Invented by Erno Rubik, the Cube came out in 1979 and became a world hit, beating the popularity record of the "sliding piece puzzle" (in french called "taquin" or "pousse-pousse") of 1879.
The picture shows my specimen. I put the letters CUBE on it, to make evident that the central pieces have four different possible orientations. As a result, I now have problems to solve it completely...
There had been speed competitions for solving the cube. The record is hold by Minh Thai (1982), who needed 23 seconds.
A more theoretical question is: what is the "best" formula to solve the cube. Mathematical considerations seem to show that there is always a way to restore the initial state in at most 18 moves. This ideal solution is called "God's algorithm".
The puzzle has eight square plates painted on both sides and tied together in a complicated way by nylon cords, which allow that the puzzle can be fold an rearranged in many ways, but it is always kept together in one piece.
The left picture shows the initial state. The aim is, to fold the puzzle correctly, in order to get, when turned on the back side, the structure shown on the right picture.
But there are other
creative ways to play with the puzzle, trying to find out
what 3D-constructions are possible, for example:
There are 9 clocks
on each side of the puzzle; on 4 corners there are wheels, and 4 pegs that
control which clocks will move if the wheels are turned. The aim is, from
a random position of the 18 pointers, to turn them all to twelve o'clock.
This game is not mechanical, but a kind of jigswaw. It consists of 25 small paper cards on which are drawn ends of cords in 4 colors. The aim is to put cards together in a square of 5x5 in a way that the color ends of the cords fit.
The figures show the two (non-equivalent) solutions for Tangle 1.
Pascal Program to find the solutions:
(takes 160 seconds on a 300MHz CPU)
When it came out, there were also 3 other sets: Tangle 2,3 and 4. It was pretended that all together could form a legendary 'big tangle' with 10x10 tiles.
The tangle tiles can also be used to form 3d cubes
Later came out a simplified version of this puzzle consisting
in 9 pieces with a pattern on both sides (but only one solution):
This is Rubik's response to the classical sliding piece puzzle.
An assembling puzzle. It is less challenging than others because cheating
is just too easy.
The puzzle is composed of 24 "triangles" (more exactly: wedges)
that are fixed together on the two small faces and can rotate on the bases.
Many figures can be formed: the most trivial is a "line", the one showed here is a "ball".
Also called Rubik's Mini Bricks. This is another classical assembling
puzzle. As you see from the picture, I have not yet managed to solve it completely.
See My small collection of beautiful wooden puzzles.
Where can the Cube (and other puzzles) be bought
Some toy stores sell reproductions of the Cube and other puzzles.
Some commercial Web Sites sell Rubik's and other Puzzles:
Some puzzle collectors (see links below) sell or exchange puzzles.
Formulas to solve the Cube and other puzzles can be found at http://rec-puzzles.org/games.html.
Many people have interesting pages about the Cube, a list of sites can be found at yahoo.
Georges Helm is a cube collector from Luxembourg.
There is an interesting site about puzzles in general at http://johnrausch.com, with pictures of puzzles and an international list of puzzle collectors.
There is also a site by Erno Rubrik himself: www.rubiks.com.
There are screensavers, online CGI-scripts and JAVA programs to solve the cube.
More extraordinary are those mechanical robots to solve the cube:
Created on Friday the 13th, 1996-12-13; last updated: 2005-12-09
Your comments are welcome! Mail to Patrick Hahn (firstname.lastname@example.org)