New FQXI essay contest Is Reality Digital or Analog?

[Fra]

And I'm still not sure I get in what way you claim that Newtonian mechanics, etc., are non-computable theories. One can completely recast these theories in terms of Turing machines, or partial recursive functions from initial to final values.

Of course to just talk about what's computable given infinite time seems like a useless classification.

The optimal action/decision problem is that you need to process a certain amount of information and use a finite computational device/brain to find your "best choice" and this must be done at a rate that is on par with the dataflow or there will be overflow. If the decision takes too long that equals no action, and the system will be torn apart by it's own environment.

With continuum models, if the convergence rate of the limits you mention is FAST enough, then the model is FIT, as the overflow will not destabilise things, if not, or of the overflown data completely fail to give priority as to WHICH data that's discarded the algorithm will not survive.

It's true that to discusse this more seriously one has to introduce the ORDER that's implicit in the dataflow and thus indirectly time.

Edit: like in crise handling, there is always a tradeoff/balance between making the RIGHT decision and making SOMETHING at all, because everyone understands that you can't sit forever and analyse what's the best action to take in the middle of the field in say a war (or chaos). You have a split second to make a decision. Errors will be made. And whoever lives through have made the right priorities. (this is also a good analogy to I how I see physics, ssytem stabilisation)

/Fredrik

 

[friend]

Edit: like in crise handling, there is always a tradeoff/balance between making the RIGHT decision and making SOMETHING at all, because everyone understands that you can't sit forever and analyse what's the best action to take in the middle of the field in say a war (or chaos). You have a split second to make a decision. Errors will be made. And whoever lives through have made the right priorities. (this is also a good analogy to I how I see physics, ssytem stabilisation)

/Fredrik

That's pretty close to saying that angels and demons fight it out for what's going to happen.

 

[Fra]

That's pretty close to saying that angels and demons fight it out for what's going to happen.

That's not what I meant though, the undecidability with respect to the observer does not imply that everything is then decided by some external entiyry: god, or demon, it just means that all we have is expectations, and all we need to do is place our bets and collect the feedback.

There is no shortcut, or simplification where you can simulate the entire universe in a pocket calculator. Instead I think that nature fundamentally works so that, all that any subsystem does is act rational according to it's expectations, and there is an oversall undecidable evolution that takes place.

It's the basic premise that everyhing has to be decided - somewehere by someone or something, be it a birds view, angels or demsons - that I think is wrong. My point is that as I see it, not all things are decidable, and the main point is that it does not have to. I even think that the fact that not everything is decidable, is at the orgin of the arrow of time, the entire arrow of time is like a spontaneous computation; but without global simplification that can be captures by an inside subsystem.

/Fredrik

 

[unusualname]

Competition closed on 15th February, although there seems to be a whole load of late submissions, you can read them all here:

http://fqxi.org/community/forum/category/31417

there are certainly some really crazy and unusual ideas out there

at least one frequent poster here has submitted an essay (looks like he got it in just on time)

 

[qsa]

Competition closed on 15th February, although there seems to be a whole load of late submissions, you can read them all here:

http://fqxi.org/community/forum/category/31417

there are certainly some really crazy and unusual ideas out there

at least one frequent poster here has submitted an essay (looks like he got it in just on time)

something has gone wrong with the website, can't read the articles. also it is strange that nobody has commented on the articles which I think summerizes all the possible ideas that could solve QG. I will do that as soon asI am able to read the articles again.

 

[Fra]

something has gone wrong with the website, can't read the articles. also it is strange that nobody has commented on the articles which I think summerizes all the possible ideas that could solve QG. I will do that as soon asI am able to read the articles again.

Seems to work now.

/Fredrik

 

[qsa]

String, LQG and the rest are great, but tweaking standard ideas to achieve full unification from the very small distance to the cosmological one is very clearly has not been able to do that. Because QM and GR fail to apply in those regimes. It is time to look at different conceptual alternatives in a serious way.

http://www.fqxi.org/community/forum/topic/950

http://www.fqxi.org/community/forum/topic/867

http://www.fqxi.org/community/forum/topic/821

http://www.fqxi.org/community/forum/topic/803

http://www.fqxi.org/community/forum/topic/884