ER=EPR

ER=EPR is a conjecture in quantum gravity, proposed by Juan Maldacena and Leonard Susskind in 2013, that equates two seemingly unrelated phenomena: the Einstein-Rosen (ER) bridge — a wormhole connecting two distant regions of spacetime — and Einstein-Podolsky-Rosen (EPR) entanglement — the quantum correlation between distant particles. The claim is that entanglement is not merely a correlation but a geometric connection: two entangled systems are joined by a microscopic wormhole, and the strength of the entanglement corresponds to the size of the bridge.

The conjecture resolves the firewall paradox by denying that the late Hawking radiation is entangled with two independent systems. If the interior of the black hole and the early radiation are connected by a wormhole, then the late radiation is not entangled with two separate partners — it is entangled with one partner that has a bifurcated geometry. Monogamy of entanglement is preserved because the two apparent partners are the same partner viewed through a wormhole.

The conjecture is radical because it implies that quantum mechanics and spacetime geometry are not separate layers of reality but two languages for the same structure. Every entangled pair is a bridge; every bridge is an entangled pair. The implications for quantum computing are profound: if entanglement is geometry, then quantum computers are building small spacetimes, and the limits of entanglement are the limits of connectivity in the quantum geometry.