The optical illusion of the impossible triangle in Perth, Australia. Seen from the right angle, this sculpture looks like a Penrose triangle. Credit: Bjørn Christian Tørrissen / Wikimedia Commons ...

But there was much more to Roger’s puzzling than this. People who know little else about what he did may be familiar with the Penrose triangle, which shares space with Escher’s prints on the walls of ...

Some have achieved pop status, including the “Penrose Triangle,” an optical illusion that Penrose devised at the age of 23 that was inspired by the work of Dutch graphic artist M.C. Escher.

This is a Penrose triangle. It is an example of an impossible object or a visual paradox. It appears to depict a contradictory object that cannot exist. Some ...