6J11.65 - Pulfrich Phenomenon - Pulfrich Pendulum
Start the pendulum in a motion perpendicular to the viewer. The viewer should put a dark piece of glass or a filter over one eye. With both eyes open look at the pendulum and notice that it now appears to be going in an elliptical orbit.
- Jerold Touger, "Which Observations Should We Believe?: An Activity Using the Pulfrich Pendulum", TPT, Vol. 48, # 1, January 2010, p. 35.
- Martin Gardner, "The Pulfrich Illusion", TPT, Vol. 33, # 2, p. 117, Feb. 1995.
- Earl Zwicker, "The Pulfrich Pendulum", TPT, Vol. 19, # 8, Nov. 1981, p. 564.
- John T. McGrath, "The Clever Brain", TPT, Vol. 20, # 2, Feb. 1982, p. 72.
- W-060: "Puhlfrich Effect", DICK and RAE Physics Demo Notebook.
- Martin Gardner, "The Pulfrich Illusion", Science Tricks, p. 65.
- Martin Gardner, "The Illusory Pendulum", Entertaining Science Experiments with Everyday Objects, p. 41.
- Jearl Walker, "7.23, Pulfrich Illusion", The Flying Circus of Physics Ed. 2, p. 314.
- Raymond Bruman, "Delayed Vision", Exploratorium Cookbook I, p. 52.1.
- Tik L. Liem, "The Elliptical Pendulum Swing", Invitations to Science Inquiry - Supplement to 1st and 2nd Ed. p. 155.
Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist. The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose. The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources. Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks. These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage. Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.