Thanks Bruno. As I understand it step 8's movie-graph argument is making a point similar to the "implementation problem" chalmers discusses in the paper at http://consc.net/papers/rock.html -- basically the problem is that there seems to be no good way to decide whether a given physical system "implements" a given abstract computation (Chalmers proposes his own rules for deciding this, but they seem a bit ad hoc to me, depending on dividing a physical system into distinct spatial regions). Anyway, even though I tend to agree with you about rejecting the idea of what you call "real ontological primitive matter", it seems to me this argument goes too far, because it could easily be modified into an argument that there's no good way to decide whether one abstract computation (including the universal dovetailer) "implements" another computation as some sort of subroutine of the first one.
Consider your movie-graph experiment, where you have a lab with a computer made of optical gates. What if, instead of a real physical lab, we imagine a program A that is running an incredibly complex simulation of the same sort of lab, down to the level of individual atoms and photons and such? And within this simulated lab is the same type of computer made of simulated optical gates, which are supposed to run some simpler program B (we could imagine B is some very simple program, say a 1D cellular automaton consisting of a small number of cells, or we could imagine B as something complicated enough to include a conscious observer, like a large simulated neural network, but still much simpler than the atom-level simulation of the lab). If the notion of one program "implementing" another as a subroutine has any meaning, then shouldn't this be a case where program A implements program B? But if the simulated lab has a simulated movie projector of the type you describe, then simulated experimenters in the lab could run the experiment you describe of knocking out logic gates and replacing them with a movie of the same gates projected from above, which provide the needed triggers to the remaining light-sensitive gates. If more and more gates are knocked out until all that's left is a simulated movie being projected on an empty table, is there still any meaningful sense that program A is implementing program B? Personally, I lean towards the idea that since any running of a Turing machine can be represented as a set of logically interconnected propositions in an axiomatic system, to say that program A "implements" program B can mean that you can map some subset of the propositions about program A to all the propositions about program B, such that all the same logical relationships between the propositions still apply. And if the physical world follows universal physical laws, then the set of all physical truths about events in spacetime and the causal relationships between them should in principle be representable as a huge set of propositions about events, and propositions about universal laws, with logical relationships between them--in that case "physical implementation" could be defined in exactly the same way as I suggest defining program A's implementation of program B above. This is the idea I discussed with you a few years ago in the post at http://www.mail-archive.com/everything-list@googlegroups.com/msg16244.htmland some of the follow-ups--I used the word "causal structure" there for this notion of isomorphisms in relations between propositions, although I think "logical structure" might be better since this could apply to collections of propositions in any axiomatic system, including arithmetic, where we don't normally think of the relationships between propositions as "causal" ones. Jesse On Tue, Dec 10, 2013 at 4:06 AM, Bruno Marchal <marc...@ulb.ac.be> wrote: > > On 09 Dec 2013, at 23:03, Jesse Mazer wrote: > > I don't have institutional access but I was able to read it online, > > > That was what Elsevier (Santa) promised. > > > > > > though not to download it as a PDF > > > Pfftt.... Santa looks like being a bit shabby those days ... > > > > > (I just copy-and-pasted all the text for future reference instead). It's > great to see each step of the argument laid out in greater detail than I've > seen on the list (admittedly I don't consistently read all the posts > here)--I still have doubts about step 8, the film-graph argument, hopefully > will have time to write up my response soon. > > > Thanks. We can come back on step 8 anytime. It shows that any > supplementary assumptions we could add to (Robinson, no induction axioms) > Arithmetic will not change anything about the belief we can have on matter, > making primitive matter into ether or phlogiston. Step 8 just reduces the > amount of occam razor that we should need in step 7, in case we want to > stop the argument at that step. > > Step 8 is not so useful in this list, because most people here are > 'everythingers', and so find quite doubtful the idea that we would live in > a unique little physical universe, which is the move you can still do at > step 7 to save the idea of real ontological primitive matter (but who needs > that?). Step 8 makes primitive matter into a god-of-the-gap explaining > nothing, not even the appearance of matter (unless you make it non Turing > emulable and playing a role in the brain, but then comp get wrong). > > UDA 1-7 is purely deductive, but step 8 is supposed to make the link with > 'reality', and so we need some use of occam razor. > > Bruno > > > > > Jesse > > > On Mon, Dec 9, 2013 at 3:32 PM, meekerdb <meeke...@verizon.net> wrote: > >> Excellent, Bruno! I'm very glad for you - and for the wider audience >> that will now read your ideas. However I notice Santa only delivers if you >> have institutional access. I do. But others on the list may not. >> >> Brent >> >> >> On 12/9/2013 2:48 AM, Bruno Marchal wrote: >> >> Hi, >> >> Santa Klaus exists, and by its magical power seems to have made my last >> paper ("The computationalist reformulation of the mind-body problem") in >> *Progress >> in biophysics and molecular biology*, *freely* available; here: >> >> *http://elsarticle.com/18AF6PI >> <http://mail.elsevier-alerts.com/go.asp?/bESJ001/mCGPFMCF/qU7YOMCF/u9PAFWV3/xFO2PNCF/cutf%2D8>* >> >> This offer seems to last up to the 31 january (Santa Klaus seems to >> have only a *finite* amount of magic). >> >> So please download, comment, ask questions, etc. it contains (again!) >> the two main parts (UDA, AUDA), but also answers to many reviewers' >> questions in an appendix. >> >> I send this also on FOAR, for Gary :) (apology for the doubletons) >> >> Bruno >> >> >> >> >> http://iridia.ulb.ac.be/~marchal/ >> >> >> >> -- >> 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 post to this group, send email to everything-list@googlegroups.com. >> Visit this group at http://groups.google.com/group/everything-list. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> -- >> 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 post to this group, send email to everything-list@googlegroups.com. >> Visit this group at http://groups.google.com/group/everything-list. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > > -- > 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 post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > > > http://iridia.ulb.ac.be/~marchal/ > > > > -- > 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 post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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