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GeezerVison is showing mathworld.wolfram.com — Helicoid -- from Wolfram MathWorld HelicoidThe (circular) helicoid is the minimal surface having a (circular) helix as its boundary. It is the only ruled minimal surface other than the plane (Catalan 1842, do Carmo 1986). For many years, the helicoid remained the only known example of a complete embedded minimal surface of finite topology with infinite curvature. However, in 1992 a second example, known as Hoffman's minimal surface and consisting of a helicoid with a hole, was discovered (Sci. News 1992). The helicoid is the only non-rotary surface which can glide along itself (Steinhaus 1999, p. 231). The helicoid is a singly periodic minimal surface under axial translations. The equation of a helicoid in cylindrical coordinates is
In Cartesian coordinates, it is
It can be given in parametric form by
which has an obvious generalization to the elliptic helicoid. Writing The first fundamental form coefficients of the helicoid are given by
and the second fundamental form coefficients are
giving area element
Integrating over
The Gaussian curvature is given by
and the mean curvature is
making the helicoid a minimal surface. The Gaussian curvature can be given implicitly by
The helicoid can be continuously deformed into a catenoid by the transformation
where
If a twisted curve Helicoids occur in architectural forms such as helical staircases and ramps, as well as in screw-type machine-building products (Bock Hyeng et al. 2025). See alsoCalculus of Variations, Catenoid, Cone, Conoid, Elliptic Helicoid, Generalized Helicoid, Helix, Hoffman's Minimal Surface, Hyperbolic Helicoid, Minimal Surface, SeashellExplore with Wolfram|AlphaReferencesBock Hyeng, C. A.; Krivoshapko, S. N.; Kouamou Nguessi, A.; Yamb Bell, E.; and Bahel, B. "Application of Curvilinear Analytical Surfaces in Forms of Architectural Objects and Machine Building Products." Int. J. Archit. Arts Appl. 11, 19-35, 2025. https://doi.org/10.11648/j.ijaaa.20251101.13.Catalan E. "Sur les surfaces réglées dont l'aire est un minimum." J. Math. Pure Appl. 7, 203-211, 1842.do Carmo, M. P. "The Helicoid." §3.5B in Mathematical Models from the Collections of Universities and Museums (Ed. G. Fischer). Braunschweig, Germany: Vieweg, pp. 44-45, 1986.Fischer, G. (Ed.). Plate 91 in Mathematische Modelle aus den Sammlungen von Universitäten und Museen, Bildband. Braunschweig, Germany: Vieweg, p. 87, 1986.Geometry Center. "The Helicoid." http://www.geom.uiuc.edu/zoo/diffgeom/surfspace/helicoid/.GRAPE. "Catenoid-Helicoid Deformation." https://archive.ins.uni-bonn.de/numod.ins.uni-bonn.de/grape/EXAMPLES/AMANDUS/cathel.html.GRAPE. "Helicoid." https://archive.ins.uni-bonn.de/numod.ins.uni-bonn.de/grape/EXAMPLES/AMANDUS/helicoid.html.Gray, A. Modern Differential Geometry of Curves and Surfaces with Mathematica, 2nd ed. Boca Raton, FL: CRC Press, pp. 449 and 644, 1997.Kreyszig, E. Differential Geometry. New York: Dover, p. 88, 1991.Meusnier, J. B. "Mémoire sur la courbure des surfaces." Mém. des savans étrangers 10 (lu 1776), 477-510, 1785.Ogawa, A. "Helicatenoid." Mathematica J. 2, 21, 1992.Osserman, R. A Survey of Minimal Surfaces. New York: Dover, pp. 17-18, 1986.Peterson, I. "Three Bites in a Doughnut." Sci. News 127, 168, Mar. 16, 1985."Putting a Handle on a Minimal Helicoid." Sci. News 142, 276, Oct. 24, 1992.Steinhaus, H. Mathematical Snapshots, 3rd ed. New York: Dover, pp. 231-232, 1999.Wells, D. The Penguin Dictionary of Curious and Interesting Geometry. London, England: Penguin, p. 94, 1991.Referenced on Wolfram|AlphaHelicoidCite this as:Weisstein, Eric W. "Helicoid." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Helicoid.html Subject classifications | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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