Each of the six centre pieces pivots on a fastener held by the centre piece, a "3D cross". A spring between each fastner and its corresponding piece tensions the piece inward, so that collectively, the whole assembly remains compact but can still be easily manipulated. The older versions of the official Cube used a screw that can be tightened or loosened to change the "feel" of the Cube. Newer official Rubik's brand cubes have rivets instead of screws and cannot be adjusted. Inexpensive clones do not have screws or springs, all they have is a plastic clip to keep the centre piece in place and freely rotate. The Rubik's Cube (3x3x3) is a cube shaped Twisty puzzle. It was invented in 1974 by a Hungarian professor named Ernő Rubik. Rubik originally name the puzzle "Magic Cube" however, in 1980 it was renamed after its creator and is generally known since as the "Rubik's Cube". During the 1980s, the Rubik's Cube became a worldwide sensation, and it is estimated that by the mid-80s, 20% of the world's population at the time had played with it - that's 1 in every 5 people on earth! Until today, more than 350 million cubes have been sold worldwide, and it is considered to be the world's best selling toy of all time. As of January 2021, the Rubik's Brand, which was formed around the Rubik's Cube and other puzzles, is owned by the Canadian toy corporation Spin Master. Rubik describes Cubed, as the product of a hermit who is “coming out of the shadows.” He refers to himself as a “concrete and intuitive thinker” and an amateur inventor, but like his invention, he defies categorization. His resume includes stints as a professor, architect, designer, editor and, now, writer. Rubik takes pride in his ability to self-teach, and bristles at the idea that those in authority are in the best position to impart knowledge.

Sitting on the patio of his home in the hills of Budapest, Rubik, now 76, fiddled with a cube as he recalled its "discovery" and accidental success. (He prefers to use “discovered,” rather than “invented” — as if the existence of the object was somehow pre-ordained).

finished cube

After the first batches of Rubik's Cubes were released in May 1980, initial sales were modest, but Ideal began a television advertising campaign in the middle of the year which it supplemented with newspaper advertisements. [23] At the end of 1980, Rubik's Cube won a German Game of the Year special award [24] and won similar awards for best toy in the UK, France, and the US. [25] By 1981, Rubik's Cube had become a craze, and it is estimated that in the period from 1980 to 1983 around 200million Rubik's Cubes were sold worldwide. [26] In March 1981, a speedcubing championship organised by the Guinness Book of World Records was held in Munich, [24] and a Rubik's Cube was depicted on the front cover of Scientific American that same month. [27] In June 1981, The Washington Post reported that Rubik's Cube is "a puzzle that's moving like fast food right now ... this year's Hoola Hoop or Bongo Board", [28] and by September 1981, New Scientist noted that the cube had "captivated the attention of children of ages from 7 to 70 all over the world this summer." [29] The Cube can be taken apart without much difficulty, typically by rotating the top layer by 45° and then prying one of its edge cubes away from the other two layers. Consequently, it is a simple process to "solve" a Cube by taking it apart and reassembling it in a solved state. 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. Each corner has three possible orientations, although only seven (of eight) can be oriented independently; the orientation of the eighth (final) corner depends on the preceding seven, giving 3 7 (2,187) possibilities. There are 12!/2 (239,500,800) ways to arrange the edges, restricted from 12! because edges must be in an even permutation exactly when the corners are. (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 2 11 (2,048) possibilities. [52] 8 ! × 3 7 × 12 ! 2 × 2 11 = 43,252,003,274,489,856,000 {\displaystyle {8!\times 3 An internal pivot mechanism enables each face to turn independently, thus mixing up the colours. For the puzzle to be solved, each face must be returned to have only one colour. It has inspired other designers to create a number of similar puzzles with various numbers of sides, dimensions, and mechanisms. The puzzle was originally advertised as having "over 3,000,000,000 (three billion) combinations but only one solution". [51] Depending on how combinations are counted, the actual number is significantly higher.

Hofstadter has heard of speedcubers, and thinks it’s fitting that the object has endured. “It's absolutely deserved,” he said. “It's a miraculous object, marvelous invention, a beautiful invention, a deep invention.” See also: Rubik's Cube in popular culture The world's largest Rubik's Cube was constructed for the 1982 World's Fair in Knoxville, Tennessee. In October 1982, The New York Times reported that sales had fallen and that "the craze has died", [34] and by 1983 it was clear that sales had plummeted. [24] However, in some countries such as China and the USSR, the craze had started later and demand was still high because of a shortage of Cubes. [35] [36] 21st-century revival Although the Rubik's Cube reached its height of mainstream popularity in the 1980s, it is still widely known and used. Many speedcubers continue to practise it and similar puzzles, and compete for the fastest times in various categories. Since 2003, the World Cube Association (WCA), the international governing body of the Rubik's Cube, has organised competitions worldwide and recognises world records. The Rubik's Cube has over 43 quintillion possible permutations - that's 43,252,003,274,489,856,000 to be exact. This number is so high it even excceeds the number of seconds passed since the Big Bang!

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In March 1981, the Cube landed on the cover of Scientific American, where Pulitzer-Prize winning scientist Douglas Hofstadter, author of "Gödel, Escher, Bach" (1979), called it “one of the most amazing things ever invented for teaching mathematical ideas.”