`Frank wrote:`

Indeed, I've always thought there was a dubious assumption there. There isn't a universal time to pace the clock tics of a simulation. Relativity forbids it. Anyway, time is a subjective illusion.

Back to the question: So what happens when the simulation "diverges" from regularity? Some possibilities: a) The universe ends b) Pink elephants pop up everywhere c) It's already happening

I like (c)

`Ok. How about:`

`The multiverse is a very long qubit-string. (This is an informal statement to drive intuition.)`

`Being a qubit string it simultaneously exhibits all of its potential information-states.`

`If there is something like this qubitstring simultaneously exhibiting all possible information`

states, then note that to do computation, within that qubit-string, no actual computational

process need take place. Any tour through any subset of the information states (i.e.

"visiting" one information-state after another after another...) can be

considered equivalent to a computation. Any tour through a subset of the information

states which is such that the "direction" of the tour is restricted to only those successor

information-states Si+1 (of the state Si we're currently at) which are different from Si

by only a single bit-flip in a single position in the bitstring, and where that bit-flip

would only happen based on some function of only the state of the bits in a local vicinity

of the flipping bit, can be considered equivalent to a computation which is comprised

solely of localized operations, similar to the kinds of computation we understand.

states, then note that to do computation, within that qubit-string, no actual computational

process need take place. Any tour through any subset of the information states (i.e.

"visiting" one information-state after another after another...) can be

considered equivalent to a computation. Any tour through a subset of the information

states which is such that the "direction" of the tour is restricted to only those successor

information-states Si+1 (of the state Si we're currently at) which are different from Si

by only a single bit-flip in a single position in the bitstring, and where that bit-flip

would only happen based on some function of only the state of the bits in a local vicinity

of the flipping bit, can be considered equivalent to a computation which is comprised

solely of localized operations, similar to the kinds of computation we understand.

`So the universe (or any observable universe) could be a tour through a subset of the`

information-states of the qubit-string multiverse, which is such that the tour

computes only self-consistent spaces and objects, perhaps using only local computational

steps (part this computational locality is part of the secret of ensuring consistency, locality,

metric etc properties of the space and the objects, prehaps).

information-states of the qubit-string multiverse, which is such that the tour

computes only self-consistent spaces and objects, perhaps using only local computational

steps (part this computational locality is part of the secret of ensuring consistency, locality,

metric etc properties of the space and the objects, prehaps).

`Observers which were self-aware substructures WITHIN the set of objects computed`

in a "consistent" tour, maybe can only observe other information states which are also

within that tour.

in a "consistent" tour, maybe can only observe other information states which are also

within that tour.

`TIME AND LIGHTSPEED`

As Wolfram postulates, the concept of time and speed of light c within such an

informational universe may be related to how fast the informational changes (from one

state to another) can propagate (across the qubitstring) using only local computations

as the medium of state-change propagation. It is wrong to suppose that this implies

"computational time" outside of the qubitstring. "How fast state-change propagates"

is purely a question of how the metric spacetime that the consistent tour defines

can evolve in form within a consistent tour.

As Wolfram postulates, the concept of time and speed of light c within such an

informational universe may be related to how fast the informational changes (from one

state to another) can propagate (across the qubitstring) using only local computations

as the medium of state-change propagation. It is wrong to suppose that this implies

"computational time" outside of the qubitstring. "How fast state-change propagates"

is purely a question of how the metric spacetime that the consistent tour defines

can evolve in form within a consistent tour.

`The tour itself could be imagined to be real if you like (with the`

qubitstring really in some god-quantum-computer-thingy which has a god's-now-program-

pointer which moves from state to state in the consistent tour).

But it is better to think of the consistent tour as a virtual tour, an abstraction,

defined by nothing more nor less than its BEING a subset of information states, and an order

of traversal of those (very large) information states which is such that the ordered set

of information-states IS and CONJURES reality.

qubitstring really in some god-quantum-computer-thingy which has a god's-now-program-

pointer which moves from state to state in the consistent tour).

But it is better to think of the consistent tour as a virtual tour, an abstraction,

defined by nothing more nor less than its BEING a subset of information states, and an order

of traversal of those (very large) information states which is such that the ordered set

of information-states IS and CONJURES reality.

`OBSERVERS, AND TOUR-TRAVERSAL AS THE TIME ARROW FOR OBSERVERS`

`An OBSERVER is a set of local subsets of the some of the set of information-states in the`

consistent tour which is the universe. The notion of locality there is information-distance.

consistent tour which is the universe. The notion of locality there is information-distance.

`OBSERVERS can observe any aspect (part) of the information states in the tour which has`

the following properties:

the following properties:

`1. The observable substates must be within a light-cone of the observer. Photons or waves of light are`

information travelling through the set of information-states. They are closely related to the putative

"local computations" which are imagined as defining sensible localized change between sets of

information states. So the observable substates are those that are reachable from the observer

states by local computations. These observation computations are computations that can

affect the observer-part of the "now" information-state based on the prior-to-now configuration

of other adjacent-to-the-observer parts of the prior-to-now information states, with the information

moving at a speed of one local computation (or is that one bitshift) per information-state-distance

in the consistent tour. Confusing? Yes I'm confused too. This bit's hard. (Pun intended)

information travelling through the set of information-states. They are closely related to the putative

"local computations" which are imagined as defining sensible localized change between sets of

information states. So the observable substates are those that are reachable from the observer

states by local computations. These observation computations are computations that can

affect the observer-part of the "now" information-state based on the prior-to-now configuration

of other adjacent-to-the-observer parts of the prior-to-now information states, with the information

moving at a speed of one local computation (or is that one bitshift) per information-state-distance

in the consistent tour. Confusing? Yes I'm confused too. This bit's hard. (Pun intended)

`2. Argument 1 implies that only parts (in some informational locality to the observer within the`

information-states) of PRIOR-IN-THE-TOUR information-states can be observed by the observer.

That's what being in the light-cone from the observer implies: 1. Informationally-local to the observer's

own states, and also 2. PRIOR in the consistent tour to the "now-in-tour" state of the observer.

information-states) of PRIOR-IN-THE-TOUR information-states can be observed by the observer.

That's what being in the light-cone from the observer implies: 1. Informationally-local to the observer's

own states, and also 2. PRIOR in the consistent tour to the "now-in-tour" state of the observer.

`In fact we will stand these arguments on their heads now, and say that the consistent-tour direction`

must be one in which an observer cannot observe (via light i.e. information packets moving by local

computation) forwards in the tour direction, but can observe (local parts of) information-states that are

backwards in the tour direction.

--------

The time-arrow (state-tour direction) is that direction of information-state-change in which the

changes are like local computations which can communicate information across from one part of the

qubit string to an observer who is (is in?) another part of the qubit string.

--------

must be one in which an observer cannot observe (via light i.e. information packets moving by local

computation) forwards in the tour direction, but can observe (local parts of) information-states that are

backwards in the tour direction.

--------

The time-arrow (state-tour direction) is that direction of information-state-change in which the

changes are like local computations which can communicate information across from one part of the

qubit string to an observer who is (is in?) another part of the qubit string.

--------

`Consistent tour direction (through a very large, or infinite?) set of very large (or infinite) discrete information`

states has a lot to do, I think, with the information-theoretic concept of entropy, and if this whole

quantum-comp hypothesis is correct, I think we'll find that information-theoretic entropy is in fact identical

to thermodynamic entropy.

states has a lot to do, I think, with the information-theoretic concept of entropy, and if this whole

quantum-comp hypothesis is correct, I think we'll find that information-theoretic entropy is in fact identical

to thermodynamic entropy.

`Particle interactions are analogous to local computations.`

`The entropic time arrow must have to do with the fact that the computations only appear to be`

a self-consistent-classical-reality-producing set of computations when the info-state-changes are considered

to be going in certain of the info-change directions that they could.

a self-consistent-classical-reality-producing set of computations when the info-state-changes are considered

to be going in certain of the info-change directions that they could.

`The direction that the consistent tour chooses (and that the particle interactions choose when observation`

from within the tour forces them to decohere into classical state) is a direction imposed by consistency

constraints. In fact, the direction is DEFINED BY the consistency-of-classical-reality constraints AND

BY NOTHING ELSE.

from within the tour forces them to decohere into classical state) is a direction imposed by consistency

constraints. In fact, the direction is DEFINED BY the consistency-of-classical-reality constraints AND

BY NOTHING ELSE.

`A way of thinking about where "NOW" is in the tour of information states is that the PAST in the tour`

is CLASSICAL (experiments have been conducted, quantum events have actually chosen a path

from their probability distributions) and the FUTURE in the tour is quantum-mechanical. The possible

successor-states have probabilities WHICH ARE BASED ON THEIR INFORMATION-DISTANCE

from the now-state in the tour.

is CLASSICAL (experiments have been conducted, quantum events have actually chosen a path

from their probability distributions) and the FUTURE in the tour is quantum-mechanical. The possible

successor-states have probabilities WHICH ARE BASED ON THEIR INFORMATION-DISTANCE

from the now-state in the tour.

`But the notion of the now-state in the tour is ILL-DEFINED as a global concept (just as it is in physics).`

We really just have a NOW-state of a local part of an information state in the tour.

We can say that, as a definition,

the consistent tour visits those information states all of whose parts can choose a successor part-state

by local computation IN A WAY THAT IS GLOBALLY CONSISTENT AT THE SPEED OF

LOCAL-COMPUTATION INFORMATION-CHANGE (i.e. at the speed of light.)

We really just have a NOW-state of a local part of an information state in the tour.

We can say that, as a definition,

the consistent tour visits those information states all of whose parts can choose a successor part-state

by local computation IN A WAY THAT IS GLOBALLY CONSISTENT AT THE SPEED OF

LOCAL-COMPUTATION INFORMATION-CHANGE (i.e. at the speed of light.)

`So ALL of the choices of successor-state for each informationally local part of the "now" information-state`

in the tour must be consistent with each other, at least in the retrospect that will happen when those

future states can be inspected (at info-lightspeed) by any observer within the tour-states.

THAT is the transformation of quantum potentialities into classical realities.

in the tour must be consistent with each other, at least in the retrospect that will happen when those

future states can be inspected (at info-lightspeed) by any observer within the tour-states.

THAT is the transformation of quantum potentialities into classical realities.

`----------`

So all in all I think I agree with Frank. The simulation DOES diverge from regularity, but

the diverging simulation is just one of many "virtual tours" through the "all-information-states"

qubitstring. Some other simulation, defined precisely as that one (or few) which does not

diverge from regularity, is also simultaneously happening (or existent, as an ordered subset)

in the qubitstring. And that non-diverging-into-noise simulation (info-state-tour, I prefer

because it implies passivity (no computer needed)) is the universe.

So all in all I think I agree with Frank. The simulation DOES diverge from regularity, but

the diverging simulation is just one of many "virtual tours" through the "all-information-states"

qubitstring. Some other simulation, defined precisely as that one (or few) which does not

diverge from regularity, is also simultaneously happening (or existent, as an ordered subset)

in the qubitstring. And that non-diverging-into-noise simulation (info-state-tour, I prefer

because it implies passivity (no computer needed)) is the universe.

`So can there be other universes?`

`One way of rephrasing this question is to put it as the question of whether there is`

more than one "lightspeed--globally-consistent" tour through a set of all possible

information states, where light is defined as communication, from one part of the

qubitstring to another via local computations, of information.

more than one "lightspeed--globally-consistent" tour through a set of all possible

information states, where light is defined as communication, from one part of the

qubitstring to another via local computations, of information.