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Ntnu Virtual Physics Lab: Thick Lens Java Applet
An interactive Java applet which allows the user to investigate the path of light through a lens shape object. The shape of the object, the index of refraction of the material, and the location of the incident rays can be altered.
Wolfram Research
Wolfram Science World: Bernoulli, Johann (1667 1748)
This site from ScienceWorld contains a short but factual biography of Johann Bernoulli. Includes a picture, along with quite a few links that contain additional information on related subjects.
Optical Society
Optical Society of America: Optics for Kids: Lose a Glass in a Glass
This is an activity that should only be done outdoors or in a well-ventilated area, with adult supervision, as it involves paint thinner. It demonstrates the concept of the index of refraction for different materials, in this case that...
Walter Fendt
Walter Fendt: Reflection and Refraction of Light
Defines the refraction of light and provides an applet for investigating it.