Dominoes are small, rectangular blocks, each bearing from one to six pips (or dots) and typically twice as long as they are wide. They may be stacked in rows or in a line, the latter called the domino string. A set of dominoes contains 28 such tiles, although many games use more than this number. Dominoes can be arranged in lines and angular patterns, and the ends of each tile are marked with values from six to zero or blank (depending on the game). This marking is called the value or rank, and it determines the “weight” of a domino. The higher the value, the heavier or more valuable a domino is.
When a domino is played, it joins the line of play, which may be lengthwise or crosswise. A double is joined to the line of play by both its open ends, and it adds to the count either as a single or a double (depending on the rules of the particular game).
Most domino games are divided into four categories: bidding, blocking, scoring, and round. Each has its own rules and variations, but all share the same basic principles: The player who starts the chain by laying the first domino has to cover it with the next available piece of his own, and then each successive tile must match that previous piece in number or in color (if the game is a matching one).
The order of play is determined by the rule of the specific game. If no such rule exists, the first player to play a tile becomes the leader and may be referred to as the setter or downer. The leader must place his tile face up on the table and begin the count of the end of the line of play (see “Order of Play”). There are also games where the tiles remain in a stock and can only be bought, or passed, later in the game.
A domino is a good model for understanding how nerve cells, or neurons, fire. When a domino is triggered, it triggers a pulse that travels along the length of an axon and affects all other neurons along its path. This is exactly how a neuron responds to an input signal.
As a child, Lily Hevesh loved setting up dominoes in straight or curved lines and flicking them with her finger. When she got older, Hevesh’s collection grew larger, and she began using them to create art. She now uses her dominoes to make drawings that are printed on paper, as well as 3-D structures such as towers and pyramids. She also works in software analytics at Domino’s, where she helps the company develop new ways for customers to order pizzas. This has been particularly important as the company has expanded its delivery service into many different parts of the country. Domino’s uses software to help its drivers track their shipments and optimize routes, as well as to allow customers to order pizzas by text or by using devices like Amazon Echo.