Domino is a small rectangular block of wood or plastic, with one face marked with an arrangement of spots like those on dice. It is usually twice as long as it is wide. The other face is blank or identically patterned, and is referred to as the end. The value of a domino is indicated by a number on either of the ends, which ranges from six to none, or by its rank, which is based on the arrangement of pips on its both faces.

A domino can be a game piece in several different types of games, and is also used as a toy for children who stack the pieces on their ends in lines to form shapes. Dominos can be arranged to make the lines of a spider web, an arch, or other structures.

In a domino game, each player takes turns playing a domino onto the table. When a player can no longer play, the person “knocks” or raps the table to stop the game and pass to the next player. The goal is to build a chain of dominoes on the table that will eventually reach the end, and the last domino to be played becomes the winner of the game.

The physics of dominoes is simple, says Stephen Morris, a University of Toronto physicist: “When a domino stands upright against the force of gravity, it stores energy — potential energy — based on its position.” When you tip over a domino, much of this energy converts to kinetic energy, which causes other dominoes to fall. Morris says the principle behind this effect is similar to how your nervous system transmits messages to other cells in your body by electric impulses, which move down long nerve cell bodies.

This idea of a domino effect is not limited to physical systems, but can apply to social and political situations as well. For example, in 1977 during the Frost/Nixon interviews, Richard Nixon defended his decision to destabilize the Salvador Allende regime in Chile by using the domino theory. He said, “Communism is like a domino. Once it gets a foothold in a country, it’s going to spread. It’s just a question of time.”

In the early days of Domino’s, Monaghan focused on opening Domino’s locations in urban areas near college campuses. This strategy gave Domino’s a steady stream of customers who wanted pizza quickly, which in turn fueled the company’s growth. The Ypsilanti-based company continues to emphasize its core values, including listening to employees and customers. It has also been a leader in developing technology that speeds up delivery times.