A mobile is a form of kinetic sculpture designed to hang weighted objects or additional rods.
Artist Alexander Calder is credited with originating the mobile. By suspending forms that respond to the movement of air, Calder brought about a revolution in sculpture. Marcel Duchamp coined the term 'mobiles' for these works. Instead of being solid, massive objects, mobiles continually redefine the space around them as they move. Calder's skillful balance of form and colour led to works that evoke an animated interpretation of paintings by his friends, such as Joan Miró.
In 1943, Albert Einstein visited an exhibition of suspended artworks created by Alexander Calder at the Museum of Modern Art and became known for his famous remark: "I wish I had thought of that."