiks.com/ - official site * http://www.puzzlesolver.com/rubik/cube/docs/history.html - interview with Rubik * http://lar5.com/cube/ - java animation of speed solution * See also TheCube for more comments - ''and movies!'' The current world record for a single solve of the 3x3x3 stands at 9.86 seconds, set by Thibaut Jacquinot at the Spanish Open 2007 competition on May 5, 2007. ---- Best ''restore'' time is as given, but how fast have people ''solved'' the cube? I took 7 hours to produce a fully working solution that gave restore times of about 5 minutes. Another 2 days and I had an algorithm with a restore time of around 2 minutes. Then I stopped. It was no longer interesting. ''I witnessed a solution time of a little less than 2 hours, iirc. No idea of what the fastest would be. If I had to guess, I would say ten or fifteen minutes would be reasonable... assuming some luck in picking approaches; it could conceivably be quite a bit longer.'' My experience was about the same. Got one almost as soon as they became popular, took a couple of days to come up with a two-minute or so solution (first person at school to do so), then stopped. Trying again recently, it appears I've forgotten how. :-( (I remembered all but one stage, and couldn't be bothered to reinvent it.) -- PaulHudson ''As was mine. I was in elementary school at the time though. Put it down until a few years later, when someone mentioned a group theory connection when I was first learning about groups... that time round was fun too.'' I had the 3x3, and then moved up to the 4x4 version. I had solved it all except for a situation where the last two out of sync parts were on the same edge. I could not get them corrected so I bought a book and its solution was some 16 or so different moves just to flip the bits. Instead of learning the 16 moves by heart (the move was only needed rarely in a normal solve) I just popped the two pieces out and flipped them and put them back in. Much faster... (taking the 4x4 apart was much easier than the 3x3.) To avoid pulling the cube apart, you could just rescramble the cube and start again. A fooler version is available for the 3x3. It's a blank 3x3 and 54 yellow stickers to plaster on the sides. Solve time: 0.00 seconds (blind folded and using only one hand!) ''Now ''that's'' T''''''hinkingOutside''''''TheCube!!!'' ---- Confession time: I have never managed to solve the cube even once. I suspect that I lack part of the specific mental wiring necessary for the task. Anyone else, or am I a lonely wallflower at the cube party? -- EarleMartin ''You're not the only one. I've never been able to sustain interest or attention long enough to solve the cube, and I suspect I might lack the ability to do it. I find the same to be true of any puzzle whose solution exists purely for its own sake. In programming contexts, I think I'm a reasonably good problem solver, but it's the fact that I have a real goal -- usually that some human will benefit from the outcome of my efforts -- that sustains my interest. Otherwise, why bother?'' -- DaveVoorhis That's me too. Same rationale goes for video games, serious chess and sudoku. -- MarkTilley ---- CategoryGame