So is physics best understood as a computer program with access to a random oracle? (Coming from 1-indeterminacy.) On Mar 31, 2013 8:13 AM, "Bruno Marchal" <marc...@ulb.ac.be> wrote:

> > On 31 Mar 2013, at 01:15, Joseph Knight wrote: > > Sorry for the vagueness of my question; I would not count pi as a physical > constant. I would count the empirically determined circumference:diameter > ratio for a circle in our observed curved spacetime as a physical constant. > > The reason I asked is because Bruno has repeatedly claimed that > COMP=>"noncomputability of physics" but I'm wondering what exactly this > would mean in practice. > > > In practice it would mean that some phenomena are not predictible or > computable. Russell and Brent are right, it comes from the FPI (first > person indeterminacy) which introduces "genuine randomness" in the first > person experience. > In fact that randomness might be so great as leading to the "white > rabbits", and with comp it is astonishing that the world around us seems so > much computable. But the redundancy of the UD, and the constraints of > correct self-reference add much structure, and if comp is true, that should > be enough. The non computable sequence will still have computable > distribution, like with QM, when, for example, we send a sheaf of electron > is the 1/sqrt(2)(up + down) on a up/down Stern-Gerlach analyser. From the > first person perspective, this leads to uncomputable sequence of events > (even incompressible strings of up and down), but statistically, with > Avogadro-like numbers of particles, the electronic sheaf will just split in > symmetrical halves, like the big number statistical laws predict. > > It is an open problem if there are non computable constants in nature, as > it is an open problem if some oracle might play a role in the development > of the appearance of physical laws in the UD (or in arithmetic). That seems > unlikely, but who knows? As Brent says, that would be hard to test, but it > might make some sense from theoretical assumption, both in comp-physics, > and in theoretical physics. Note that it is easy to build a non computable > solution to the SWE (something like Ae^ikHt, with k a non computable > number, but it is impossible to test the non computability of such wave in > case they occur. Machines can prove only the individual incompressibility > of a *finite* number of strings. > > Bruno > > > > On Mar 30, 2013 6:53 PM, "Russell Standish" <li...@hpcoders.com.au> wrote: > >> On Sat, Mar 30, 2013 at 04:15:54PM -0700, Joseph Knight wrote: >> > True or False: COMP implies that any fundamental physical constant is >> non >> > computable? >> > >> >> I would say false, unless you can say that pi is _not_ a physical >> constant. Another example that springs to mind is the magnetic moment >> of the neutron which is definitely physical, but maybe not fundamental. >> >> -- >> >> >> ---------------------------------------------------------------------------- >> Prof Russell Standish Phone 0425 253119 (mobile) >> Principal, High Performance Coders >> Visiting Professor of Mathematics hpco...@hpcoders.com.au >> University of New South Wales http://www.hpcoders.com.au >> >> ---------------------------------------------------------------------------- >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "Everything List" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/everything-list/53ZNGv7qPpo/unsubscribe?hl=en >> . >> To unsubscribe from this group and all its topics, 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?hl=en. >> 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?hl=en. > 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 a topic in the > Google Groups "Everything List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/everything-list/53ZNGv7qPpo/unsubscribe?hl=en > . > To unsubscribe from this group and all its topics, 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?hl=en. > 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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