The short answer is yes, Many Worlds is falsifiable. For example, right now there are experiments underway in an attempt to prove that the GRW theory of objective quantum wave collapse makes predictions that Many Worlds does not, if they are successful it will prove that Everett was dead wrong, it's as simple as that. GRW claims that Schrodinger's equation is incomplete and that another very complex term needs to be added to it because it's the only way they could think of to get rid of all those worlds that for some reason they dislike, there was simply no other reason to add that extra term. With this new term Schrodinger's equation is no longer completely deterministic because a random element is added such that the larger the wave function is (the more particles it has) the more likely the quantum wave function will objectively collapse. They carefully tuned their very complex extra term inserted into Schrödinger's equation in just such a way that, because an individual electron is so small the probability of you being able to observe one objectively collapse is almost but not quite zero; but the probability of you NOT observing something as large as a baseball NOT collapsing is also almost, but not quite, zero. Despite heroic efforts. up to the present day nobody has found a speck of experimental evidence in support of the GRW theory of objective quantum wave collapse, and until and unless they do Many Worlds must be the preferred theory according to Occam's razor because it makes fewer assumptions, it has no need to complicate matters by adding that extra term to Schrodinger's equation.
But GRW is not the only or even the most popular competitor to Many Worlds, that honor would have to go to the Copenhagen interpretation, and there is certainly no way to falsify that, but back in 1986 in his book "The Ghost in the Atom" David Deutsch proposed another 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. It must be admitted that like every theory Many Worlds makes predictions that cannot be tested, but a theory is not judged on the basis of what predictions it makes that have neither been confirmed nor falsified experimentally, instead they are judged by how well they conform to experiments that HAVE been performed, and in Many Worlds case it conforms to every physics experiment that has ever been made up to the present day. Yes Everett's idea produces a lot of worlds, but Occam does NOT say the best theory is the one that produces the simplest outcome, the best theory is the one that makes the fewest assumptions and still agrees with experimental observations. John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> fwm -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv3u585mWchs4ZYhrB5_2%3Di9VjhNZB-6VK7t%2BZNShDvFYA%40mail.gmail.com.
