1. Optics Refraction and Reflection

2. Law of Refraction How it works:

3. Law of Refraction n 1 sin Θ 1 = n 2 sin Θ 2 n = index of refraction = c/v Vacuum: n = 1 Air: n ~1.0003 (sunset) Water ~ 1.3 (aquarium) Glass ~ 1.5 (optics) Highest? … … diamond

4. Atmospheric Optics: Rings

5. Source of 22 O Angle

6. How it works Blue refracted more than red – this is called dispersion

7. Rainbows

8. Optics of Rainbows Total internal reflection

9. Images

10. Extended Object

11. Diverging Lenses

12. Applications to Eyewear How it works

13. Problems with lenses…

14. The fix

15. Another problem

16. Other problems with lenses Glass must be pure and clear Glass sags—lenses only supported at edge Solution ….

17. Reflective Optics First-surface mirror!

18. Images

19. Extended Objects

20. This divergence is used to extend the focus in reflecting telescopes… Diverging Mirrors

21. Magnification = F O /F E Example: 50/0.5 = 100x Magnification is the least important characteristic of a ‘scope! The most important is the diameter of the objective! Refracting (lens based) Telescopes