Putting a spin on it
A new book about the dynamics of Frisbees, boomerangs, samaras and skipping stones just published
More Frisbees are sold each year than baseballs, basketballs, and footballs combined. Yet these familiar flying objects have subtle and clever aerodynamic and gyrodynamic properties which are only recently being documented by wind tunnel and other studies.
In Spinning Flight, Ralph Lorenz discusses familiar, but largely undeveloped, topics concerning spinning objects in an accessible manner. "Toys" familiar to all of us are covered as well as high-tech products of the aerospace industry. The amply illustrated book includes not only the latest published results but also describes Lorenz's own experiments, with "how-to" instructions on how readers can do their own experiments.
Boomerangs, which represent another category of spinning aerodynamic body, are also discussed. Supported by equations and graphs, Lorenz explains how the shape and throw of a boomerang relates to its trajectory. The natural world presents still other examples, namely the samaras or "seed-wings" of many tree species, which autorotate during their descent, like a helicopter whose engine has failed. In addition to spinning objects of various shapes, the book also discusses several exotic manned aircraft with disc platforms – these include a Nazi "secret weapon" and the De Havilland Avrocar.
Ralph D. Lorenz is by training an aerospace engineer, but works as a planetary scientist. His main project during his 15-year career as an engineer and scientist has been the Huygens probe. In early 2005 this probe descended through the atmosphere of Saturn's moon Titan.
Ralph D. Lorenz
Dynamics of Frisbees, Boomerangs, Samaras, and Skipping Stones
Springer. 2006, 346 pp., 118 illus.
Hardcover EUR 34.95, £24.00, $49.95, sFr 64.00
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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