Half century of black-hole theory: from physicists' purgatory to mathematicians' paradise

TL;DR

Over the past fifty years, black hole theory has evolved from initial physicist skepticism to a rich mathematical field, revealing beautiful structures despite ongoing debates about singularities' physical meaning.

Contribution

This paper reviews the historical development and mathematical beauty of black hole theory over fifty years, highlighting its transition and current controversies.

Findings

Black hole theory matured over fifty years with significant mathematical insights.

Physicists' understanding of black holes has deepened, revealing complex structures.

Controversies about the physical significance of singularities persist.

Abstract

Although implicit in the discovery of the Schwarzschild solution 40 years earlier, the issues raised by the theory of what are now known as black holes were so unsettling to physicists of Einstein's generation that the subject remained in a state of semiclandestine gestation until his demise. That turning point -- just half a century after Einstein's original foundation of relativity theory, and just half a century ago today -- can be considered to mark the birth of black hole theory as a subject of systematic development by physicists of a new and less inhibited generation, whose enthusastic investigations have revealed structures of unforeseen mathematical beauty, even though questions about the physical significance of the concomitant singularities remain controversial.