A domino (also known as bones, cards, men, pieces or tiles) is a small rectangular block used as a gaming object. Each domino is marked on one face with an arrangement of spots or pips resembling those on dice. The other face is blank or marked with a number that indicates its value when placed on an end of a chain. The domino’s value is sometimes called its rank or weight. The higher the rank of a domino, the more valuable it is.
Dominoes are generally twice as long as they are wide, allowing them to be stacked vertically. They are most often made of a hard material such as wood, ivory or bone. Modern sets may also be made of plastics or other manmade materials.
Traditionally, dominoes are set up on a table with the ends touching each other. The players in turn play a domino by placing it on the edge of the table, positioning it so that its matching end touches either side of an adjacent existing domino. If played correctly, the domino will form a chain of tiles which, when finished, will show a number on both ends. The most common game is called double-six, although rules exist for many other games that use a standard domino set of 28 tiles.
The resulting chains of dominoes are not only fun to build and watch, they can also be an excellent tool for teaching math and number recognition. The most important thing to remember is that every domino must touch the previous domino before it in order to create a chain of tiles that shows a particular number on both ends. This is why it is recommended that people play on a hard surface, such as a hardwood floor.
As the chain of dominoes grows, it becomes more difficult to predict how the result will be. This can be very exciting for the players and, as the chain is built, it is possible to see a variety of effects, such as the “domino effect.”
An interesting thing about dominoes is that they do not move unless someone pushes or pulls on them. However, when the first domino is positioned correctly and a little bit of friction is created between the tiles, there is a buildup of energy which can be released with a single nudge.
Physicist Lorne Whitehead proved the potential power of the domino effect in 1983, when he successfully set up 13 dominoes that knocked down a structure about three and a half times larger than itself. His demonstration has since been replicated many times, indicating that the force required to cause a domino to fall is proportional to its size. This principle is called the law of the domino effect. It is the reason why a person can knock over hundreds of dominoes, even though each domino weighs only a tiny fraction of the structure that it is knocking down. This principle has many practical applications, including predicting how an accident will affect the surrounding traffic.