<agrays...@gmail.com> wrote: > >>> >> >>> As for collapse, it's easily seen in the double slit experiment. The >>> electron, say, moves >>> >>> through space as a wave -- which explains the interference effects due >>> to splitting into >>> t >>> wo waves, each emanating from one of the slits >> >> > > >> >> Then after it passes the double slit and that electron hits the >> photographic >> plate >> why does it always produce one and only one spot, not a smudge as one >> wave should and not a interference pattern as as 2 waves should? > > > > > It probably is a smudge, consistent with the UP.
NO! The electron NEVER produces a smudge on that photographic plate regardless of if it went through one slit or 2 slits or no slit at all. It ALWAYS produces a localized spot unless there is information on which slot the electron went through. And even if there is which way information if that information is erased after it passed the slits but before it hits the photographic plate there will be a interference pattern. Think about that for a minute, its in the past, the electron either went through a slit or it didn't and if the arrow of time is real then there is nothing you can do about it now, but apparently you can. Many Worlds can explain this without the future changing the past, Copenhagen can't. > and is ALWAYS observed as localized in space, aka a PARTICLE. But that particle is NEVER localized at the two slits, it's only localized at the photographic plate, so "observation" made it localized. And as they can't say how observation does this, what qualifications it takes to be considered a legitimate observer, or even explain exactly what "observation" is , Copenhagen might just as well say magic made it localized. > > > That is, the wave collapses > > into a particle! And it does this because of a thing called "observation" aka magic. > > There is no other reasonable interpretation of results of the double slit > experiment, There are no reasonable interpretations of the double slit experiment ! Nature is nuts, you may not like it but that's the way it is. >> >> So tell me exactly what this *observer* thing is. Exactly what is it >> about observation that allows it to collapse the wave particle? > > > > > Dunno. I've noticed. > > But using MWI without collapse, why do we get some particular value and > not others? A version of John Clark sees that particle have every value that doesn't violate the laws of physics. T he reason any particular John Clark sees only one value is because when the particle splits at the 2 slits John Clark splits too. >> >> those infinite number of observers are indistinguishable from only one, >> and that's pretty simple. >> > > > > As simple as a woman who gives birth to twins, millions of times over and > then some? I have no idea what that question means, but I do know that a billion or even a infinite number of identical universes is indistinguishable from only one, both objectively and subjectively. >> >> Amongst the "Yes, I think MWI is true" crowd listed are Stephen Hawking >> and Nobel Laureates Murray Gell-Mann andRichard Feynman. Gell-Mann and >> Hawking recorded reservations with the name "many-worlds", but not with the >> theory's content. Nobel Laureate Steven Weinberg is also mentioned as a >> many-worlder " > > > > > Your source is fact-challenged. Weinberg thinks MULTIVERSE may have merit, > but NOT the MWI, Then give me some facts! Where does Weinberg say that? And how can you have a multiverse without many worlds or many worlds without a multiverse? > > > which he characterized as "repellent". He said it was repellent, he did not say it was untrue, Weinberg also said *"The more the universe seems comprehensible, the more it also seems pointless"*; I'm sure he doesn't like pointlessness but he wasn't implying that the universe didn't exist. And Weinberg admits that repellent or not he doesn't have a better idea. You didn't supply Weinberg's entire quote so I guess I'll have to: *"the measuring apparatus and the physicist are presumably also governed by quantum mechanics, so ultimately we need interpretive postulates that do not distinguish apparatus or physicists from the rest of the world, and from which the usual postulates like the Born rule can be deduced. This effort seems to lead to something like a "many worlds" interpretation, which I find repellent. Alternatively, one can try to modify quantum mechanics so that the wavefunction does describe reality, and collapses stochastically and nonlinearly, but this seems to open up the possibility of instantaneous communication. I work on the interpretation of quantum mechanics from time to time, but have gotten nowhere."* Richard Feynman felt much the same way, he wasn't happy with Many Worlds but he had nothing better: "*The * *many-world picture says that the wave function ψ is what's real, and damn the torpedos if there are so many variables. All these different worlds and every arrangement of configurations are all there just like our arrangement of configurations, we just happen to be sitting in this one. It's possible, but I'm not very happy with it." * Lets see what some other world class scientists have to say about it. Quantum theorists David Deutsch says the results of the two slit experiment are so clear that its silly to call Many Worlds a interpretation at all: *"calling many worlds a interpretation is like talking about dinosaurs as an 'interpretation' of fossil records. The evidence that other universes exist is at least as strong as the evidence for pterodactyls or quarks.”* Quantum computer expert Scott Aaronson says: *"* *MWI is not some crazy speculative idea that runs afoul of Occam’s razor. On the contrary, MWI really is just the “obvious, straightforward” reading of quantum mechanics itself, if you take quantum mechanics literally as a description of the whole universe, and assume nothing new will ever be discovered that changes the picture."* leading Cosmologist Sean Carroll says: *"* *The conclusion, therefore, is that multiple worlds automatically occur in quantum mechanics. They are an inevitable part of the formalism.[...] The formalism predicts that there are many worlds, so we choose to accept that. This means that the part of reality we experience is an indescribably thin slice of the entire picture, but so be it. Our job as scientists is to formulate the best possible description of the world as it is, not to force the world to bend to our pre-conceptions."* > > The only way to understand double slit experiment is via superposition of > states, which means no definite state before measurement! Does NOT apply to > macro objects where interference does not manifest. But why? Many Worlds can explain why we don't see interference in macro objects but Copenhagen can't. Many Worlds says interference can't occur unless 2 different universes evolve in such a way that they become identical and merge, and that is only likely to happen if the difference between the two universes is very small, and a macro change in a macro object is not small so the two universes are unlikely to ever be identical again. > > I won't say it again! Promises promises. > >> >> If the which way information is retained the interference pattern is >> destroyed, if the information is destroyed then you have interference, and >> that is what Many Worlds predicts. > > > > > ??? No interference in which-way experiment. Huh? Is that a question a comment or neither? >> >> I agree, interference effects only manifest in special circumstances, >> when a world splits become different and then the two evolve in such a way >> that the two become identical again and so merge back together, and that is >> only likely to happen if the difference between the two worlds is very >> small; that's why we don't see weird quantum stuff in our macro world, like >> in the Earth Moon system > > > > But since the many worlds are disjoint, we don't SEE anything. Of course I see something. If I'm observing the slits I see the photon go through the left slit, the universe splits, and I split with it and I see the photon go through the right slit too. And each individual I sees the photon go through one and only one slit because when the photon splits so does I. > > > Moreover, they can't become identical > > if they differ in what's measured! They CAN become identical again if all the records of that difference measurement is erased. After the photon hits the photographic plate it no longer exists in either universe, however in one I have the memory of the photon going through the left slit and in the other I have the memory of it going through the right slit. Information is physical so the arrangement of atoms in the two brains must still be different, so the universes do *not* merge and *no* interference pattern exists. However if I never knew which slot the photon went through or if that information was erased then when the photon hits that plate and no longer exists in either universe they are identical again and merge back together, but indications remain that once there was a difference and that causes the interference. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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