 The Sun gives off different kinds of energy, including heat, visible light, and invisible light such as ultraviolet or UV energy. UV can be harmful to living things if they get too much of it, but luckily the Earth's atmosphere protects us from most of the harmful UV rays. Some of it still gets through, but we can protect ourselves in other ways. In this bag I have beads that detect the ultraviolet light coming from the Sun. They start out white and turn purple when they are exposed to UV light. The darker the bead, the more ultraviolet light is hitting the bead. Let me show you. I've got some materials here to test out. Do you think they'll protect us from ultraviolet light? Well, let's use our UV detectors and try them. Take one of these objects and I'll pass out some beads. Be sure to keep the beads in your hands and out of the sunlight until you've put them under your object. I've attached them to these pipe cleaners so that they're easier to handle. Are we out of things to test? You can use your glasses or the edge of your shirt. These sunglasses protect us from UV? How about your eyeglasses? What about water? Do you want to try your detector in the shade? What other conditions or materials might protect us from UV? Do you have anything else you'd like to try? Yes! Let's see about your hat.