1. Electromagnetic Spectrum

2. Radiation Energy In the form of waves or particles
Travels and spreads out

4. Radio Waves Longest wavelengths in the electromagnetic spectrum
Range from the length of a football to larger than Earth
Objects in space can emit radio waves
Used for communications

5. Microwaves Range from a few centimeters to football length
Can penetrate haze, light rain and snow, clouds, and smoke
Used for cooking, communication, remote sensing

6. Infrared Range of wavelengths
“Far” infrared rays are thermal – we feel them as heat
“Near” infrared cannot be felt; used for remote controls

7. Visible Light Only electromagnetic waves we can see
The colors of the rainbow
Each color has a different wavelength
Red is longest ; Violet is shortest wavelength
When all the waves are seen together, they make white light

8. Ultraviolet Some insects can see these waves Responsible for sunburns
Useful for studying stars and galaxies

9. X-Rays X-ray light tends to act like particles
Hard to penetrate atmosphere, placed on satellites for space exploration
Used in medicine

10. Gamma Rays Created by radioactive atoms & nuclear explosions
Can kill living cells; used to treat cancer