Roger Penrose proposed that in the macro-world, quantum uncertainty vanishes due to gravity: it acts slightly differently on the two branches of a superposition, breaking their coherence. Incorporating spin into the model based on Einstein's theory yielded an unexpected result — centrifugal forces accelerate the decay. It's like a carousel: two balls try to stay in two places at once, but the spinning knocks them into a single position. So gravity and rotation together speed up decoherence and collapse, destroying quantum entanglement even more effectively.

The effect is noticeable on objects ranging from levitating nanospheres to neutron stars. This gives experimentalists a great opportunity: the higher the spin rate, the more quantum properties are suppressed. Measurements on rapidly rotating particles will help refine the uncertainty principle of Heisenberg and explore the region where spacetime curvature meets the quantum.