Experiment Hh-03

Brownian Motion

Description: The stage of a microscope is fitted with a small cell which can transmit light. After the microscope is focused, the television hookup is set on the ocular of the microscope. The cell is filled with smoke from a cigarette or an extinguished match, closed and placed on the stage. Laser light is aimed through the cell to illuminate the smoke particles. Once the original turbulence subsides (about 5 minutes), the chaotic motion of these particles can be observed on the television.


Demonstration setup: the microscope (left) and laser (right) have been adjusted so that the laser light is horizontal to the lab bench and passes through the gas cell.


Smoke particles illuminated by laser light.



Materials: microscope with TV hookup, TV, laser, gas cell, source of smoke (cigarette or match)


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This page was last updated on Friday August 15, 2008 8:37 PM