Ultraviolet Radiation
Ultraviolet radiation is light from the sun that you cannot see but can cause sunburns.
A toaster coil glows red and heats your bread, but it also sends out heat you cannot see. The sun works the same way. You feel its warmth on your skin, but hidden rays called ultraviolet light hit you too. Those unseen rays are the ones that cause sunburns.
Explaining ultraviolet radiation by grade level
The sun sends out light you can not see. This light can burn your skin. That is why you wear sunscreen at the beach. It blocks the rays that hurt you.
Projects that explore ultraviolet radiation
Ultraviolet radiation is invisible light from the sun that can cause sunburns, and different materials block different amounts of it. Spectacle lens materials and coatings vary widely in how much UV they absorb, so a UV intensity meter can measure how much invisible light passes through each one. Testing a polarized lens against plain glass reveals which material provides the best UV protection for your eyes.
Ultraviolet radiation from the sun can cause sunburns, but different types of glass filter out different amounts. A tinted car windshield blocks nearly all UV rays, while regular window glass lets most of them through. Placing a UV meter inside a box and covering it with each glass type shows how much invisible light passes through.
Clothing color affects how much ultraviolet radiation reaches your skin. Black and blue cloth block the most UV rays, while white cloth lets almost all of them through. A UV meter inside a glass aquarium covered with different colored fabric measures how much invisible sunlight each color stops.