# The Domino Effect

A domino is a small rectangular game piece with anywhere from 0 to 6 dots. It’s the basis for a variety of games that are played by matching adjacent sides. In some cases, dominoes are stood up and allowed to fall on their own in complex patterns that look amazing. When a single domino falls, it can trigger hundreds and even thousands of others to fall as well. The idea of one action causing another inspired the term “domino effect.”

Dominoes can be used to create art, and you don’t have to be an artist to enjoy them. You can draw arrows on a piece of paper to show how you want a domino track to fall, and then plan out the pieces that will be needed. The designs can be as simple or elaborate as you want – straight lines, curved lines, grids that form pictures when they fall, stacked walls, and 3D structures like towers and pyramids.

The largest domino art installations take several nail-biting minutes to fall, and they aren’t easy to set up. The physics behind them is pretty simple, though: each domino that’s standing upright has potential energy that’s based on its position. When a domino falls, much of that energy is converted to kinetic energy, which causes it to topple and trigger a chain reaction. Physicist Stephen Morris, who works on domino designs, says that gravity is key to this process. “When you pick up a domino and stand it upright, it’s lifting against the force of gravity,” he explains. “That gives it potential energy, and when it falls, a lot of that gets converted into kinetic energy.”

While the most common domino games in the West are played with a standard 28-piece set, players can use a double-twelve or even a double-nine set to play. In the case of both, each player takes turns playing tiles so that their exposed ends are either identical (e.g., 5 to 5) or some specified total. The player who reaches the target score in a given number of rounds wins the game.

There are a variety of rules for different domino games, and some include the ability to score points by matching adjacent sides of a tile. Other rules specify how doubles count (e.g., a 6-6 counts as six or 12) and double-blanks may count as either zero or 14.

Dominoes have been used in political rhetoric for centuries. In the 1977 Frost/Nixon interviews, Richard Nixon defended the United States’ destabilization of Salvador Allende’s regime in Chile using the domino theory: If Chile fell, it would cause Cuba to fall, and once that happened, the rest of Latin America would follow suit. Other politicians have cited the domino theory to justify their military interventions in Central America and elsewhere. A more recent example of the domino theory in action came during the Arab Spring, when President Obama warned that dictators could be pulled down “like dominoes.”