On Fri, Aug 9, 2019 at 7:25 PM Bruno Marchal <[email protected]> wrote:
> On 9 Aug 2019, at 02:59, Bruce Kellett <[email protected]> wrote: > > On Thu, Aug 8, 2019 at 6:50 PM Bruno Marchal <[email protected]> wrote: > >> > On 7 Aug 2019, at 21:04, 'Brent Meeker' via Everything List < >> [email protected]> wrote: >> > >> > On 8/7/2019 6:40 AM, Bruno Marchal wrote: >> >> It is like the difference between the human existence and the human >> non existence, for an alien situated in a very far away galaxy. The fact >> that this alien cannot detect us does not make the human disappearing. >> >> >> >> It is like the other side of the moon before we built rocket. >> >> >> >> It is like taking our theory at fave value, instead of eliminating >> some terms in the equation by sheer coquetry. >> > >> > Except in the case of quantum mechanics the theory you are saying >> predicts other worlds, also predicts they are inaccessible. >> >> That is right, but the theory predicts that they are indirectly playing >> an important role without which QM explains nothing. >> > > No, the theory does not predict that these parallel worlds are playing an > important role. The theory (QM) explicitly predicts that such other worlds > are orthogonal to observation; they do not interact; and they are in > principle inaccessible. They can, therefore, play no "important role > without which QM explains nothing". I think you are very confused about how > QM works, Bruce > > The theory does not predict that the superposition plays an important role. > That is not what I said. I said that parallel worlds do not play any important role. > That is simply contradicted by the two slit experiments. No interaction > does not imply no statistical interference, or QM would not makes any sense > at all. Dirac considered the principle of superposition as the main quantum > feature. > > “Parallel world” is the same as superposition of state/histories. > That is where the trouble lies. Your identification of any superposition as a parallel world. There is a vast difference between superpositions and parallel world, or "relative states" a la Everett. Any quantum state can be described as a superposition of a set of basis vectors in the corresponding Hilbert space. This basis set is not unique. In fact, there are an infinity of possible sets of basis vector for any Hilbert space. This is just a simple observation about vector spaces. When you start identifying this infinity of possible basis sets with possible parallel worlds, then you get into big trouble understanding quantum mechanics. It has long appeared to me that you have suffered from this confusion. Maybe that is the real basis of the fact that we can never agree on things about elementary quantum mechanics.......... It is not a matter of the difference between collapse or no-collapse models -- it is a matter of the basic interpretation of what Everett's "relative states" actually are, and why the basis problem is so important for Everett. 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/CAFxXSLSjKUw2WKLOCBsHr_2ML1PD3ZBu65poXVCLdMatM1wbRg%40mail.gmail.com.
