Reconsidering Schwarzschild's original solution

TL;DR

This paper revisits Schwarzschild's original solution, clarifying the nature of the singular surface at the Schwarzschild radius and its relevance to the Kerr-Newman solution, emphasizing historical and invariant perspectives.

Contribution

It provides a historical analysis and an invariant definition of the Schwarzschild singular surface, extending insights to the Kerr-Newman solution.

Findings

Clarifies the invariant nature of the Schwarzschild radius

Provides a historical perspective on Schwarzschild's original solution

Extends the invariant analysis to Kerr-Newman solution

Abstract

We analyse the Schwarzschild solution in the context of the historical development of its present use, and explain the invariant definition of a singular surface at the Schwarzschild's radius, that can be applied to the Kerr-Newman solution too.