Dominoes are small, rectangular blocks used as a game or as decorative art. They are often made of wood or bone, but may be plastic as well. Each domino has a line down the center, and one or both ends contain a number. The most common type of domino is marked with an arrangement of dots, similar to the numbers on a die, but the numbering on the ends of a domino can also be used to indicate a set number, such as a double-six.
A single domino has no intrinsic value, but the combination of many such dominoes can create a chain reaction that eventually causes them all to fall over. The energy that is released as each domino falls is converted from potential energy (the energy stored in its upright position) to kinetic energy (energy of motion). This energy travels from one domino to the next, and then to any other dominoes that it hits. The chain reaction continues until the last domino is knocked over.
Physicist Stephen Morris notes that a domino that is standing upright has potential energy, or stored energy based on its position. When a domino is moved, its potential energy is converted to kinetic energy—the energy of motion—and this energy moves from the dominant to other nearby dominoes. The energy is transmitted from domino to domino until all of the dominoes are in motion and have lost their potential energy.
The domino is a popular game with children and adults, and it can be used to teach them about the principles of physics, such as momentum and gravity. The game is also useful for practicing math skills, as players must add or subtract the numbers on the ends of a domino to calculate its total value.
Dominoes can be arranged to make straight lines, curved lines, grids that form pictures when they fall, stacked walls, or 3D structures such as towers or pyramids. When creating a domino layout, it is important to consider the theme and purpose of the installation. For example, a person might want to create a track for a train or a scene from a movie.
The word “domino” and the game itself appeared in the mid-18th century in Italy, Austria, southern Germany, and France. The term derived from an earlier sense of the word, denoting a long hooded cloak worn together with a mask during carnival season or at a masquerade. The earlier sense also refers to the cape worn by a priest over his surplice. It is likely that the playing piece evoked the image of the hooded garment and this led to its later association with the game. A fad for the game was particularly strong in France.