1. We receive electromagnetic radiation from the sun.
- Infrared Radiation (IR) is not visible with our eyes and has a wavelength longer than that of visible light. It is felt as heat.
- Visible Light is visible as colors. Each color of light has a different wavelength (red is the longest and violet is the shortest).
- Ultraviolet Radiation (UV) is not visible with our eyes and has a wavelength shorter than visible light. UV radiation causes sunburn.
2. Not all sunlight makes it to earth's surface. About half of the energy from the sun is absorbed by the earth. The rest is reflected or absorbed by the atmosphere or reflected by the earth. See picture from class.
3. Scattering is when particles in the air reflect light in many directions. The short blue wavelengths of light are scattered at make the sky appear blue.
4. The greenhouse effect is when gases in the atmosphere form a blanket that traps heat around the earth. The greenhouse effect is a natural process and is needed to keep it warm enough on earth for organisms to live.