The illusion is based on a geometrical puzzle known as the Penrose tribar, from the name of the mathematician whose researches were inspired by Escher’s work. The tribar is a triangle in which each of ...

The late Dutch artist M.C. Escher is perhaps best known for his tessellations that fool the eye, like “Sky and Water I,” where birds in the air trade off negative space with fish underwater. But there ...

In an impossible figure, seemingly real objects—or parts of objects—form geometric relations that physically cannot happen. Dutch artist M. C. Escher, for instance, depicted reversible staircases and ...