花瓣的弧形

From the 1930s on, Calder created non-mechanized hanging, standing, and wall-mounted mobiles, whose movement was driven by random air currents. Early versions often used scavenged bits of glass or pottery, while later ones were generally comprised entirely of flat metal shapes painted solid red, yellow, blue, black, or white, such as this work. Calder succeeded in integrating natural movement into sculpture by assembling elements that balance themselves naturally by weight, surface area, and length of wire "arm." The basic equilibrium he struck guarantees compositional harmony among the parts, no matter their relative positions at any given moment. Though many other artists have since created works based on his principles, even now, decades later, Calder is still the undisputed master of this form of sculpture.