Edi Lanners (1929–1996)

We've all been confronted by a difficult puzzle that was easily solved after its secret working was revealed. Take the Nine Dots Puzzle, for instance, where we must connect the dots by drawing four straight, continuous lines, never lifting our pencil from the paper, a puzzle that is easily solved by drawing the lines outside of the boundaries of the square area defined by the nine dots themselves.

"Columbus's Egg" refers to a "Voila!" experience. The expression itself comes from a popular story about Columbus. At a banquet, Columbus was told by some of the guests that discovering the Americas was no great accomplishment. Upon hearing that, Columbus challenged his critics to make an egg stand on its tip. After his critics gave up, Columbus showed them how to do it. He tapped an egg on the table so as to flatten its tip, then stood it on end.

This book is full of mystifiers, stupifiers, and teasers, like Columbus' Egg, along with their solutions. Today, educators refer to problem-solving like this as "thinking outside the box," an expression inspired by the solution to the Nine Dots Puzzle.

A Word to the Wise: It seems to me that thinking outside the box is becoming so popular among educators today that thinking inside the box is becoming unconventional. Don't forget Occam's Razor, the principle that we should always prefer the simplest explanation of events. Thinking outside the box should be used to solve problems only when thinking inside the box fails.

The Moral of the Story: Once people are shown how a feat can be done, anyone can do it.… (mere)