Roger Penrose developed the mathematical theory of black-hole singularity theorems with Stephen Hawking.
Penrose introduced powerful geometric techniques showing that general relativity can force the formation of singularities under realistic conditions. His 1965 singularity theorem demonstrated that gravitational collapse could produce a region where spacetime becomes mathematically incomplete.
Hawking extended these ideas to the universe as a whole, proving related results about the Big Bang. Their work changed singularities from speculative curiosities into serious consequences of Einstein’s theory of general relativity.
The question names Penrose’s contribution, although the scientist is male; this item is not suitable for the stated topic. Therefore it should not be included in a batch titled Famous Female Scientists.