Two couriers leave the same city in opposite directions. An hour later, each opens an envelope: one contains a slip marked “plus,” the other “minus.” How did they know who would get which? In the quantum world, such a pair is called entangled, and its particles behave exactly the same way: measuring one instantly determines the state of the other, even if they are kilometers apart.
Standard physics forbids superluminal signals, so the correlations of entangled particles are considered inexplicable in ordinary spacetime. The author of the new work proposes a toy model: the two couriers do not communicate directly, but both call a hidden dispatch center located in a second time dimension. The signal travels there at a finite speed, but for us, living in a single time, the conversation appears instantaneous.
The model reproduces the standard correlations for an entangled pair: if one particle collapses into the “plus” state, the other collapses into “minus.” The key prediction is the appearance of the same correlations between particles from different pairs, if their detectors are closer to each other than to their partners. This can be tested by measuring the parameter S in Bell's inequality: for independent particles it should be no more than 2, while the model allows up to 2√2 ≈ 2.828.
The work differs from neighboring approaches by using an extra time dimension instead of extra spatial dimensions or superluminal signals. This preserves causality while providing a “mechanism” for the correlations. If the experiment confirms the hypothesis, information would gain ontological status, as Wheeler suggested. If not, a new constraint would be established, limiting models with extra time dimensions.
For now, this is pure knowledge, with no applications in sight. But two couriers with envelopes are no longer just a trick: they are a possible trace of a hidden tunnel through which nature sends messages faster than we can notice.
Extra temporal dimensions are usually avoided because of the 'grandfather paradox': time travel could allow you to kill your ancestor. The author sidesteps this by assuming that only the subquantum field lives in two times, while particles remain in one.