USA - California - San Francisco - Exploratorium

The red arch was built on a hinged building surface. Once the blocks were correctly positioned over an outline of the arch, we lifted the wooden platform to bring the blocks to a vertical position. Then we lowered the backboard, leaving the arch free-standing.

The shape the arch takes is called a catenary. The catenary is the curve that an idealized hanging cable or chain with very short links assumes under its own weight when supported only at its ends.Hands-on exhibits explore biology, physics, listening, cognition, and visual perception in the Exploratorium. You can really touch and try everything.The Exploratorium is a museum of science, art, and human perception in San Francisco. It is similar to the Hungarian 'Palace of Miracles' (Csodák Palotája), just about five-times larger.

It was founded in 1969 by physicist and educator Frank Oppenheimer, who was the younger brother of J. Robert Oppenheimer, often called the