Threads

At some point in the remote past I acquired Introduction to Astronomy, by Cecelia Payne-Gaposchkin. She was subsequently a professor at Harvard, and the book is derived from a series of popular lectures she gave to the undergraduate students there. It is a most unlikely textbook, beautifully written, clear and concise, but also quite a work of art. There are quotations from literature on most pages illustrative of the depth and breadth of her learning. Cecelia Payne was born in England in 1900, and educated at Cambridge where she attended lectures from Rutherford. It was a talk by Sir Arthur Eddington on the 1919 expedition to photograph stars during a total eclipse of the sun and verify General Relativity, that engendered in her a fascination with astronomy.
 
In the early 1920s it was impossible for a woman to pursue a career in astronomy in the UK, and the new director of the Harvard Observatory, Harlow Shapley, offered ‘Miss Payne’ a position at Cambridge, Massachusetts. Her job title was ‘computer’, one of a number of women working on the classification of astronomical data, mainly stellar spectra. By applying physics to the interpretation of stellar spectra, Cecelia Payne was able to overturn the current theory that the stars are composed of similar elements, and in similar concentrations, as are found on Earth. She showed that the various spectral types differed mainly in surface temperature, and that the stars overwhelmingly consist of hydrogen and helium. This was so revolutionary and contrary to the current received wisdom, that she was obliged in her doctoral thesis to say that the conclusion—regarding stellar composition—was unlikely. Nevertheless, her thesis was very highly thought of, and gradually the great and the good in the astronomical establishment came to accept her findings. With all of that, Shapley kept her on a derisory salary, she was constantly passed over for promotion, and only very much later was elevated to a professorship.
 
Enthused by reading a new biography of Dr Payne-Gaposchkin, I was looking at a list of telescopes at the Harvard Observatory and saw that one of them had the name ‘Ealing’ appended to it. Investigation showed that the telescope mirror had been purchased from the estate of a noted British amateur astronomer, Andrew Ainslie Common, who died in 1903, and lived at Eaton Rise, Ealing, West London. I grew up in Ealing, and I know Eaton Rise well; what on Earth was an amateur astronomer in Ealing doing with anything that would interest Harvard Observatory? Apparently he had two 36 inch mirrors made by George Calver an ‘East-Anglian telescope maker’, whose premises were in Widford, a small village adjacent to Chelmsford barely a mile from where I currently live... 
 
To anyone wanting a general introduction to astronomy, Cecelia Payne-Gaposchkin’s book is hard to beat. It dates from the mid 1950s, so the photographs are from that era and modern developments in astronomy and astrophysics are absent. But there is a sort of hands-on authenticity about her account. In that pre-digital, pre-space age, observations were made by astronomers spending hours in freezing-cold observatories staring into telescope eyepieces. Photographs were made on wet-developed glass plates, and computations were done using slide-rules and logarithm tables. There was no knowledge of Dark Matter or Dark Energy, Fred Hoyle had only just coined the term ‘Big Bang’, and the discovery of the Cosmic Microwave Background Radiation was ten years in the future. Nevertheless, the basics of the subject as it was then are unchanged now, and the wealth of literary references make the book a positive pleasure to read.