Hot Air

Students witness light refracting through air everyday.On hot days, “ripples” rise from the ground or roadways. Stars twinkle in the night sky. The Sun looks squashed on the horizon at sunrise and sunset. Students can explore the interaction between air and light through this “Hot Air” activity in order to understand more complicated everyday phenomena.

What Students Do

Students set up an experiment to investigate the effects of hot air on the path of a laser beam. They obseserve the wandering position of the laser beam spot on the wall after the light travels through hot air rising from the candle flame.

Materials You Will Need

For each student group:

• Candle holder (modeling clay, or sticky adhesive putty)
• Candle (birthday cake size) and matches or lighter
• Laser pointer
• Binder clip
• Graph paper (8.5 x 11 inches with 1/4 inch grid size)
• Masking tape
• Cup (8 to 12 inches high) preferably non-flammable.
• Meter stick