One of the most famous questions related to Rubik’s Cube is: “How many movements are required to solve the Rubik’s Cube?” That is, what is the minimum number of moves I need to solve any Rubik’s cube position.
It may seem that this is an easy problem to solve using today’s computers. However, a Rubik’s Cube can be in so many different positions, that this problem can not be solved testing positions one by one.
God number is 20
Because of the headaches that caused this issue, the number of moves needed to solve any Rubik’s Cube was called “god number”. In 1981 it was discovered that this number was bounded between 18 and 52. The margin of error was decreased in 1995, reducing the uncertainty between 20 and 29 movements.
Finally, in 2010, 29 years after the first estimation, it was found that the God number was exactly equal to 20. That is, any position of Rubik’s cube can be solved in 20 moves or less. To obtain this number were necessary Group Theory skills (remove symmetries and related positions), and the use of Google supercomputers.
Can I solve the Rubik’s cube in 20 steps?
Because this information is not always given accurately, many people wonder if there is an algorithm they can use to solve the Rubik’s cube in 20 moves. Nope. Keep in mind that even if you can solve the Rubik’s cube in 20 moves, these moves will be completely each time. And because of the large number of possible positions, this knowledge can be useful to solve a Rubik’s cube with a computer, but not for a person.
So if you want to learn how to solve the Rubik’s Cube, you better start by our tutorial