Book Review: Galactic Encounters

" Galactic Encounters " by Sheehan and Conselice provides a view of galaxies telling the story of how astronomers have pieced together what is known about the modern view of the Universe. The book helps the reader to understand " why " we know what we do, not simply " what, " starting with the development of the telescope that coincides with the modern picture of the Universe. William Sheehan is a noted historian of astronomy but also a Doctor of Medicine, specializing in psychiatry. In this perspective, he has a unique insight into the personalities of the pioneering figures of the history of science. Christopher Conselice is a Professor of Astrophysics at the University of Nottingham, who studies the formation of galaxies, addressing the issue of " how " rather than " when " galaxies form. Reading the book, amateur astronomers would have been able to feel what actually drives them: " it is the desire to participate in this vast universe, in their own small way,... and not let the experts do everything for them. " I have to admit that I have also quite enjoyed the author's remark pertinent to the history and philosophy of science about the distinction, nowadays, between " polymaths " and " monomaths. " The book is divided into 16 chapters starting from mentioning the early astronomy findings of Galileo, Huygens, and Newton. Then the evolution of a long glorious parade begins with Messier, William Herschel (the musician who underwent a dramatic metamorphosis into the astronomer!) and his discoveries, John Herschel (William's son), and other eminent and esteemed astronomers of the eighteenth century. William Herschel was the first astronomer to push his investigation beyond the Solar System to stars and nebulae. In chapter 6, the story reaches to Fraunhofer and the dawn of spectroscopy while chapter 7 proceeds to the fields of glory with our own Milky Way Galaxy. This chapter introduces Edward Emerson Barnard, the foremost practitioner of celestial photography of his era, who is remembered for his pioneering (and in some ways still unsurpassed) wide-angle photographs of our galaxy. It is worth mentioning that Barnard was, in contrast to most of the figures encountered in the book so far, " decidedly not born with a silver spoon in his mouth. " The chapter includes some of the most wonderful pictures of Milky Way and devotes approximately 25 pages to Barnard's contributions …