6A10.17 - Mirror Box Puzzle

Code Number:
6A10.17
Demo Title:
Mirror Box Puzzle
Condition:
Good
Principle:
Angle of Incidence = Angle of Reflection for Plane Mirror
Area of Study:
Optics

Disclaimer

Equipment:
Covered mirror box with 5 to 6 movable mirrors inside, Laser.
Procedure:

This is an educational test designed to reinforce the concept of angle of incidence = angle of reflection for plane mirrors.  The box has 8 holes in it.  It can be set up so the laser beam enters one of the holes and exits any of the other holes with the proper orientation of the desired amount of mirrors (up to 6).  Once this is set up the box is closed so that the students only see where the beam enters and exits.  The teacher will tell the students how many mirrors are in the box and their positions.  The students are also told that the laser beam is bounced off every mirror in the box.  The challenge for the students is to predict the correct orientation of the mirrors.  The box can then be opened to see whether their prediction is correct.

A commercial version of the mirror puzzle box with its own laser diode style lasers.

References:
  • J. Christopher Moore and Louis J. Rubbo, "Modeling Hidden Circuits: An Authentic Research Experience in One Lab Period", TPT, Vol. 54, #7, Oct. 2016, p. 423.
  • Scott Miller, "Modeling the Nature of Science with the Mystery Tube", TPT, Vol. 52, #9, Dec. 2014, p. 548.
  • Dean Zollman, "Resolution: A Simple Demonstration", TPT, Vol. 12, #2, Feb. 1974, p. 89.
  • Jearl Walker, "6.67, A Sideshow Laser Shoot", The Flying Circus of Physics Ed. 2, p. 268.
  • Bobby Mercer, "Black Box", Junk Drawer Chemistry, 2016, p. 52.

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.