For the Reader Who Wants It in One Paragraph

Gravity holds the door open. Electromagnetism walks through it. Gravity maintains every room in the building so that anything can happen in any of them; electromagnetism picks one room and makes something happen there. Gravity is possibility. Electromagnetism is actuality. Quantum mechanics is the physics of possibility; general relativity is the physics of actuality. They looked incompatible because nobody noticed they were two ends of the same hallway. The ratio between them — 10⁴⁵ — is the number of rooms in the building: twenty-one channels, each compounding the coupling by one factor of 1/137, plus one extra factor of 1/π for the round hole the electron holds open. That is the hierarchy. That is the unification. One building. One break. One axiom: 1:1 + 1×ε.