Summer's first chosen activity in her kitchen science kit was to make meringues. First she checked each egg to make sure they were fresh (do they float or sink in salt water? If they sink they are fresh, if they float they are old). After the baking was done, we read up on why egg whites are so magically transformed upon being beaten. I've always been curious! Apparently the albumen protein gets trapped in the air bubbles upon beating and produces a foam, which solidifies on cooking.