This is pretty cool, especially the physical applications sections. And it brought back some memories from various physics classes on the enigmatic questions t

This is pretty cool, especially the physical applications sections. And it brought back some memories from various physics classes on the enigmatic questions that lead to the development and understanding for some of these functions. See the Bessel Function, http://dlmf.nist.gov/10.73 http://dlmf.nist.gov/10.73: "Bessel functions first appear in the investigation of a physical problem in Daniel Bernoulli’s analysis of the small oscillations of a uniform heavy flexible chain."