DNA and Bessel functions

I was reading a book on the history of the discovery of the structure of DNA [1] and was surprised by a few passing references to Bessel functions. According to Claude, When X-rays are diffracted by a helical structure, the resulting diffraction pattern breaks into a series of horizontal layer lines. Cochran, Crick, and Vand [ ] The post DNA and Bessel functions first appeared on John D. Cook .