Kinetic art expressions based on optical and luminous phenomenon as well as painting illusionism. The expression "kinetic art" in this modern form first appeared at the Museum für Gestaltung of Zürich in 1960, and found its major developments in the 1960s. In most European countries, it generally included the form of optical art that mainly makes use of optical illusions, such as op art, represented by Bridget Riley, as well as art based on movement represented by Yacov Agam, Carlos Cruz-Diez, Jesús Rafael Soto, Gregorio Vardanega, or Nicolas Schöffer. From 1961 to 1968, GRAV ("Groupe de Recherche d’Art Visuel") founded by François
Crater illusion Crater illusion The Crater Illusion also known as the Crater/Dome Illusion or Dome Illusion is an optical illusion which causes impact craters in some images to appear as domes or mountains. It is believed to be caused by our being accustomed to seeing light from overhead. When some images are taken from orbit, the light from the sun is nearly horizontal. This is the only time shadows are seen. Our brains are tricked into thinking that the interior of the crater is above the surrounding terrain instead of below it. In September 2015, NASA released the image on the left