On Mon, Jun 12, 2017 at 8:32 PM, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
>> >> I agree Interference must take place in a single world, but where did >> all the information that produced the interference come from, where did the >> computations that produced all those wrong answers (and a few correct ones) >> come from? > > > > > What calculations are performed in these parallel worlds? > Whatever algorithm you and your doppelgangers decided to run on their quantum computer. > > > And what performs those calculations? > Computers made of matter that obey the laws of physics. > > > You are the one who insists that calculation is possible only on a > physical computer. > Yes, but you almost make that sound as if it were a contradiction of some sort. > > > Who constructed all these physical computers in the parallel worlds? > If the MWI is correct and if you're a computer engineer then you and your doppelganger s made the quantum computer, made lots and lots of them actually. > >> >> Even the 2-slit experiment will not produce interference if you remove >> the photographic plate and just allow the photons to continue into infinite >> space after they pass the slits because then the world splits but the two >> never recombine again so no interference. > > > > > Of course the interference continues -- for ever if necessary. The screen > or photographic plate is only there to enable you to see it. > No, in the Many World's theory it doesn't matter if anybody sees the results, in fact a brick wall would work just as well as a screen or a photographic plate, the only thing the MWI is interested in is that all of those things destroy the photon. After the photon passed the slits that photon was the only difference between those 2 universes, when it is destroyed in both universes by a screen or photographic plate or brick wall there is no longer a difference between universes so they merge back together, but indications it went through slot A and indications it went through slot B remain. And that produces the interference pattern. We don't usually see this weird quantum effect in our everyday macro-world because when a large change is made between universes it's hard to arrange things so they evolve together toward the same point, become the identical again, and thus merge back together. That's why making a quantum computer is hard. > > > Of course the interference continues -- for ever if necessary. > [...] > Try moving the position of the screen, what happens? What happens is if you remove the screen or photographic plate or brick wall and just let the photon continue on into infinite space then *NON*-interference will continue forever because the 2 universes will always remain different and thus never recombine. In the MWI the rules are crystal clear about when things split and when things merge back together. And In MWI everything that can happen does happen, so when a photon approaches 2 slits the universe splits and one photon goes through the right slit and one goes through the left slit. After those 2 photon s hit a photographic plate or screen or a brick wall the photons no longer exist in either universe and so they merge back together into one universe , and this merger causes the interference lines. If instead , after passing the slits there is no photographic plate or screen or brick wall and the photons are allowed to continue on into infinite space then the 2 universes remain different and remain separated forever. And so no interference between them ever occurs. > > Superpositions occur everywhere, and no new worlds are split off until > there is decoherence. But we don't ALWAYS see a superposition of states. You can place a detector next to one of the slits so you you know which slit each photon went through, but if you do that the interference pattern disappears because interference needs at least 2 different things to interferer with and with this modified experiment the universe doesn't split so it can't recombine so you see no interference pattern. In the unmodified experiment after the photon makes its decision on which of the 2 slits to go through i t then hits a screen or photographic plate or brick wall. When that happens the photons in both universes are destroyed and thus there is no longer any difference between the two, so the universes will merge back together. T hen you will see a superposition of states. Then you will see indications that you live in a universe where the photon went through slot A only and indications you live in a universe where the photon went through slot B only, and that is why you see an interference effect even if you only send one photon at a time at the slits. If you got rid of the film (or the brick wall) and let the photon head out into infinite space after it passed the slits then the universes, and you, will split and never recombine, and so of course you will see no interference effect. The beautiful part of the Many World Interpretation is that unlike its rivals it doesn't have to explain what an observer is or what consciousness is all about because whether a universe splits or not has nothing to do with any of that , a brick wall will work just as well as a screen or a photographic plate. All of them will destroy the photon and that is the only difference between one universe and the other. John K Clark > > -- 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 post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
