Refraction: Disappearing Test Tube -Group Activity

Experiment uses glycerine and pyrex similar refractive index, so the test tube in the glycerine is almost invisible. The worksheet asks the group to examine the setup, discuss some questions and then try to think up a magic trick which makes use of this property. A good trick is to smash a test tube with a mallet, drop the shards into a glass bowl of pyrex, say the magic words and then use tongs to extract from the bowl the magically repaired test tube (which of course was there all along - just invisible). The sheet may needs adapting to give students a bit more help and guidance.