This kept Scott and I entertained for an entire Saturday morning. It’s from Penn & Teller’s How To Play With Your Food, which is, sadly, out of print. Take a box of cornstarch and add a cup and a half of water. If you play with the mixture gently it’s all oozy, if you, say, punch it, it turns into a solid. The book recommends that you pat some of it into a ball and toss it to an unsuspecting someone, it will then ooze through their fingers. It’s hard to explain, but seriously, try this. A bit of scientific info from the book: “You’ll notice right away that your mixture is viscoelastic. The cornstarch forms really long-chain molecules. When the gunk is diluted or deformed gently and slowly, these honking chains can rearrange themselves and stay liquid. But, when there’s enough of these molecules crammed together and the impact is fast and hard enough, they don’t have the time or room to rearrange their big old selves. They stay all tangled, and the viscosity becomes enormous. With violence all around it, the slime cops to a solid.” Cool huh?