A pirate captain presents his prisoner with eight golden coins and a challenge: if the prisoner can identify the single genuine gold doubloon in the bunch, he can keep the coin, and his life. If he...
The "Burr," "Knot" or "Chinese Cross" is one of the oldest and most popular mechanical puzzles in the world. The origin of the puzzle is unknown but the earliest known record is an engraving from 1...
The "Droste effect" refers to the technique of creating a recursive image or, put more simply, a picture inside of itself. The Droste effect gets its name from the image on the packaging of a popul...
The Zoetrope or “wheel of life” is an analog animation device that predates the dawn of cinema. Invented by William George Horner in 1834, the machine was first marketed in 1887, before most people...
History of the Nine Dot Problem
The nine dot problem is a classic lateral thinking exercise that gained widespread popularity in the 1970's and 80's. Participants are presented with a set of dots arranged in a 3x3 grid and challe...
13 Clever Ways to Use a Playing Card
Over the years we've gathered a collection of unique, sometimes strange, ways to use a playing card. These are practical uses of a playing card beyond the ordinary poker night, card trick or house ...
