A 11:16 +0100 9/06/99, Marchal a écrit: >WHY PHYSICAL LAWS ? >------------------- > >>Chris Maloney wrote: >><<< The answer is that the structure(s) we are in obey physical laws, >>not because they were cast by fiat from some omnipotent being, but >>simply because the structures that do obey physical laws are more >>numerous than those that do not, and hence we are likely to find >>ourselves in those. >> >>GSLevy wrote: >><< We can find ourselves ONLY in those structures that obey physical >>laws because these are the ONLY structures that can support us as >>rational beings (SAS). The assumption that worlds with (rational) >>physical laws are more more numerous than those without is therefore >>unwarranted. In fact I would believe in the opposite. That the worlds >>without rational physical laws, (if these could be called worlds at >>all), are more numerous than those with rational physical laws. > > >I agree with GSLevy. >I agree with Chris Maloney. > >What GSLevy says is a consequence (with comp) of Cantor diagonal argument. >What Chris Maloney says is a consequence (with comp) of the PE-omega >thought experiment (see the archive of the list). > >We can find ourselves ONLY in those structures which are relatively >numerous, not to survive but to remain with others and a (relatively) >stable environment. > >[I would say *sharable histories* instead of *structures* but precise >words here are probably premature] > >Once you experience a *deep histories* with friends, what you can >communicate, in some verifiable way, with those friends *are* the physical >laws. >But this only works (with comp) if the physical laws are such that >"*deep histories* with friends" have some kind of measure one with respect >to each "observer-moment" (or instant, I borrow the word of Hal, do I?) >belonging to such deep history. (= relative strong SSA). > >I agree with GSLevy when he says: the "worlds without rational physical >laws" are more numerous than those with rational physical laws. But, at >least with comp, we must explain why, from the point of view of a >sufficiently rich (cognitively) observer, non aberrant worlds (histories) >are relatively more numerous than aberrant one (cf PE-omega). >I should say: non aberrant (sharable) continuations (in the computer >science sense) are relatively more numerous than aberrant one. >
I suspect that the comp hypothesis would in fact favour the solution where there is actually no external world at all, but only your (for me, my!) mind, because it is much shorter to describe ONLY a brain state than the whole Universe surrounding it, although perfectly equivalent regarding our sensations. So no world, no friends and no physical laws. We would be back to some kind of solipsism, which has been known for a long time to be unprovable and undisprovable- just desperately useless. However it is not obvious at all why such a mind would require the appearance of physical laws. Most things are too complicated to be described by precise laws, although they are handled rather properly by the mind: feelings, language, and almost all human behaviours do not obey any mathematical equation. It is perfectly CONCEIVABLE that physical experiments could show that matter behaves like human beings, without any good mathematical description. Even if we are made of this matter, precise mathematical laws are not required to make an organized system work: civilizations are made of individuals, and they are well structured despite the absence of a good mathematical description of each individual. I think in fact that there are indeed much more "brain -like" computations without this constraint than with it, and the appearance of physical laws would thus be difficult to understand. A(nother) stone in the garden of computationalism? Gilles
