PSC-1121 Lecture Set #1

1. PSC-1121Lecture Set #1

2. This week • We will have a “pre-test”. • We will begin to study time and standards. • We will begin to use the clickers even though registration lists may not be ready. • As I write this, I am not sure that WebAssign rosters have been done yet.

3. Pre-Test

4. Music … What is it? Buddy you're a boy make a big noisePlayin' in the street gonna be a big man some dayYou got mud on your faceYou big disgraceKickin' your can all over the placeSing it!We will we will rock youWe will we will rock youBuddy you're a young man hard manShoutin' in the street gonna take on the world some dayYou got blood on your faceYou big disgraceWavin' your banner all over the placeBuddy you're an old man poor manPleadin' with your eyes gonna make you some peace some dayYou got mud on your faceBig disgrace-Somebody better put you back into your place

5. Music Is Sound But .. What is SOUND???

6. What Was in the Music • Rhythm • Timing – what is time? How do you measure it? • Notes • Musical tones – What are they? How do you know? • Chords • Multiple tones sounded together – WHY do they sound good TOGETHER? • Voice • How does that work? Why does it sound good? • Words … meaning. But words are not necessary!

7. Unfair Clicker Question If a tree falls in a forest and there is nobody around to hear it fall, does it make a sound? • Yes • No • Too early in the morning to think about this kind of stuff!

8. Where did the Queen music come from? ? ? ? ? ?

9. Another Issue http://www.youtube.com/watch?v=F0WykZvfg_k&NR=1

10. Observation • First the lightening • Then the thunder • Light travels faster than sound?? • What does this mean?? • Observable: Distance and time

11. Sound --- A “disturbance”Music is SOUND

12. How do we explain all of this? • We use the “scientific method” • Define the fundamentals • Observe under MANY circumstances • Model • Predict • Verify • If this doesn’t work, scrap or modify the theory. • It must explain everything it is supposed to explain or it is dog poo. • Keep the loop going … forever!

13. Examples of Scientific “Theories” • Newtonian Mechanics (in its realm of applicability) • Gravity • Quantum Mechanics • Relativity • Evolution

14. BASICS OF SCIENCE • Careful Measurement based upon standards. • Theory based upon these measurements • Predictions based upon the theory • Verifications of the predictions • Refine the theory • Scrap the theory

16. Measurements on Objects • Distance • Time • Amount of material in an object • Weight?? • Mass?? • What about • Color • Shape • Location

17. Let’s Talk About Time • Music • The “Beat” • The time between the notes • Indirectly – the tone of the individual notes • Physics • Objects move in time so time is an important variable in describing motion. • We will do a lot of this.

18. Approaches to TIME • 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”

19. 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.

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

21. Escapement Spring Wound Pendulum

22. Sun Clock

23. Water Clocks

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

25. ~ $200

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

27. Now that we can measure TIME, let’s talk about Helmholtz. • Physicist • Mathematician • Musician Hermann Ludwig Ferdinand von Helmholtz Born: 31 Aug 1821 in Potsdam, Prussia, GermanyDied: 8 Sept 1894 in Berlin, Germany

28. A Little Bit about Helmholtz • Born in 1821; learned the classical languages as well as French English and Italian. His native language was German. • Initially got a medial degree. While in medical school, he attended physics classes and learned advanced mathematics on his own. • He also learned to play the piano. • A classic underachiever!!

29. More about Helmholtz • He invented the ophthalmoscope and the opthalmometer that allowed for the proper prescription of eyeglasses. • He published “The Handbook of Physiological Optics” (2 volumes). • He wrote “On the Sensation of Tone as a Physiological Basis for the Theory of Music” (1863).

31. Before moving on … Let’s quickly review GRAPHS

32. Let’s review graphs. • A Graph is a way of visually presenting data from a table. • It usually has two axes. These axes can be anything but in science it is often an x- and y- axis. • Sometimes a graph is three dimensional.

33. An Important Graph DJIA ($) 1 box = 1 month time The Dow Jones Industrial Average (CNN-money 7-08

34. Another Important Graph 10 years of data – a different view! 6 mos

35. Back to Helmholtz

36. Siren … a scientific instrument

37. The Graph open closed

38. a milli-WHAT???

39. who the heck is milli ?? • Milli = 1/1000 • Millimeter = 1/1000 meter = 0.001 meter • Milli-second = 1/1000 sec = 0.001 seconds

40. The Graph puff open closed

41. 10 puffs in 10 milli-seconds

43. The number of times that something (repetitive) happens in a second is called the FREQUENCY: f f=1000 sec-1= 1000 Hertz New Unit

44. The Siren Creates A Musical Tone

45. Aside – Helmholtz knew how to do this

46. 100 Bottles of beer on the wall (Beer bottles make a sound too!)

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

48. Helmholtz Resonators

49. Resonators • Each resonator has a certain volume and resonates to a certain tone. • It resonates to only ONE tome. • Each one was “tuned” to a different note on the piano. • The speed of the siren was adjusted to match the same tone.

50. The Graph AgainThis is faster than Helmholtz could see.How did he measure it?? open closed