The Strange Thermal Behavior of Ice and Water 
The Strange Thermal Behavior of Ice and Water
by Prof. Miller
Video Lecture 21 of 46
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Date Added: February 5, 2015

Lecture Description

Of all the things of Nature WATER must rank as one of the strangest. It is indeed an incredible STUFF. Its behavior is uncommon and its properties serve man in extraordinary ways.

A. We first show the changes which occur when we consider ONE gram
of ice at 0°C to which heat energy is conveyed. We note that in
CHANGE OF STATE no change in temperature takes place. The
Heat energy therefore must go into "tearing" the bonds which hold
the stuff together. We discover from this sequence of operations
that the liquid state is more "energetic" than the solid state and
the vapour (vapor) state - or gaseous - more energetic than the
liquid.

B. We observe the behavior of a thermometer in a beaker of ice. As
the ice melts we might - if we did not know better! - we might
expect the thermometer to show a rise. But it does not. As long
as any vestige of ice remains the thermometer will read 0°C -
if this is the temperature of the ice to begin with. Change of state - NO change in temperature.

C. Consider a glass of ice-and-water — so called ice-water - resting on the table. Let the vessel be FULL absolutely full.
That means that some ice is ABOVE the level of the water. Now as time goes some ice melts. Question: Will the water run over — will the glass - as we say - overflow? Answer: NO. Since 1. 1 cmJ of ice = 1.0 cm of water. Most of the ice of an iceberg is below the level of the sea. Question that comes to me suddenly: Is an iceberg salty?

D. We take a huge block of ice - support it on a platform - and
put around it a wire loaded on both ends. The wire in due course
'sinks" into the ice - cuts into the ice. .The pressure of the wire melts the ice - the water which arises again freezes. This process is called regelation. We encounter this when we make a snowball by squeezing the snow in hand. The snow melts under the pressure; the water refreezes and we have an "ice ball".

E. Here is a demonstration for engagement at the DINNER TABLE.
We have ice water served to each guest. Each guest is supplied
with a tiny length of string - three inches or so. The problem
is this: Get out a hunk of ice - a cube of ice - using the string as the agent for lifting out the ice. Some try to tie the string to a cube of ice! But it is too short for this! SOLUTION: Lay the string atop a hunk of ice. Gently pour on the string some fine salt from the salt shaker. Wait a few seconds. The salt melts some of the ice immediate to the string. This ice water at once refreezes. The string is thereby fixed to the ice. Now gently pull up on the free end of the string.

F. We show an array of photographs of men who gave us abundant
knowledge of these things. It is very important to have a mind to
MEN AND EVENTS and to the national origin of these people —
Maxwell — a Scot — Joule an Englishman — Bernoulli a Swiss —
and so on.

Course Index

  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

Course Description

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.

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