Oscar Reutersvard is a Swedish artist known as the "father of impossibility". He was born in Stockholm in 1915, and taught art by the Russian emigrant David Katz. He created his first impossible figure in 1934 by accident. Since then, he has created thousands of geometrical drawings of shapes and forms which cannot possibly exist in physical space. His works are essentially three-dimensional objects which can only be perceived by us in two-dimensional space.
One of his better known works is the "impossible staircase", which was rediscovered and published by M.C. Escher and Roger Penrose in 1958. They had not known of Reutersvard's previous work. In 1982, his works were honoured with a series of postage stamps in Sweden. His art is unique in that it challenges basic theories of geometry and perception.