Mathematicians often take delight in Cat's Cradle, the age-old game of making string figures on one's fingers. In the most familiar form of this game, one person starts out with a simple rectangle of yarn or string, and then makes a simple figure by looping different parts of the yarn around his or her fingers. This figure is then passed to the fingers of a second player, who introduces another layer of complexity into the figure before passing the increasingly complex string figure to a third player. And so on, until the figure becomes so complex that it becomes impossible to go further, at least with a two-foot length of yarn.
