Geodesic Dome

A geodesic dome is an almost spherical structure (often a building) in which the supporting network of struts are positioned on great circles (called geodesics), which lie on the surface of a sphere. It is composed of a lattice of interconnecting tetrahedrons (a pyramid with three sides and a base) and octahedrons (an

eight-sided figure—two pyramids with four sides and a base, placed base to base).

The first contemporary geodesic dome on record is the one built by German inventor and engineer Walter Bauersfeld. He realized the utility of projecting the constellations on the inner surface of an icosasphere, Omnimax-style, thereby creating a breakthrough planetarium in Jena, Germany, in 1922. After gaining the patient on the invention, the geodesic dome was constructed at the German optical company Carl Zeiss, where Bauersfeld worked. However, the geodesic dome common today was invented and patented in the United States by American architect Buckminster Fuller (1895–1983) in 1947.

Geodesic domes are fractional parts of complete geodesic spheres. Actual structures range from less than 5 to 100% (a full sphere). The Spaceship Earth Pavilion constructed by Tishman Construction for AT&T at Walt Disney World’s EPCOT is the bestknown example of a full sphere.

Several physical and mathematical ideas factor into building a geodesic dome. For example, a con-vexly curved surface is stronger than a flat one, most materials are stronger in tension than in compression, and the most rigid structure is a triangle. A hemisphere encloses the most space with the least amount of material while the tetrahedron encloses the least volume with the most surface. These principles make geodesic domes the strongest, lightest, most energy efficient buildings ever devised. Structural patterns of geodesic domes vary in complexity. Some domes have been built using simple interconnecting triangles as a support structure while others have icosahedrons as their supporting structure. An icosahedron is the geometric form having the greatest number of identical and symmetrical faces—it has 20 faces, 12 vertices, and 30 edges. The more complex the structure is, the stronger it is.

Geodesic spheres and domes come in various frequencies. The frequency of a dome relates to the number of smaller triangles into which it is subdivided. A high frequency dome has more triangular components and is more smoothly curved and sphere-like.

Geodesic dome structures are used as private residences, commercial buildings, places of worship, schools, sports arenas, theaters, and vacation homes. Dome homes can be found in all 50 of U.S. states. They can be found in many places throughout the world such as China, Africa, Europe, and the Antarctic. Some notable geodesic domes are the Climatron, a climate controlled botanical garden in St. Louis, Missouri (which was built in 1960), the Houston Astrodome (1965), and the dome for the American pavilion (now called the Montreal Biosphere) at Expo ’67 in Montreal (1967). In addition, humans have been living in domes such as mud huts, igloos, and thatch huts for millions of years.