Light Energy

1. Light Energy Energy given off by electrons. It travels in waves, and can travel through space.

2. Light is a form of electromagnetic radiation, a combination of electrical and magnetic energy

3. Radio Waves • Radio waves can be longer than a football field or as short as a football • Used for TVs, radios, and cell phones to transmit information

4. Microwaves • Wavelengths can be measured in centimeters • Microwave ovens use wavelengths close to a foot in length • Good for transmitting information because microwaves can penetrate haze, light rain, cloud and smoke. • Used in radars, like doppler radar for sensing weather forecasts.

5. Infrared Rays • Longer infrared rays have wavelengths about the size of a pinhead; these longer rays are thermal. Experience everyday in the form of heat! • Some animals, like vipers, can see infrared • Shorter rays are about the size of cells. These aren’t hot; used in TV remotes. • People, animals, stars, galaxies all emit infrared

6. Visible Light • Only radiant energy we can see • All wavelengths see together make white light • ROY G BIV

7. Ultraviolet Light (UV Rays) • Can’t see with the human eye, but some insects, like bumblebees can see them! • Sun emits light at all wavelengths. But UV rays are responsible for sunburns • Most are blocked from entering by the ozone layer • Scientists use UV rays to detect stars and galaxies

8. X-rays • X-rays can travel through skin • But things like bone, metal, or teeth are more dense than skin, and thus absorb the X-rays. X-rays show us a “shadow” of these denser materials. • Many things in space emit X-rays: black holes, stars (like the Sun and others), supernova remnants, comets!

9. Gamma rays • Gamma rays have the smallest wavelengths, and they have the most energy • Generated by radioactive atoms, nuclear explosions, or supernova explosions • Can kill cells • Used to kill cancerous cells or kill bacteria on fruit

10. Gamma Ray Gun (NOTE: This is notreal!!!)