6A20.30 - Mirrors - Image of a Light Bulb

Code Number:
6A20.30
Demo Title:
Mirrors - Image of a Light Bulb
Condition:
Excellent
Principle:
Concave, Convex Mirrors, Focal Lengths
Area of Study:
Optics
Equipment:
Large Parabolic Mirror, Inverted Light Bulb in a Box, Candle, Grill Lighter, and Small Spherical Mirror.
Procedure:

Clean the parabolic mirror thoroughly.  Position the box in front of the mirror as shown.  Care must be taken to position the box so that the light bulb image is on the dummy socket.

A candle can be made to appear to burn at both ends.  Place the candle horizontal and at the focal point of the mirror and when lined up, light the candle.

One end of the candle will have the flame pointing upward while the other end of the candle will have the candle pointing downward.

References:
  • Thomas B. Greenslade Jr., "A Scientific Mystery", TPT, Vol. 57, #4, Apr. 2019, p. 221.
  • Robert M. Graham, "Real Image Produced by a Concave Mirror", TPT, Vol. 44, #3, Mar. 2006, p. 186.
  • Robert M. Graham, "Convincing Students of the Existence of a Real Image", TPT, Vol. 32, #4, Apr. 1994, p. 238.
  • R. D. Edge and Edwin R. Jones, Jr., "Optical Illusions", TPT, Vol. 22, #9 , Dec. 1984, p. 591.
  • Christopher Conery, "The Reality of a Real Image", TPT, Vol. 21, #9, Dec. 1983, p. 589.
  • Robert M. Graham, "Real Image Produced by a Concave Mirror", TPT, Vol. 15, #2, Feb. 1977, p. 116.
  • D. Rae Carpenter Jr. and Richard B. Minnix, "O-165. Burn Candle at Both Ends", DICK and RAE Physics Demo Notebook, 1993.
  • D. Rae Carpenter Jr. and Richard B. Minnix, "O-160. Is a Bulb in Socket? - Toy", DICK and RAE Physics Demo Notebook, 1993.
  • G. D. Freier and F. J. Anderson, "Oc-10", A Demonstration Handbook for Physics.
  • G. D. Freier and F. J. Anderson, "Oc-4", A Demonstration Handbook for Physics.
  • George M. Hopkins, "Phantom Bouquet", Experimental Science, p. 211.
  • David Kutliroff, "6. Burning a Candle at Both Ends", 101 Classroom Demonstrations and Experiments For Teaching Physics, p. 29.
  • R. Gardner, "The Little Bulb That Isn't There", Make an Interactive Science Museum, p. 86 - 89.
  • Raymond Bruman, "Touch the Spring", Exploratorium Cookbook I, p. 16.1 - 16.2.
  • "Touch the Spring", Exploratorium Science Snackbook, 100.1 - 100.2.
  • Brian Jones and Matt Fackelman, "Phantom Light Bulb", Don't Forget the Duct Tape, p. 89 - 92.
  • "Spherical Mirrors", Selective Experiments in Physics, CENCO, 1962.


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.