2007 - Week 1.2

1. 2007 - Week 1.2 Some Fundamental Items from PHYSICS

2. Assignment- • Begin reading the Background Notes that are posted on the website. • Roughly pages 1-18

3. From Our Discussion • Elements of Music • Structured/Designed Sound • Some pleasant – bells, most musical instruments • Some nasty – whip • Some intermediate - drums • Rhythm (time) • Tones (Not defined, though) • Loudness • Pleasurable ???? • Message ???? Must there be one? What Kind?

4. Bone Flute – Music is older than I am! 50,000 years or more Neanderthal reconstructions

5. Where did instruments come from???

6. What does this mean?

7. Lightening • Takes time to get to you or you are in big trouble. • Speed = distance/time • What is distance? • What is time?

8. Sound --- A “disturbance”

9. Important Definitions • Length or Distance • How “far” something moves or travels. • Measured against some agreed upon standard. Length Standard .. The Gorf 1 2 3 4 1/8 = 4 1/8 Gorfs Unknown Length

10. The real standard: The Meter

11. Systems of Units • SI Units …. Meters, Seconds, Newtons/Kilograms • English System ….. Feet/yards, seconds, pounds/poundals

12. More Important Definitions • TIME • The subjective “distance” between two EVENTS. • It needs to be objective … ie measurable and reproducible. • Original Clock – The Earth’s Rotation • “It is two days journey” • Today’s Clocks – • “He ran the race in 4 hours, 2 minutes and 21.85 seconds”

13. Things that “tick” at some rate • The planet … once a day • The Pendulum .. Depends on a number of things; • Parameters: Mounting Length Weight, whatever that is.

14. In case you care….. We will discuss this “g-thing” when we get to acceleration.

15. Sun Clock

16. Water Clocks

17. And so on … Rolex (~$10K) Atomic Clock (NASA) $ megabucks

18. The music clock: the Metronome 112 quarter notes per minute. Tempo Kind of Pendulum

19. We hear music (and other noise) in our brains. Sound

20. And you didn’t even know that you have one! Sound Waves push against your TympanicMembrane What is a wave, what is a push??

21. D d Inside your head To Brain

22. In order to understand musical tones and their relationship to each other, we need to understand GRAPHS!

23. 100 snail distance (meters) 50 rabbit 1 2 time (seconds) A graph … what does it all mean?

24. Speed

25. 100 snail distance (meters) 50 rabbit 1 2 time (seconds) So…. Snail goes 100 meters in 2 seconds … Speed=100m/2s Speed = 2 meters/second

26. Notice

27. Also • Velocity is speed in a particular direction. • Velocity: 120 m/hr NORTH • Speed: 120 m/hr (or mph)

28. Example • Sound travels about 1100 ft per second. • How much time does it take for sound to travel about 1 mile?

29. 1.5 1 0.5 0 disturbance 0 5 10 15 20 25 -0.5 -1 -1.5 Time (seconds) Another Graph .. a biggy!

30. Important Definitions The PERIOD, T is the time it takes to go from one condition to the next time that exact condition is repeated. The frequency, the number of oscillations per second, is given by:

31. 1.5 1 0.5 disturbance 0 0 5 10 15 20 25 -0.5 -1 -1.5 Time (seconds) Period = 6 seconds Frequency=1/6 per sec (Hz) =0.16 sec = 160 ms 6 sec

32. Siren … a scientific instrument

33. The Graph

34. 100 Bottles of beer on the wall …

35. Resonance (later) Loudness Rotational Speed (Turns/second)

36. Helmholtz Resonators

37. Piano Keyboard

38. Helmholtz’s Results

39. Next ... Fun with Strings