Want a surefire bet for your next cocktail party? First, tell your guests
that aquatic life-at least in temperate
climates-depends largely on the fact
that ice floats. If it sank, lakes would freeze solid instead of forming an
insulating layer of ice on top, killing all the fish. Now bet that you can
magically make an ice cube sink. Grab one from a glass of special cubes
you've strategically placed nearby, and drop it into a cup of ordinary
water. Collect your guests' money.