Optimal solutions for Rubik's Cube.
The Rubik's Cube is a 3-dimensional mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture Erno Rubik. In a classic Rubik's Cube, each of the six faces is covered by nine stickers, among six solid colours (traditionally white, red, blue, orange, green, and yellow). A pivot mechanism enables each face to turn independently, thus mixing up the colours. For the puzzle to be solved, each face must be a solid colour. Although there are a significant number of possible permutations for the Rubik's Cube, there have been a number of solutions developed which allow for the cube to be solved in well under 100 moves. This can easily be done in less than 3 minutes for any experienced solver. But these methods are certainly not the fastest way to the solved state. An omniscient being, like god, or a computer, would solve any cube in the least amount of moves. Hence, the maximum amount of required moves for all possible cubes is called 'God's Number'. The question of what value it is was first postulated in 1980 and it has been unanswered in 30 years. This webpage summerizes the problem(s), the details and the ideas behind how God's Number was found.
Page of content:
What you need to know.
Lower & upper bounds.
References and further reading.All rights reserved by Kris Schoorl.