Bohmian mechanics is a rather nice way of side-stepping the measurement problem by having a deterministic dynamics that generates the same experimental predictions as more orthodox interpretations of Quantum Mechanics.
Famously, however, Bohmian mechanics suffers from having to make the quantum equilibrium hypothesis (QEH) that the initial distribution of the particles matches the wavefunction, i.e., that the initial particle density is given by (at least approximately) |ψ|2. In other words, Bohmian mechanics requires the initial conditions to be fine-tuned for the theory to work, and we can then think of Bohmian mechanics as deterministic Bohmian dynamics plus QEH.
Can we give a fine-tuning argument for the existence of God on the basis of the QEH, assuming Bohmian dynamics? I think so. Given the QEH, nature becomes predictable at the quantum level, and God would have good reason to provide such predictability. Thus if God were to opt for Bohmian dynamics, he would be likely to make QEH true. On the other hand, in a naturalistic setting, QEH seems to be no better than an exceedingly lucky coincidence. So, given Bohmian dynamics, QEH does support theism over naturalism.
Theism makes it possible to be an intellectually fulfilled Bohmian. But I don’t know that we have good reason to be Bohmian.
Alex
ReplyDeleteWhy would a Bohmian interpretation require more fine-tuning than other interpretations? Isn't the the fine-tuning argument supposed to show that, on naturalism, the existence of the universe is an exceedingly lucky coincidence anyway?
The problem I see with a Bohmian interpretation is that it suggests a fully deterministic account of God's creative act, which, in turn, contradicts libertarian free will.
The Bohmian interpretation requires a precise correlation between the initial values of the wavefunction and the distribution of particle positions, a correlation which the theory does not posit. This is actually a *massive* amount of finetuning.
ReplyDeleteAs for determinism, it could always be that our acts of free will are miracles from the point of view of physics.
Alex
ReplyDeleteIt can be argued that on a Bohmian interpretation only one universe is possible, namely ours.
Compare that to the hypothesis that God could only have created one universe, namely ours. The second option is less parsimonious.
So, actually, the Bohmian interpretation supports naturalism over theism.
I remember you said in an older post that non-Bohmian interpretations of QM might leave us in a superposition between an ordinary universe and various skeptical scenarios; I don't know if you still think this, but if you do, could that potentially give us good reason to be Bohmians?
ReplyDeleteI don't remember saying that, but it's an interesting observation. :-)
ReplyDeleteI am not sure, however, that it's a problem for the non-Bohmian, as long as the total weight of the skeptical scenarios in the wavefunction is small.
The total weight of the skeptical scenarios likely would be quite small, no? Small enough that they likely wouldn't pose much of a problem? BTW, here's the original blog post: https://alexanderpruss.blogspot.com/2016/10/sceptical-scenarios-and-quantum.html
ReplyDeleteIf you don't mind me asking, which interpretation of QM do you lean towards?
I am somewhat fond of this one: http://alexanderpruss.com/papers/TravelingForms.pdf
ReplyDeleteOut of curiosity, are you personally worried by the potentially skeptical implications of QM, or do you think the chances of it being a problem are low enough that it can be safely dismissed?
ReplyDeleteI am not convinced that low probability issues lead to scepticism.
ReplyDeleteForgive me, do you mean that the probabilities of the skeptical scenarios are sufficiently low, or that you don't find probabilistic scenarios in general to be troubling?
ReplyDeleteI meant the former, though the latter is true.
ReplyDelete