1. Refraction Refraction is the bending of light when it passes from one transparent medium to another This bending is caused by differences in the speed of light in the media

3. NormalLine More Dense Less Dense

4. WATER AIRNormal Line #1 Slow Fast Light Beam AIR

5. NormalLine More Dense Less Dense

6. WATER AIRNormal Line #1 Slow Fast Light Beam Fast AIR Normal Line #2

7. Refraction Examples Light slows down when it goes from air into water and bends toward the normal. An Analogy: A car slows down when it goes from pavement onto gravel and turns toward the normal. An Illusion : Fish in the water appear closer and nearer the surface. (See Figure 28.27)

8. http://cougar.slvhs.slv.k12.ca.us/~pboomer/physicslectures/secondsemester/light/refraction/refraction.html

9. Refraction WATER AIR Observer True Fish False Fish

10. Atmospheric Refraction Our atmosphere can bend light and create distorted images called mirages.

13. Lenses Diverging Lens A lens that is thinner in the middle than at the edges, causing parallel light rays to diverge. Converging Lens A lens that is thicker in the middle and refracts parallel light rays passing through to a focus.

14. C F C F Diverging or Concave Lens

15. C F C F Converging or Convex Lens

16. C F C F

17. C F C F

18. C F C F

19. C F C F

20. C F C F

22. Myopia (Near-Sightedness) People with near-sightedness cannot see clearly at distance.

23. Hyperopia (Farsightedness) People with far-sightedness cannot see clearly up close

24. Total Internal Reflection... …is the total reflection of light traveling in a medium when it strikes a surface of a less dense medium

25. WATER AIR LightSource Critical Angle TotalInternalReflection Refraction

26. http://cougar.slvhs.slv.k12.ca.us/~pboomer/physicslectures/secondsemester/light/refraction/refraction.html

27. Total Internal Reflection occurs when the angle of incidence is greater than the critical angle. The critical angle for an air-water interface is 48°. Fish can see everything above the water’s surface in a 96 ° cone of vision. Demo - Laser and light pipe

28. http://cougar.slvhs.slv.k12.ca.us/~pboomer/physicslectures/secondsemester/light/refraction/refraction.html

31. Dispersion... …is the separation of white light into pure colors (ROY G. BIV). Dispersion Examples: Prisms Diffraction Gratings CD’s Raindrops

34. Rainbows Raindrops refract, reflect and disperse sunlight. Rainbows will always appear opposite of the Sun in the sky. You cannot run from or run to a rainbow!