Rubik's Cube

The Rubik's Cube is a 3D combination puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik. It was first sold in the UK by Pentangle Puzzles in 1978 and later by Ideal Toy Corp in 1980. The cube became popular around the world and won the 1980 German Game of the Year award for Best Puzzle.

The classic Rubik's Cube has six faces, each with a single color: white, red, blue, orange, green, and yellow. Turning each layer mixes up the colors, and the goal is to get each face to show just one color. Over time, the cube inspired many similar puzzles with different shapes and sizes.

Even though it was most popular in the 1980s, the Rubik's Cube is still loved today. Many people, called speedcubers, practice solving it quickly and compete in events organized by the World Cube Association. Since 2003, they have kept track of world records for the fastest times.

History

In 1970, Larry D. Nichols made a smaller puzzle cube and got a patent for it in 1972. That same year, Frank Fox tried to get a patent for a sliding puzzle on a sphere.

In the mid-1970s, Ernő Rubik, a teacher in Budapest, invented the Rubik's Cube. He wanted to create a three-dimensional puzzle that could twist without breaking. When he mixed up the colors and tried to fix it, he found it fun. Rubik applied for a patent in Hungary in 1975.

The first Rubik's Cubes were made and sold in Budapest in 1977. They were strong and easy to twist. A businessman named Tibor Laczi showed the Cube at a toy fair in Germany in 1979. Tom Kremer saw it and thought it could become very popular. The Cube was shown at toy fairs in London, Paris, Nuremberg, and New York in early 1980. After some safety changes, it was named "Rubik's Cube" and became very popular.

After the Rubik's Cube was released in 1980, it didn’t sell much at first. But after TV ads started, it became a big sensation. By 1981, it was a worldwide craze. Speedcubing contests began, and books on how to solve the Cube were very popular. It was even shown in museums and on TV.

By 1982, sales began to drop, though in some places like China and the USSR, people were just starting to get excited about it.

In the 2000s, interest in the Rubik's Cube grew again. The 2003 World Championship in Toronto helped start the World Cube Association. By 2008, about 15 million Rubik’s Cubes were sold each year. After Rubik’s patent ended in 2000, new brands, especially from China, made cubes that were good for quick solving. In 2020, Spin Master bought the Rubik's Cube brand.

Imitations

At first, there were not enough real Rubik's Cubes, so many copies and new versions appeared. Some of these may have broken the rules about using the original design. In 2000, the rules about the design ended, and many companies, especially in China, started making their own versions or improving the original Rubik's Cube and V-Cube.

Patent history

A man named Nichols gave his patent to a company called Moleculon Research Corp. This company took another company, Ideal, to court in 1982. In 1984, Ideal lost but went to a higher court. In 1986, the higher court said one smaller cube, the Rubik's 2×2×2 Pocket Cube, broke Nichols's patent, but the regular 3×3×3 Cube did not.

A man in Japan named Terutoshi Ishigi asked for a patent for a very similar cube design in 1976. Until 1999, Japan allowed patents for designs that were not shared with the rest of the world. Rubik later asked for more patents and, in the United States, he received one for the Cube on 29 March 1983. This patent ended in 2000.

Trademarks

The company that owns the Rubik's brand has legal rights to the names "Rubik" and "Rubik's" and to the pictures of the cube. These rights were supported by a decision in the European Union in 2014. But European toy makers can still make puzzles that look different but work in a similar way, like the Skewb, Pyraminx, or Impossiball.

In 2016, after ten years of fighting, the highest court in the European Union decided that the shape of the Rubik's Cube alone was not enough to protect it as a trademark.

Mechanics

A standard Rubik's Cube is about 5.6 centimetres (2+1⁄4 inches) on each side. It is made up of 26 small pieces, called "cubies" or "cubelets". Each piece fits together like puzzle parts and can move to different spots.

The six centre pieces on each face are fixed and help the other pieces turn. Inside, there are springs and fasteners that keep everything together. The cube has six centre pieces with one colour, twelve edge pieces with two colours, and eight corner pieces with three colours. By turning the outer layers, you can mix up the pieces. The goal is to get all the colours to match again on each side.

Mathematics

The Rubik's Cube has many different ways to arrange its pieces. The total number of possible arrangements is about 43 quintillion, which is a very big number! This means there are many different ways the cube can be mixed up, but only one way to solve it completely.

Mathematicians have studied the Rubik's Cube using a branch called group theory. This helps people learn tricks and methods to solve the puzzle more easily. The cube can also be linked to ideas in quantum physics.

Solutions

Singmaster notation

Many Rubik's Cube fans use a special way to write down the moves they make, created by David Singmaster. This helps them share their solving steps with others. The notation uses letters to show which side of the cube to turn and how to turn it.

F (Front): the side facing you
B (Back): the side opposite the front
U (Up): the top side
D (Down): the bottom side
L (Left): the side to the left of the front
R (Right): the side to the right of the front

Adding a prime symbol (′) after a letter means to turn that side the opposite way. A number 2 after a letter means to turn it all the way around.

Optimal solutions

There are many ways to solve the Rubik's Cube, and some can be done in under 100 moves. One common way is to solve it layer by layer. In 2010, researchers proved that any Rubik's Cube can be solved in 20 moves or fewer.

Speedcubing methods

Speedcubers often use a method called CFOP, which stands for Cross, F2L, OLL, PLL. It solves the cube faster by using many special steps. Another method, created by Lars Petrus, solves small sections first to reduce the total moves needed.

Beginners' methods

Beginners usually start with solving the cube one layer at a time. Some books offer easier steps to learn how to solve it.

Competitions and records

Speedcubing competitions

Main articles: Speedcubing and World Cube Association

Speedcubing is when people try to solve a Rubik’s Cube as fast as they can. There are many competitions around the world for this.

The first big competition happened in Munich on March 13, 1981, organized by Guinness World Records. Since 2003, winners are decided by taking the average time of five solves, dropping the fastest and slowest. The World Cube Association keeps track of the best times ever recorded. They also have special events like solving the cube blindfolded, using just one hand, or solving it in the fewest moves possible.

Records

Competition records

Single time: The world record for solving a 3×3×3 Rubik’s Cube is 2.76 seconds.
Average time: The world record average time is 3.51 seconds, set by Yiheng Wang of China.
One-handed solving: The fastest one-handed solve is 5.66 seconds. The fastest average of five one-handed solves is 6.99 seconds, set by Zhen Chen of China.
Blindfold solving: The fastest blindfolded solve is 11.56 seconds, set by Tommy Cherry of the United States.
Multiple blindfold solving: The record is solving 63 out of 65 cubes in 58 minutes and 23 seconds.
Fewest moves solving: The record for the fewest moves to solve a cube is 16 moves.

Other records

Non-human solving: A robot named Rubik’s Contraption solved a cube in 0.38 seconds.
Highest order physical n×n×n cube solving: A person solved a 21x21x21 cube in 95 minutes and 55.52 seconds.
Group solving (12 minutes): The record for most people solving a Rubik’s Cube in twelve minutes is 134 people.
Group solving (30 minutes): In 2012, 1,414 people solved Rubik’s Cubes in under 30 minutes at the O2 Arena in London. Later that year, 3,248 people in Pune, India, also solved Rubik’s Cubes in 30 minutes.

Variations

There are many different kinds of Rubik's Cubes. The most common ones change the "order" of the cube, meaning the size. 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) are well known.

There are also special electronic versions of the Rubik's Cube, like the Rubik's TouchCube. This cube uses lights to show the colors. It was shown at the American International Toy Fair in New York in February 2009.

The Rubik's Cube has inspired many other puzzles with different shapes, such as the tetrahedron (Pyraminx), the octahedron (Skewb Diamond), and the dodecahedron (Megaminx). There are also puzzles that change shape, like Rubik's Snake and the Square One.

Exhibits and art

The Liberty Science Center in Jersey City, New Jersey and Google made an interactive exhibit about the Rubik's Cube. It opened in April 2014 to celebrate the cube's 40th birthday and traveled around the world for seven years. The exhibit had a very tall cube made of lights, a giant cube showing how the puzzle works inside, and robots that could solve the cube.

Artists have used Rubik's Cubes to make interesting art for many years. In New York City, there is a large, spinnable cube statue called Alamo, also known as The Astor Place Cube. Some students at the University of Michigan made a huge Rubik's Cube on their campus as a fun joke for April Fool's Day in 2008.

Some artists use many small Rubik's Cubes together to create pictures, a style called Rubik's Cubism. One artist named "Invader", also called "Space Invader", showed pictures made with Rubik's Cubes in 2005 in Los Angeles. Another artist, Pete Fecteau, made a special tribute to Martin Luther King Jr. using thousands of Rubik's Cubes in 2010.