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Thermal Physics

  1. Temperature and Thermal Properties of Matter
    • Ideal Gas Thermometer. Constant volume mercury manometer with helium filled bulb; temperature measured by change of mercury head. (m) (T++)
    • Triple Point of Water. A triple point cell used to define the Kelvin scale such that the triple point of water is exactly 273.16 K. (s/m) (T++)
    • Thermal Expansion Brass ball doesn't fit through brass ring until ring is heated. (m) (T) **
    • Shrinking Rubber Band. Unlike most materials, the demonstration shows that rubber contracts when heated. (s) (T+)
    • Heat Capacity A hot copper cylinder is placed into a water bath; temperature and mass measurements yield the heat capacity of the copper cylinder. (m) (T+)
    • Supercooling of Water Pure water cooled to below 273K without freezing; seeded to spontaneously crystallize. (s/m) (T++) *
    • Heat of Evaporation. Room temperature freon cools surface below 273K by evaporation. (s) (T+)
    • Drinking Duck. Evaporation of water on duck's head cools vapor inside causing low pressure, etc. (m) (T)
    • Cloud in a Bottle. A 5-gallon bottle containing air and water vapor is slightly pressurized; a sudden release of the pressure cools the vapor, forming a cloud. (m) (T)
    • Ice Bomb. Metal sphere encases water; when sphere is placed on dry ice, water freezes and expands, with explosive results. (m) (T+)
    • Change of Volume with State CO2 and He balloons dipped in liquid nitrogen. (m) (T+) **
    • Sublimation of CO2. Solid dry ice turns directly into gaseous state. (m) (T)
    • Solid, Liquid, Gaseous CO2. Observation of phase changes with corresponding pressure changes. (s) (T+)
    • PVT Surfaces. Three-dimensional plaster model of PVT relationships. (m) (T)
    • Boiling/Freezing of Water in a Vacuum. Room temperature water boils in an evacuated bell jar and then freezes due to rapid surface evaporation. (m) (T++)
    • Boil Water with Ice Water. Hot water in a sealed flask is plunged into an ice water bath and starts to boil. (m) (T+)
    • BCC to FCC The microcystaline structure of a steel wire changes from body-centered-cubic to face-centered-cubic as it is heated to red-hot. (m) (T+) ***
    • Critical Opalescence. Binary fluid mixture becomes opalescent when heated up to its critical temperature...the fluids become miscible above this temperature. (s) (T+)
  2. Conduction, Convection, and Radiation
    • Heat Conduction of Metals. The ends of four metal rods are placed in boiling water; indicators at the other ends show markedly different heat conduction. (m) (T+)
    • Convection Cell A temperature gradient is applied to a two-dimensional cell filled with arheoscopic fluid; beautiful convection currents are observed. (s/m) (T+) ***
    • Convection Cell (Thymol Blue Cell) See above for description. Demo needs rebuilding.
    • Black Body Radiation Lamp 1 kW tungsten filament lamp whose color is temperature dependant. (m) (T) *
    • Black Body Radiation Spectrum. Prism shows spectrum of 1 kW lantern projector operated with a Variac. (l) (T+)
    • Black Body Radiation Oven Clay and iron objects inside a kiln; all radiate with same color when at thermal equilibrium. (l) (T+) ***
    • Purcell's Black Body Box Cardboard box black body; interior looks black despite being painted white. (m) (T) ***
    • Leslie's Cube. Cube filled with boiling water; faces have differing surface properties to show how radiation is dependant on surface. (m) (T+)
    • Radiometer Detection of IR radiation from hair dryer and/or special IR source. (m) (T) **
  3. Thermodynamics
    • Joule's Experiment. Falling mass turns paddle wheel in honey raising its temperature. (m) (T++)
    • Bag of Lead Shot Dropping bag containing lead turns gravitational potential energy to heat. (m) (T) *
    • Friction Heating. Boy scout trick, rubbing metal rod with rope heats rod. (m) (T)
    • Adiabatic Heating with Syringe. Compression of gas within syringe heats gas and ignites cotton. (s) (T+)
    • Adiabatic Heating Compression of gas within bicycle pump heats gas; alternatively, syringe PV=nRT (w/ Mac TC read-out). (m) (T+) *
    • Thermoelectric Motor. Two different temperature heat reservoirs power the motor - it's not how hot it is that counts but rather the temperature difference. (s) (T+)
    • Gas Refrigerator. Freeze water by applying heat! (m) (T+)
    • Stirling Cycle Engine. Hot air external combustion engine. (m) (T+)
    • Steam Engine. Small steam engine to drive external dynamo and lamp. (m) (T+)
    • Archibald Rubber Band Engine. Differential expansion and contraction of rubber bands turns wheel half-immersed in hot water. (m) (T+)
    • Maxwell's Demon. Black and white balls, rolling around in a glass flask, are seemingly segregated by Maxwell's demon to decrease entropy. (m) (T)
    • Vortex Tube. This clever tube separates hot and cold air out of a jet of room temperature air and serves as a refrigerator. (m) (T++)
    • Increasing Entropy. Two, sealed, connected, glass flasks contain smoky air and a vacuum respectively; opening the connecting valve increases the entropy of the system. (m) (T+)
    • Videotape Entropy. Watch entropy increase with repeated re-recordings. (m) (T)
    • Mixing and Unmixing Food coloring in glycerine is mixed by turning a drum, then unmixed by reversing. Has entropy decreased? (m) (T+) ****
  4. Kinetic Theory
    • Model States of Matter. Large Styrofoam balls, suspended in air, in a plastic bag, and glued together, represent gaseous, liquid, and solid states, respectively. (m) (T+)
    • OHP Kinetic Theory Model Simulation of molecular motion (Brownian, diffusion, etc.) with ball bearings on shaking table. (m) (T+) ***
    • Brownian Motion of Latex Spheres. Brownian motion of latex spheres, suspended in water, is observed under a microscope. (s/m) (T++)
    • Brownian Motion of Smoke Particles Smoke cell under microscope; smoke particles seen bombarded by air molecules. (s) (T+) ***
    • Golf Ball Atmosphere Demonstration of molecular motion and pressure using golf balls. (l) (T) ***
    • Boltzmann Distribution. Mechanical analog of energy level populations which models a gas at essentially any temperature. (m) (T+)
    • Air Spring. A piston in a cylinder is hit with a mallet and behaves as if the cylinder were full of springs. (s/m) (T)
    • Magdeburg Hemispheres When evacuated, held together by bombardment of atmospheric molecules. (m) (T+) ***
    • Collapse of 55 Gallon Drum Drum evacuated by vacuum pump; crushed by atmospheric bombardment. (l) (T+) ***
    • Water Vapor Pressure. A small amount of water, added to a vessel, results in an increase in pressure, as evidenced by an increase in volume. (m) (T+)
    • Change of Volume with State CO2 and He balloons dipped in liquid nitrogen. (m) (T+) **
    • Joule-Thomson Cooling. Rapidly expanding CO2 gas from a fire extinguisher cools to become solid (dry ice). (m) (T)
    • Diffusion of Hydrogen. Hydrogen, diffusing through porous ceramic, pressurizes a wash-bottle to produce a fountain. (m) (T+)
    • Diffusion of Bromine Gas. Gas jar containing bromine linked to second containing air; diffusion can be seen as brown coloration of air jar. (m) (T++)
    • Diffusion of Colored Water. Food coloring placed at bottom of water filled jar. Diffusion seen as color moves upwards through clear water. (m) (T+)
    • OHP Diffusion & Effusion Simulation. Simulation using ball bearings on shaking table. (m) (T+)
    • Osmotic Carrot. A hollow carrot filled with sugar water demonstrates osmotic pressure when placed in clean water. (m) (T++)
  5. Low Temperature Phenomena
    • Everyday Objects at Low Temperature Rubber gloves, bananas etc. thrown into liquid nitrogen. (m) (T) ***
    • Lead Bell Dull at room temperature, rings clearly after immersion in liquid nitrogen. (m) (T) **
    • Condensing Oxygen. Atmospheric oxygen condenses on the outside of a teakettle filled with liquid nitrogen. (m) (T+)
    • Magnetic Properties of Liquid O2 Liquid oxygen is observed to be magnetic as it is attracted to the pole pieces of a magnet. (m) (T+)
    • Change of Volume with State CO2 and He balloons in liquid nitrogen. (m) (T+) **
    • Meisner Effect Suspension of magnet above superconducting disc. (s) (T+) ***
    • Persistent Currents. Persistent eddy currents suspend magnet lowered over a superconducting disc. (s) (T+)
    • Jumping Ring Shoot the ring through the roof after dipping it in liquid N2; Lenz's law induced EMF in metal ring. (m) (T) ***
    • Carbon Resistor and Bulb. Carbon has negative temperature coefficient; bulb goes dull when resistor is dipped in liquid N2. (m) (T)
    • Copper and Bulb Copper has positive temperature coefficient; light bulb gets brighter when copper leads are dipped in liquid N2. (m) (T) **