We’ve all seen those domino constructions where, after tipping the first piece ever-so-slightly, all the rest fall in a beautiful cascade of rhythmic motion. That’s what’s known as the “domino effect,” and it’s a great metaphor for anything that cascades out from one action to the next, whether we’re talking about building a house of cards or a chain reaction in a political crisis.
A domino is a rectangular tile that has a line down the middle and an arrangement of spots, or pips, on each end. Each domino is also blank on one side. A traditional domino set contains 28 tiles, but larger sets exist.
Dominoes are used to play a wide variety of games, both solo and multi-player, with either layout games or blocking games. Generally, the winner is the player who can place all of his or her remaining pieces before the game ends. A player who cannot lay a tile passes his or her turn to the next player.
Most dominoes are made of a polymer material, such as plastic or wood. However, some are made of natural materials like bone, silver lip ocean pearl oyster shell (MOP), ivory or ebony with contrasting black or white pips. These sets are often more expensive than those made from polymer, but they are regarded as works of art because of the quality of their materials and detailed craftsmanship.
A physicist named Stephen Morris has studied the dynamics of dominoes and has found that, when a domino is stood upright, it has potential energy based on its position. As the domino falls, much of that potential energy is converted to kinetic energy that causes other dominoes to topple as well.
Just as the energy of a nerve impulse travels at a constant speed regardless of the size of the stimulus that triggers it, the energy of falling dominoes is independent of the number of pieces or their distance from each other. In other words, a chain reaction of dominoes is all or nothing: each piece must be toppled before the next can start.
The physics of dominoes is an important model for the behavior of nerve cells, or neurons, in your body. In fact, a well-known neuroscientist recently suggested that we can use the concept of dominoes to explain how nerve impulses are transmitted through our bodies. To test this idea, you can experiment with a physical domino model: Set a domino on its edge and place it gently against another domino. Barely touch the first domino with your finger and observe what happens. Repeat this several times with different amounts of force and notice the results. If you want to compare the speed of various dominoes, you can also try measuring their speed with a ruler.