Amazon.com description: Product Description: In this book the author reconstructs the path of discovery that led A.S. Eddington to formulate the Mass-Luminosity Relation (ML Relation) for stars in 1924. Until now it was not at all clear how Eddington came across this important astronomical finding. For the first time, the historical evidence is consistently organised in support of a reconstruction, which shows that, although unexpected, the discovery of the ML Relation was, by no means, the result of a flash of inspiration. Through the methodical frame of the discovery's path it also becomes clear how the ML Relation relates to a star that once played a primary role in astrophysics, namely Sirius B. Finally, it is shown how Eddington, after his discovery, placed a fundamental element of the context of discovery into the context of justification, thus blurring their boundary.