The student is told he's stuck on a deserted island and can only gather water from rainfall using materials at hand, and he is asked what would have the best water collecting capacity: seashell, mudbowl, coconut, or straw basket; also, the student is asked to determine the ratio of light gathering power between various aperture telescopes.
keywords: light gathering power, desert island, rainfall, seashell, mudbowl, coconut, straw basket, water, telescope
swf file: ca_telescopes_lightgatheringpower.swf