Rubik's Cube

What is Rubik's Cube?

Rubik's Cube is a 3-D combination puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik. Originally called the "Magic Cube", the puzzle was licensed by Rubik to be sold by Ideal Toy Corp. in 1980 via German businessman Tibor Laczi and Seven Towns founder Tom Kremer, and won the German Game of the Year special award for Best Puzzle that year. As of January 2009, 350 million cubes had been sold worldwide making it the world's top-selling puzzle game. It is widely considered to be the world's best-selling toy.

Rubik's Cube 3x3x3

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, where white is opposite yellow, blue is opposite green, and orange is opposite red, and the red, white and blue are arranged in that order in a clockwise arrangement). 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 consisting of one colour. Similar puzzles have now been produced with various numbers of sides, dimensions, and stickers, not all of them by Rubik.

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 practice it and other twisty puzzles and compete for the fastest times in various categories. Since 2003, The World Cube Association, the Rubik's Cube's international governing body, has organized competitions and kept the official world records.

Competitions 

• Blindfolded solving 
• Solving the Cube with one person blindfolded and the other person saying what moves to make, known as "Team Blindfold" 
• Multiple blindfolded solving, or "multi-blind", in which the contestant solves any number of cubes blindfolded in a row 
• Solving the Cube underwater in a single breath 
• Solving the Cube using a single hand 
• Solving the Cube with one's feet 
• Solving the Cube in the fewest possible moves 

Speedcubing (or speedsolving) is the practice of trying to solve a Rubik's Cube in the shortest time possible. There are a number of speedcubing competitions that take place around the world.
In addition to official competitions, informal alternative competitions have been held which invite participants to solve the Cube in unusual situations. Some such situations include:

Of these informal competitions, the World Cube Association sanctions only blindfolded, multiple blindfolded, fewest moves, one-handed, and feet solving as official competition events.

In blindfolded solving, the contestant first studies the scrambled cube (i.e., looking at it normally with no blindfold), and is then blindfolded before beginning to turn the cube's faces. Their recorded time for this event includes both the time spent examining the cube and the time spent manipulating it.
In multiple blindfolded, all of the cubes are memorized, and then all of the cubes are solved once blindfolded; thus, the main challenge is memorizing many - often ten or more - separate cube positions. The event is scored not by time but by the number of solved cubes minus the number of unsolved cubes after one hour has elapsed.
In fewest moves solving, the contestant is given one hour to find his or her solution, and must write it down as an algorithm.


Sources:
http://en.wikipedia.org/wiki/Rubik's_Cube
http://www.funtrivia.com/en/Hobbies/Rubiks-Cube-17422.html