Mathematicians break world record
More than 30 years after Hungarian building engineer and architect Ern? Rubik patented his six-sided puzzle in 1975, mathematicians, with the help of a new theory and a high performance computer, have broken a world record, proving that the Rubik’s cube can be restored to its original state from any position in just 26 moves.
The Rubik’s cube is not only one of the great symbols of the ’80s, mathematicians, such as Gene Cooperman and Dan Kunkle from the
The pair uses group theory to compute moves and sequences of moves by putting all the possible configurations of a Rubik’s cube into what are called coset groups.
The researchers then applied a single move to all of the configurations of a coset at once with the aid of computer using 7 terabytes of distributed disk as an extension to RAM, which calculated the simulation at a rate of 100,000,000 moves per second.
A step below
Unlike other programs, which first carry out pre-calculations, the program of Cooperman and Kunkle takes around a second to find a solution for every position of the cube in 26 steps or under.
That means the two mathematicians have broken the world record, which until now was 27 steps.
The need for speed
Rubik’s puzzle, however, not only occupies mathematicians, but also those of a distinctly competitive nature: speedcubers aim to solve a randomly scrambled cube in as little time as is possible.
This is less about using as few moves as possible, since generally that is only possible with the help of computers or extensive tables of positions. Instead it requires speed, dexterity and the ability to memorise a high number of pre-prepared moves.
Tough not tough enough
World championships are even held in speedcubing: the first was held in March 1981 in
Another discipline is blindfold cubing, in which the players memorise a scrambled cube and then solve the puzzle with their eyes bound. The American Chris Krueger holds the world record in this discipline: this year he realigned a scrambled cube in 75.6 seconds – including memorisation.