PURPOSE: To show how air currents cause the "twinkling" of a star.
DESCRIPTION: A laser beam is directed on a distant wall or screen. When the heater is positioned below the laser beam, hot air convection currents and density changes cause the beam to move continuously, or "twinkle."
REFERENCES: (PIRA unavailable.) See also demonstration E2-48: NON-TWINKLING PLANET
EQUIPMENT: Laser cart with hot plate.
SETUP TIME: 5 min.
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