Testing Gravity's Quantum Nature with Spin ⚡ экспресс
Scientists have proposed using entanglement induced by gravity to test whether gravity has quantum properties. Unlike previous studies limited to the Newtonian approximation, this work explores for the first time entanglement generated by frame dragging (the Lense–Thirring effect) — a relativistic effect of rotating masses. The entanglement phase was calculated using two independent methods, and the results matched: it equals the proper time difference between the interferometer arms. This opens the door to tabletop experiments testing the quantum nature of gravity in the post-Newtonian regime. Interestingly, accounting for gravitational retardation makes the description local and causal, without the 'spooky action' paradox.
Einstein's theory says: a rotating massive body drags space along with it, like a spoon pulling through thick honey. This phenomenon is called frame-dragging, and it's especially pronounced around black holes and neutron stars. But a faint trace exists even in objects on a lab bench.
In a new experiment, a microparticle will fly past a heavy rotating sphere along two different paths. Because the "honey" flows at slightly different speeds on each lane, time ticks unevenly for the particle. The difference is a tiny fraction of an atom's jitter, but that's enough to entangle the paths at the quantum level. At the meeting point, the particle will reveal itself as having traveled both routes at once, and the detector will record it.
If it works, this will be the first demonstration that gravity plays by quantum rules. Physics today is fractured: relativity describes stars, quantum mechanics describes atoms, and together they don't mesh. This tabletop experiment would be a bridge to a unified picture, linking black holes with the first moments of spacetime curvature after the Big Bang.
🎯 Earth's rotation also drags space: in 2011, the Gravity Probe B satellites confirmed that our planet twists spacetime around itself, shifting gyroscopes by 37 milliarcseconds per year.
🎬 Quantum gravity inspires sci-fi writers to imagine devices that manipulate spacetime—from warp drives to gravity suits.