A - We have a wind-chest - an air-tight box so equipped at the top that we can place pipes in holes so they can be blown simultaneously. We start with two identical pipes - identical length - identical diameter - and therefore identical pitch. We sound them together. They emit alike. Now the question: How can we change the pitch of a pipe? Answer: By various means. First we change its length with a sliding sleeve. Doing this gives rise to beats with the other pipe. The greater the difference in lengths the greater the beat frequency. If one pipe has a frequency f. and another a frequency f„ -the beat frequency will be f„ - f,. And now else can we change the pitch? By changing the medium with which the pipe sings. So we heat one pipe and beats again rise. The higher the temperature of the air in the pipe the higher the velocity of sound in the pipe and the higher the pitch.

B - We show the amazing performance of thermally-excited pipes. A metal pipe has a bit of metal screen lodged in it. We heat the screen. Re¬move the pipe from the heat source. And an enchanting thing is witnessed. The pipe sings! With the pipe held horizontally no convection can exist so no music can come out. As I like to say: The music cannot fall out when the pipe is horizontal! And further exploration of this sort-reveals what we expect: Longer pipes have lower pitch. AND - note well this detail: These metal pipes with wire screen sing AFTER they are removed from the heat source.

C - We now explore the enchanting behavior of CARDBOARD TUBES - the like of which rugs come rolled on. This I call intellectual fun! These pipes can sing while they are being energized! A whole array of these could provide a Bach choral! Are we not agreed that SINGING PIPES have enchantment abundant?

1. The Idea of the Center of Gravity
2. Newton's First Law of Motion: Inertia
3. Newton's Second Law of Motion: The Elevator Problem
4. Newton's Third Law of Motion: Momentum
5. Energy and Momentum
6. Concerning Falling Bodies & Projectiles
7. The Simple Pendulum and Other Oscillating Things
8. Adventures with Bernoulli: Bernoulli's Principle
9. Soap Bubbles and Soap Films
10. Atmospheric Pressure
11. Centrifugal Force and Other Strange Matters
12. The Strange Behavior of Rolling Things
13. Archimedes' Principle
14. Pascal's Principle: The Properties of Liquids
15. Levers, Inclines Planes, Geared-wheels and Other Machines
16. The Ideas of Heat and Temperature
17. Thermometric Properties and Processes
18. How to Produce Heat Energy
19. Thermal Expansion of Stuff: Solids
20. Thermal Expansion of Stuff: Gases & Liquids
21. The Strange Thermal Behavior of Ice and Water
22. Heat Energy Transfer by Conduction
23. Heat Energy Transfer by Convection
24. Heat Energy Transfer by Radiation
25. Evaporation, Boiling, Freezing: A Dramatic Adventure
26. Miscellaneous Adventures in Heat
27. The Drama in Real Cold Stuff: Liquid Nitrogen
28. The Physics of Toys: Mechanical
29. The Physics of Toys: Acoustic and Thermal
30. Waves: Kinds of Properties
31. Sound Waves: Sources of Sound & Pitch and Frequency
32. Vibrating Bars and Strings: The Phenomenon of Beats
33. Resonance: Forced Vibrations
34. Sounding Pipes
35. Vibrating Rods and Plates
36. Miscellaneous Adventures in Sound
37. Electrostatic Phenomena: Foundations of Electricity
38. Electrostatic Toys, Part 1
39. Electrostatic Toys, Part 2
40. Adventures with Electric Charges
41. Adventures in Magnetism
42. Ways to "Produce" Electricity
43. Properties and Effects of Electric Currents
44. Adventures in Electromagnetism
45. Further Adventures in Electromagnetism
46. Miscellaneous and Wondrous Things in E&M

Demonstrations in Physics was an educational science series produced in Australia by ABC Television in 1969. The series was hosted by American scientist Julius Sumner Miller, who demonstrated experiments involving various disciplines in the world of physics. The series was also released in the United States under the title Science Demonstrations.

This program was a series of 45 shows (approximately 15 minutes each) on various topics in physics, organized into 3 units: Mechanics; Heat and Temperature / Toys; and Waves and Sound / Electricity and Magnetism.