How cold can STUFF get? Theory tells us that the very lowest we can EVER hope to get is -273 C - called Absolute Zero. But who really knows? It might be lower somewhere in this Universe! For ordinary ad¬ventures we can get the following: Ice and salt -20°C or so. Dry Ice and alcohol -78.5°C or so. Liquid Nitrogen -195°C. And this is pretty cold — as we shall see.
A. A teakettle filled with liquid nitrogen boils on a cake of ice!
B. And now we proceed with a number of things - all showing how this VERY COLD STUFF changes the properties of ordinary things: a. We freeze a "hot dog". b. We freeze an onion. c. A lead spring which is : lifeless" at room temperatures becomes VERY SPRINGY AND ELASTIC. d. A rubber ball which bounces at room temperature becomes frightfully brittle when made so cold. e. A lead plate which hardly "sings" at room temperature emits a beautiful high note when very cold. It becomes elastic. f. A lamp lights so bright - or dim - at room temperature. We lower the temperature of the coil connected to it. The lamp now flares up. WHY? The electrical resistance of conductors goes down with drop in temperature. . .so the electrical conductivity is higher.
Thus we see that the properties which STUFF possesses changes with the temperature. An understanding of this is very important. The pistons in your automobile engine get very hot. Space vehicles get very cold. On the Moon - with no atmosphere - as we now believe - you could stand at the very edge of light and dark and freeze one side of you and boil the other.
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.