Algodoo

A neat type of engine I learned about recently. Use 2 and 1 to raise and lower the heat.
Ignore the spring and the laser. They're just there for the scripted bits (also, the spring turns red
when there is force on it).

How a Stirling Engine Works:
In the pressure chamber (the thing right above the heat source), the bottom is hot, while the top
is relatively cool. The Displacer shifts the air between the hot side and the cool side. When the air is at
the hot bottom, it heats up and expands, pushing on the piston. When the displacer pushes it to the
cool top, it contracts, and the piston comes back down. The Flywheel keeps things moving when the
piston isn't actively pushing on the crankshaft.
These engines are surprisingly easy (and cheap) to build. There are numerous videos on YouTube
explaining how to build them. Some empty soda cans, an old CD, a bit of wire, and a few other easily
obtained materials is all you need, really.