Reply To: Explicit models of retrocausation

[Ken Wharton]

Hi Nathan,

I’m still meaning to get to the “Stochastic Quantization” literature you mentioned, but I did look at your summary of it, and I’m a bit concerned about this “extra” time dimension you noted in a footnote. (Some discussion of “meta-time” has also recently come up in Cohen’s topic and Elitzur’s topic, and I hope to get a broader discussion about that issue going soon. Also, it’s relevant for Kastner’s general approach…)

But for now I would like to delve into your model a bit. I do think it is the first explicit retrocausal entanglement model in the literature. (Perhaps Rod Sutherland would lay claim to that with his Bohmian approach, actually; he’s just posted an updated version of that model in this forum.) I do think that your original model is almost the same as my model (in the gamma->zero limit), but I see a few small distinctions and want to raise them here.

First of all, you’re using information about the future settings to impose a special *initial* boundary constraint on the hidden polarization. In contrast, I find it more natural to impose a *final* boundary constraint that leads to much the same effect. Do you see this as an essential difference, or have a strong opinion about where the boundary should be imposed? One thing I’ll note is that if there is some intermediate polarization-rotation between the entanglement source and the final measurement, you’ll have to change your initial distribution to account for it. But if you put the boundary constraint on the *end*, then it’s accounted for automatically.

Another difference between our models arises at the one future measurement where the angles don’t match. I’m not positive exactly what you see happening to the polarization at that point, as I didn’t see it noted explicitly. Does your model imply a sort of “collapse” of the mismatched polarization at that point? (Where it snaps to alignment, one way or the other, according to Malus’s Law?) If so, I wonder if you see this as a time-asymmetry at that particular detector. Because run backward in time, the polarization would “snap” from a *matching* angle to a *mismatching* angle. Or maybe you’re envisioning a less-collapsey version of Malus’s Law, more along the lines of the anomalous-rotations in my model?

Best,

Ken