8B10.30 Sunspot Simulation

Place clear lightbulb on overhead projector. Connect to variac. Adjust variac until glows (~25 on variac scale). The filament image will be projected by projector. Turn on projector. The filament will now look dark compared to bright background.

Setup Requirements: Assembled as needed. Need variac, clear lightbulb, overhead projector and extension cord. 

Equations: None

Safety Issues: AC Voltage, Hot lightbulb

8B10.70 Twinkle Twinkle Little Star

Demonstrate " twinkle twinkle little star" by putting slide of constellation in slide projector and adjusting so beam passes just over top of hot hotplate. Adjust so a little out of focus to enlarge star images.

Setup Requirements: Use movie screen or white cardboard. Works best if you have a small class that can come up to the front to see effect. Dark room needed. 

Equations: None

Safety Issues: Red hot hotplate