It was more or less directly as a result of my visit to Piet Mondrian’s studio in 1930, and the sight of all his rectangles of color deployed on the … - Alexander Calder

We notice the movement of automobiles and beings in the street, but we do not notice that the earth turns. We believe that automobiles go at a great speed on a fixed ground; yet the speed of the earth's rotation at the equator is 40,000 km every 24 hours.

Question: Which has influenced you more, nature or modern machinery?
I haven't really touched machinery except for a few elementary mechanisms like levers and balances. You see nature and then you try to emulate it. But, of course, when I met Mondrian [Paris, 1930] I went home and tried to paint [for a while]. The basis of everything for me is the universe. The simplest forms in the universe are the sphere and the circle. I represent them by disks and then I vary them. My whole theory about art is the disparity that exists between form, masses and movement. Even my triangles are spheres, but they are spheres of a different shape.

As truly serious art must follow the greater laws, and not only appearances, I try to put all the elements in motion in my mobile sculptures.