A domino is a tile with a specific arrangement of spots, called pips, on each half of its face. The domino is a versatile toy that can be used in a wide variety of games, from simple stacking to building complex designs. They are normally twice as long as they are wide, and are arranged end to end in lines. When a domino is tipped over, it affects the next domino down the line, and so on. This chain reaction is what has given rise to the term “domino effect,” which describes a small action that causes larger-and sometimes catastrophic-consequences.
Dominos are typically made from pressed clay or polymer, but have been produced in many other materials: stone (e.g., marble, granite, soapstone), wood (e.g., ebony); metals (e.g., brass); ceramic clay; and even frosted glass. Traditionally, sets were crafted from these natural materials for their beauty and weight; these sets often feature the top half thickness in mother of pearl, ivory, or a dark hardwood such as ebony, with contrasting black or white pips.
Like playing cards, of which they are a variant, dominoes have an identity-bearing face on one side and a blank or identically patterned other face. They are distinguished from ordinary dice by the fact that their pips have a particular arrangement, so that each number corresponds to a particular spot on the domino face. The pips on each side of the domino are marked either with 1, 2, 3, 4, 5, 6, or 7, although some of the spaces are left empty.
When a person sets up a domino, it is usually placed on a hard surface so that it stands upright. When a domino is tipped, it will spill over the edge of the set, and the other pieces will fall over in turn. The dominoes will continue falling until all of the ones on the table are knocked over.
Physicists have demonstrated that, though each domino may seem insignificant on its own, when the entire set is tipped, it can bring down an object about a-and-a-half times its size. University of British Columbia physics professor Lorne Whitehead once set up 13 dominoes, each a millimeter tall and no thicker than a Tic Tac. His final set was more than three feet tall and weighed over 100 pounds.
When author Jennifer Hevesh creates her mind-blowing domino installations, she uses a version of the engineering-design process. She considers the theme or purpose of an installation, brainstorms images and words that relate to the idea, and then tries out different possibilities for the domino layout. The result is a beautiful, awe-inspiring sequences of events that show the domino effect in action.