2. PSC-1121 Lecture Set #1

3. 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.

5. Music … What is it? Buddy you're a boy make a big noise Playin' in the street gonna be a big man some day You got mud on your face You big disgrace Kickin' your can all over the place Sing it! We will we will rock you We will we will rock you Buddy you're a young man hard man Shoutin' in the street gonna take on the world some day You got blood on your face You big disgrace Wavin' your banner all over the place Buddy you're an old man poor man Pleadin' with your eyes gonna make you some peace some day You got mud on your face Big disgrace- Somebody better put you back into your place

6. But.. What is SOUND???

7. 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!

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

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

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

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

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

13. 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!

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

15. 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

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

18. 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.

19. 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”

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

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

22. Escapement Spring Wound Pendulum

23. Sun Clock

24. Water Clocks

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

26. ~ $200

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

28. 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, Germany Died: 8 Sept 1894 in Berlin, Germany

29. 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!!

30. 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).

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

33. 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.

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

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

36. Back to Helmholtz

37. Siren … a scientific instrument

38. The Graph open closed

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

41. The Graph open closed puff

42. 10 puffs in 10 milli-seconds

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

45. The Siren Creates A Musical Tone

46. Aside – Helmholtz knew how to do this

47. 100 Bottles of beer on the wall (Beer bottles make a sound too!)

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

49. Helmholtz Resonators

50. 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.

51. The Graph Again This is faster than Helmholtz could see. How did he measure it?? open closed

52. Back to the Siren 12 holes in the outer ring

53. Back in his laboratory R

54. For each turn of the large wheel, the smaller wheel will turn MORE. We can figure out this “leverage” from the two radii. We won’t dwell on the calculation. For those who are interested, though …. R

55. R Turn the wheel once. The belt will travel a distance 2  R. The second, smaller (inner) wheel turns the same “distance”. That distance results in many more turns. The number of turns is 2  R/ 2  r=R/r. The outer ring of holes has 12 holes. So one turn produces 12 x R/r puffs. No.. You don’t have to know this stuff but we can still talk about it.

56. R With a clock, we can measure the time for a turn of the big wheel. The number of puffs.. That is the frequency per timed turn is now known. You can now demonstrate the correspondence between particular “note” on the piano with a frequency!

58. Helmholtz’s Results Note from Middle CFrequency C264 D297 E330 F352 G396 A440 B496

59. Today, we use a “scope” Oscilloscope

60. A Bit Magnified (poor resolution)

61. Another Graph.. “sine curve” -1.5 -0.5 0 0.5 1 1.5 0510152025 Time (seconds) disturbance

62. -1.5 -0.5 0 0.5 1 1.5 0510152025 Time (seconds) disturbance 6 sec Period = 6 seconds Frequency=1/6 per sec (Hz) =0.16 sec = 160 ms

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

64. The Standard Meter

65. Measurements If someone offered to sell a bar of gold for $200, you would immediately ask, “How large is the bar?” –The size of the bar obviously determines whether it is a good buy. A similar problem existed in the early days of commerce. –Even when there were standard units of measure, they were not the same from time to time and region to region. Later, several standardized systems of measurement were developed.

66. Systems of Measurement Measurements The two dominant systems are the U.S. customary system, based on the foot, pound, and second, and the metric system, based on the meter, kilogram, and second. Thomas Jefferson advocated that the United States adopt the metric system, but his advice was not taken. As a result, most people in the United States do not use the metric system. It is used, however, by the scientific community and those who work on such things as cars. –England and Canada have now officially changed to the metric system. The United States is the only major country not to have made the change.

67. Systems of Measurement Measurements There are obvious advantages in having the entire world use a single system. The metric system has advantages over the U.S. customary system and was the system chosen in 1960 by the General Conference on Weights and Measures. The official version is known as Le Système International d’Unités and is abbreviated SI.

68. The Metric System Measurements Smaller distances are measured in such units as the centimeter (cm). –centi = one-hundredth; 100 centimeters = 1 meter The other prefixes are given on the next slide (Table 1-3 in text) along with their abbreviations and various forms of their numerical values. This stuff is a real pain. Most if the music related stuff in this course will be done in the so-called English System – feet, pounds,seconds.

69. The Metric System Measurements Next Time

70. Next Up – Some Tools Scientific Notation Graphs Conversion of units (inches to feet, years to hours) 1 hour = 60 seconds

71. fini