Impossible object

Impossible figures are graphically two-dimensional, three-dimensional constructs ostensibly in art, which can not exist corporeally. In the figures it is either paradox or optical illusions. First, they were developed by Oscar Reutersvärd; the Dutch graphic artist MC Escher has created numerous such impossible figures in the 20th century.

The solution of the contradiction arises from the extensive display in two dimensions and three-dimensional structures of sense-perception.

• Some of impossible figures

Impossible cube.

The Penrose stairs.

The impossible crate