Dominos are a classic toy, and the best ones have an attractive pattern of dots that make them pretty. But a domino can also serve as an interesting way to show how physics works. A few of the many ways that a domino can be used include playing games, creating art, and even making a structure that’s a model for a science experiment.
In the western world, a domino is a rectangular tile with an arrangement of spots, called “pips,” on one side and a blank or identically patterned side. The pips mark the value of each tile in a specific combination. The most popular set of dominoes contains 28 unique tiles, each with two ends that are either marked with a number or blank. The numbering on each end indicates how many of the domino’s sides are able to be connected. In a game of domino, each player is dealt seven tiles, and additional tiles may be added to a hand as the need arises.
Each time a person adds a tile to a line, the connecting ends of the other dominoes must match, either all the pips matching or all the blanks matching. A tile with a matching pair of exposed ends is known as a “double.” In most games, additional dominoes can only be played on the open or “open” ends of a double. A player is awarded a certain number of points depending on the matching and connecting rules of the game.
Lily Hevesh has been fascinated by dominoes since she was 9 years old, when her grandparents gave her a classic 28-pack. She soon started creating and posting videos of her own domino designs. Her YouTube channel now has more than 2 million subscribers. Hevesh is an expert in the art of creating mind-blowing domino setups, including curved lines and grids that form pictures when they fall.
When Hevesh sets up her creations, she usually has a theme in mind. She’ll brainstorm images or words that can fit with the intended purpose of the layout. She then creates a diagram of her design on paper, and calculates how many dominoes she needs to complete the project.
Stephen Morris, a physicist at the University of Toronto, says that gravity plays an important role in a domino’s ability to cause a chain reaction. “When you stand a domino upright, it stores energy in its position, due to the force of gravity,” he says. “When that first domino falls, its potential energy is converted to kinetic energy—energy of motion.”
The kinetic energy of the falling domino then pushes on the next domino and causes it to fall, and so on. The chain of reactions continues until all the dominoes have fallen. Hevesh has created installations that take several nail-biting minutes to fully collapse. Each domino has inertia, a tendency to resist movement when no outside forces are applied, but all it takes is a tiny nudge to tip them over.
