I was aware of the limitation on *precision* implied by the HUP. I was addressing whether *simultaneous* measurements are possible despite the HUP. I think they are possible. But my main point is that acausality is tantamount to unintelligible. IMO, there's a huge difference between being unable to perfectly predict the time evolution of a system, and it being uncaused. AG
On Sunday, April 17, 2022 at 6:19:44 PM UTC-6 [email protected] wrote: > The authors point out that the Heisenberg uncertainty principle limits the > accuracy of determining initial conditions even if the physics of evolution > is perfectly deterministic. > > I addressed your issue because you posted it here...as a courtesy. If you > don't want it addressed...why post it. > > Brent > > > On 4/17/2022 4:11 PM, Alan Grayson wrote: > > No. I didn't read your original post on this thread. But I see the authors > assume quantum fluctuations, and therefore deny causalty. You get what you > pay for. In my example, there surely are *caused* probabilities, even if > we don't have complete understanding of the initial conditions. But why > address my issue if a link satisfies you? AG > > On Sunday, April 17, 2022 at 4:01:03 PM UTC-6 [email protected] wrote: > >> >> >> On 4/17/2022 7:11 AM, Alan Grayson wrote: >> >> A simple example of your point is a gas at some temperature and pressure, >> confined in some volume. For a given particle in the ensemble, we can't >> determine its exact path because we lack information about its >> interactions. But if we had that knowledge, we could determine its exact >> path, and any uncertainties in that information would translate into >> uncertainties in its path. But inherent randomness in QM is different and >> probably has nothing to do with the UP. >> >> Did you read the paper I cited?: https://arxiv.org/abs/1212.0953v3 >> >> Brent >> >> For example, for a small uncertainty in position, there is a large >> uncertainty in velocity, so we *can* get simultaneous measurements of >> position and velocity, but the latter will manifest large fluctuations for >> succeeding measurements. Thus, the "inherent randomness" in QM is the >> assumption that every individual trial or outcome of a measurement is >> UNcaused; that is, the particular outcome can't be traced to some prior >> state -- what AE called God playing dice with the universe. AG >> >> On Saturday, April 16, 2022 at 6:34:51 PM UTC-6 [email protected] >> wrote:; >> >>> Consider the converse. When you comprehend some physical evolution, is >>> it essential that it be deterministic. Every event has many causes, do you >>> have to know every one of them to comprehend it? Think of all the things >>> you would have to say did NOT happen in order that your comprehension be >>> complete. The way I look at it, we call classical mechanics deterministic >>> only because *most of the time* there are a few (not a bazillion) >>> factors we can *approximately determine* in advance, so that an* almost* >>> certain prediction, *within a range of uncertainty*, is possible. Even >>> within strict determinism there are at this very moment gamma rays from >>> distant supernova approaching you and which cannot be predicted but which >>> might influence your thoughts and instruments. >>> >>> Brent >>> >>> >>> On 4/16/2022 5:08 PM, Alan Grayson wrote: >>> >>> I think you're fooling yourself if you think a non-determinsitic process >>> is comprehensible. AG >>> >>> On Saturday, April 16, 2022 at 5:46:09 PM UTC-6 [email protected] >>> wrote: >>> >>>> >>>> >>>> On 4/16/2022 4:24 PM, Alan Grayson wrote: >>>> >>>> >>>> >>>> On Saturday, April 16, 2022 at 5:03:55 PM UTC-6 [email protected] >>>> wrote: >>>> >>>>> >>>>> >>>>> On 4/16/2022 2:58 PM, Alan Grayson wrote: >>>>> >>>>> >>>>> >>>>> On Saturday, April 16, 2022 at 1:44:09 PM UTC-6 [email protected] >>>>> wrote: >>>>> >>>>>> >>>>>> >>>>>> On 4/16/2022 8:34 AM, Alan Grayson wrote: >>>>>> >>>>>> Of course I favour the first version of the argument, using the >>>>>>> many-world formulation of collapse, to avoid the "God plays dice" >>>>>>> nightmare. >>>>>>> >>>>>>> >>>>>>> Why this fear of true randomness? We have all kinds of classical >>>>>>> randomness we just attributed to "historical accident". Would it >>>>>>> really >>>>>>> make any difference it were due to inherent quantum randomness? >>>>>>> Albrect >>>>>>> and Phillips have made an argument that there is quantum randomness >>>>>>> even >>>>>>> nominally classical dynamics. https://arxiv.org/abs/1212.0953v3 >>>>>>> >>>>>> >>>>>> True randomness implies *unintelligibility*; that is, no existing >>>>>> physical process for *causing *the results of measurements. AG >>>>>> >>>>>> >>>>>> "It happened at random in accordance with a Poisson process with rate >>>>>> parameter 0.123" seems perfectly intelligible to me. There is a >>>>>> physical >>>>>> description of the system with allows you to predict that, including the >>>>>> value of the rate parameter. It only differs from deterministic physics >>>>>> in >>>>>> that it doesn't say when the event happens. >>>>>> >>>>>> I always wonder if people who have this dogmatic rejection of >>>>>> randomness understand that quantum randomness is very narrow. Planck's >>>>>> constant is very small and it introduces randomness, but with a definite >>>>>> distribution and on certain variables. It's not "anything can happen" >>>>>> as >>>>>> it seems some people fear. >>>>>> >>>>>> Brent >>>>>> >>>>> >>>>> Every single trial is unintelligible. AG >>>>> >>>>> >>>>> I find that remark unintelligble. I don't think "intelligble" means >>>>> what you think it means. >>>>> >>>>> Brent >>>>> >>>> >>>> It means there exists no definable physical process to account for the >>>> outcome of a single trial. AG >>>> >>>> >>>> That's what is usually called "non-deterministic". "Unintelligble" >>>> means not understandable or incomprehensible. >>>> >>>> Brent >>>> >>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Everything List" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/everything-list/f873f226-b8f7-40db-9036-ceb8b31427een%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/everything-list/f873f226-b8f7-40db-9036-ceb8b31427een%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "Everything List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/everything-list/2d3b652e-8a5d-4755-962f-52a5d7691f71n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/everything-list/2d3b652e-8a5d-4755-962f-52a5d7691f71n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> >> -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/cfc653e0-ddf1-4d17-a1ac-cd6a69ecc209n%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/cfc653e0-ddf1-4d17-a1ac-cd6a69ecc209n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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