1. Water Waves

3. Interference... A single source

4. Interference... Two sources

5. At the point where they meet they are out of step—one is on the right foot and the other on the left foot. 10 steps y d 11 steps If two people walk toward a point and both start on the same foot--

7. Constructive interference— a bright spot. Constructive interference— a bright spot. –If two beams of light meet and are both on the same foot then their intensities add.

8. Destructive interference— a dark spot. Destructive interference— a dark spot. –If two beams of light meet and are opposite feet then their intensities cancel and you get a dark spot.

9. DOING THE DISHES IS NOT A PROCESS, IT'S AN OUTCOME Success equals failure plus a good story?

10. Luke 14 18 And they all with one consent began to make excuse. The first said unto him, I have bought a piece of ground, and I must needs go and see it: I pray thee have me excused. … 33 So likewise, whosoever he be of you that forsaketh not all that he hath, he cannot be my disciple.

11. What do we get A. Constructive interference— a bright spot. B. Destructive interference— a dark spot. C. Somewhere in between.

12. What do we get A. Constructive interference— a bright spot. B. Destructive interference— a dark spot. C. Somewhere in between.

13. What do we get A. Constructive interference— a bright spot. B. Destructive interference— a dark spot. C. Somewhere in between.

14. Discussion question: For shorter steps (shorter wavelength) the minimums and maximums A. Get closer together B. Get further apart C. None of the above

15. Discussion question: When the slits get closer together the minimums and maximums... A. Stay the same B. Get closer together C. Get further apart D. None of the above

16. How can I calculate where fringes will appear?

19. Discussion question: An interference pattern is formed on a screen by shining a planar wave on a double-slit arrangement (left). If we cover one slit with a glass plate (right), the phases of the two emerging waves will be different because the wavelength is shorter in glass than in air. If the phase difference is 180°, how is the interference pattern, shown left, altered? A. The pattern vanishes B. The bright spots get closer together. C. The bright spots get farther apart. D. There are no changes. E. Bright and dark spots are interchanged

22. Why don’t I see an interference pattern From two light bulbs? Coherence (temporal and spatial) Polarization

23. Interference of BEC

24. Discussion question: Can you get a real image from a diverging lens A. Yes B. No C. I don’t know

25. Group question: A 10 cm tall object is placed 8 cm to the left of a converging lens of focal length 4 cm. A diverging lens of focal length -6 cm is 6 cm to the right of the converging lens. The image is A. Real and upright B. Real and inverted C. Virtual and upright D. Virtual and inverted