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American Journal of Physics paper

Complete long paper

Sections of the long paper, as follows.

I. Introductory - This describes the contents of the paper and consists largely of the Home page and this page.

II. History - The discovery of Clarkia pulchella and the men involved are treated here. It was found by Meriwether Lewis in 1806 in Idaho on the return trip of the Lewis and Clark expedition. It was named and published in 1814 in England by Fredrick Traugott Pursh. Its seeds were first collected and sent to England in 1826 from the Northwest Pacific coast by David Douglas. They arrived in London in 1827 and were grown there, providing flowers for Brown's investigations. This section contains subsections devoted to each man.

III. Jiggly - Here is an in-depth review of Brown's paper, with many quotes, as well as some remarks on Brown's microscopes and on Brownian motion.

IV. Botany - Some history of early pollen research and a summary of some present understanding of pollen physiology is presented here.

V. Microscopy - This contains a discussion of quantitative observations with modern apparatus which shed light on Brown's qualitative observations. It begins with a description of how one may go about growing Clarkia pulchella, how to prepare its pollen for observation, and what one sees. Studies are made of particle sizes. A discussion is given of how diffraction affects what is seen, and comparison is made of the spherosome sizes Brown reported, the sizes seen through a modern day compound microscope and the actual sizes. The amyloplast Brownian motion and rotation is observed and compared with theory. It is shown how to construct a one-lens microscope using a readily available product, a ball lens, and observations of amyloplast sizes are made with it and compared with what Brown saw.

VI. Theory - This is meant for advanced physics undergraduate students or graduate students, and their teachers. It consists of seven theoretical appendices which are tutorials on aspects of classical physics. Most of this material has been known for over a century. Some of it has found its way into textbooks. Apart from the benefit of finding all the relevant material in one place, in self-contained form, each appendix contains some novel treatment.

Appendix A - Brownian Motion Theory

Appendix B - Viscous Force and Torque

Appendix C - WKB derivation of geometrical optics (the eikonal equation)

Appendix D - Application to mirrors and lenses

Appendix E - Huyghens-Fresnel-Kirchhoff construction

Appendix F - Imaging of a point source of light, with diffraction and spherical aberration receiving a unified treatment

Appendix G - Imaging of an illuminated disc

Bibliography - Contains references and remarks