Superfluid Helium Feels How the Earth Spins ⚡ экспресс
A lab experiment is proposed for the local measurement of the frame-dragging effect on Earth using the macroscopic quantum properties of superfluid ⁴He in a gyroscope based on a single Josephson junction. Expressions have been derived for the contributions of frame-dragging, geodesic, and Thomas effects to the dynamics of the superfluid gyroscope, and a method for their experimental measurement is described. The thermal noise threshold is estimated, and it is shown that at millikelvin temperatures expected for future Josephson junctions with nanoporous 2D materials, very high sensitivity is achievable. Using materials with minimal mechanical losses, the noise spectral density is 5×10⁻¹⁷ rad/s/√Hz at 10 mK, which is sufficient to resolve the dragging rate with 0.2% accuracy in one second, corresponding to a rotational sensitivity of one rotation in 4 billion years. This extreme sensitivity is equivalent to measuring a proper time difference on the order of 10⁻³⁵ s.
According to Einstein's theory, Earth's rotation drags space-time itself along — like a spoon dragging thick honey. This effect is incredibly weak: about one revolution in billions of years. But it can be caught. Scientists propose a tabletop experiment: a sensitive detector is placed in superfluid helium — a liquid that flows without any friction. The rotation creates microscopic quantum vortices in the helium, and the device counts them with fantastic precision. Calculations show it will notice even a turn lasting four billion years — almost as long as Earth has existed. Such precision will allow testing gravity theory right in the lab, not just in space.
The device's sensitivity is such that it captures rotation trillions of times slower than the movement of a clock's hour hand. For comparison: around black holes, this same drag effect accelerates matter to near-light speeds.
🎯 The effect was predicted in 1918, but it was only measured in 2004 — with the help of satellites.
🎬 In "Interstellar", this effect twists space-time around a black hole so strongly that on Miller's planet, giant waves surge up.