Rainbow creation, Hard Boiled vs. Fresh Egg, What is This, Mothball Frost, Random Computer Numbers, Wildlife Center, Nutty Surprise Reaction, Weightless Clothespins, Plastic Water Bottle Fountain, and more. Heather comes upon Mr. Wizard sprinkling the lawn. He asks her to describe a rainbow. He notes that a rainbow is formed when there are tiny drops of moisture in the air, and you look at them with the sun behind you.