Rubik's+Cube

We are going to talk about the Rubik's Cube.

- It's a 3D mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture, Erno Rubik. - Originally called the Magic Cube, the puzzle was licensed by Rubik to be sold by Ideal Toy Corp in 1980, and won the German Game of the year special award for the best puzzle that year. - In a classic Rubik's Cube, each of the six faces is covered by nine stickers, each of one of six solid colours (traditionally white, red, blue, orange, green, and yellow). - To solve the puzzle each face must be returned to consisting of one colour.

Records
Single time: the current world record for single time on a 3×3×3 Rubik's Cube was set by an Australian teenager and master [|speedsolver], [|Feliks Zemdegs], who had a best time of 5.66 seconds at the Melbourne Winter Open 2011 in Australia.

Non-human solving: the fastest non-human time for a physical 3×3×3 Rubik's Cube was set by a [|robot] specifically designed for the task by final year computing students at [|Swinburne University of Technology] in Melbourne, Australia in 2011. The robot, Ruby, can complete the task in 10.69 seconds, including the time required to scan the initial status of the cube, well ahead of the previous record of 18.2 seconds

Variations
There are different variations of Rubik's Cubes with up to seven layers: the 2×2×2 ([|Pocket/Mini Cube]), the standard 3×3×3 cube, the 4×4×4 ([|Rubik's Revenge/Master Cube]), and the 5×5×5 ([|Professor's Cube]), the 6×6×6 ([|V-Cube 6]), and 7×7×7 ([|V-Cube 7]).



Permutations
The original (3×3×3) Rubik's Cube has eight corners and twelve edges. There are [|8!] (40,320) ways to arrange the corner cubes. Seven can be oriented independently, and the orientation of the eighth depends on the preceding seven, giving 37 (2,187) possibilities. There are 12!/2 (239,500,800) ways to arrange the edges, since an [|even permutation] of the corners implies an even permutation of the edges as well. (When arrangements of centres are also permitted, as described below, the rule is that the combined arrangement of corners, edges, and centres must be an even permutation.) Eleven edges can be flipped independently, with the flip of the twelfth depending on the preceding ones, giving 211 (2,048) possibilities.[|[][|22][|]] which is approximately forty-three [|quintillion].[|[][|23][|]] The puzzle is often advertised as having only "[|billions]" of positions, as the larger numbers are unfamiliar to many. To put this into perspective, if one had as many 57-[|millimeter] Rubik's Cubes as there are [|permutations], one could cover the Earth's surface 275 times. The preceding figure is limited to permutations that can be reached solely by turning the sides of the cube. If one considers permutations reached through disassembly of the cube, the number becomes twelve times as large: which is approximately five hundred and nineteen quintillion[|[][|23][|]] possible arrangements of the pieces that make up the Cube, but only one in twelve of these are actually solvable. This is because there is no sequence of moves that will swap a single pair of pieces or rotate a single corner or edge cube. Thus there are twelve possible sets of reachable configurations, sometimes called "universes" or "[|orbits]", into which the Cube can be placed by dismantling and reassembling it.

This is a video to learn how we can solve the Rubik's Cube:

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Anabel and Andrea