Entanglement is the strangest feature of quantum theory, often dubbed ''spooky action at a distance’’.
Quantum entanglement can occur on a macroscopic scale with trillions of electrons, leading to new forms of matter with properties of technological importance. Related entanglement structures arise across black hole horizons, giving rise to Hawking’s information puzzle. I will describe a simple model of many-particle entanglement which has shed light on these distinct fields of physics.