On Wed, Oct 26, 2022 at 5:41 AM John Clark <[email protected]> wrote:
> > There is no way to falsify the conventional Copenhagen interpretation, > but back in 1986 in his book "*The Ghost in the Atom*" David Deutsch > proposed a way to falsify Everett's Many Worlds; the experiment would be > difficult to perform but Deutsch argues that is not Many Worlds fault, the > reason it's so difficult 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. > > In Deutsch's experiment, to prove or disprove the existence of many worlds > other than this one, a conscious quantum computer shoots electrons at a > metal plate that has 2 small slits in it. It does this one at a time. The > quantum computer has detectors near each slit so it knows which slit the > various electrons went through. The quantum mind now signs a document for > each and every electron saying it has observed the electron and knows which > slit it went through. It is very important that the document does NOT say > which slit the electron went through, it only says that it went through one > and only one slit and the mind has knowledge of which one. Now just before > the electron hits the plate the mind uses quantum erasure to completely > destroy the memory of what slits the electrons went through, but all other > memories including all the documents remain undamaged. After the document > is signed the electron continues on its way and hits the photographic > plate. Then after thousands of electrons have been observed and all > which-way information has been erased, 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 interpretation is correct. > > Deutsch is saying that 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 when the electrons hit the > photographic film because the two universes will no longer be different > (even though they had different histories), but their influence will still > be felt. In the merged universe you'll see indications that the electron > went through slot X only and indications that it went through slot Y only, > and that's what causes interference. > > I know that what I said in the above is a fair representation of what > Deutsch was saying because some years ago I wrote to him about this and > he said it was an accurate paraphrase. > One of the main troubles with this is that the Copenhagen Interpretation, insofar as there is any such thing, does not entail that the wave function collapses when the result enters consciousness. This was a mad idea put forward by Wigner, and it was soon realized that the idea was just silly, and could never work. So that idea has long been abandoned. Deutsch's attempted proof involves comparison with an abandoned idea of quantum mechanics, so it doesn't really prove anything. Besides, the whole set-up involves assumptions about quantum computers and consciousness that are far from obvious, and probably not even correct. Bruce -- 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/CAFxXSLQ8sa6WP6e-DjHrKsJGb%2BVr1f_OKmqZkPTvKqUOqsa8Vg%40mail.gmail.com.
