On 25 Jul 2013, at 23:01, Joseph Knight wrote:

So is physics best understood as a computer program with access to arandom oracle? (Coming from 1-indeterminacy.)

`That is possible but should remain to be proved. A priori, physics`

`emerges from all computations, and the mixing of computability and non`

`computability might be non equivalent with computable + a random`

`oracle. I suspect it not, both empirically and theoretically with`

`computationalism.`

Bruno

`PS I will have to put my computer in a box, as I am moving, so I will`

`be disconnected for awhile. Thanks for being patient for a possible`

`answer to your next possible comment.`

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 aphysical constant. I would count the empirically determinedcircumference:diameter ratio for a circle in our observed curvedspacetime as a physical constant.The reason I asked is because Bruno has repeatedly claimed thatCOMP=>"noncomputability of physics" but I'm wondering what exactlythis would mean in practice.In practice it would mean that some phenomena are not predictible orcomputable. 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 "whiterabbits", and with comp it is astonishing that the world around usseems so much computable. But the redundancy of the UD, and theconstraints of correct self-reference add much structure, and ifcomp is true, that should be enough. The non computable sequencewill still have computable distribution, like with QM, when, forexample, we send a sheaf of electron is the 1/sqrt(2)(up + down) ona up/down Stern-Gerlach analyser. From the first person perspective,this leads to uncomputable sequence of events (even incompressiblestrings of up and down), but statistically, with Avogadro-likenumbers of particles, the electronic sheaf will just split insymmetrical halves, like the big number statistical laws predict.It is an open problem if there are non computable constants innature, as it is an open problem if some oracle might play a role inthe development of the appearance of physical laws in the UD (or inarithmetic). That seems unlikely, but who knows? As Brent says, thatwould be hard to test, but it might make some sense from theoreticalassumption, both in comp-physics, and in theoretical physics. Notethat it is easy to build a non computable solution to the SWE(something like Ae^ikHt, with k a non computable number, but it isimpossible to test the non computability of such wave in case theyoccur. Machines can prove only the individual incompressibility of a*finite* number of strings.BrunoOn 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 physicalconstant 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 momentof the neutron which is definitely physical, but maybe notfundamental.-- ---------------------------------------------------------------------------- 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 inthe 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-l...@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 GoogleGroups "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-l...@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 inthe 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 GoogleGroups "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.

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