# What is the Domino Effect?

Dominoes are a fun way to pass the time and entertain kids of all ages. They’re used for a variety of games and can be lined up to create artistic patterns. Dominoes are also a useful tool for teaching physics and engineering principles. Today’s Wonder of the Day was inspired by Juan, who asks, “What is the domino effect?”

A domino is a rectangular tile with two matching ends. Its value is determined by the number of dots on the ends. The simplest dominoes have just one value, but more sophisticated sets can contain up to 20 pips per end. The ends of a domino are usually divided by a line or ridge to distinguish them visually. The values of the pips are indicated by an arrangement of spots, or spots and circles (also known as tittles) resembling the markings on a die.

The first player, designated either by drawing of lots or by the heaviest hand, places the first domino on the table. The next player, if holding the highest value domino in their hand, plays it to the left or right of the previous tile. If the exposed ends of the first double match (one’s touch one’s, or two’s touch two’s), the player is awarded the number of points displayed on that side of the domino. Once a domino is placed, other tiles may be laid on it to form a chain. In a chain of this type, all the exposed ends must be connected to adjacent dominoes. Normally, a domino is played square to the initial tile unless it is a double, then it is placed diagonally.

Whether we’re playing dominoes or plotting our next novel, the domino effect helps us answer the key question: What happens next? In this article, we’ll explore some of the ways we can use the domino effect to guide our storytelling.

While we know a lot about how the domino effect works, we still don’t fully understand all the details. A common theory is that the energy from an initially tipped domino is transferred to the rest of the chain, causing the remaining dominoes to fall in a controlled sequence. However, this explanation has some problems.

Another theory is that the weight of a domino, along with gravity’s pull on it, causes it to topple. When a domino is standing upright, it has potential energy—energy that’s stored in its position. When the domino falls, much of that energy is converted to kinetic energy, which makes it move forward in an arc. It’s important to note that both theories have problems, but the kinetic energy theory is generally accepted by scientists. It has the advantage of being simple and mathematically tractable, whereas CFD/FEM models and probabilistic models are complex and computationally intensive. This has made the kinetic energy theory a popular model for studying the domino effect.