Spooky Action at a Distance

I have recently been attempting to understand “spooky action at a distance.” This was Einstein’s irritated phrase for quantum entanglement, in which two particles appear to remain mysteriously correlated no matter how far apart they are. It sounds dramatic. It is dramatic. It is also, apparently, experimentally verified and mathematically unavoidable.

I have read about Bell’s theorem. I have read about measurement axes. I have read about probability amplitudes that must be squared before they become probabilities, which feels faintly indecent. I have read about hidden variables that cannot be local and local variables that cannot be hidden. At some point, I found myself muttering “statistics, shmatistics” at the laptop.

Logic suggests the whole thing is not as problematic as advertised. If two particles are created together and must conserve spin, why not assume that from the start one is simply the opposite of the other? Symmetry maintained, books balanced, distance irrelevant. The particles separate, each carrying its assigned role. No drama. No metaphysics. Just tidy accounting.

The physicists, however, insist that this perfectly sensible picture will not survive contact with rotated measurement axes and large data sets. There is, apparently, no pre-written answer sheet listing what each particle would do if measured in every possible direction. Classical intuition would very much like there to be. Quantum mechanics politely declines.

Apparently the failure is not of statistics, but of classical statistics. Which is the sort of sentence that makes you put the kettle on.

And then it happened.

While I was deep in Hilbert space, wondering whether locality or realism was the sacrificial lamb, I noticed movement in the herb bed.

Spooky.

Spooky is one of the neighbourhood cats.

He was not in the garden. Then he was. I did not observe his arrival. No trajectory. No intermediate states. One moment absence, the next moment presence. A full collapse of the feline probability waveform.

I stepped outside. He vanished. I returned indoors. The rosemary was disturbed again. Non-local. Quite clearly non-local.

This is what the physicists are up against. They worry about entangled electrons separated by kilometres. I worry about a cat entangled with three gardens, two compost bins and a suspiciously shredded cushion on our patio furniture.

Unlike electrons, Spooky definitely carries hidden variables. If measured along the axis of food, he is always spin up. If measured along the axis of obedience, he is catastrophically spin down. No statistics required.

The physicists can keep their Bell inequalities. I will settle for a functioning fence.