How a Classical Pendulum Creates Quantum Entanglement ⚡ экспресс
The debate on the possibility of entangling quantum states through a classical intermediary is directly linked to the question of the quantum nature of gravity. The answer depends on the choice of hybrid quantum-classical theory. In this work, it is shown that within van Hove's hybrid theory, entanglement through a classical channel is achievable, refuting the universality of known impossibility theorems. Using the example of two quantum spins coupled by a classical harmonic oscillator, the spin density matrix is derived. Comparison with a purely quantum analog confirms the emergence of entanglement in both cases; this is quantitatively demonstrated through purity and concurrence of the system. The results indicate that experiments with quantum entanglement cannot rule out viable theories with classical gravity.
For a long time, physicists were certain: quantum entanglement requires direct quantum contact. A new study refutes this. Two microscopic magnetic particles, connected only by a classical spring, successfully become entangled. The spring oscillates strictly according to Newton's laws, without any quantum weirdness, but its behavior surprisingly resembles the curved space around massive bodies. Thus, simple mechanics becomes an analogue of gravity. Calculations confirmed genuine entanglement. To measure it, entropy is used—a measure of disorder. And in the hybrid system, it increased exactly to the same level as with quantum contact. The classical spring performed like an ideal quantum channel. This result overturns the conviction that only quantum objects can transmit entanglement. This discovery challenges experiments that seek the quantum nature of gravity through particle entanglement. If a classical pendulum yields the same picture, then classical gravity can also 'glue' matter at the quantum level. It turns out that Einstein's idea that gravity is purely classical is not so wrong after all. It recalls the story of gravitational waves: long considered merely a mathematical abstraction, until they were detected.
🎯 Entanglement is measured via entropy—a measure of disorder. In the spring system, this entropy increased just as it would if the mediator were quantum. The classical spring performed just as well as the most perfect quantum channel.