6J11.55 - Perception - Optic Tops

Code Number:
6J11.55
Demo Title:
Perception - Optic Tops
Condition:
Good
Principle:
Depth Perception by the Eye
Area of Study:
Optics, Human Biology

Disclaimer

Equipment:
Optic Top with Spirals, Spiral Cutout, CD's, and Pennies.
Procedure:

Spin the disk and observe it for 30 seconds without moving your eyes from the center of the disk.  If you look away from the disk and stare at another surface, the surface will appear to expand or contract.  The effects seen will depend on the direction in which the disk was spun.

A set of optics tops are in 6J11.30 with the Zoetrope.

References:
  • Jair Lúcio Prados Ribeiro, "Myopia Glasses and Optical Power Estimation: An Easy Experiment", TPT, Vol. 53, #2, Feb. 2015, p. 101.
  • Martin Gardner, "The Bent Playing Card", TPT, Vol. 30, #9, Dec. 1992, p. 532.
  • Frank Oppenheimer, "The Study of Perception as a Part of Teaching Physics", AJP, Vol. 42, #7, July 1974, p. 531.
  • George M. Hopkins', "An Artificial Spectrum", Experimental, Science Volume Two, p. 243.
  • Martin Gardner, "The Bent Playing Card", Science Tricks, p. 74.
  • Paul Doherty and Don Rathjen, "Depth Spinner", The Cheshire Cat, p. 43.
  • Paul Doherty and Don Rathjen, "Squirming Palm", The Cheshire Cat, p. 97.
  • Janice VanCleave, "Wagon Wheel", 201 Awesome, Magical, Bizarre, & Incredible Experiments, p. 37.
  • Janice VanCleave, "Wagon Wheel", Biology for Every Kid - 101 Easy Experiments That Really Work, p. 160 - 161.
  • Raymond Bruman, "Shimmer", Exploratorium Cookbook I, p. 39.1 - 39.2.
  • Raymond Bruman, "Three Spinners", Exploratorium Cookbook I, 41.1 - 41.4.
  • Brown, "An Optical Illusion", More Science for You - 112 Illustrated Exp., p. 4.
  • Bobby Mercer, "Mesmerizing CD Top", Junk Drawer Physics, IBSN 978-1-61374-920-3, p. 1 - 4.
  • Jess Romeo, "The Original Illusions", Popular Science, Spring 2020, p. 114.

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.