1958, in the American Journal of Psychology, Penrose published his insoluble triple persistence. As shown in figure 1- 1. He called it a three-dimensional rectangular structure: three right angles, vertical, but impossible to exist in space, because three right angles seem to be one here? Triangle? But the triangle is a plane rather than a three-dimensional figure, and the sum of the three internal angles is 180? , not 270? .
Figure 1- 1
Figure 1-2
In 1950s, Rogge and Penrose wrote an article about impossible figure, describing a kind of? Stairs with no end? Stepping on the stairs seems to rise step by step, but the stairs stay on a horizontal plane. As shown in figure 1-2.
Figure 1-3
Escher, a famous Dutch painter, is regarded as a master of optical illusion painting in the 20th century. His works are particularly valued by scientists because of their profound mathematical and physical significance. As shown in figure 1-3, the logo he made for the 10th International Mathematical Congress (Austria, 198 1) is a three-dimensional impossible figure.