Английская Википедия:Infinity cube

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Файл:Infinity Cube.gif
An Infinity cube made of dice being played with
Файл:Magic Folding Cube.gif
An animation showing different moves and states of the Infinity cube (click to animate)

An Infinity cube is a kind of mechanical puzzle toy with mathematical principles. Its shape is similar to a 2×2 Rubik's cube. It can be opened and put back together from different directions, thus creating a visually interesting effect.

Construction

Файл:Infinity cube.svg
The hinges are coloured, the glow denoting the next hinges to be employed. From the 6 cycle state of the Infinity cube, you can see that its group representation is isomorphic to <math>\mathbb Z_6</math>.

The principle of the infinity cube is simple and can be made by hand with simple paper cutting and pasting. First make 8 small cubes, then arrange the small cubes in a 2 by 2 by 2 way, and tape 8 edges together. When combined, there are 28 small squares exposed and 20 small squares hidden inside.

Mathematics

Like the Rubik's Cube, the various states of the Infinity Cube can be represented as a group, but the Infinity Cube has far fewer permutations than the Rubik's Cube.

Rubik's Cube group have <math>43{,}252{,}003{,}274{,}489{,}856{,}000\,\! = \frac{12!}{2} \cdot 2^{12-1} \cdot 8! \cdot 3^{8 - 1}</math> permutations[1][2] and isomorphic to the below groupware <math>A_n</math> are alternating groups and <math>\mathbb Z_n</math> are cyclic groups

<math>(\mathbb Z_3^7 \times \mathbb Z_2^{11}) \rtimes \,((A_8 \times A_{12}) \rtimes \mathbb Z_2).</math>

The largest group representation for Infinity Cube only contains 6 elements, and can be represented as:

<math>\mathbb Z_6</math>

See also

References

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External links

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  1. Шаблон:Cite web
  2. Tom Davis, "Rubik's Cube. Part II", p.23 in, Zvezdelina Stankova, Tom Rike (eds), A Decade of the Berkeley Math Circle, American Mathematical Society, 2015 Шаблон:ISBN.