The Penroses '' by
M. C. Escher Escher, in the 1950s, had not yet drawn any impossible stairs and was not aware of their existence. Roger Penrose had been introduced to Escher's work at the
International Congress of Mathematicians in Amsterdam in 1954. He was "absolutely spellbound" by Escher's work, and on his journey back to England he decided to produce something "impossible" on his own. After experimenting with various designs of bars overlying each other he finally arrived at the impossible triangle. Roger showed his drawings to his father, who immediately produced several variants, including the impossible flight of stairs. They wanted to publish their findings but did not know in what field the subject belonged. Because Lionel Penrose knew the editor of the
British Journal of Psychology and convinced him to publish their short manuscript, the finding was finally presented as a
psychological subject. After the publication in 1958 the Penroses sent a copy of the article to Escher as a token of their esteem. While the Penroses credited Escher in their article, Escher noted in a letter to his son in January 1960 that he was: Escher was captivated by the endless stairs and subsequently wrote a letter to the Penroses in April 1960: At a conference in Rome in 1985, Roger Penrose said that he had been greatly inspired by Escher's work when he and his father discovered both the Penrose tribar structure (that is, the Penrose triangle) and the continuous steps.
Oscar Reutersvärd The staircase design had been discovered previously by the Swedish artist
Oscar Reutersvärd, but neither Penrose nor Escher was aware of his designs. Inspired by a radio programme on
Mozart's method of composition—described as "creative automatism"; that is, each creative idea written down inspired a new idea—Reutersvärd started to draw a series of impossible objects on a journey from Stockholm to Paris in 1950 in the same "unconscious, automatic" way. He did not realize that his figure was a continuous flight of stairs while drawing, but the process enabled him to trace his increasingly complex designs step by step. When M.C. Escher's
Ascending and Descending was sent to Reutersvärd in 1961, he was impressed but didn't like the irregularities of the stairs (). Throughout the 1960s, Reutersvärd sent several letters to Escher to express his admiration for his work, but the Dutch artist failed to respond. Roger Penrose only discovered Reutersvärd's work in 1984. ==See also==