# Thompson's Lamp **URL:** \ **Category:** Great Debates\ **Created:** [December 3, 2021, 11:17pm UTC](https://boards.straightdope.com/t/thompsons-lamp/955473 "2021-12-03T23:17:30Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [December 13, 2021, 4:28am UTC](https://boards.straightdope.com/t/thompsons-lamp/955473/41 "2021-12-13T04:28:26Z")
> [@Half\_Man\_Half\_Wit](#): > > Bohmian mechanics is completely equivalent in terms of observations, yet deterministic But AIUI, is nonlocal and so trashes SR. I know which part of the overall shebang I’d choose to keep. And also, while originally set up as a pure causal deterministic model, DB-B now seems to include a stochastic component so … isn’t _really_, is it? ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [December 13, 2021, 6:10am UTC](https://boards.straightdope.com/t/thompsons-lamp/955473/42 "2021-12-13T06:10:53Z")
> [@MrDibble](#): > > But AIUI, is nonlocal and so trashes SR. I know which part of the overall shebang I’d choose to keep. It’s nonlocal, yes, but it’s also non-signalling—meaning it’s perfectly compatible with special relativity, since the latter only prohibits the exchange of information with a speed greater than that of light, which isn’t possible in Bohmian mechanics. So at best, you might complain about it violating ‘the spirit’ of SR. But if that sort of thing bothers you, there’s other options for a deterministic version of QM. For instance, [superdeterminism](https://en.wikipedia.org/wiki/Superdeterminism) is both local and deterministic, although it has other issues that I don’t find very attractive in a theoretical model. We should be clear about the fact that this is a choice, though, and not ultimately mandated by anything in physics. In fact, that’s all it ever can be—since deterministic Turing machines and probabilistic ones compute all the same functions, you can always find a deterministic reformulation of any allegedly indeterministic theory. So when one argues about determinism, one is always talking metaphysics—which is perfectly fine, of course, but I think needs to be made clear. (OK, in the interest of accuracy, there’s a caveat here: if quantum randomness is not algorithmically random, then it is in principle possible to carry out an experiment that will eventually uncover the possibility of superluminal signaling; but first of all, this is really a statement of initial conditions, not about the theory, and second, while for any model, there is such an experiment, for any such experiment, there is also a non-algorithmically random model that will escape detection, so this can only ever tell us that QM’s randomness is non-algorithmically random, not that it is.) > [@MrDibble](#): > > And also, while originally set up as a pure causal deterministic model, DB-B now seems to include a stochastic component so … isn’t _really_ , is it? That’s news to me—where did you get that from? ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [December 13, 2021, 7:59am UTC](https://boards.straightdope.com/t/thompsons-lamp/955473/43 "2021-12-13T07:59:20Z")
> [@Half\_Man\_Half\_Wit](#): > > when one argues about determinism, one is always talking metaphysics—which is perfectly fine, of course Sure, metaphysics is fine but it’s also no longer science, and people can’t have their cake and eat it when it comes to talking about the mind - either it’s metaphysics, or it’s meat machines and chemical gradients. > [@Half\_Man\_Half\_Wit](#): > > That’s news to me—where did you get that from? That’s what I get from Bohm et al’s later extension of the original DB-B thory into the quantum non-equilibrium hypothesis. Admittedly, I only have first year physics so am way out of my depth when it comes to the intricacies of QM _anything_. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [December 13, 2021, 9:21am UTC](https://boards.straightdope.com/t/thompsons-lamp/955473/44 "2021-12-13T09:21:52Z")
> [@MrDibble](#): > > Sure, metaphysics is fine but it’s also no longer science, Sure. My point was just that there’s really no sense in which you could appeal to science as settling the ‘determinism vs randomness’-issue. > [@MrDibble](#): > > either it’s metaphysics, or it’s meat machines and chemical gradients. Not sure what you mean, here—the idea that ‘it’s meat machines and chemical gradients’ _is_ a metaphysical one, encapsulating a commitment to physicalism/materialism. > [@MrDibble](#): > > That’s what I get from Bohm et al’s later extension of the original DB-B thory into the quantum non-equilibrium hypothesis. Ah. But at that point, it’s no longer an interpretation of QM, but a bona fide alternative theory, with in-principle observable differences from vanilla QM. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [December 13, 2021, 9:28am UTC](https://boards.straightdope.com/t/thompsons-lamp/955473/45 "2021-12-13T09:28:05Z")
> [@Half\_Man\_Half\_Wit](#): > > My point was just that there’s really no sense in which you could appeal to science as settling the ‘determinism vs randomness’-issue. Oh, sure, I agree - hell, at some point it’s almost _aesthetic_, which side you favour.. > [@Half\_Man\_Half\_Wit](#): > > Not sure what you mean, here—the idea that ‘it’s meat machines and chemical gradients’ _is_ a metaphysical one, encapsulating a commitment to physicalism/materialism. The commitment to meat aspect _is_ metaphysical (and also not something where I disagree, I’m no dualist), but the details of how that works in relation to being non-causal, which is what I’ve been discussing WRT how chemical gradients have random components, is not metaphysics, just physics. [Previous page](https://boards.straightdope.com/t/thompsons-lamp/955473.md?page=2)