Domino (pronounced d
Dominoes are usually twice as long as they are wide, making it easier to stack them after use. They have a line in the middle to divide them visually into two squares, called ends. Each end has a value, called pips or spots, from six to none. Some games are played with tiles that have no pips; they are referred to as blanks or wild pips.
In some domino games, a single end of a row is closed and cannot be played. This is usually the case in British public houses and social clubs, where a scoring version of 5s-and-3s is popular. The objective is to connect a single tile from the hand to one end of a row that is already established so that the sum of the resulting tiles is divisible by five or three.
There are many variants of dominoes, each with different rules and strategies. There are also special tiles called “bongos”, which are a single-ended, four-piece domino that can be used to form a single line of dominoes.
The most common type of domino is the double-six set. The most common combination of pips is six, with a variety of other values, including none and blanks. The number of pips in a particular domino is also known as its rank or weight.
Larger sets are called extended domino sets. These range from the double-nine, 55-tile set to the double-18, 190-tile set. These sets are often more difficult to read than the originals, but they allow for a greater number of unique combinations of ends.
These variations can add a new dimension to the traditional block and scoring games. A few of them include “5s-and-3s” and a version called “concentration,” which is played with a double-six set.
While it’s easy to see how a single piece of domino can be used to build a chain that can knock down larger dominoes, it can also be very difficult to determine how much energy is released when dominoes are knocked down. Stephen Morris, a physicist at the University of Toronto, explains that the dominoes store potential energy as they stand upright; when they fall, some of this energy is converted to kinetic energy, which creates the chain reaction.
Several physicists have studied this phenomenon and have discovered some interesting results. According to Stephen Morris, for example, the amount of energy released by domino number 13 in this progression represents an amplification factor of about 2 billion.