Alexander Calder created beautiful mobiles and other sculptures. Balanced perfectly on the centroid of each piece, his work hangs in The National Gallery of Art in Washington D.C., as well as in many other galleries.

Alexander Calder (1898-1976) Born in Lawnton, Pennsylvania (now part of Philadelphia) in 1898 Alexander Calder came from a family of famous artists. Though demonstrating prodigious artistic ability as a child, a pursuit encouraged by his parents, he elected to study engineering at the Stevens Institute of Technology in Hoboken, New Jersey. A drafting assignment early in his engineering career brought him back to art. Two years later, he enrolled in an evening art class at a New York City public school. Finally, in 1923, at age 25, he abandoned engineering to become a full-time student at New York's Art Students League. Calder's fame and his career as a sculptor began with an assignment from the National Police Gazette to illustrate the Barnum and Bailey Circus. That job inspired some of his most enchanting works: miniature circus figures with cork and wood bodies and articulated wire arms and legs. Calder's first abstract sculpture, initially exhibited in Paris in 1931, was described by artist Fernand Leger as "serious without seeming to be." His first mobiles were exhibited in Paris in 1932. Calder's sculptures exist the world over, in city squares, in nature settings, in museums, and in public buildings.

White Cascade, one of Alexander Calder's last and greatest motorized sculptures, was installed in the court of the Federal Reserve Bank of Philadelphia in 1976. It is the largest indoor mobile in the world.

Here is a picture of another Calder mobile, in Paris: At the time, the largest mobile in Europe,because of its 10 meter height, this piece is made of black steel and weighs two tons. Each arrow is 7m long. The mobile presents a harmoneous figure as the five balanced arms are put into motion with the slightest gust of wind. Constructed from the top down, the mobile was brought to Paris and assembled in two days.

"Spiral" (1958) Alexander Calder (United States of America 1898-1976) UNESCO Art Gallery

Our geometry class constructed a simple mobile made of matt board triangles balancing on their centroids:

The triangle centers have connections to many different fields. These applications include using radar and sonar in navigation of airplanes, ships and submarines, undersea explorations in marine biology and oceanography, weather surveillance, the collection of data on the movements of animals and migration patterns of birds.

http://www.janes.com/

Air traffic controllers use radar to track the locations and flight paths of airplanes

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http://www.marine-group.com/SonarPrimer/SideScanSonar.htm#Introduction

The things you have learned about the center of a triangle also have applications in locating the epicenter of an earthquake, in writing and following a treasure map, and in architectural design. Look for new applications and information on this page, soon to come.

Architects use geometry in designing everything from homes to office buildings. This drawing is an example of a high-rise building designed by a company called Art-Hit. This drawing was done on a computer, using Computer Aided Drafting (CAD) For more information about this architectural design company, click on the link below: