Solar Heat Spinner
A pinwheel suspended above a warm surface turns from rising air — a model of convection at work.
Start building ↓The build
Cut the vanes
Make a light spiral or pinwheel of foil.
Balance on a pivot
Rest it on a needle point so it turns freely.
Add heat below
Place a warm lamp underneath (not touching).
Watch it turn
Rising warm air spins the vanes.
Heat warms the air below, which rises and pushes against the tilted vanes, nudging the spinner around — convection currents made visible.
A closer look
Warm air is less dense and rises; the moving air transfers momentum to the angled vanes, demonstrating heat-driven fluid motion.
Variables to test
- 1 Compare a hot vs cool lamp — spin speed?
- 2 Try foil vs paper vanes; which spins easier?
More Physics
Homopolar Motor
A single AA battery, a magnet and a copper-wire loop spin into the simplest electric motor that actually works.
Switchable Electromagnet
Coil insulated wire around an iron bolt and a battery turns it into a magnet you can switch on, off, and strengthen at will.
Pendulum Timer
A swinging mass keeps remarkably steady time — build one and discover what really sets its rhythm.