6J11.11 - Optic Top - Benham's Disk

See paragraph one in the procedure section.
Code Number:
Demo Title:
Optic Top - Benham's Disk
Integration of Light Pulses by the Eye
Area of Study:
Optics, Human Biology
Benham's wheel top, Benham's wheel cutouts, used CD's, pennies, Op-Tric Set.

Spin the disk under bright or normal lighting.  Even though the disk is black and white, when spun the strobing effect will make it appear that the disk has colors.  Reds and yellows are most apparent, but greens and blues can be seen if observed carefully.

The Op-Tric set has several top patterns that will also show colors when spun.  

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

  • Laxmipuram P. Sri Vatsa, "Prevost-Fetchner-Benham Effect", AJP, Vol. 40, #6, June 1972, p. 914.
  • D. James Baker, Jr., "Time Dependence of Flourescent Lamp Emission - A Simple Demonstration", AJP, Vol. 34, #7, July 1966, p. 627.
  • C. L. Strong, "The Amateur Scientist: "Generating Visual Illusions with Two Kinds of Apparatus",  Scientific American, Vol. 224, # 3, March 1971, p. 110.
  • George M. Hopkins, "Experiments with the Scientific Top", Experimental Science, p. 174.
  • Paul Doherty, Don Rathjen, "Benham's Disk", The Cheshire Cat, p. 12.
  • Martin Gardner, "Swizzle-Stick Code", Entertaining Science Experiments with Everyday Objects, p. 72.
  • Martin Gardner, "Color That Isn't There", Entertaining Science Experiments with Everyday Objects, p. 71.
  • Robert L. Wild, "Psychological Color - B/W Disk Plus Stripes", Low-Cost Physics Demonstrations # 170, p. 96.
  • 5.130:  Jearl Walker, "Colors in a Black and White Disc",  The Flying Circus of Physics with Answers.
  • 5.131:  Jearl Walker, "Color Effect from Fluorescent Lights",  The Flying Circus of Physics with Answers.
  • Janice VanCleave,  "Color Trickery",  Gooey, Slippery, Slimy, Weird, & Fun Experiments, p.  38.
  • Janice VanCleave,  "Color Trickery",  Biology for Every Kid - 101 Easy Experiments That Really Work, 162-163.
  • Raymond Bruman,  "Three Spinners",  Exploratorium Cookbook I, 41.1 - 41.4.
  • "Benham's Disk",  The Exploratorium Science Snackbook, 5.1 - 5.2.
  • R.D. Edge, "Benham's Top", String & Sticky Tape Experiments, p. 13.01.

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.