Disc

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A disc (or the more common name Frisbee) is generally plastic, roughly 20 to 25 centimeters (8–10 in) in diameter, with a lip. They are designed to fly aerodynamically when thrown with rotation and can be caught by hand. The name Frisbee is a registered trademark of the Wham-O toy company, but the term is often used generically (and erroneously) to describe all versions of the flying disc.

A wide range of Frisbee (flying Discs) variants are available commercially. Disc golf discs are usually smaller but denser and are tailored for particular flight profiles to increase/decrease stability and distance. When it was discovered that dogs enjoyed chasing and retrieving the slow-moving discs, special discs were designed with more pliable material that would better resist a dog's bite, and prevent possible injury that may occur with more rigid materials. Disc dog competitions, in which dogs' disc-catching skills are judged, have become quite popular as well. Ring-like discs shaped like a Saturn's ring, known as Aerobies, typically fly significantly farther than any traditional flying disc. The evolution has continued with the advancement of lighting a flying disc for evening and night-time play. By using a Flashflight disc, players can extend the throw and catch playing time after the sun goes down.

Contents

[edit] History

The modern day frisbees are developed from the "Flying-Saucer", originally invented by Erich Drafahl and codeveloped and financed by Warren Franscioni in 1948. However, that initial disc was largely unsuccessful. A later model made by Morrison in 1955 and sold as the "Pluto Platter" was bought by Wham-O on January 13, 1957. In the next year, Wham-O renamed the toy "Frisbee", a (probably deliberate) misspelling of the name of the Frisbie Pie Company of Bridgeport, Connecticut, whose pie tins had been used by Yale University students in the campus for similar purposes.

[edit] Games using flying discs

Main article: Flying disc games

[edit] Physics

The rotating flying disc has angular momentum perpendicular to the horizontal plane, stabilizing the disc's attitude in high-speed flight. Small ridges near the leading edge act as turbulators, reducing flow separation by forcing the airflow to become turbulent after it passes over the ridges. Lift is generated in primarily the same way as a traditional asymmetric airfoil, that is, by accelerating upper airflow such that a pressure difference gives rise to a lifting force.

Even a slight deformation in a disc, called a "taco" as extreme cases look like a taco shell, can cause adverse affects when throwing long range. It can be observed by holding the disc horizontally at eye level and looking at the rim while slowly rotating the disc.

Richard Feynman in his book Surely You're Joking, Mr. Feynman! suggests that watching the wobble of a plate tossed in the Cornell University cafeteria stimulated him to develop mathematics that eventually led to his Nobel prize winning work in quantum electrodynamics [1].

For a detailed paper on the physics of disc flight see Sarah Hummel's paper in the further reading section of this entry.

[edit] Trivia

  • In the animated motion picture The Secret of NIMH, the main character's name was changed in post-production from "Frisby" to "Brisby" to avoid potential trademark infringements.

[edit] See also

[edit] Further reading

  • Frisbee, A Practitioner's Manual and Definitive Treatise Stancil E.D. Johnson, M.D. Workman Publishing Company, New York (July, 1975) ISBN 0-911104-53-4
  • The Official Frisbee Handbook Goldy Norton, Bantam Books, Toronto/New York/London (July, 1972) no ISBN
  • Frisbee Players' Handbook Mark Danna, Dan Poynter, Parachuting Publications, Santa Barbara, California (1978) ISBN 0-015516-19-5
  • Frisbee Sports & Games Charles Tips, Dan Roddick, Celestial Arts, Millbrae, California (March 1979) ISBN 0-89087-233-3
  • Frisbee by the Masters Charles Tips, Celestial Arts, Millbrae, California (March 1977) ISBN 0-89087-142-6
  • Frisbee Flight Simulation and Throw Biomechanics Research of Sarah Hummel http://mae.engr.ucdavis.edu/~biosport/frisbee/frisbee.html

[edit] External links

  • Frisbee, about.com
  • Ultimate Players Association sports governing body of Ultimate in the USA
  • World Flying Disc Federation international sports governing body for all flying disc sports
  • Discraft manufacturer of flying discs for Ultimate, Disc Golf, and Freestyle
  • Wham-O Frisbee disc website manufacturer of Frisbee brand flying discs
  • UK Ultimate Association
  • frisbeecollective.com
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