Rubik's Cube

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Rubik's Cube is a 3-D puzzle combination created in 1974 by the sculptor and professor of Hungarian architecture Ern? Rubik. Originally called the Magic Cube , the puzzle was licensed by Rubik for sale by Ideal Toy Corp in 1980 through businessman Tibor Laczi and founder of Seven Towns Tom Kremer, and won a special German Game of the Year award for Best Puzzle that year. In January 2009, 350 million cubes have been sold worldwide to become the best-selling puzzle game in the world. It is widely regarded as the world's best-selling toy.

In the original classical Rubik Cube, each of the six faces is covered by nine stickers, each one of six solid colors: white, red, blue, orange, green, and yellow. The current cube version has been updated to a colored plastic panel, which prevents exfoliation and fading. In the model currently sold, white is yellow opposite, blue is green in reverse, and orange is opposite to red, and red, white and blue are arranged in that order in a clockwise setting. At the beginning of the cube, the color position varies from cube to cube. The internal pivot mechanism allows each face to rotate independently, thus mixing the colors. For the puzzles to be solved, each face must be returned in order to have only one color. Similar puzzles have now been produced with various sides, dimensions, and stickers, not all of them by Rubik.

Although the Rubik's Cube reached the peak of mainstream popularity in the 1980s, it is still widely known and used. Many speedcubers keep practicing and other twisty puzzles and compete for the fastest time in various categories. Since 2003, The World Cube Association, the international governing body of Rubik's Cube, has organized worldwide competitions and kept official world records.

Conception and development

Previous attempt

In March 1970, Larry D. Nichols found a Puzzle 2ÃÆ' â € "2ÃÆ' â €" 2 "with Pieces of Rotatable in Groups" and applied for a Canadian patent for him. Nichols cube united by magnets. Nichols provided US. Patent 3,655,201 on April 11, 1972, two years before Rubik discovered his Cube.

On April 9, 1970, Frank Fox patented his "Spherical 3ÃÆ' â €" 3ÃÆ' â € "3". He received his British patent (1344259) on January 16, 1974.

Rubik Discovery

In the mid-1970s, Ern? Rubik works in the Interior Design Department at the Academy of Applied Arts and Crafts in Budapest. Although it is widely reported that the Cube was built as a teaching tool to help its students understand 3D objects, the real purpose was to solve the structural problem of moving its parts independently without the whole messy mechanism. He did not realize that he had made a riddle until the first time he ruffled his new cube and then tried to return it. Rubik obtained the Hungarian patent HU170062 for his "Magic Cube" in 1975. The Rubik Cube was first called the Magic Cube (B? VÃÆ'¶s kocka) in Hungary.

A series of first tests of the Magic Cube were produced in late 1977 and released in Budapest toy stores. Magic Cube is held together with interlocking plastic pieces that prevent the puzzle being pulled easily, unlike the magnets in the Nichols design. With Ern? License Rubik, businessman Tibor Laczi took the Cube for the Nuremberg Toy Fair Germany in February 1979 in an effort to popularize it. It was noticed by Seven Towns founder Tom Kremer and they signed a deal with Ideal Toys in September 1979 to release Magic Cube worldwide. Ideal want at least a name recognized as a trademark; Of course, the arrangement put Rubik in the spotlight because the Magic Cube was renamed after its discoverer in 1980. The puzzle made its international debut at the toy show London, Paris, Nuremberg and New York in January and February 1980.

After its international debut, the Cube advances to shelves of toy stores in the West briefly stopped so that they could be made to Western security and packaging specifications. A lighter cube is produced, and Ideal decides to change its name. "The Gordian Knot" and "Inca Gold" were considered, but the company finally decided on "Rubik's Cube", and the first batch was exported from Hungary in May 1980.

Video Rubik's Cube

Next history

1980s Cube craze

After the first batch of Rubik's Cubes was released in May 1980, the initial sale was very simple, but Ideal started a mid-year television advertising campaign equipped with newspaper advertising. In the late 1980s Rubik's Cube won the German Game of the Year special award, and won a similar award for best toys in Britain, France and the United States. In 1981 Rubik's Cube has become a favorite, and it is estimated that in the 1980-1984 period about 200 million Rubik Cubes were sold worldwide. In March 1981 the first speedcoping championship held by the Guinness Book of World Records was held in Munich, and the Rubik's Cube was pictured on the front cover of Scientific American in the same month. In June 1981 The Washington Post reported that the Rubik's Cube is a "puzzle that moves like fast food now... this year's Hoola Hoop or Bongo Board", and in September 1981 Scientists New notes that the cube has "captivated the attention of children from ages 7 to 70 around the world this summer."

Since most people can only complete one or two sides, many books published include David Singmaster's Notes on Rubik's "Magic Cube" (1980) and Patrick Bossert You Can Do the Cube (1981). At one stage in 1981 three of the top ten bestsellers in the United States were the books to break the Rubik's Cube, and the best-selling book of 1981 was James G. Nourse's Simple Solution for Rubik's Cube that sold over 6 million coffee. In 1981, the Museum of Modern Art in New York showed off Rubik's Cube, and at the 1982 World Exposition in Knoxville, Tennessee, a six-foot cube was on display. ABC Television even developed a cartoon show entitled Rubik, the Amazing Cube . In June 1982, the first Rubik World Championships were held in Budapest, and will be the only officially recognized competition until the championship was revived in 2003.

In October 1982 The New York Times reported that sales had fallen and that "madness was dead", and by 1983 it was clear that sales had plummeted. However, in some Communist countries, such as China and the Soviet Union, the madness has started later and demand is still high because of the shortage of the Cube.

The rise of the 21st century

Rubik's cube continued to be marketed and sold throughout the 1980s and 1990s, but it was not until the early 2000s that interest in the Cube began to increase again. Sales in the US doubled between 2001 and 2003, and The Boston Globe states that "it's cool to have Cube again". Game World Championship 2003 Rubik is the first speedcubing tournament since 1982. The event was held in Toronto and was attended by 83 participants. The tournament led to the formation of the World Cube Association in 2004. The annual sales of Rubik's branded cubes are said to have reached 15 million worldwide in 2008. Part of the new appeal is thought to be derived from the rise of internet video sites, such as YouTube, which allows fans to share strategies solution. After the end of Rubik's patent in 2000, other cube brands emerged, mainly from Chinese companies. Many of these Chinese branded stones have been designed for speed and are favored by speedcubers.

Maps Rubik's Cube

Imitation

Taking advantage of the initial shortcomings of the Cubes, many imitations and variations emerge, many of which may have violated one or more patents. Today, patents have expired and many Chinese companies produce copies, and in almost all cases, top repairs, Rubik designs and V-Cube.

Patent history

Nichols was assigned his patent to his employer Moleculon Research Corp, who sued the Ideal in 1982. In 1984, Ideal lost a patent infringement lawsuit and filed an appeal. In 1986, the appellate court affirmed the verdict that Rubik's 2ÃÆ'â € "2ÃÆ'â €" 2 Pocket Cube violated Nichols patent, but canceled the judgment on the Rubik 3ÃÆ'â € "3ÃÆ'â €" 3 Cube.

Even when the Rubik patent application is being processed, Terutoshi Ishigi, a self-taught engineer and owner of an iron factory near Tokyo, filed a Japanese patent for an almost identical mechanism, granted in 1976 (Japanese patent publication JP55-008192). Until 1999, when the amended Japanese patent law came into effect, the Japanese patent office granted Japanese patents for undisclosed technology in Japan without requiring anything new around the world. Therefore, Ishigi's patent was generally accepted as an independent reinvention at the time. Rubik appealed for more patents in 1980, including another Hungarian patent on 28 October. In the United States, Rubik is given AS. Patent 4,378,116 on March 29, 1983, for Cube. This patent expires in 2000.

The Greek inventor, Panagiotis Verdes, patented the method of making the cube beyond 5ÃÆ' â € "5ÃÆ' â €" 5, to 11ÃÆ'â € "11ÃÆ'â €" 11, in 2003. In 2017, 5ÃÆ' â € "5ÃÆ' â €" 5, 6ÃÆ' â € "6ÃÆ' â €" 6, 7ÃÆ' â € "7ÃÆ'â €" 7, 8ÃÆ' â € "8ÃÆ' â €" 8 and 9ÃÆ'â € "9ÃÆ'â €" 9 models in production in its "V-Cube" line. V-Cube also produces 2ÃÆ' â € "2ÃÆ' â €" 2, 3ÃÆ' â € "3ÃÆ' â €" 3 and 4ÃÆ' â € "4ÃÆ' â €" 4.

Trademark

Rubik's Brand Ltd. also holds registered trademarks for the words Rubik and Rubik and for 2D and 3D visualization of the puzzle. The trademark has been enforced by the EU General Court ruling on November 25, 2014 in a successful defense against a German toy manufacturer who sought to cancel it. However, European toy manufacturers are allowed to create different shaped puzzles that have the same rotary or twist functions of component parts such as Skewb, Pyraminx or Impossiball.

On November 10, 2016, Rubik's Cube lost ten years of fighting over a major trademark issue. The highest court of the European Union, the Court of Justice ruled that the puzzle form was not enough to provide trademark protection.

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Mechanics

The standard Rubik Cube measures 5.7 cm ( 2 ¹ / ₄ on each side. The puzzle consists of twenty-six unique miniature cubes, also called "cubes" or "cubelets". Each includes extensions into hidden ones that interlocks with other cubes while allowing them to move to different locations. However, the center cube of each of the six faces is just a single square façade; sixth is attached to the core mechanism. It provides structures for other pieces to enter and rotate. So there are twenty-one sections: a single core piece consisting of three axes intersecting holding six middle squares in place but letting them spin, and twenty smaller plastic pieces that go into it to form the assembled puzzle.

Each of the six center portions rotates on the screws (binding) held by the center, a "3D cross". The springs between each of the screw heads and their corresponding pieces cause internal tension, so collectively, the whole assembly remains compact, but can still be easily manipulated. Screws can be tightened or loosened to change the "feel" of the Cube. The newer Rubik brand cubes have non-screw rivets and can not be adjusted.

The cube can be separated without much difficulty, usually by rotating the top layer 45 Â ° and then prying one side of the cube from the other two layers. Consequently, it is a simple process to "break" the Cube by separating it and rearranging it in an unsolvable state.

There are six central pieces showing a colored face, twelve edge pieces showing two colored faces, and eight corner pieces showing three colored faces. Each section shows a unique color combination, but not all combinations are present (for example, if red and orange are on the opposite side of the broken Cube, no edges with red and orange sides). The locations of these cubes relative to each other can be changed by rotating the outer third of the Cube 90 °, 180 ° or 270 °, but the relative colored side locations of each other in the finished state of the puzzle can not be changed: it is fixed by the relative position of the center squares. However, Cubes with alternative color settings also exist; for example, with a yellow face across the green, a blue face across the white, and the remaining red and orange facing each other.

Douglas Hofstadter, in the July 1982 edition of Scientific American, points out that the Cubes can be colored in such a way as to emphasize angles or sides, rather than faces like standard colors; but none of these alternative dyes ever became popular.

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Math

Permutations

The original (3ÃÆ' â € "3ÃÆ' â €" 3) Rubik's Cube has eight corners and twelve sides. There are 8! (40,320) ways to arrange a corner cube. Each angle has three possible orientations, though only seven (eight) can be independently oriented; the orientation of the eight angles (end) depends on the previous seven, giving 3 ⁷ (2,187) possibilities. There are 12!/2 (239,500,800) how to set its limits, limited from 12! because the edges must be in the exact same permutation when the angle is located. (When the center setting is also allowed, as described below, the rule is that the combined arrangement of angles, edges, and centers should be a uniform permutation.) Eleven edges can be reversed independently, with flips of twelve depending on the previous one, giving 2 ¹¹ (2,048) possibilities.

${\ displaystyle {8! \ times 3 ^ {7} \ times (12!/2) \ times 2 ^ {11}} = 43,252,003,274,489,856,000}$

which is approximately 43 trillion.

The puzzle was originally advertised as having "over 3,000,000,000 (three billion) combinations but only one solution". To put this into perspective, if one has a lot of standard size Rubik's Cubes because there is a permutation, one can cover the Earth's surface 275 times.

Previous numbers are limited to permutations that can be achieved only by rotating the sides of the cube. If one considers the permutation achieved through dismantling the cube, the number becomes twelve times greater:

${\ displaystyle {8! \ times 3 ^ {8} \ times 12! \ times 2 ^ {12}} = 519,024,039,293,878,272,000.} Â Â$

which is roughly 519 trillion possible arrangement of pieces that make up the Cube, but only one of the twelve is really solvable. This is because there is no movement sequence that will swap a pair of pieces or rotate one corner or edge of the cube. So there are twelve sets of configurations that can be reached, sometimes called "the universe" or "orbit", where the Cube can be placed by unpacking and rearranging.

Middle face

The original Rubik's Cube has no orientation mark on the central face (although some carry the words "Rubik Cube" in the middle square of a white face), and therefore solve it does not require attention to steer the faces correctly. However, with a marker, one can, for example, mark the center box of a non-scrambled Cube with four colored marks on each side, each corresponding to an adjacent face color; cubes marked in this way are referred to as "supercube". Some Cubes have also been commercially produced with signs on all the boxes, such as the Lo Shu magical square or playing suit cards. The cube has also been produced in which nine stickers on the face are used to create a single larger image, and the center orientation is also important for this. Thus one can nominally break the Cube but have signs in rotated centers; it then becomes an additional test to complete the center as well.

Marking the Cube Rubik Center increases its difficulty as it extends a distinguishable set of configurations. There are 4 ⁶ /2 (2.048) ways to orient the centers because the permutations evenly from the corners imply even the number of quarter centers as well. Specifically, when the cube is not random apart from the orientation of the central square, there will always be a quadratic center number requiring a quarter of a turn. So the center orientation increases the total number of possible cube permutations from 43,252,003,274,489,856,000 (4.3ÃÆ' â € "10 ¹⁹ ) to 88,580,102,706,155,225,088,000 (8.9ÃÆ' â €" 10 < soup> 22 ).

When flipping the cube is considered a permutation change then we also have to calculate the setting of the center face. Nominal there are 6! how to set the six faces of the center of the cube, but only 24 can be achieved without disassembling the cube. When the center orientation is also calculated, as above, this increases the total number of possible cube permutations from 88,580,102,706,155,225,088,000 (8.9ÃÆ'â € 10 ²² ) to 2,125,922,464,947,725,402,112 (2.1ÃÆ' â € "â € <â € <10 ²⁴ ).

Algorithm

In Rubik's cubers' language, the sequence of memorized steps that have the desired effect on a cube is called an algorithm. This terminology derives from the mathematical use of the algorithm , which means a well-defined list of instructions for performing tasks from a given initial state, via a clearly defined state, to the desired end state. Each method to solve Rubik's Cube uses its own algorithm, along with a description of what effects the algorithm has, and when it can be used to bring the cube closer to solve.

Many algorithms are designed to change only a small part of the cube without disturbing other parts that have been solved so that they can be applied repeatedly to different parts of the cube until they are solved. For example, there is a famous algorithm for cycling three corners without altering the rest of the puzzle or reversing the orientation of a pair of sides while leaving the other one intact.

Some algorithms do have certain desired effects on the cube (for example, swapping two corners) but may also have side effects altering other parts of the cube (such as multiple side permutations). Such algorithms are often simpler than those without side effects and are used early in the solution when most of the puzzles have not been solved and the side effects are not important. Most are long and hard to memorize. Toward the end of the solution, more specific (and usually more complicated) algorithms are used instead.

Relevance and application of mathematical group theory

Rubik's Cube is suitable for the application of mathematical group theory, which has helped to infer certain algorithms - in particular, that have commutator structure XYX ^-1 < i> Y ^-1 (where X and Y are certain moves or moves and X > ^-1 and Y ^-1 are each inverse), or conjugate structure, ie XYX ^-1 , often called by everyday language speedcubers as "setting steps". In addition, the fact that there is a well-defined subgroup within the Rubik Cube group allows the puzzle to be learned and mastered by moving through the complete "degree of difficulty". For example, a "level" like that can involve breaking cubes that have been randomized only by 180 degrees of rotation. This subgroup is the underlying principle of computer cubing method by Thistlethwaite and Kociemba, which solves the cube by further reducing it to other subgroups.

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Solution

Moving notation

Many 3ÃÆ'â € "3ÃÆ'â €" 3 Rubik Cube fans use the notation developed by David Singmaster to show the sequence of movements, referred to as "Singmaster notation". Its relative properties allow the algorithm to be written in such a way that it can be applied regardless of which side is designated or how the color is set to a specific cube.

• F (Front): the current one facing the breaker
• B (Back): the opposite side to the front
• U (Up): up or up side
• D (Bottom): the side across the top, under the Cube
• L (Left): the direct side to the front left
• R (Right): direct side to right front
• ? (Two front layers): the side facing the breaker and corresponding middle layer
• b (Back two layers): the opposite side of the front and the center alignment that matches
• u (Two-lined up) Ã,: the up side and the appropriate middle layer
• d (Decrease two layers) Ã,: bottom layers and corresponding middle layer
• l (Two layers left) Ã,: side to front left and middle center corresponding
• r (Two layers right) Ã,: the right side of the front and the middle center of the sheet
• x (rotate): rotate the entire Cube to R
• y (rotate): rotate the entire Cube to U
• z (rotate): rotate the entire Cube to F

When the main symbol (Ã,? Ã,) follows the letter, it shows the face changing counterclockwise, while the letter without the main symbol indicates clockwise rotation. The letters followed by a 2 (sometimes superscript ² ) show two turns, or turns 180 degrees. R is the right side clockwise, but R ' is the right side counterclockwise. The letters x , y , and z are used to indicate that all Cubes must be changed about one of their axes, corresponding to R, U, and F each. When x , y or z is programmed, this is an indication that the cube should be rotated in the opposite direction. When they are squared, the cube must be rotated 180 degrees.

The most common deviation from Singmaster notation, and in fact the current official standard, is to use "w", for "width" instead of lowercase to represent the two-layer movement; thus, the Rw step is equivalent to one of r .

For methods that use intermediate layer corners (especially the first-corner method) are generally accepted "MES" extensions to the notation of the letter M , E , and S indicates the middle layer changes. It's used for example in the Marc Waterman Algorithm. M (Central): the layer between L and R, rotate the direction as L (top-down)

E (Equator): the layer between U and D, rotate the direction as D (left-right)

S (Stand): the layer between F and B, turn the direction as F

Cubes 4ÃÆ' â € "4ÃÆ' â €" 4 and larger use an extended notation to refer to an additional middle layer. In general, capital letters ( F B U D L R ) refer to the outer portion of the cube (called the face). The small letter ( f b u d l r ) refers to the inside of the cube (called the slice). An asterisk (L *), the number in front of it (2L), or two layers in parentheses (Ll), means changing two layers at the same time (either inside or outside left) For example: ( Rr ) ' l 2Ã, f ' means to change the two rightmost layers counterclockwise, then the left inner layer twice, and then the inner front of the layer in opposite direction clockwise. With the extension, for 6x6 and larger cubes, the three-layer movement is denoted by 3, for example, 3L.

Alternative notation, Wolstenholme notation, is designed to make the sequence of memorizing movements easier for beginners. This notation uses the same letter for the face unless it replaces U with T (top), so everything is consonant. The main difference is the use of vowels O, A and I for clockwise, counterclockwise and 180 degrees, resulting in sequences such as LOTA RATO LATA RATE (equivalent to LU? R? UL? U? RU2 in Singmaster Notation). Addition C implies a rotation of the entire cube, so the ROC is a clockwise rotation of the cube around its right face. The middle layer of the move is denoted by adding M to the corresponding facial movement, so RIM means 180 degree turn of the middle layer adjacent to the R face.

Another notation appeared in 1981 The Simple Solution to Rubik's Cube. Singmaster notation is not widely known at the time of publication. The faces are named Top (T), Down (B), Left (L), Right (R), Front (F) and Posterior (P), with for clockwise, - for counterclockwise and 2 to 180 degrees alternately.

Another notation appeared in 1982's "Ideal Solution" for Rubik's Revenge. Horizontal plane is recorded as a table, with table 1 or T1 starting from the top. The front-to-back vertical plane is recorded as a book, with book 1 or B1 starting from the left. The left-to-right vertical plane is recorded as a window, with window 1 or W1 starting from the front. Using the front face as a reference display, the movement of the table is on the left or right, the movement of the book up or down, and the movement of the window clockwise or counter-clockwise.

Optimal solution

Although there are a large number of possible permutations for Rubik's Cube, a number of solutions have been developed that allow the completion of cubes under 100 movements.

Many of the common solutions for Rubik's Cube have been found independently. David Singmaster first published his solution in Rubik's "Rubik Cube" in 1981. This solution involves breaking the Cube layer by layers, in which one layer (designated the top) is completed first, followed by the middle layer, and then the final and bottom layers. After enough workout, solving the Cube layer after layer can be done in less than a minute. Other common solutions include the "first angle" method or a combination of several other methods. In 1982, David Singmaster and Alexander Frey hypothesize that the number of motions required to complete the Rubik's Cube, provided by the ideal algorithm, may be in "low twenties". In 2007, Daniel Kunkle and Gene Cooperman used a computer search method to show that the 3A 3 Ã-3 Rubik Cube configuration can be completed in 26 or fewer motions. In 2008, Tomas Rokicki lowered the figure to 22 movements, and in July 2010, a research team including Rokicki, working with Google, proved what he called "God number" to 20. This is optimal, as there are some early positions that requires at least 20 steps to solve. In general, it has been shown that the Rubik's Cube can be resolved optimally ?? ( n ² Ã,/Ã, log ( n )) move.

Speedcubing Method

In 1981, the thirteen-year-old Patrick Bossert developed a solution for solving cube, along with graphic notation, designed to be easily understood by beginners. It was then published as You Can Do The Cube and became the best-seller.

The common solution used by speed cubers was developed by Jessica Fridrich. This method is called "CFOP," standing for "cross, F2L, OLL, PLL". This is similar to the layer-by-layer method but uses a large number of algorithms, especially for the orientation and permutation of the last layer. The cross is done first, followed by the first and second layer layers of the second layer simultaneously, with each angle paired with a second side layer cut, thus completing the first two layers (F2L). This is then followed by orientating the last layer, then overriding the last layer (OLL and PLL respectively). Fridrich's solution requires learning about 120 algorithms but allows the Cube to be completed with just 55 moves on average.

Philip Marshall's

takes a different approach, averaging only 65 bends but requires only the memorization of the two algorithms. The cross is solved first, followed by the remaining edge, then five corners, and finally the last three corners.

The now famous method developed by Lars Peter. In this method, part 2ÃÆ' â € "2ÃÆ' â €" 2 is completed first, followed by 2ÃÆ' â € "2ÃÆ' â €" 3, and then the wrong end is solved by using a three-step algorithm, which eliminates the need for 32-step possibility algorithm later.. The principle behind this is that layer by layer you must constantly break and fix the first layer; 2ÃÆ' â € "2ÃÆ' â €" 2 and 2ÃÆ' â € "2ÃÆ' â €" 3 parts allow three or two layers to be reversed without damaging progress. One of the advantages of this method is that it tends to provide solutions in fewer movements.

The Roux method, developed by Gilles Roux, is similar to the Petrus method because it relies on block building rather than layer, but comes from the first-corner method. At Roux, the block 3ÃÆ'â € "2ÃÆ'â €" 1 was completed, followed by 3ÃÆ'â € "2ÃÆ'â €" 1 on the opposite side. Furthermore, the top layer corners are solved. The cube can then be solved simply by using the movement of the U layer and the piece M.

In 1997, Denny Dedmore published a solution described using icons of diagrams that represent movements to be made, not ordinary notations.

Starter Method

Most novice solution methods involve solving one layer cubes at a time, using algorithms that preserve what has been solved. The easiest layer by layer method requires only 3-8 algorithms.

Cube Rubik solver program

The most online Rubik cube solver program is online using the Herbert Kociemba Two-Phase Algorithm which can usually determine solutions of 20 or fewer movements. Users must set the color configuration of the scrambled cube and the program returns the necessary steps to complete it.

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Competitions and recordings

Fast race contest

Speedcubing (or speedolving) is the practice of trying to solve Rubik's Cube in the shortest time possible. There are a number of speedcubing competitions taking place around the world.

The first world championship organized by the Guinness Book of World Records was held in Munich on March 13, 1981. All cubes were moved 40 times and lubricated with petroleum jelly. The official winner, with a record of 38 seconds, is Jury Froeschl, born in Munich. The first international world championships were held in Budapest on 5 June 1982, and won by Minh Thai, a Vietnamese student from Los Angeles, with a time of 22.95 seconds.

Since 2003, the winners of the competition are determined by taking an average time of three of the five middle efforts. However, the best time of all experiments was also recorded. The World Cube Association maintains a history of world records. In 2004, WCA required to use a special time device called the Stackmat timer.

In addition to the 3x3x3 main event, WCA also holds events where the cube is completed in various ways:

• Troubleshooting with blindfold
• Multiple blindfolded solving, or "multi-blind", in which the contestant solves a number of cubes that are blindfolded in a row
• Solve Cube using one hand
• Solve the Cube with one's foot
• Solve Cube in the least movement possible

In a blindfolded settlement, the first contestant learns the randomized cube (ie, sees it normally without blindfold), and then blindfolds before starting to rotate the cube face. Their recording time for the event includes the time spent memorizing the cube and the time spent manipulating it.

In some closed eyes, all cubes are memorized, and then all cubes are solved after eyes are closed; thus, the main challenge is to memorize many - often ten or more - separate cubes. This event is judged not by time but with the number of cubes completed minus the number of unsolved cubes after an hour has passed.

There are various variations of Rubik's Cube with thirty-three layers: 2ÃÆ' â € "2ÃÆ' â €" 2 (Pocket/Mini Cube), 3ÃÆ' â € "3ÃÆ' â €" 3 standard cubes, 4ÃÆ' â € "4ÃÆ' â €" 4 (Rubik's Revenge/Master Cube), and 5ÃÆ' â € "5ÃÆ' â €" 5 (Professor Cube) is the most famous. 17ÃÆ' â € "17ÃÆ'â €" 17 "Over The Top" cube (available end of 2011) until December 2017 the largest (and most expensive, worth over two thousand dollars) is sold commercially. Design work for 22ÃÆ' â € "22ÃÆ'â €" 22 cubes exist and is demonstrated in January 2016, and 33x33 in December 2017. China ShengShou manufacturer has been producing cubes of various sizes from 2ÃÆ' â € "2ÃÆ' â €" 2 to 10ÃÆ'â € "10ÃÆ' â €" 10 (as of late 2013), and also came out with 11x11x11.

The non-licensed physical cube of 13ÃÆ'â € "13ÃÆ'â €" 13 based on the V-Cube patent is commercially available for the mass market around 2015 in China; this represents the limits of practicality for the purpose of "speeding up the settlement" on a competitive basis (as cubes become increasingly awkward and resolve-times increasing quadratically).

There are many variations of the original cube, some of which are made by Rubik. Mechanical products include Magic Rubik, 360, and Twist. Also, electronics like Revolution and Slide Rubik are also inspired by the original. One of the 3ÃÆ' â € "3ÃÆ' â €" 3 latest Cube variants is Rubik's TouchCube. Sliding fingers all over its face causes a pattern of colored lights to rotate in the same way as in a mechanical cube. TouchCube also has buttons for hints and self-solving, and that includes a charging booth. TouchCube was introduced at the American International Toy Fair in New York on February 15, 2009.

The Cube has inspired all the same puzzle categories, usually referred to as the puzzle winding , which includes cubes of different sizes mentioned above as well as various other geometric shapes. Some such forms include tetrahedron (Pyraminx), octahedron (Skewb Diamond), dodecahedron (Megaminx), the icosahedron (Dogic). There are also puzzles that change shape like Rubik's Snake and Square One.

In 2011, Guinness World Records won the "largest Rubiks magic cube" to 17ÃÆ'â € "17ÃÆ'â €" 17 cubic, made by Oskar van Deventer. On December 2, 2017, GrÃÆ' Â © goire Pfennig announced that he had broken this record, with 33ÃÆ'â € "33ÃÆ'â €" 33 cubes, and that his claim had been submitted to Guinness for verification. On April 8, 2018, GrÃÆ' Â © goire Pfennig announced another world record, 2x2x50 cube. Whether this is a replacement for a 33x33x33 record, or an additional note, remains to be seen.

Since 2015, with mass production of Icosaix, all five analog platoon solids with Rubik's cubes (face-turning by cutting one-third of every face, except Pyraminx, which also has turnable tips) become available. In addition to the Rubik's cube, tetrahedron is available as Pyraminx, octahedron as Face Turning Octahedron, dodecahedron as Megaminx, and icosahedron as Icosaix.

Some puzzles have also been made in the Kepler-Poinsot polyhedra form, such as Alexander's Star (a big dodecahedron).

Customized puzzles

The puzzle has been built to resemble a Rubik Cube or based on the inner workings. For example, the cube is a puzzle based on Rubik's Cube, but with different functional dimensions, such as 2ÃÆ' â € "2ÃÆ' â €" 4, 2ÃÆ' â € "3ÃÆ' â €" 4, and 3ÃÆ' â € "3ÃÆ' â €" 5. Many cuboids are based on mechanisms 4ÃÆ' â € "4ÃÆ' â €" 4 or 5ÃÆ' â € "5ÃÆ' â €" 5, through the construction of plastic extensions or by directly modifying the mechanism itself.

Some special puzzles do not come from existing mechanisms, such as Gigaminx v1.5-v2, Bevel Cube, SuperX, Toru, Rua, and 1ÃÆ' â € "2ÃÆ' â €" 3. These puzzles usually have a set of 3D master printed, which is then copied using the printing and casting techniques to make the final puzzle.

Other Rubik Cube modifications include cubes that have been extended or truncated to form a new shape. An example of this is the Octahedron Trabjer, which can be built by cutting and extending parts of the usual 3ÃÆ' â € "3. Most mod shapes can be adapted to a higher cube. In the case of Dodbreakedron Rhombic Tony Fisher, there are 3ÃÆ' â € "3, 4ÃÆ' â €" 4, 5ÃÆ' â € "5, and 6ÃÆ' â €" 6 versions of the puzzle.

Rubik's Cube Software

Puzzles such as Rubik's Cube can be simulated by computer software, which provides functions such as recording player metrics, storing random Cube positions, conducting online competitions, analyzing moving sequences, and converting between different mobile notations. The software can also simulate enormous enigmas that are not practical to create, such as 100ÃÆ' â € "100ÃÆ'â €? 100 and 1,000ÃÆ'â €" 1,000ÃÆ'â € "1,000 cubes, as well as virtual puzzles that can not be built physically, like analog 4 and 5 dimensions. of the cube.

Chrome Cube Lab

Source of the article : Wikipedia