On Fri, May 30, 2014 at 06:17:40PM +0200, Bruno Marchal wrote: > > On 30 May 2014, at 02:53, Russell Standish wrote: > > >On Wed, May 28, 2014 at 08:15:30PM +0200, Bruno Marchal wrote: > >> > >>On 28 May 2014, at 03:24, LizR wrote: > >> > >>>As far as I can see Bruno has a logical argument which happens to > >>>segue into a theory of physics. To disprove it, one merely needs > >>>to show that either his premises or his argument is wrong... > >> > >> > >>Not exactly. The premise can be wrong, true, or indeterminate, > >>without making the reasoning invalid. In fact, in the classical > >>frame, a refutation of the premise would make the reasoning > >>vacuously valid. Now that reasoning shows a means to refute the > >>premise: basically: compare the physics found in the head of all > >>universal Turing machine, and if it is contradicted by nature then > >>the premise are false (or I, or we, are dreaming or live in a > >>second-order reality) > >> > > > >This last qualification is disturbing, as it would appear remove the > >possibility of falsification of COMP. > > I see you did not follow my thread with Quentin (or Brett Hall a > much longer time ago). No problem. It is a delicate point. > > But it is also a relatively "trivial" (conceptually simple) point, > embedded already in the "Dream argument" and that "lucidity" is a > relative notion, even a graded one, like in "Inception" (a less nice > movie by the author of "the prestige" (in my opinion and taste)). > > > > > > >But before we go that far, why would COMP predict a different sort of > >physics for "dreaming" or "second order reality"? > > If only to account of dreams and video games. If comp is true, and > the level enough high, I can emulate you in a computer together with > an environment disobeying the physical laws. > > Suppose now that you want to test if you are in my video game, > (second order dream) or in the physical reality (first order > "dream", the one emerging from *all* computations going through your > state. Well, if the laws of physics that you can "observe" in the > virtual environment differs from the one you extract from comp, you > can know that you belong to a second order simulation (like a dream > of video game), or you can also abandon comp. Those do not obey > physics, but you keep existing (with the normal probability) in > them, because they inherit the normality of first order physical > reality which comes from *all* worlds/computations (which obey > S4Grz1, or Z1*, or X1*). > > If not, we would not been able to play with a video game, the > consistency selection would eliminate *all* white rabbits, even the > one in Alice in Wonderland! > > So if QL differs from comp-QL, which is testable, we know that we > are in a Bostrom-like simulation or that comp is false, or that the > classical theory/definition of knowledge is false (which I am not > sure makes sense). > > But this is true for all physical tests. We can only say that the > LARC has confirmed the existence of the boson, or we are dreaming or > in an emulation of the standard theory in some unknown "real > theory". So it is not a so big weakening of the falsification of > comp, as it is implicit in all experimental science. It is related > to the fact that with respect to the normal computations, the > universal beings emerging from that can still lie to each others. > > The way QL differs from the comp-QL(s) might provide some > information on how to proceed to decide if comp is false, or if we > belong to a virtual machine made by our descendents, à-la Boström. > > Bruno > >
I gather you think it might be possible to distinguish between being in a virtual reality, and being in the real reality. David Deutsch introduced the concept of a CantGoTu environment. It is basically an environment formed by diagonalising on the list of all possible virtual realities. Consider the discussion between pages 127 and 130 of Fabric of Reality. He goes on to prove that it is not possible to prove within a finite amount of time that one is in a CantGoTu environment. Yet it seems to me that CantGoTu environments and other non-virtual reality environments have measure one in the space of environments hosted by the UD, as UD* has the cardinality of the continuum, whereas virtual reality environments are strictly aleph_0. But we can never know that we're in one. DD does later in the chapter speculate about VR environments that one can know one is trapped in a VR, such as being inside a game of chess. This is because the "rules of physics" of such an environment are inconsistent, especially with the presence of an observer. But provided the rules of physics are consistent with yourself as an observer, then there doesn't appear to be any way of knowing whether you're in a simulation of not, as per the CantGoTu argument above. The rules of physics (whether under COMP or not) must be those that allow the presence of observers, and of observation. All else _has_ to be geography. The only way we can prove we're actually in a simulation is if the Anthropic Principle were to suddenly fail. Cheers -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au Latest project: The Amoeba's Secret (http://www.hpcoders.com.au/AmoebasSecret.html) ---------------------------------------------------------------------------- -- 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 post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
