Minimal surface
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In mathematics, a minimal surface is a surface with a mean curvature of zero. These include, but are not limited to, surfaces of minimum area subject to various constraints.
Physical models of area-minimizing minimal surfaces can be made by dipping a wire frame into a soap solution, forming a soap film, which is a minimal surface whose boundary is the wire frame.
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[edit] Examples
Classical examples of minimal surfaces include:
- catenoids: minimal surfaces made by rotating a catenary once around the axis.
- helicoids: A surface swept out by a line rotating with uniform velocity around an axis perpendicular to the line and simultaneously moving along the axis with uniform velocity
- the Enneper surface
Recent work in minimal surfaces has identified new completely embedded minimal surfaces, that is minimal surfaces which do not intersect. In particular Costa's minimal surface was first described mathematically in 1982 by Celso Costa and later visualized by Jim Hoffman. This was the first such surface to be discovered in over a hundred years. Jim Hoffman, David Hoffman and William Meeks III, then extended the definition to produce a family of surfaces with different rotational symmetries.
Minimal surfaces have become an area of intense mathematical and scientific study over the past 15 years, specifically in the areas of molecular engineering and materials science, due to their anticipated nanotechnology applications.
[edit] Definition
Given an embedded surface, or more generally an immersed surface (which may have a fixed boundary, possibly at infinity), one can define its mean curvature, and a minimal surface is one for which the mean curvature vanishes.
The term "minimal surface" is because these surfaces originally arose as surfaces that minimized surface area, subject to some constraint, such as total volume enclosed or a specified boundary, but the term is used more generally.
Minimal surfaces are the critical points for the mean curvature flow: these are both characterized as surfaces with vanishing mean curvature.
The definition of minimal surfaces can be extended to cover constant mean curvature surfaces: surfaces with a constant mean curvature, which need not equal zero.
[edit] See also
- soap bubble
- Plateau's problem
- curvature
- Weaire-Phelan structure
- Tensile architecture
- Enneper-Weierstrass parameterization
[edit] References
- Robert Osserman (1986). A Survey of Minimal Surfaces. New York: Dover Publications. ISBN 0-486-64998-9. (Introductory text for surfaces in n-dimensions, including n=3; requires strong calculus abilities but no knowledge of differential geometry.)
- Hermann Karcher and Konrad Polthier (1995). Touching Soap Films - An introduction to minimal surfaces. Retrieved on December 27, 2006. (graphical introduction to minimal surfaces and soap films.)
- Various (2000-). EG-Models. Retrieved on September 28, 2004. (Online journal with several published models of minimal surfaces)
- Stewart Dickson (1996). Scientific Concretization; Relevance to the Visually Impaired Student. VR in the School, Volume 1, Number 4. Retrieved on April 15, 2006. (Describes the discovery of Costa's surface)
- Martin Steffens and Christian Teitzel. Grape Minimal Surface Library. Retrieved on April 15, 2006. (An collection of minimal surfaces)
- David Hoffman, Jim Hoffman et al.. Scientific Graphics Project. Retrieved on April 24, 2006. (An collection of minimal surfaces with classical and modern examples)
- Jacek Klinowski. Periodic Minimal Surfaces Gallery. Retrieved on December 15, 2006. (An collection of minimal surfaces with classical and modern examples)