In 1915, Einstein published his seminal work on general relativity. Just a year later, German physicist Karl Schwarzschild found an exact solution to those equations, which implied the existence of extreme objects now known as black holes. These are objects with mass so concentrated that nothing—not even light—can escape their gravitational pull, hence the term “black.”
From the beginning, however, problematic aspects emerged and sparked a decades-long debate. In the 1960s, it became clear that spacetime curvature becomes truly infinite at the center of a black hole: a singularity where the laws of physics—or so it seems—cease to apply.
If this singularity were real, rather than just a mathematical artifact, it would imply that general relativity breaks down under extreme conditions. For much of the scientific community, invoking the term “singularity” has become a kind of white flag: it signals that we simply don’t know what happens in that region.
So how do the new models account for the black holes we detect at the center of most galaxies?
A singularity isn’t required for a black hole, just a large mass compressed smaller than the Shwartzchild radius. It might be that singularities are just mathematical artifacts. The article has examples.
