Gravity — the curvature of spacetime — has long evaded a quantum description. To prove its quantum nature, you typically need to create entanglement between two massive objects, which is technically unfeasible. Physicists proposed a different path: monitor a single atom.

The quantum behavior of an atom is like a dance. The particle is in two places at once, and gravity guides its movements. If this dance obeys the Schrödinger equation, then two atoms automatically synchronize — their states become intertwined through gravity. Such 'steps' can be captured by matter-wave interferometers, noting the slightest shifts.

The sensitivity of the instruments is astonishing: they detect the attraction of a brick at a meter's distance. That's enough to notice quantum jitter. Just as detectors catch gravitational waves from black holes, new setups will reveal the gravitational dance of a particle. One precisely measured step will prove: gravity can entangle. Einstein's theory and quantum mechanics are converging.