Title: 'The History and Interpretion of Black Hole Solutions'
The history and philosophy of physics community has spent decades grappling with the interpretation of the Einstein field equations and its central mathematical object, the metric tensor. However, the community has not endeavoured a detailed study of the solutions to these equations. This is all the more surprising as this is where the meat is in terms of the physics: the confirmation of general relativity through the 1919 observation of light being bent by the sun, as well as the derivation of Mercury’s perihelion, both depend much more on the use of the Schwarzschild solution than on the actual field equations. Indeed, Einstein had not yet found the final version of the field equations when he predicted the perihelion of Mercury. The same is true with respect to the recently discovered black holes and gravitational waves: they are, arguably, tests of particular solutions to the Einstein equations and how these solutions are applied to certain observations. Indeed, what is particularly striking is that all the solutions just mentioned are solutions to the vacuum Einstein equations rather than to the full Einstein equations. This is surprising given that black holes are the most massive objects in the universe, and yet they are adequately represented by solutions to the vacuum field equations.
In this talk, I shall discuss the history and the diverse interpretations and applications of three of the most important (classes of) black hole solutions: I will address especially how the free parameters in these solutions were identified as representing the mass, charge and angular momentum of isolated objects, and what kind of coordinate conditions made it possible to apply the solutions in order to represent point particles, stars, and black holes.