Alexander Calder (July 22, 1898 - November 11, 1976) was an American sculptor and artist. Calder is most famous for his "mobiles" - wire structures that were balanced both elegantly and whimsically - allowing motion and light to change and add to the piece. Calder invented this medium of moving abstract sculpture in 1925, which was given the name "mobile" by Marcel Duchamp. (Jean Arp suggested that non moving sculpture should similarly be referred to as "stabiles", but this failed to catch on widely.)
In addition to mobile and stable sculpture, Alexander Calder also created paintings, lithographs, and tapestry, and designed carpets.