The secret of Rubik's cube solved

Collect the Rubik's cube from any initial state can be no more than 20 moves, say U.S. scientists from the University of Kent in Ohio.
The study was structured in the following way, using the computer Park of Google, the researchers looked at all possible combinations of 54 colored squares that form the puzzle.





The result that received at least 20 moves, which is called the number of God. "We know now for sure that this magic number is 20," said study leader, Professor Morley Davidson.
As the scientist reports, the total number of the initial position of the Rubik's cube 43 trillion (billion billion). Of them, as shown by calculations, there are more than 100 thousand items, which can be solved in 20 moves. However, most of these solutions can be achieved from 15 to 19 moves.
Until today, the experts believed that the theoretical minimum moves for the Rubik's cube is the number 18. Then research mathematician Michael Reid showed that there are initial configurations that cannot be solved in less than 20 moves.
However, Professor Davidson believes that this figure is purely hypothetical, because nobody not yet was able to calculate every possible configuration. For the analysis of all these combinations, the researchers broke the 54 element cube them into 2.2 billion groups, which received the name of Koslov, each of which contains 20 billion combinations.





"It would be absolutely hopeless to try to calculate all groups. We therefore reduced their number by identifying duplicates and using the theory of symmetry to identify similar combinations. In the end we managed to reduce the number of kositov to 56 million," said Professor Davidson.
Davidson added that in his time the mystery of the Rubik's cube and made him study mathematics. According to him, a group of researchers, headed by him, can now tackle such problems for more complex versions of the puzzle Rubik in the form of the octahedron or of the ball.
In 2009, in stores of the European Union and the United States received a new game by Professor Erno Rubik – Rubik 360.





A new puzzle is a rotating on axes of three transparent spheres, one to another. Inside the Central sphere to six coloured balls. The purpose is to through the holes in the fields to bring every ball to the socket with the corresponding color located on the outer sphere.
Erno Rubik himself has said that though the task at first glance looks simple to make it happen is very difficult, as the game interferes with gravity.





Source: /users/276

Tags

See also

New and interesting