> On 15 Jan 2021, at 06:01, Alan Grayson <agrayson2...@gmail.com> wrote: > > > > On Thursday, January 14, 2021 at 3:15:47 PM UTC-7, Pierz wrote: > > > On Thursday, January 14, 2021 at 11:07:59 PM UTC+11 agrays...@gmail.com <> > wrote: > On Thursday, January 14, 2021 at 2:26:42 AM UTC-7 Pierz wrote: > On Thursday, January 14, 2021 at 2:42:43 PM UTC+11 agrays...@gmail.com <> > wrote: > On Wednesday, January 13, 2021 at 8:29:16 PM UTC-7 Pierz wrote: > On Thursday, January 14, 2021 at 1:23:11 PM UTC+11 agrays...@gmail.com <> > wrote: > On Wednesday, January 13, 2021 at 4:33:20 PM UTC-7 Pierz wrote: > On Wednesday, January 13, 2021 at 5:50:29 PM UTC+11 agrays...@gmail.com <> > wrote: > On Tuesday, January 12, 2021 at 10:19:59 PM UTC-7 Pierz wrote: > > > On Monday, January 4, 2021 at 12:09:06 PM UTC+11 agrays...@gmail.com <> wrote: > On Sunday, January 3, 2021 at 3:56:51 PM UTC-7 johnk...@gmail.com <> wrote: > On Sun, Jan 3, 2021 at 5:21 PM Alan Grayson <agrays...@gmail.com <>> wrote: > > > The MWI doesn't guarantee that these subsequent measurements, for > > subsequent horse races say, are occurring in the SAME OTHER worlds as > > trials progress, to get ensembles in those OTHER worlds. > > I don't know what you mean by "SAME OTHER worlds", the same as what? In one > world Alan Grayson remembers having seen the electron go left, in another > world Alan Grayson remembers having seen the electron go right, other than > that the two worlds are absolutely identical, so which one was the "SAME > OTHER world"? > > > You seem to avoid the fact that no where does the MWI guarantee [...] > > Quantum mechanics is not in the guarantee business, it deals with > probability. > > > I don't think you understand my point, which isn't complicated. > > Yes, your point is very simple indeed, but the word simple can have 2 > meanings, one of them is complementary and the other not so much. > > In first trial, the MWI postulates other worlds comes into existence. Same > other worlds in second trial? Same other worlds in third trial, etc? Where > does the MWI assert these other worlds are the SAME other worlds? Unless it > does, you only have ONE measurement in each of these worlds. No probability > exists in these other worlds since no ensemble of measurements exist in these > other world. AG > > You grossly misunderstand MWI. There are no "same other" worlds. The worlds > that arise at each trial are different in precisely one way and one way only: > the eigenvalue recorded for the experiment. The different eigenvalues will > then give rise to a "wave of differentiations" as the consequences of that > singular difference ramifies, causing the different worlds generated by the > original experimental difference to multiply. "World" really means a unique > configuration of the universal wave function, so two worlds at different > trials can't possibly be the "same world", and yes, there is only one > measurement in each. > > This is what I have been saying all along! AG > No it isn't. I agree you have been saying there is only one measurement > outcome in each world. However this business about "same other worlds" > betrays your lack of comprehension. It's not that MWI "doesn't guarantee" > that the the worlds at each trial are the same world. It's that the whole > notion of "same other worlds" means nothing in this context and has no > bearing on anything. A bit like arguing when we add 1 and 1 twice whether we > are guaranteed that the ones we add each time are the "SAME ones" at each > addition. If mathematics can't guarantee that then how can we be sure the > answer is the same? Basically the only answer to that is "WTF?" > > That is precisely the stipulation of MWI. If we have a quantum experiment > with two eigenvalues 1 and 0, and each is equally likely per the Born rule, > then the MWI interpretation is that - effectively - two worlds are created. > You, the experimenter, end up in both, each version knowing nothing about the > other. > > Again, what I have been saying all along! AG > If you get that, then the next bit follows. > > So, in the "objective world" (the view from outside the whole wave function > as it were), no probability is involved. But if you repeat this experiment > many times, each version of you will record an apparently random sequence of > 1s and 0s. Your best prediction of what happens in the next experiment is > that it's a 50/50 toss up between 1 and 0. Objectively there's no randomness, > subjectively it appears that way. > > Here's where you go astray. AG > > So you say! Without justifying yourself in any way. You seem to be saying > that probability can't describe QM experiments because in each world there is > only one outcome and therefore no "ensemble" of outcomes from which a > probability can be derived. That is totally wrong-headed. There are two > "ensembles": the ensemble of different multiverse branches at each > experiment, and the ensemble of each experimenter's prior measurements, and > those are enough to derive the appearance of randomness and to justify a > probabilistic description despite the objective lack of randomness. If you > agree with "what you have been saying all along", then you must agree that > every experimenter in every world in an MWI multiverse will see a record of > an apparently random sequence of 1s and 0s in the described experiment. > Right? And if not why not? > > IMO, since the trials are independent, the other observers are disjoint from > each other and each records only one measurement. So the only observer who > sees an ensemble is the observer in THIS world. To get an ensemble of > outcomes in those other worlds, and hence a probability, you need to appeal > to a non-existent observer, also called the Bird's Eye observer. AG > > Respectfully, you did not answer my question. Do you agree or not that every > experimenter in every branch of the multiverse who records a series of > experiments as described in my scenario will record a seemingly random string > of 1s and 0s? If you do, that's really all that's required. Abstract debates > about "ensembles required to get a probability" are moot. If the world is as > described by MWI, the appearance of probability is an outcome, and > probability is the best possible description of how quantum experiments turn > out from any real observer's POV (as opposed to the Bird's Eye observer). If > you disagree that experimenters will get a seemingly random string of 1s and > 0s, then you'll need to explain why you think that. > > I did answer your question. Since the trials are independent, a NEW OTHER > WORLD observer is created on each THIS WORLD trial. So the other observers > see ONE outcome each. No reason to assume otherwise. You need another > postulate for this to work. AG > > You're talking like a politician. Does each observer in each world who > repeats said experiment record a seemingly random series of 1s and 0s or not? > Yes/no. It's not hard. Come on, you can do it now... > > The answer is NO. In the spin experiment we're discussing, AG in this world > measures an apparently random sequence of 0's and 1's. > > That's all we need. Remember, we are talking about if MWI were true here. > This is a thought experiment in which we are imagining how things would go if > the MWI picture were correct. So if you're admitting that, in such a world, > "AG in this world measures an apparently random sequence of 0's and 1's", > then you have all the preconditions for making probabilistic predictions from > it. > On each trial an imaginary other AG measures the complement of what AG in > this world measured. > > They are not imaginary in MWI. I agree with this statement once you remove > the word "imaginary", which we can do ex-hypothesi. I'm not asking you to > believe in them here, only to advance an argument based of "if" MWI were true. > Now since the trials are independent, different imaginary AGs always measure > complements, but none measure more than ONE RESULT. > > Again, discarding the word "imaginary", I agree. Of course they don't measure > more than one outcome at the same trial. > > I meant, of course, that each other AG measures ONE value when created for > some trial, but that's all this observer EVER observes because, unless you > can offer an argument, he's disjoint, that is NOT related or connected any > other "other AG". AG > > As I previously indicated, these other AGs are disjoint from each other. > > What do you mean by "disjoint" exactly? Mathematically "disjoint" means > "having no elements in common". In the case of AG's who have measured > different results, initially their worlds have only this difference between > them, so in that sense they are not disjoint. If you mean they cannot > interact with one another, and inhabit diverging realities, then that is only > the case discounting interference, which we cannot do, because without > interference effects we dot have quantum mechanics. This word disjoint seems > to be central to your objection, but you need to define precisely what is > meant by it or we cannot assess the validity of your claims. > > The only way to remedy this situation is to add another postulate to your > MWI. AG > > No idea what we need to remedy. I'll ask my question again, adjusting it > slightly. Does AG record a seemingly a random string of 1s and 0s in this > experiment if MWI describes reality? > > You seem to be assuming the other worlds created according to the MWI > interact with other due to interference. Since these other worlds are never > observed, I call them "imaginary"; and more important, no observations of > interacting other worlds have ever been made, within QM or without QM. So the > MWI is a huge stretch, at best. AG
Histories (world if you want) interfere statistically, without any interaction. You don’t need interaction to change the statistical outcome of an history. Adding different histories change the statistic, even if they do not interact with each other. That happens already in arithmetic. Bruno > > > > -- > 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 everything-list+unsubscr...@googlegroups.com > <mailto:everything-list+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/9028f9b4-f111-4366-bb84-f4024d15202do%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/9028f9b4-f111-4366-bb84-f4024d15202do%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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/2A487FD6-471E-4E06-94AE-B496CCA2A5DD%40ulb.ac.be.
