1. 18.3 Behavior of Light Light and Materials – How light behaves when it hits a surface depends on the material it is made of Materials can be Transparent - A material that transmits (allows through) light unaffected Translucent - A material that transmits light but scatters it into different directions Opaque – A material that does not transmit any light. Light is either absorbed, reflected, or both.

2. The jelly fish is Transulcent

3. These bananas are opaque

4. This cell phone is transparent

5. 18.3 Behavior of Light Interactions of Light – When light strikes a new medium there are three possible outcomes I Reflection II Absorption III Transmission

6. Reflection - Light bouncing off an object to form an image. We depend on reflection to see. Regular reflection – light bounces off an object in the same direction to from a reflected image Diffuse reflection – light bounces off an object in different directions no reflected image formed

7. Regular and Diffuse Reflection

8. Images are formed by Regular reflection

9. NOTE: Absorption of light produces the colors we see. Only the color reflected reaches our eyes

10. When light is transmitted there are three possible outcomes I Refraction – Bending of light as it enters a new medium (Chapter 17) II Polarization – Occurs when light waves vibrate in only one plane. III Scattering – Light waves are bent as it diffracts around tiny particles in the atmosphere

11. I. Refraction of light causes this affect

12. Remember the light changes speed as it enters the new medium causing it to change direction

13. A mirage is caused by diffraction of light through different layers of heated air http://www.youtube.com/watch?v=_M0FcpQ Wh5E://

14. II. Most light is unpolarized and vibrates in all directions a polarizing filter will allow only light vibrating in a single plane to pass.

15. Reflected light (glare) is often polarized and is blocked by polarized glasses

16. The sky looks blue because of scattering and sunsets Look red.

17. This sunset is caused by scattering. Only the longer wave lengths get through.