Code Number: 6A44.57
Demo Title: Submerged Light Bulbs
Condition: Good
Principle: Lenses and Image Formation
Area of Study: Optics
Equipment: Frosted light bulbs or radiometers.
Procedure:
Place the frosted bulbs into a tank of water. The glass envelope will appear to thicken and the frosted coating will appear to shrink as the bulb is submerged.
A glass radiometer can be substituted for the frosted light bulb.
References:
- James E. Kettler, "Some Optical Effects Using a Hollow Sphere and an Aquarium", TPT, Vol. 22, #3, Mar. 1984, p. 171.
- Van E. Neie, "Optical Effects in a Neutral Buoyancy Simulator", TPT, Vol. 19, #1, Jan. 1981, p. 53, also A Potpourri of Physics Teaching Ideas - Optics and Waves, p. 211.
- Richard Breslow, "Optics in a Fish Tank", TPT, Vol. 14, #4, Apr. 1976, p. 234, also A Potpourri of Physics Teaching Ideas - Opics and Waves, p. 209.
- Mark C. James, "Novel Optical Properties of a Submerged Light Bulb", AJP, Vol. 76, #9, Sept. 2008, p. 856.
- Doug Johnson, "Future Index of Refraction Demo", Tap-L discussions, Sept. 24, 2008.