Sir David Brewster

Sir David Brewster, while studying polarization, came up with the idea for the kaleidoscope and patented it in 1817.


What to Do:

  1. Aim the clear side of the kaleidoscope at what you want to look at.
    • Some suggestions are:
    • Objects in the room.
    • The fluorescent lights overhead.
    • Your hand, while moving your fingers together and apart.
  2. Look through the small hole.


What do you think is inside the kaleidoscope that makes the image repeat in wedges around a circle?

Answer: This kaleidoscope has two mirrors inside separated by a 45 degree angle by a dark piece of cardboard.

What is going on?


The image seen in the triangular aperture between the two inclined mirrors is the result of reflections and appears to be a symmetrical figure. The separation of 45 degrees between the two mirrors gives the final image an 8-fold symmetry.  This means that the image repeats 8 times!