> On 17 Jan 2021, at 03:03, Pierz Newton-John <[email protected]> wrote: > > > > On Sun, 17 Jan 2021 at 3:49 am, Alan Grayson <[email protected] > <mailto:[email protected]>> wrote: > What would be the mechanism or process for other worlds to interact with each > other, that is to interfere with each other? This is the gorilla in the room > that many MWI enthusiasts ignore; awesome speculation with zero grounding in > empirical evidence. Something definitely awry with this pov. AG > > I’m not an “enthusiast”. It’s a physical theory not a football team. If > anything I dislike the idea of all those alternative variants of me and my > life. If MWI is disproved I’ll be perfectly happy. It’s just that it > unfortunately makes more sense in my assessment than any other alternative, > so I entertain it as the most likely explanation for the observed data. To > say it has zero grounding in empirical data is simply false - it’s the > theory that simply takes the empirical data to its logical conclusion without > adding a collapse postulate. The wave function is the whole thing. Asking > what the mechanism is for worlds to interfere with one another is the same as > asking what the mechanism is for the Schrödinger wave function to interfere > with itself. In the dual slit experiment it’s an observed fact. It makes no > sense for it to behave that way if we stick to the old view of matter as > little hard balls, but there you go. When we talk of “worlds”, it just refers > to a ramifying quantum state, and it is in the nature of quantum states to > interfere with themselves per the dual slit experiment, even if they become > large and complex. Interference ceases when two branches of the universal > quantum state diverge far enough that they completely decohere. When you say > “what is the mechanism?” that really means “what is the mathematical > description?” in physics. Anything else is just imprecise circumlocution like > the word “world” in this context. So the mechanism for interference is the > Schrödinger equation, which predicts such interference. MWI adds precisely > nothing to that mathematical description.
Yes. To avoid the MWI, the early founders of QM *added* an axiom: the wave collapse postulate. But it introduce a non intelligible dualism with an unknown theory of mind. It makes everything more complicated, for reason of philosophical taste, which is alway dubious. Occam Razor favour the theory with as much axioms as possible. Especially if one believe in Mechanism. This asks us to believe that 2+2=4 & Co., which entails the existence of all computations, with a extraordinary complex redundancy of those computations, implying the existence of a (Lebgues) Measure on their first person limit (the “observer” cannot be aware of the number of steps of the universal dovetailing (which occur in all models of any theory of arithmetic). So ... Bruno > > > On Saturday, January 16, 2021 at 9:32:49 AM UTC-7 Alan Grayson wrote: > On Saturday, January 16, 2021 at 1:23:52 AM UTC-7 Pierz wrote: > On Sat, 16 Jan 2021 at 2:18 pm, Alan Grayson <[email protected] <>> wrote: > > > On Friday, January 15, 2021 at 6:16:25 PM UTC-7 Pierz wrote: > On Sat, 16 Jan 2021 at 5:56 am, Alan Grayson <[email protected] <>> wrote: > > > On Thursday, January 14, 2021 at 11:36:39 PM UTC-7 Pierz wrote: > On Fri, 15 Jan 2021 at 4:01 pm, Alan Grayson <[email protected] <>> 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 [email protected] <> > 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 [email protected] <> > 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 [email protected] <> > 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 [email protected] <> > 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 [email protected] <> wrote: > On Sunday, January 3, 2021 at 3:56:51 PM UTC-7 [email protected] <> wrote: > On Sun, Jan 3, 2021 at 5:21 PM Alan Grayson <[email protected] <>> 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 > > Of course? I’m starting to think your picture of MWI is even more > misconceived than I imagined. Look, the MWI multiverse has the structure of a > tree, where each branch event is a different possible eigenvalue of some > observable. But - again ex hypothesi - all branches of the tree are > ontologically equal. They are all as real as one another. > > I'm really dumb. Ask Bruce for confirmation. I agree; in a horse race there's > no difference between AG observing the winner, and a MWI enthusiast imagining > another winner in another world. AG > > Bruce thinks that MWI violates Born’s rule and generally hates MWI. I don’t > think his argument about the Born rule holds water, though it’s a well-known > one. David Deutsch’s chapter on MWI in The Beginning of Infinity presents a > refutation of that argument that I personally find convincing. But Bruce does > at least understand MWI. I’m sure that while he shares your disdain for it, > he would not accept that your specific argument against is valid. All you are > doing is asserting that the other observers are imaginary, which is not a > valid form of argument. > > Each AG’s past at a particular trial is the same as all the other AGs at that > trial, though each AG’s future diverges into further trees of different > observed realities. The equal status of all branches means that your idea > that AG observers on other branches are in some way different from the AG > branch you happen to be on in that they only ever have one observation is > just totally misconceived. To be blunt, you don’t get it. > > What I get is that "ex hypothesi" covers a multiple of sins, including a > complete disregard of experimental verification in physics. AG > > A hypothesis by definition has no experimental verification - yet! The same > objection could have been made against General Relativity in 1915. But I’m > not trying to convince you of MWI. Only that your argument about it not > giving rise to probabilities is not valid. You can’t assume the hypothesis > isn’t valid in your argument against it. You have to show how it’s logically > inconsistent. > > Your comparison with GR is plainly deficient if not silly. GR was published > in Nov 1915, and with it was a postulated empirical test which the theory > passed in 1920 (the bending of starlight as it passes the Sun). By > comparison, the MWI was published around 1957, and now, after about 63 years, > there's no proposal for a test of its validity. As for the observers being > imaginary, I contend they remain in that status until they are experimentally > detected. Have you seen one? As for Bruce's position, I don't know his > perspective on my argument, nor do I particularly care. But I am pretty sure > he would not agree on the absolute thematical reliance on mathematics as > support for the Interpretation. After all, he put forth the horse racing > model to cast grave doubt on the MWI. AG > > If your argument is that MWI is wrong because it hasn’t been “proved” yet (or > supported by empirical test) you’re welcome to hold that position and I won’t > argue with you. My point relates to the internal logic of your argument. > You’re saying the other observers are imaginary and then using that to build > a case against MWI giving rise to probabilities. That’s illogical. If you > want to argue against the internal logic of MWI, you have to start by > accepting what it proposes then proceeding to demonstrate how that leads to > internal inconsistency. However I can see the futility of trying to hold you > to the finer points of logic so I will bow out at this point - as I note many > here have before me. > > If you don't like my characterization of those other worlds as "imaginary", > then you should certainly accept their status as "speculative", as well as > the idea that these other worlds interact with each other. It's not that I > oppose speculation, but given the lack of any empirical evidence of such > other worlds, seems to be a strong point against their existence! But for you > and others who apply Trumper-type logic to physics, the lack of empirical > evidence, after 63 years, has no argumentative weight and the postulates > remain "consistent". AG > > If you consider them imaginary I don’t have a problem with that. It’s not the > point! I’m happy to call them speculative if you like. They exist or they > don’t, right? I’m not 100% sure they do. Of course not. Neither my opinion > nor yours has any bearing on their existence or otherwise. But when we debate > whether MWI is theoretically consistent with observation, we can disregard > the question of whether other observers/worlds are speculative or imaginary. > Otherwise your argument assumes it’s premises. Effectively you’re saying “MWI > can’t be right because the other worlds are purely imaginary”. > > “There’s no ensemble from which to derive probabilities because all the other > observers are purely imaginary” is thus a circular argument. That is my > point. Please try to get over your abhorrence for MWI long enough to get it. > > > 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 > > Im not assuming it. It’s part of QM that wave functions interfere with > themselves. In MWI that translates to different “worlds” interfering. That > interference is extremely limited since it only occurs to the extent that two > branches can become identical again after having diverged. Nonetheless it is > the basis for proposed experimental proofs of MWI. One argument goes that if > we can make a quantum computer with a sufficiently large number of qubits, we > can prove the existence of other worlds because the other worlds are the only > place we can get all that information from. So, no, this is not my > assumption, it’s intrinsic to MWI. Again, if you don’t get that, you don’t > get MWI. You can’t expect your arguments to be taken seriously if you don’t > understand basics like this. > > > > -- > You received this message because you are subscribed to a topic in the Google > Groups "Everything List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe > <https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > [email protected] <>. > 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 a topic in the Google > Groups "Everything List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe > <https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > [email protected] <>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/a4966dac-4001-47ff-9d33-1ccb39c047fen%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/a4966dac-4001-47ff-9d33-1ccb39c047fen%40googlegroups.com?utm_medium=email&utm_source=footer>. > > -- > You received this message because you are subscribed to a topic in the Google > Groups "Everything List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe > <https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > [email protected] <>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/97460a4a-2141-4db6-88df-56158edffe89n%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/97460a4a-2141-4db6-88df-56158edffe89n%40googlegroups.com?utm_medium=email&utm_source=footer>. > > -- > You received this message because you are subscribed to a topic in the Google > Groups "Everything List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe > <https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/b2dddd36-e9ba-4777-abe0-e9f7ac01e0a2n%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/b2dddd36-e9ba-4777-abe0-e9f7ac01e0a2n%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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAArMS03MsDJ2tEOOvU-vFXDJbWUqgATnV4Bf55EAtU6ftGyopw%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAArMS03MsDJ2tEOOvU-vFXDJbWUqgATnV4Bf55EAtU6ftGyopw%40mail.gmail.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/4B19BB4C-A963-48BC-AC15-11917DA96BD8%40ulb.ac.be.
