Quantum gravity sensor opens window into world beneath our feet

N.B. this is a device that uses quantum effects to measure the strength of gravity, not anything to do with a quantum theory of gravity. Still quite an achievement from what I understand.

> The sensor uses a quantum technique called atom interferometry. Ultra-cold rubidium atoms, falling under the influence of gravity, are illuminated with laser beams. The resulting interference patterns depend on the speed with which they are falling — and indicate with great precision the strength and gradient of the local gravitational field, which is influenced in turn by what lies beneath the ground.