Physics Faculty Co-Author Paper
By Holly Foster 315-859-4068
January 3, 2011
Ken Bart, Brian Collett and Phil Pearle (together with three coauthors from the University of Montana) published a paper in the American Journal of Physics in December (Vol. 78, pp. 1278-1289) titled "What Brown saw and you can too." In addition, they have launched a more detailed website. Bart is director of the Microscopy and Imaging Facility and Collett and Pearle are professors of physics.
The authors discuss, reproduce and extend, with modern instruments, the seminal research of the eminent British botanist and microscopist Robert Brown. In the summer of 1827. Brown was looking through his microscope at pollen of a plant called Clarkia pulchella immersed in water, when it burst: two kinds of particles emerged, and they jiggled about in the water.
This "Brownian motion" as it is now called, never understood by Brown, is due to uneven impacts on the particles by water molecules. Two questions not treated in current literature are answered: the nature of the particles Brown observed, and the optical effect of lens diffraction which led Brown to initially think that he was observing fundamental organic building blocks of nature. In addition to detailed discussions of history, Brown's paper, botany, observations and associated mathematical analysis, this work also contains electron microscope pictures, optical microscope pictures, videos (available on the web site) and detailed instructions how to build a simple high magnification one-lens microscope akin to Brown's.