Visual illusions where you experience two equally possible interchangeable states in perception are called “bistable illusions“. The Necker cube and the Rubin vase are ones of the most classic examples of a *bistable* figure. I have discovered that all over India, you may see many variants of an interesting bistable depiction, which represents a bull and an elephant with distinct bodies and only one head (painted or sculpted at least 850 years ago). If you look carefully at the whole picture, you may see how the body parts of both animals are skillfully overlapped. For instance, the trunk of the elephant is also the hump of the bull. The horns and ears of the bull have become the mouth or snout of the elephant. These are ones of the earliest documented “ambiguous figure” illusions…

# Paradox

## TangraMagic Puzzle

*TangraMagic*, a new manipulative puzzle for classrooms or just for fun..

*TangraMagic*

This unique puzzle of my creation is ideal for teaching math basic skills, problem solving and critical thinking in an exciting way! The vanishing geometrical effects will hold juniors and seniors’ attention. All the secret of this game is concealed in two numbers: 5 and square root of 7.

## A Geometric Paradox

Where does the extra skull come from? Magic? Can you explain how does this trick work?

This puzzle is available as print from my online store.