What did we do?

We found sunscreens with three levels of SPF: 4, 15 and 30. Just for fun, we also tested regular cooking shortening and olive oil to see how they blocked the rays. To test each lotion, we slapped the lotions on a water bottle made of a special kind of plastic that turns color in the sun. Then we exposed the lotion-covered bottle to the rays for eight minutes. That's about the amount of time it takes for a fair-skinned person to start burning. Finally, we rated the color of the water bottle on a scale of 1-5, with 5 showing the most color or "burning" and 1 showing the least color. more...