6B40.20 - Hole in a Box - Bichsel Boxes

Code Number:
Demo Title:
Hole in a Box - Bichsel Boxes
Area of Study:
White Box with Hole, Felt, and Construction Paper and Black Boxes - One White Inside, and One Black Inside.

This demonstration shows that a cavity is blacker than any substance, and as such is a good approximation to an ideal black body.

Holes in black boxes are blacker than the boxes themselves, even though one box is painted white on the inside.

A variation is to have a box that is painted white inside and out.  Place a black construction paper dot and a black felt cloth dot beside the hole that is in the box.  The hole still looks blacker.

Irises may be placed on the holes in the boxes if desired.   This is especially useful for the box that is lined with mirrors on the inside.  When the hole is small compared to the dimensions of the box you see nothing but black.  When the hole approaches 1/10th the width of the box or larger, a significant portion of the light entering the box is also reflected back out.

  • John Harris, "Another Way of Making Black", TPT, Vol. 31, #5, May 1993, p. 262.
  • Martin Gardner, "Blacker than Black", TPT, Vol. 31, #2, Feb. 1993, p. 94.
  • Chris D. Zafiratos and John C. Groft, "A Black Surface Fabrication from Specular Reflectors", TPT, Vol. 20, #5, May 1982, p. 316.
  • A. J. Dahm and D. N. Langenberg, "Blackbody Radiation from a Single-Mode Source: A Demonstration", AJP, Vol 43, #11, Nov. 1975, p. 1004.
  • Philip F. Schewe, "The Blackest Material Ever Made", Physics Today, Vol. 61, #4, Apr. 2008, p. 28.
  • G. D. Freier and F. J. Anderson, "Hf-2. Hole in a Box", A Demonstration Handbook for Physics.
  • Robert Ehrlich, "I.2. Hole in a Box", Turning the World Inside Out and 174 Other Simple Physics Demonstrations, p. 117.
  • Martin Gardner, "Blacker than Black", Martin Gardner's Science Tricks, p. 69.
  • Borislaw Bilash II and David Maiullo, "Blackbody Radiation", A Demo a Day: A Year of Physics Demonstrations, p. 360 - 361.
  • Janice VanCleave, "49. Why Outer Space is Dark", Teaching the Fun of Physics, p. 78.
  • Jearl Walker, "6.69. Shiny Turns to Black; Blacker Than Black", The Flying Circus of Physics Ed. 2, p. 136.
  • Thomas D. Rossing and Christopher J. Chiaverina, "Experiments for Home, Laboratory, and Classroom Demonstration. Blacker than Black", Light Science: Physics and the Visual Arts, p. 149.
  • Thomas D. Rossing and Christopher J. Chiaverina, "6.1. Blackbody Radiation", Light Science: Physics and the Visual Arts, p. 129 - 131.
  • Ron Hipschman, "Recipe No. 165: Color Table, Exploratorium Cookbook III, p. 165-1 - 165-3.
  • "P2-21: Black Body Model", University of Maryland.

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