Tracking and Analyzing Brownian Motion with Video Microscopy System and Open Source Program
GAO Yan-Jing1,2, ZHANG Jun-Yi3
1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Nano Science and Technology Institute, University of Science and Technology of China, Suzhou 215000, China
Abstract The kinetic molecular theory of Brownian motion, coupled with experimental confirmation, offered the proof of existence of molecules and enabled the early determination of Brownian particle size, diffusion coefficient and Avogadro's constant. Here, a sequence of images converted from videos of Brownian motion, was run through a widely used open source image processing package, which permits more convenient measurement of physical quantities. Additionally, we established an graphical user interface for the program for easy operation. This study provides students with the opportunity to conduct experiment and statistical calculations, which engages students in fuller conceptual realization of the random nature of particle dynamics.
