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From: CMR <jackogreen.domain.name.hidden>

Date: Mon, 26 Jan 2004 13:49:02 -0800

*> The problem is that there is a large class of physical systems that
*

are

*> not "computable" by TMs, i.e., they are "intractable". Did you read the
*

*> Wolfram quote that I included in one of my posts? Please read the entire
*

*> article found here:
*

*> Another way of thinking of this is to concider the Laplacean notion
*

*> where given the specification of the "initial conditions" and/or "final
*

*> conditions" of the universe that all of the kinematics and dynamics of the
*

*> universe would be laid out. The modern incarnation of this is the
*

so-called

*> 4D cube model of the universe. Again, these ideas only work for those who
*

*> are willing to completely ignore the facts of computational complexity and
*

*> the Heisenberg Uncertainty principle.
*

*>
*

Stephen,

Am I correct that you're essentially saying that our universe is

algorithmically incompressible? If so I would agree and, interestingly, so

does my friend Jim in a parallel thread I sparked from this very thread on

the infophysics list a week or so back; thought I'd post it because he

represents the "hard" info physical view on this subject much better than I

could:

From: "Jim Whitescarver" <jim.domain.name.hidden>

Subject: Re: [InfoPhysics] Fw: Is the universe computable

In so far as the universe is logical it can be modeled as a logical

information system. The information nature of the quantum makes such a

model convenient. It seems surprising how closely nature obeys logic

granting validity to science.

If we suppose that it is indeed logical and has no other constraints

outside that logic, we then find it is an incompressible computation, that

cannot be represented with fewer states. The universe is computably as it

is a computer, but only a computer larger than the universe itself could

model it. In this sense, the universe is not technically computable in

practical terms.

Intractability, however, is not exclusive of there existing good

solutions. Unknowability is inherent in complex systems and we can

capitalize on the the uniformity of the unknowable in the world of the

known.

Consider a pure entropy source, e.g. a stationary uncharged black hole.

It effective eats all the information that falls in irretrievably

randomizing it into the distant future. It is not that systems falling in

stop behaving determistically, it is that we no longer care what their

state is effectively randomized and outside our window of observation.

Nothing in our world covaries with what happens inside the black hole but

we know that there would be correlations due to the determinism that

exists independently on the inside and the outside.

I am not saying we can compute all of this. What happens at any point is

the result of the entire universe acting at that point at this instant.

Clearly this is not knowable. Causes are clearly not locally

deterministic.

But we can represent the black hole as a single integer, its mass in Plank

action equivalents. From this all it's relevant properties to our

perspective are known in spite of however complex it is internally.

All participants, modeled as information systems, are entropy sources like

black holes, but we get samplings of their internal state suggesting a

finite state nature and deterministic behavior. The distinction is

whether we can determine what that deterministic systems is or not. We

cannot without communicating with all the participants and that is not

always possible.

But given a set of perspectives, there is no limit to how closely we can

model them. Where no model works randomness may be substituted and often

we will get good, if not perfect, results.

Even legacy quantum mechanics, misguidedly based on randomness, yields

deterministic results for quantum interactions shown accurate to many

dozens of decimal places. This suggests that simple deterministic models

will most likely be found.

Jim

Received on Mon Jan 26 2004 - 19:35:27 PST

Date: Mon, 26 Jan 2004 13:49:02 -0800

are

so-called

Stephen,

Am I correct that you're essentially saying that our universe is

algorithmically incompressible? If so I would agree and, interestingly, so

does my friend Jim in a parallel thread I sparked from this very thread on

the infophysics list a week or so back; thought I'd post it because he

represents the "hard" info physical view on this subject much better than I

could:

From: "Jim Whitescarver" <jim.domain.name.hidden>

Subject: Re: [InfoPhysics] Fw: Is the universe computable

In so far as the universe is logical it can be modeled as a logical

information system. The information nature of the quantum makes such a

model convenient. It seems surprising how closely nature obeys logic

granting validity to science.

If we suppose that it is indeed logical and has no other constraints

outside that logic, we then find it is an incompressible computation, that

cannot be represented with fewer states. The universe is computably as it

is a computer, but only a computer larger than the universe itself could

model it. In this sense, the universe is not technically computable in

practical terms.

Intractability, however, is not exclusive of there existing good

solutions. Unknowability is inherent in complex systems and we can

capitalize on the the uniformity of the unknowable in the world of the

known.

Consider a pure entropy source, e.g. a stationary uncharged black hole.

It effective eats all the information that falls in irretrievably

randomizing it into the distant future. It is not that systems falling in

stop behaving determistically, it is that we no longer care what their

state is effectively randomized and outside our window of observation.

Nothing in our world covaries with what happens inside the black hole but

we know that there would be correlations due to the determinism that

exists independently on the inside and the outside.

I am not saying we can compute all of this. What happens at any point is

the result of the entire universe acting at that point at this instant.

Clearly this is not knowable. Causes are clearly not locally

deterministic.

But we can represent the black hole as a single integer, its mass in Plank

action equivalents. From this all it's relevant properties to our

perspective are known in spite of however complex it is internally.

All participants, modeled as information systems, are entropy sources like

black holes, but we get samplings of their internal state suggesting a

finite state nature and deterministic behavior. The distinction is

whether we can determine what that deterministic systems is or not. We

cannot without communicating with all the participants and that is not

always possible.

But given a set of perspectives, there is no limit to how closely we can

model them. Where no model works randomness may be substituted and often

we will get good, if not perfect, results.

Even legacy quantum mechanics, misguidedly based on randomness, yields

deterministic results for quantum interactions shown accurate to many

dozens of decimal places. This suggests that simple deterministic models

will most likely be found.

Jim

Received on Mon Jan 26 2004 - 19:35:27 PST

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