> On 16 Oct 2019, at 00:29, Philip Thrift <[email protected]> wrote: > > > > On Tuesday, October 15, 2019 at 4:14:39 PM UTC-5, John Clark wrote: > On Tue, Oct 15, 2019 at 1:50 PM 'Brent Meeker' <[email protected] > <javascript:>> wrote: > > > Curiously, Deutsch used a quantum computer in a thought experiment to prove > > multiple worlds. > > He did indeed, I read about it 30 years ago in Deutsch's book "The Ghost In > The Atom" and that was when I started to take the MWI seriously. Deutsch's > test would be very difficult to perform but the reason it's so difficult is > not the Many World's fault, the reason is that the conventional view says > conscious observers obey different laws of physics, Many Worlds says they do > not, so to test who's right we need a mind that uses quantum properties. > Quantum Computers have advanced enormously over the last 30 years so I > wouldn't be surprised if it or something very much like it is actually > performed in a decade or two. > > An intelligent quantum computer shoots photons at a metal plate one at a time > that has 2 small slits in it, and then the photons hit a photographic plate. > Nobody looks at the photographic plate till the very end of the experiment. > The quantum mind has detectors near each slit so it knows which slit the > various photons went through. After each photon passes the slits but before > they hit the photographic plate the quantum mind signs a document saying that > it has observed each and every photon and knows which slit each photon went > through. It is very important that the document does NOT say which slit any > photon went through, it only says that they went through one slit and only > one slit and the mind has knowledge of which one. There is a signed document > to this effect for every photon it shoots. > > Now the mind uses quantum erasure to completely destroy its memory of which > slit any of the photons went through; the only part remaining in the universe > is the document which states that each photon went through one and only one > slit and the mind (at the time) knew which one. Now develop the photographic > plate and look at it. If you see interference bands then the Many World > interpretation is correct. If you do not see interference bands then there > are no worlds but this one and the conventional quantum interpretation is > correct. > > This works because in the Copenhagen interpretation when the results of a > measurement enters the consciousness of an observer the wave function > collapses, in effect all the universes except one disappear without a trace > so you get no interference. In the Many Worlds model all the other worlds > will converge back into one universe because information on which slit the > various photons went through was the only thing that made one universe > different from another, so when that was erased they became identical again > and merged, but their influence will still be felt, you'll see ambiguous > evidence that the photon went through slot A only and ambiguous evidence it > went through slot B only, and that's what causes the interference pattern. > > John K Clark > > > But the path integral is both interpretation of quantum computing - > https://arxiv.org/abs/quant-ph/0607151 (2006) - and algorithm for the Google > quantum computer simulator - https://arxiv.org/abs/1807.10749 (2018). The > Google quantum computer paper does not mention "many worlds”.
“Many-worlds” is synonymous with “no collapse”. The worlds are the terms in any superposition, written in any base. That some base are better for consciousness to stabilise is no more strange that some planet configuration are better for life to develop. No need to take the word “world” to much seriously, those are only computations, which exists already in all models of any theory of natural numbers in which you can define addition and multiplication. Bruno > > @philipthrift > > -- > 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/0376cafc-00ec-4446-9beb-a92cbe657188%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/0376cafc-00ec-4446-9beb-a92cbe657188%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/9DB02D9F-E215-4C8E-85EF-DEF9EA01E52F%40ulb.ac.be.
