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Two 10 inch polaroid filters, assorted smaller polaroid filters, lucite nutcrackers, prepared cellotape sheet, calcite crystal, 35 mm projector and 3 mm aperture metal piece
A piece of lucite in the form of a “lucite nutcracker” can be placed between crossed polaroids. Squeezing the arms of the nutcracker will produce strain patterns.
* Use a transparency with printing on the overhead projector and lay the calcite crystal over the top of the printing. The double refraction can be seen and rotation of the crystal rotates the image of the extra-ordinary ray about the image of the ordinary ray. * Now use the 33 mm projector with a metal screening piece and a 3 mm diameter hole in the slide holder. Place the calcite crystal in front of this (a piece of folded paper holds it at the correct height). A double circular image can be focussed on the screen. A polaroid filter can now be rotated in front of the projector to show that two circular images are polarized at right angles. * The polaroid effect is demonstrated in the pictures below. It is not extremely clear, but in the bottom photo the polaroids are darker than in the other photo. Updated on: 06/13/13
Demo room information