1. Music, Math, and Motion with Dr. E.J. Zita & Dr. Arun Chandra The Evergreen St. College Winter week 2 Tuesday 13 Jan.2009

2. Physics of Sound Overview What is sound? Waves: simple harmonic motion Representing sound waves mathematically Sources of sound Wavelength and frequency Speeds of sounds and sources Perception of sound Resonance Applications Sound waves in nature

3. What is sound? Sound waves: Compressions and expansions of a medium such as air

4. Waves & simple harmonic motion

5. Representing sound mathematically s

6. Sources of Sound Strings Open pipes Closed pipes

7. Wavelength and frequency Wavelength Period Tspace time

8. Speeds of sounds and sources

9. Perception of sound Intensity = Power / Area

10. Resonance: an object oscillates at the same frequency as the driving source http://www.youtube.com/watch?v=j-zczJXSxnw http://www.labinalorry.co.uk

11. Harmonics http://abcnews.go.com/Technology/wireStory?id=6604532 http://academic.evergreen.edu/curricular/mmm/documents/SoundScience/MosquitoesMatcWingbeats.pdf Females typically beat wings 400 times per second Males typically beat wings 600 times per second What harmonic of both frequencies matches? 1200 Hz = 3*400 = 2*600

12. Applications Doppler effect Beats Sonic boom Ultrasound Interference

13. Sound waves in nature Big Bang Pulsating stars Planets’ atmospheres Insects & Trees Whales drink sounds Sand dunes Chimps … more …

14. Whales drink sounds http://academic.evergreen.edu/curricular/mmm/documents/SoundScience/WhalesDrinkSounds.pdf

15. Ultrasound from pine bark beetles & dying trees http://academic.evergreen.edu/curricular/mmm/documents/SoundScience/PopChirpFigs.pdf

16. Goals and activities

17. Physics of Sound syllabus Thursday 3:00-5:00: Physics Help Session in CAL Friday 1:00-5:00: Physics of Sound in CAL (Lab II)

18. Week 2 overview http://academic.evergreen.edu/curricular/mmm/#syl

19. Coming up next: Seminar on Kuhn (first half) and Brün (paradigms) Do you have questions of FACT about scientific examples in Kuhn? If so, let’s spend a short time answering them before seminar.

20. Seminar groups