Hi Grayson, Hi everybody, Like every years, the quantity of work is growing, more or less up to June, so I apologise in advance for answering more slowly.
> On 12 Mar 2019, at 22:54, agrayson2...@gmail.com wrote: > > > > On Tuesday, March 12, 2019 at 12:18:50 PM UTC-6, Bruno Marchal wrote: > >> On 11 Mar 2019, at 09:54, agrays...@gmail.com <javascript:> wrote: >> >> >> >> On Monday, March 11, 2019 at 1:43:05 AM UTC-6, Liz R wrote: >> I thought QM was deterministic, at least mathematically - and I guess in the >> MWI? >> >> QM is deterministic, but only as far as reconstructing wf's as time is >> reversed, but it can't reconstruct individual events which are without >> ostensible cause. As for the MWI, I don't think it's deterministic since the >> different branches are never in causal contact. AG > > It has to be. > > So If I am in one world of many, how can I time reverse my outcome to > reconstruct something from another world, the one that gave rise to the many > worlds? AG By amnesia, like Belinfante showed that we can reverse the Schoredinger cat experience, and even statistically get the cat alive back, with a chance of 1/4. That is sometimes used to claim that Everett theory (QM without collapse) is testable. > > Without wave collapse the evolution is “just” a unitary transformation. It is > a vector rotating in some (Hilbert) space. Only the wave collapse postulate > bring 3p-indterminacy. In Everett the indeterminacy is explained like in > arithmetic, or combinator, with the digital mechanistic hypothesis (in the > cognitive science, not in physics).. > > Can't we keep your theory out of this? AG My theory, Mechanism (in cognitive science), is the same as the one used by Everett, or Darwin. I have no theory of mine. I have a theorem, or proposition. If you are skeptical, that is the good attitude. Yet, without mechanism, I can hardly make sense of QM at all, nor of consciousness, etc. Things get to much “magical” for me. You say also, in the next post, > On Tuesday, March 12, 2019 at 12:18:51 PM UTC-6, Bruno Marchal wrote: > >> On 11 Mar 2019, at 03:16, agrays...@ <>gmail.com <http://gmail.com/> wrote: >> >> They say if information is lost, determination is toast. > > That is not correct. If information is lost, reversibility is toast, but > determination can be conserved. > > If reversibility is lost, how can determinism be preserved? It can't, and > this is the position Hawking took IIUC. What's your definition of > determinism? Doesn't it require the laws of physics to be time reversible? AG If reversibility is lost, you can’t recover the past from the present, but you might still been able to predict the future. Reversibility is a sort of determinism on the past, which breaks down when you loss information. The computation of 2+2 is deterministic on all computer, but not all would be able to go from the result (4) to the past (2+2). But with a reversible computer when computing 2 + 2, you will get 4, plus some information that is locally discarded, but still retrievable in principle, so that you can come back to “2+2”. > Typically the Kestrek bird K is irreversible, as it eliminates information > Kxy = x. From KSI you get S, but from S, even knowing it comes from the > application of K, you cannot retrieve I. Similarly with addition and > multiplication in arithmetic. From 18 you can’t guess it cames from 7 and 11. > Erasing information is common. > > Some does not tolerate that, so Church works in the base {I, B, W, C}, where > I is [x]x, B is [x][y][z] x(yz), etc. > > That base is not combinatorial complete, but is still Turing complete, > illustrating that we can do computation without eliminating any information. > (None of I, B, C and X eliminates information) > > But the quantum eliminates even the combinator W (Wxy = xyy), or the lamda > expression [x][y]. xyy. That is, we cannot eliminate information, but we > cannot duplicate it either! > > Now, the problem is that the BCI combinator algebra are not Turing-complete. > It is the core of the physical reality, and Turing universality needs the > addition of modal “combinators”. > > I have no idea what you're referring to. AG I guess you have not followed the combinator thread. It starts from zero. Unlike QM which asks for a serious background in mathematics, combinators can be understood by any kids, without any mathematical knowledge. I have very young students this year who asked me this introduction. The recent thread on the combinators comes from that experience. Just look at the first thread and ask question. It is very easy, and the combinators are very handy to talk about low level computation, including how to illustrate determinism and reversibility. It is not needed, and if you have no the time nor the interest, it is OK. Soon, or a bit later, I will propose an “official” definition of what a computation is (mainly a sequence of combinator obtained by the application of the two laws of K and S). Combinators describes both Turing machine and instantaneous state of a computation. Bruno > > Bruno > > > >> >> I mean everyone can't have forgotten quantum indeterminacy when discussing >> the BHIP, surely? >> >> >> >> -- >> 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-li...@googlegroups.com <javascript:>. >> To post to this group, send email to everyth...@googlegroups.com >> <javascript:>. >> Visit this group at https://groups.google.com/group/everything-list >> <https://groups.google.com/group/everything-list>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. > > > -- > 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 > <mailto:everything-list+unsubscr...@googlegroups.com>. > To post to this group, send email to everything-list@googlegroups.com > <mailto:everything-list@googlegroups.com>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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