Entropy and The Second Law Topic

Entropy

Concept 3 demos

Two large round-bottom glass flasks on clear cylindrical bases, each containing four white and four red foam balls. The balls sit mixed in the flask bodies and necks.

Maxwell's Demon

Two identical-looking flasks of colored balls are spun — one separates by color, the other doesn't. Demonstrates that apparent ordering requires an outside energy-dissipating mechanism, connecting to the Second Law …

Top: Full setup showing the vortex tube on the lecture bench with two projection thermometers displayed on an overhead projector. Bottom: Close-up of the vortex tube mounted on a base plate with thermometer probes inserted into both outlet ends on rod stands.

Vortex Tube

Compressed air entering a vortex tube (Ranque-Hilsch tube) spontaneously separates into hot and cold streams at opposite ends. Students observe a striking, counterintuitive result that appears to violate the Second …

Bright yellow-orange fireball from an ignited hydrogen balloon, with the candle stick visible entering from the lower right

Hydrogen Balloon

Igniting a hydrogen-filled balloon produces a dramatic fireball and loud bang, demonstrating exothermic combustion. Contrasting with an inert helium balloon highlights the difference between reactive and noble gases. The sound …

Heat Cycles

Concept 5 demos

Small Stirling engine on a black base with "STIRLING ENGINE" label. The engine has a finned displacement cylinder on the left, a power cylinder with connecting rod in the center, and a flywheel on the right. An alcohol burner sits beneath the displacement cylinder.

Small Stirling Engine

A small alcohol-fired Stirling engine demonstrates heat engine operation: cycling hot and cold pistons convert a temperature difference into continuous mechanical work. Students see the Second Law in action — …

Visible Stirling engine at rest: clear acrylic flywheel disc with two diagonal holographic tape strips, gold brass displacer cylinder, small gray power piston at the base, mounted on a black plate with white foam displacer visible through the side

Visible Stirling Engine

A transparent Stirling engine converts small temperature differences into visible mechanical work. Students observe the displacer and power pistons operating 90° out of phase and see that any temperature gradient …

Bicycle wheel mounted vertically on a white stand with rubber bands stretched from an offset center hub to the rim. A large black cylindrical heat lamp is positioned to one side, plugged into a switch box on the base.

Rubber Band Heat Engine

Rubber bands contract when heated — the opposite of most materials — due to entropic elasticity. A bicycle wheel with matched rubber bands rotates continuously under a heat lamp, demonstrating …