|John Bardeen, Leon Cooper, John Robert Schrieffer physics
John Bardeen collaborated with Leon Cooper and John Robert Schrieffer to explain superconductivity using Cooper’s concept of Cooper pairs. The Pauli exclusion principle creates a Fermi surface that warps in the presence of an electron to attract a second electron, overcoming their Coulomb repulsion. The electron pairs create a Fermionic condensate and vibrates in a shared quantum state to become superfluidic, superconductive, and diamagnetic.
It was an educated guess confirmed by later experiments. It was only a theory that predicted testable implications. It was an approximation and further work was needed.
Theoretical physics, a math problem, a concept of how things work together becomes less theoretical when it changes lives and makes miracles common.