Sound waves on a chip usually spread in all directions, like whispers echoing around a dome. In a gyroscope, this creates noise that obscures rotation. But a new design forces sound into a one-way flow. By tapping the sound path at several points with precise timing, backward-traveling waves cancel out, while forward waves reinforce. The result is a whisper that only travels forward, slashing noise.
This directionality lets the chip detect tiny rotations. It approaches the stability of a pulsar, a neutron star spinning with clock-like precision, and edges against the fundamental limits of the Heisenberg uncertainty principle.
Such a gyroscope might one day aid the hunt for gravitational waves, filtering noise in massive detectors.
Sound, like light, comes in packets — phonons. This gyroscope can detect rotation using just a few of them, making it exquisitely sensitive.
The precision of such gyroscopes could one day guide spacecraft through asteroid fields as smoothly as the navigators in 'The Expanse' plot complex courses, though here it's about real-world physics.