Merging the Sun and the Stars: the hybrid images of the 1919 eclipse

The pioneering observation of the gravitational deflection of light at the solar eclipse of 1919 required the development of new visual tools and techniques.  The evidence for Einstein’s theory was, in the end, a series of photographs that were presented as records of a genuinely novel phenomenon.   It was challenging to connect these material records to the abstract concepts of general relativity, though, and their validity was only established by connecting back to already-established methods.  Frank Dyson and Arthur Eddington, the leaders of the observational project, persuaded the scientific community of the validity of the observations by fusing two distinct traditions in astronomical photography – eclipse images and astrometry - to create a new visual approach specific to general relativity.