Evidence for the simulation argument
Jason
could be constructed that could perform an infinite number of
computations with a finite amount of energy, but only if the
computations done on that computer are logically reversible.
Performing a non-reversible computation results in an increase in
entropy for the system and thus would not be sustainable. (see
http://en.wikipedia.org/wiki/Reversible_computing)
The physical interactions that occur in this universe are also
reversible. e.g. An electron can accept a photon and move to a higher
energy state or an electron can emit a photon and move to a lower
energy state. Does reversible physics imply that a computational model
of said physcis would involve entirely reversible computations? I
believe that if past states of the universe could be calculated from
future ones, then those computations would have to be reversible.
Assuming the above is true, it would have consequences for any
civilization in a universe like this one (with finite energy); it would
mean that said civilizations could only simulate universes using purely
reversible computations without exhausting the finite amount of useful
energy in their universe. This also hits on a topic Wei Dai brought up
earlier about how it seems impossible to delete any information in this
universe.
Brent Meeker
>
> It's been known since the 1970s that arbitrarily efficient computers
> could be constructed that could perform an infinite number of
> computations with a finite amount of energy, but only if the
> computations done on that computer are logically reversible.
> Performing a non-reversible computation results in an increase in
> entropy for the system and thus would not be sustainable. (see
> http://en.wikipedia.org/wiki/Reversible_computing)
>
> The physical interactions that occur in this universe are also
> reversible. e.g. An electron can accept a photon and move to a higher
> energy state or an electron can emit a photon and move to a lower
> energy state. Does reversible physics imply that a computational model
> of said physcis would involve entirely reversible computations? I
> believe that if past states of the universe could be calculated from
> future ones, then those computations would have to be reversible.
I don't think the calculation has to be reversible in order to be the calculation of a reversible phenomena. We use irreversible computations all the time to calculate simple Newtonian processes which are certainly reversible.
>
> Assuming the above is true, it would have consequences for any
> civilization in a universe like this one (with finite energy); it would
> mean that said civilizations could only simulate universes using purely
> reversible computations without exhausting the finite amount of useful
> energy in their universe.
They could simulate a smaller or simpler universe, which is what, for example, a computer game does. The irreversible computation just dumps entropy into the universe which is far below it's maximum entropy (thanks to inflation). This of course depends on a a coarse-grained view of entropy. At the microscopic level, if we could keep track of all the quantum entanglement we'd presumably see that the fine-grained entropy doesn't increase.
Brent Meeker
Jason
> I don't think the calculation has to be reversible in order to be the calculation of a reversible phenomena. We use irreversible computations all the time to calculate simple Newtonian processes which are certainly reversible.
>
I agree that a computation of a reversible phenomenon could make use of
non-revsible computations, but the bigger question is: are any
reversible physical processes that cannot be simulated using only
reversible computations? I haven't been able to think of any such
examples off hand, but if you are aware of any I would be interesting
in seeing them.
> They could simulate a smaller or simpler universe, which is what, for example, a computer game does. The irreversible computation just dumps entropy into the universe which is far below it's maximum entropy (thanks to inflation). This of course depends on a a coarse-grained view of entropy. At the microscopic level, if we could keep track of all the quantum entanglement we'd presumably see that the fine-grained entropy doesn't increase.
>
Even if the simulated universe was much smaller and simpler than their
own, each time a non-reversible computation was performed it would
decrease the amount of useful energy available to that civilization,
and when that amount reached zero they would die. Note that I am also
assuming that the minds of everyone in such a civilization are also
being computed on this maximally efficient computer which is designed
to run forever. Therefore those inside it would be averse to running
any computations that would deplete useful energy, even if only a small
amount.
Mark Peaty
please excuse my ignorant interjections here but, as a non-mathematician, non-philosopher, I need to work things into a plain English version before I can feel that I understand them, and even then the edges of things get fuzzy with far more ease than they get straight and clear cut. Furthermore I am beginning to wonder if the apparently 'straight' and clear cut boundaries to concepts and so forth are not merely figments of my imagination. I don't think I go anywhere as far as John M. in this but then maybe that is just because I fear to let go of my sceptical reductionist walking stick. :-)
Jason: 'perform an infinite number of
MP: Surely 'logically reversible' does not necessarily imply no entropy, just that for the purposes of the concerned observer, the computing system can return to a state that is sufficiently close to the original state so that the inputs can be discovered. More or less by definition, entropy increases and manifests as deterioration of the substrate and as the need to supply more energy to travel through the system than otherwise is calculated to be necessary to obtain the minimum changes needed to embody the changes of state in the calculating system.
Jason: 'The physical interactions that occur in this universe are also
energy state or an electron can emit a photon and move to a lower
energy state. Does reversible physics imply that a computational model
MP: This concept of 'reversible' is very useful, but to how great an extent is it just a convenient fiction? My understanding is that you can't fire *a particular* photon at a particular atom and guarantee that your favourite electron will rise to the predicted level. I mean it either will or it won't. Conversely as I understand it [AIUI] the subsidence of an electron to a lower orbital is only predictable in a statistical sense. Once again is it not that the real world entities must be dealt with in a statistical manner, either as bulk substances, predictable due to the averaging of activities of the individual quantum particles, or as individual quantum items manifesting radical indeterminacy? Either way AIUI, the computational model will manipulate symbols denoting the real world physics and there is no guarantee that any such computing system could overcome the limits imposed by entropy and quantum indeterminacy.
Wei Dai
Let me state the facts as I understand them and you can check them against
your assumptions or correct me if I'm wrong.
The only reason we need reversible computation to do an infinite number of
computations is that physics is reversible. If we had irreversible physics,
then we would be able to do an infinite number of computations with
irreversible computations. Also, "reversible" and "irreversible" computation
refers to the method of implementing the computation, not the content of the
computation. Reversible computation can be used to simulate an irreversible
universe, and vice versa.
A big problem with reversible computation is that the energy efficiency is
inversely related to speed. In order to do an infinite number of
computations, you have to do them infinitely slowly. Which means a
civilization in a reversible universe with finite energy can only do an
infinite amount of computation if it had absolute security from both
external and internal threats (and therefore nobody has to worry about "use
it or lose it"). Given what we know today about security and the physics of
our universe, it's hard to imagine how this could be achieved. And my
intuition says only a small subset of reversible universes that allow the
evolution of intelligence would also allow this kind absolute security.
Jason
Mark Peaty wrote:
> Hello Jason,
> please excuse my ignorant interjections here but, as a
> non-mathematician, non-philosopher, I need to work things into a plain
> English version before I can feel that I understand them, and even then
> the edges of things get fuzzy with far more ease than they get straight
> and clear cut. Furthermore I am beginning to wonder if the apparently
> 'straight' and clear cut boundaries to concepts and so forth are not
> merely figments of my imagination. I don't think I go anywhere as far as
> John M. in this but then maybe that is just because I fear to let go of
> my sceptical reductionist walking stick. :-)
>
> Jason: 'perform an infinite number of
> computations with a finite amount of energy, but only if the
> computations done on that computer are logically reversible.'
>
> MP: Surely 'logically reversible' does not necessarily imply no entropy,
> just that for the purposes of the concerned observer, the computing
> system can return to a state that is sufficiently close to the original
> state so that the inputs can be discovered. More or less by definition,
> entropy increases and manifests as deterioration of the substrate and as
> the need to supply more energy to travel through the system than
> otherwise is calculated to be necessary to obtain the minimum changes
> needed to embody the changes of state in the calculating system.
>
Right, logically reversible computations on their own do not imply no
increase in entropy by the computing system, but for a computing system
to operate with no net increase in entropy, the computations it
performs must be logically reversible. This is because: "For a
computational operation in which 1 bit of logical information is lost,
the amount of entropy generated is at least k ln 2, and so the energy
that must eventually be emitted to the environment is E ≥ kT ln 2." (
http://en.wikipedia.org/wiki/Reversible_computing#More_on_Landauer.27s_principle
) Note that the computing substrates needed to implement such an
efficient computer are well beyond our current level of technology and
are only theoretical. However there is as of yet, no known reason why
an arbitrarily efficient computer could not be built.
A reversible computation is one that has a 1 to 1 mapping between input
and output. For example if if I compute x=x+3, every input has a
unique output, given the function and the result it is possible to
determine the input. However the same could not be said of a function
defined as x=x modulo 3, or x=0, where there are a finite number of
outputs. These computations are not reversible because it is
inpossible to get the input given function and the output.
> Jason: 'The physical interactions that occur in this universe are also
> reversible. e.g. An electron can accept a photon and move to a higher
> energy state or an electron can emit a photon and move to a lower
> energy state. Does reversible physics imply that a computational model
> of said physics would involve entirely reversible computations? '
>
> MP: This concept of 'reversible' is very useful, but to how great an
> extent is it just a convenient fiction? My understanding is that you
> can't fire *a particular* photon at a particular atom and guarantee that
> your favourite electron will rise to the predicted level. I mean it
> either will or it won't.
By physically reversible I don't mean we as humans can undo anything
that happens, rather physical interactions are time-invertible. If you
were shown a recording of any physical interaction on a small scale, an
elastic collision of particles, the decay of a nucleus, burning of
hydrogen, it would be impossible for you to tell if that recording were
being played in reverse or not, since it is always possible for that
interaction to occur as it does in either direction of time.
> Conversely as I understand it [AIUI] the
> subsidence of an electron to a lower orbital is only predictable in a
> statistical sense. Once again is it not that the real world entities
> must be dealt with in a statistical manner, either as bulk substances,
> predictable due to the averaging of activities of the individual quantum
> particles, or as individual quantum items manifesting radical
> indeterminacy?
Quantum mechanics makes the universe seem random and uncomputable to
those inside it, but according to the many-worlds interpretation the
universe evolves deterministically. It is only the observers within
the quantum mechanical universe that perceive the randomness and
unpredictability, but this unpredictability doesn't exist at the higher
level where the universe is being simulated (assuming many-worlds).
>Either way AIUI, the computational model will manipulate
> symbols denoting the real world physics and there is no guarantee that
> any such computing system could overcome the limits imposed by entropy
> and quantum indeterminacy.
>
I'm not sure what you are saying here. Are you saying that a perfectly
efficient computer could not be built or that the physics of this
universe are not computable?
Jason
Jason
Wei Dai wrote:
> Jason, I think there may be some incorrect assumptions behind your argument.
> Let me state the facts as I understand them and you can check them against
> your assumptions or correct me if I'm wrong.
>
> The only reason we need reversible computation to do an infinite number of
> computations is that physics is reversible. If we had irreversible physics,
> then we would be able to do an infinite number of computations with
> refers to the method of implementing the computation, not the content of the
> computation. Reversible computation can be used to simulate an irreversible
> universe, and vice versa.
If that is true then my underlying assumptions were flawed. My
argument assumed that a non-reversible universe could not be simulated
by a computer with bounded memory and using only reversible
computations. The way I arrived at this assumption was imagining a
non-reversible universe, such as the John Conway's game of life. If
the computer that implements this simulation has limited memory then in
order for the simulation to continue forever, prior states cannot be
saved in memory and instead old states would have to be overwritten.
This destruction of information which cannot be undone would be
logically irreversible as I understand it. However if the simulation
were one where each state has a 1 to 1 mapping, overwritting old states
does not destroy them forever because previous states could always be
computed from the current state.
Jason
Wei Dai
> If that is true then my underlying assumptions were flawed. My
> argument assumed that a non-reversible universe could not be simulated
> by a computer with bounded memory and using only reversible
> computations. The way I arrived at this assumption was imagining a
> non-reversible universe, such as the John Conway's game of life. If
> the computer that implements this simulation has limited memory then in
> order for the simulation to continue forever, prior states cannot be
> saved in memory and instead old states would have to be overwritten.
> This destruction of information which cannot be undone would be
> logically irreversible as I understand it. However if the simulation
> were one where each state has a 1 to 1 mapping, overwritting old states
> does not destroy them forever because previous states could always be
> computed from the current state.
Ok, I understand your argument more clearly now. But, why do you assume a
computer with bounded memory? Even with a finite amount of energy, we can
(theoretically) obtain unbounded memory by spreading it over an unbounded
volume of space. I'd guess that in practice this has approximately the same
level of difficulty as achieving an unbounded number of computations from a
finite amount of energy.
Brent Meeker
>
> Brent Meeker wrote:
>> I don't think the calculation has to be reversible in order to be the
>> calculation of a reversible phenomena. We use irreversible
>> computations all the time to calculate simple Newtonian processes
>> which are certainly reversible.
>>
>
> I agree that a computation of a reversible phenomenon could make use of
> non-revsible computations, but the bigger question is: are any
> reversible physical processes that cannot be simulated using only
> reversible computations? I haven't been able to think of any such
> examples off hand, but if you are aware of any I would be interesting
> in seeing them.
I think Feynman showed that a reversible computer has general computing power.
>
>> They could simulate a smaller or simpler universe, which is what, for
>> example, a computer game does. The irreversible computation just
>> dumps entropy into the universe which is far below it's maximum
>> entropy (thanks to inflation). This of course depends on a a
>> coarse-grained view of entropy. At the microscopic level, if we could
>> keep track of all the quantum entanglement we'd presumably see that
>> the fine-grained entropy doesn't increase.
>>
>
> Even if the simulated universe was much smaller and simpler than their
> own, each time a non-reversible computation was performed it would
> decrease the amount of useful energy available to that civilization,
> and when that amount reached zero they would die.
That's exactly our situation. But nobodies worried because the difference between the maximum entropy of the universe and it's current entropy is some 80 orders of magnitude - besides which it's expansion is accelerating.
Brent Meeeker
Jason Resch
I am reminded of the thread you started titled "why can't we erase information". Which discussed anthropic reasons for why it appears impossible to physically delete information. Hal Finney mentioned on that same thread that assuming many-worlds we can't create information either. My argument would say that if our universes is simulated in a physical universe with similair laws to our own (impossible to create or destroy matter and energy) that could explain why we too cannot create or destroy information. Creating it in an unlimited manner would eventually use up the finite memory of the computer simulating us. By the same measure deleting information would eventually use up all the useful energy that computer had to run.
Of course for any of the above to be relavent assumes that simulated observers have a high measure, which is possible. For example David Deutsch belives that "a universal quantum computer, capable of rendering any physically possible environment, actually exists near the end of spacetime in every universe and is maintained by sentient beings with the knowledge required to increase its memory, computing cycles, and energy supply." ( http://en.wikipedia.org/wiki/David_Deutsch#The_Turing_principle ) My addition would be that if such sentient beings cannot continue to increase its memory and energy supply ad infinitum, they'll have to limit themselves to certain types of simulations.
Jason
Brent Meeker
> Hello Jason,
> please excuse my ignorant interjections here but, as a
> non-mathematician, non-philosopher, I need to work things into a plain
> English version before I can feel that I understand them, and even then
> the edges of things get fuzzy with far more ease than they get straight
> and clear cut. Furthermore I am beginning to wonder if the apparently
> 'straight' and clear cut boundaries to concepts and so forth are not
> merely figments of my imagination. I don't think I go anywhere as far as
> John M. in this but then maybe that is just because I fear to let go of
> my sceptical reductionist walking stick. :-)
>
> Jason: 'perform an infinite number of
> computations with a finite amount of energy, but only if the
> computations done on that computer are logically reversible.'
>
> MP: Surely 'logically reversible' does not necessarily imply no entropy,
> just that for the purposes of the concerned observer, the computing
> system can return to a state that is sufficiently close to the original
> state so that the inputs can be discovered. More or less by definition,
> entropy increases and manifests as deterioration of the substrate and as
> the need to supply more energy to travel through the system than
> otherwise is calculated to be necessary to obtain the minimum changes
> needed to embody the changes of state in the calculating system.
I think there is a confusion creeping in here. I don't think "logically reversible" is misleading. It is only physical processes that can be termed reversible or irreversible. Logic lives in a timeless Platonia. Computers operated irreversibly, they dissipate heat when they they erase data. Feynman pointed out that this was not necessary and a computer that did not erase data could operate without dissipating heat (no increase in entropy).
Brent Meeker
John Mikes
(I have no intention to join the professional discussion (Wei Dai et al.) - what can a former polymer chemist say in it, who's 'scientific' career.concentrated in times before the expansion of the computer-usage, anyway? )
Mark brought my name into your thread so I want to explain what I THINK Mark might have been referring to (I really do not try to outguess him<G>)
Mark wrote in his post:
"... >Furthermore I am beginning to wonder if the apparently
> 'straight' and clear cut boundaries to concepts and so forth are not
> merely figments of my imagination. I don't think I go anywhere as far as
> John M. in this but then maybe that is just because I fear to let go of
How far do I think I do go?
In my 5 decades of polymer and technology R&D I arrived at an agnostic point: to consider common sense instead of the (so far) discovered epistemic mass in human (scientific??) cognitive inventory. The ever increasing knowledge-base means a reduced basis for any consciously performed computation with the already given (known) conditions. (Cf: Robert Rosen's unlimited interconnection- based complexity with its Turing non-emulable impredicativity).We just don't know (yet?) everything that may be relevant.
Our concept-identifications are formed by the past knowledge-base (from millennia ago to the preceding second) which is in congruence (in my mind) with Mark's reductionist walking stick.(maybe 'not quite' the figments of the imagination).
I believe in further epistemic enrichment and so whatever we can include NOW as parameters into our computations will be "improved" later on. I don't know how Wei Dai's "unbounded memory spread over unbounded space" may work.
but by common sense I hold on to our present ignorance (vs.'later' learning more) as a support for Mark's uncertainty against our existing 'clear cut' concepts.
"I just don't know" (=we are by far not omniscient) is that "all the way" I go for.
Final (unrestricted) conclusions in ongoing reductionist sciences sound hollow.
I cannot help to compare them with earlier 'conclusions' that had to be changed - and THEN I apply strong induction for the unforeseeable changes our present wisdom will undergo over future epochs.
People involved in practical developmental work should not listen to me.
John Mikes
Wei Dai
>I assumed bounded memory due to the limited amount of matter and energy
> available to build the computer. For instance I've seen it said that the
> total information content of this universe is about 10^90 bits. If a
> civilization gathered all the mass and energy available in their universe
> to
> build a computer, they could only accurately simulate universes with an
> information content less than or equal to that of their host universe.
But as I said, limited amount of matter and energy only implies limited
memory if space is also bounded. See
http://en.wikipedia.org/wiki/Bekenstein_bound. By spreading the energy over
an ever increasing volume of space, we can obtain unbounded memory. This is
essentially the same principle as get an unlimited number of computational
steps from finite energy by continually slowing down the rate of
computation. So again I don't know why you assume one thing but not the
other.
Perhaps a more general form of your argument (which doesn't depend on the
above assumption) is that any kind of computational limits we see today (in
practice, not just in theory) could be taken as evidence that we're in a
simulated universe, since simulated universes are likely to have fewer
computational resources than base universes. The fact that we can
theoretically obtain unbounded memory or number of computational steps would
be irrelevant to this argument since the simulation could end before we have
the technology to do so.
An alternative explanation that I favor for the presence of computational
limits is that they are necessary for the evolution of sentience. Without
computational limits, an organism can respond to its environment in an
apparently intelligent manner by using brute force algorithms, therefore
sentience would have little evolutionary advantage. If this explanation is
correct, then all civilizations have to go through a early phase where they
are computational constrained, and the presence of computational limits is
no longer an additional argument for being in a simulation. ("Additional"
here means additional to the fact that we seem to be living in an early
phase of a civilization, which I think is the evidence of the original
simulation argument.)
As for the simulation argument itself, I've suggested previously that
instead of thinking "which kind of universe am I likely to be in", it makes
more sense to consider myself as being "simultaneously" in all universes
that contain me, and to decide my actions based on their effects on the
overall multiverse. Given this kind of philosophy, we can see that while
there may be many many simulated universes that contain us, the effects of
our actions on a single base universe (which may be computationally
unlimited once we move beyond this early phase) can easily outweigh the
effects on all of the simulated universes. Therefore it doesn't make sense
to place more consideration on the simulated universes when we reason or
make choices.
Jason
Wei Dai wrote:
> Jason wrote:
> >I assumed bounded memory due to the limited amount of matter and energy
> > available to build the computer. For instance I've seen it said that the
> > total information content of this universe is about 10^90 bits. If a
> > civilization gathered all the mass and energy available in their universe
> > to
> > build a computer, they could only accurately simulate universes with an
> > information content less than or equal to that of their host universe.
>
> But as I said, limited amount of matter and energy only implies limited
> memory if space is also bounded. See
> http://en.wikipedia.org/wiki/Bekenstein_bound. By spreading the energy over
> an ever increasing volume of space, we can obtain unbounded memory. This is
> essentially the same principle as get an unlimited number of computational
> steps from finite energy by continually slowing down the rate of
> computation. So again I don't know why you assume one thing but not the
> other.
>
Before you mentioned it in this thread, I was not aware that infinite
memory could be obtained through spreading energy over an infinite
amount of space. That is a very interesting result, and has forced me
to reconsider my original hypothesis. One of my motivations for
posting this was to see if anyone on this list could poke holes in or
otherwise find problems with my speculation. I thank everyone who
responded for their input.
>
> An alternative explanation that I favor for the presence of computational
> limits is that they are necessary for the evolution of sentience. Without
> computational limits, an organism can respond to its environment in an
> apparently intelligent manner by using brute force algorithms, therefore
> sentience would have little evolutionary advantage.
>
I see your point. Enegry for metabolism needs to be a limited resource
to spur competition and drive evolution. This has the consequence that
energy is also limited for other purposes, such as computation.
> Therefore it doesn't make sense
> to place more consideration on the simulated universes when we reason or
> make choices.
Agreed.
Mark Peaty
Jason: "By physically reversible I don't mean we as humans can undo anything
were shown a recording of any physical interaction on a small scale, an
elastic collision of particles, the decay of a nucleus, burning of
hydrogen, it would be impossible for you to tell if that recording were
being played in reverse or not, since it is always possible for that
interaction to occur as it does in either direction of time."
Jason: "Quantum mechanics makes the universe seem random and uncomputable to
universe evolves deterministically. It is only the observers within
the quantum mechanical universe that perceive the randomness and
unpredictability, but this unpredictability doesn't exist at the higher
level where the universe is being simulated (assuming many-worlds). "
That is one thing. Another thing is that no entity or set of entities could know if their 'simulation' attempt was doing what they wanted in every detail because to attempt to find this out would interfere irreversibly with the unfolding of the world. This latter objection can be sidelined by accepting that there are no entities with any such intention therefore it is irrelevant. For those who would be 'believers' in Sky God, as well sceptics, this puts divine intervention pretty much off limits.
OK, that leaves the concept of pseudo-emulation: another hidden 'level' of structure embodied in calculation. I guess this can be represented by either
1/ the movie '13th Floor' - which I think much better than 'Matrix' 1, 2, and 3 in terms of its encapsulation of interesting philosophical questions - or
2/ Bruno's 'Yes Doctor' hypothesis.
These might seem to be very different but I don't think so. The key point is that a wilful entity or conspiracy seeks to emulate all or part of another wilful entity's world to the extent that the latter can't tell the difference when the change is made. Doubtless Bruno has a far more exacting definition and sets of caveats, but I insist on plain-English. As far as I can see, the assertion that this MUST be possible in principle because 'we' can imagine a mathematical implementation, just begs the question. I do not think there is anything shameful in 'reifying' physics, because if we exist and know that we do it has to be because we BELIEVE in ourselves and our world. Believing in something IS reifying it. When we understand that the basic mechanism underlying this process is the activation of a model of whatever it is, the whole question of mind and consciousness is demystified. This does not remove the wonder, or the challenges, of living in the amazing universe. It should mean that we spend less money on snake oil though!
Stathis Papaioannou
Jason: "Quantum mechanics makes the universe seem random and uncomputable to
those inside it, but according to the many-worlds interpretation the
universe evolves deterministically. It is only the observers within
the quantum mechanical universe that perceive the randomness and
unpredictability, but this unpredictability doesn't exist at the higher
level where the universe is being simulated (assuming many-worlds). "
MP: I don't think I can accept this. Maybe I sound arrogant in saying this, but I think the idea of simulation is used a bit too loosely. I know there are those lurking on the Mind & Brain list and JCS-online who would say I am 'the pot calling the kettle black', because I am always asserting what I call UMSITW [pronounced um-see-two for English speakers] - updating the model of self in the world - is the basis of consciousness. But they misunderstand me, because I do not say there is anyone else doing simulation, merely that we experience being here because the universe has evolved self sustaining regions within itself which maintain their structure by means of dynamically modelling themselves and their local region so as to avoid fatal dangers while obtaining everything they need from their environments. My point here is simply that the universe is its own best simulation and that any ideas of something greater, such as a Matrix type operation, are science fiction only. Why? Because for a feasible universe like the one we seem to inhabit to be deterministic does not require that it is predictable nor that it can be repeatable. Nobody knows to what extent quantum level events are intrinsically random as opposed to being _pushed from 'behind' or 'below'_ so to speak.
Stathis Papaioannou
Jesse Mazer
>
>This is yet another delayed response; the story of my life really ...
>
>Jason: "By physically reversible I don't mean we as humans can undo
>anything
>that happens, rather physical interactions are time-invertible. If you
>were shown a recording of any physical interaction on a small scale, an
>elastic collision of particles, the decay of a nucleus, burning of
>hydrogen, it would be impossible for you to tell if that recording were
>being played in reverse or not, since it is always possible for that
>interaction to occur as it does in either direction of time."
>
>MP: This is only true for 'individual' reactions on the micro scale, but
>even then the 'truth' about the reversibility can only really be
>maintained by hiding the truth about the context. For example, it is
>logically possible for certain atomic nuclei to collide at just the
>right velocities and fusion will occur. In reality however the
>probability of what are normally fission products coming together to
>make a uranium nucleus is so close to zero you are never going to see
>it. [I don't know much about the physics but my casual believe is that
>heavy elements are created through various long and complex 'ratchet'
>accretion pathways in which nuclear isotopes of H or He enter heavier
>nuclei.] Like wise the burning of hydrogen; it seems simple enough and
>yes it is 'reversible', but does the reverse occur? Not where you and I
>can see it.
But according to modern physics, at maximum entropy the probability of any
reaction should be identical to the probability of its time-inverted one
(actually, there are a few weak nuclear reactions where you'd need to invert
charge and parity as well--the laws of fundamental physics are
CPT-symmetric, but not always T-symmetric). It's thought that the only
reason some reactions are more likely to happen in the forward direction
than the backward direction in the real world is because of the low-entropy
initial boundary conditions of the universe; if we lived in a universe with
low-entropy final boundary conditions on the big crunch and no constraints
on the big bang, then the "arrow of time" would be reversed. And the reasons
for the low-entropy big bang remain fairly mysterious, we may not understand
it without a complete theory of quantum gravity or TOE (in the physics sense
of unifying all four forces, not in the list's sense).
Jesse
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Mark Peaty
Can you point to any aspect of the world which can't be simulated no matter how powerful the computer?
Well, as curious people keep asking questions about their world, so more and more pervasive and detailed application of scientific theory occurs. Curious kids grow up to be curious adults, and some are always going to refuse to be fobbed off with the 'because it IS' response. And the ways of asking questions are potentially infinite because answers get re-input as new questions, which more or less guarantees non-linear results. So newer experiments get created which just by the by incorporate new juxtapositions of previously accepted results as part of the experimental set up. Over time this effectively demands that the accepted theories have to be 100% correct because any slight errors will be multiplied over time. Now I realise this is a rather informal way of asserting this but, as I said before, plain-English is what I want and yes I know this does seem to make things long winded. But the bottom line here is that, over time, scientific theories are constrained to be ever more exactly correct with less and less margin for error. In effect the human species will test just about all significant and practically useful theories to vanishingly small tolerances so whatever might be 'simulating' the universe as seen from planet Earth has ever less margin for error. Simply put the 'universe in the bottle' has to be perfectly consistent and ontologically complete.
So the conspiratorial simulators must have 'computers' that are able to increase their representational power to infinite precision when needed. And can the conspirators predict before they start the simulation running just precisely what tests and outlandish ideas the humans will come up with? I think not.
I think this means that Stathis's 'no matter how powerful the computer?' is a bit of a cheat [nothing personal you understand; what I am saying is that I think the whole project of Mathematical universe and 'Comp' may be just a very sophisticated house of cards.] I believe that either all of our universe as seen on, at and from planet Earth is being simulated perfectly or none of it is being simulated at all.
Stathis Papaioannou wrote:
Brent Meeker
This is mixing Everett's relative state interpretation with the idea that the world is a simulation. These are not the same and maybe not even compatible. The world evolves deterministically in Hilbert space and the "many-worlds" are projections relative to us. Whether this can be simulated, except in a quantum computer, is questionable because the Hilbert space is infinite dimensional. Is some fixed finite resolution sufficient for simulation?
>
> MP: I don't think I can accept this. Maybe I sound arrogant in saying
> this, but I think the idea of simulation is used a bit too loosely. I
> know there are those lurking on the Mind & Brain list and JCS-online who
> would say I am 'the pot calling the kettle black', because I am always
> asserting what I call UMSITW [pronounced um-see-two for English
> speakers] - updating the model of self in the world - is the basis of
> consciousness. But they misunderstand me, because I do not say there is
> anyone else doing simulation, merely that we experience being here
> because the universe has evolved self sustaining regions within itself
> which maintain their structure by means of dynamically modelling
> themselves and their local region so as to avoid fatal dangers while
> obtaining everything they need from their environments. My point here is
> simply that the universe is its own best simulation and that any ideas
> of something greater, such as a Matrix type operation, are science
> fiction only. Why? Because for a feasible universe like the one we seem
> to inhabit to be deterministic does not require that it is predictable
> nor that it can be repeatable. Nobody knows to what extent quantum level
> events are intrinsically random as opposed to being _pushed from
> 'behind' or 'below'_ so to speak.
>
> That is one thing. Another thing is that no entity or set of entities
> could know if their 'simulation' attempt was doing what they wanted in
> every detail because to attempt to find this out would interfere
> irreversibly with the unfolding of the world.
This assumes that the simulation must be quantum mechanical - but I think that would defeat the whole point of assuming a simulation. If the world can be simulated classically, then it can be monitored without interference.
Brent Meeker
John Mikes
by Mark's remark:
is just because I fear to let go of my sceptical reductionist walking stick. "
them ....37,38,39, - then stopped and said: well. so far it was a match, let me believe that the rest is also OK.
We are much earlier into the completion of what we know about our existence.
Then again you both wrote about simulations (even: emulations) horribile dictu:
" The key point is that a wilful entity or conspiracy seeks to emulate all or part of another wilful entity's world to the extent that the latter can't tell the difference when the change is made."
Untold: "restricted to details known" Nobody can simulate or look for unknown details. Of course "the latter" can't tell whether 'simulated' if looking only at the portion that matches. (I am not clear about "wilful entity".)
The fallacy of the simulational business is more than that: you (get?) simulate(d?) HERE and NOW and continue HERE under these conditions, while THERE the simulacron lives under THOSE conditions and in no time flat becomes different from you original. That the world of THERE is also simulated? Just add: and lives exactly the life of THIS one? then the whole thing is a hoax, a mirror image, no alternate.
*
Jason: " A reversible computation is one that has a 1 to 1 mapping between input
and output. " Going up in the $100 bills to #45, the map may change. Don't tell me please such "Brunoistic" examples like 1+1 = 2, go out into the 'life' of a universe (or of ourselves).
How can you reverse the infinite variations of a life-computation? You have got to restrict it into a limited model and work on that. Like: reductionist physics (QM?) .
It seems to me like a return to Carnot, disregarding Prigogine, who improved the case to some (moderate) extent from the classical reversible even isotherm thermodynmx,
from which I used to form the joke (as junior in college) that it shows how processes would [theoretically] proceed, wouldn't they proceed as they do proceed.
We can reverse a closed model content, all clearly known in it. Not life.
Just count into the simulations and reversals the constantly (nonlinearly!) changing world not allowing any 'fixing' of circumstances/processes. No static daydreams.
*
those inside it, but according to the many-worlds interpretation the
*
Sorry for the length and my unorthodoxy.
John M
Brent Meeker
You seem to have two themes: (1) The universe is more complex than current physics makes it out and may not be computable, and in comparison, (2) Our ability to comprehend things is quite limited. But these two together imply that is quite possible that we live in a simulation. If the simulation is being performed in a universe like ours, one with very complex physics, then the physics of that universe could provide a simulation that was beyond our ability to discern as a simulation - because of our limited comprehension. The point is that the simulation doesn't have to simulate the whole complicated universe, only the part we can investigate and understand.
Brent Meeker
Mark Peaty
the simulation doesn't have to simulate the whole complicated universe, only the part we can investigate and understand'
MP: as I argued in my response to Stathis, the 'part we can investigate and understand' can be ever expanding and the exactitude of our understanding can in time reach just about arbitrarily fine degrees of resolution. Or, which would be more the worry for 'emulators' who wished to remain invisible, the emulation would need to be able to be controlled to a finer resolution than scientists' contemporary measurement skills.
Brent Meeker
> Brent: '
> the simulation doesn't have to simulate the whole complicated universe,
> only the part we can investigate and understand'
>
> MP: as I argued in my response to Stathis, the 'part we can investigate
> and understand' can be ever expanding and the exactitude of our
> understanding can in time reach just about arbitrarily fine degrees of
> resolution. Or, which would be more the worry for 'emulators' who wished
> to remain invisible, the emulation would need to be able to be
> controlled to a finer resolution than scientists' contemporary
> measurement skills.
Which scientists...ours of theirs?
I don't disagree, but suppose the level at which we could see it was a simulation was the Planck scale. This is not entirely speculative, since the Planck scale is where a conflict between quantum mechanics and general relativity must manifest itself. If the Simulators were only interested in how the world operates far above that level then maybe they were sloppy and just left potential inconsistencies in the simulation. The program will crash when we do the right experiment to reveal it. But that level is thirty orders of magnitude smaller than anything we can reach now.
Brent Meeker
Stathis Papaioannou
I think we have been through this before actually.
Thanks for being patient, sometimes I just like to argue :0
Can you point to any aspect of the world which can't be simulated no matter how powerful the computer?
MP: For us mortals, this universe is in many respects infinite. If 'someone' IS running it within a 'computer' then they have to be running all of it. Why? Because humans can do science. This means that our little brains can come up with questions about everything and we do; in fact we can say that 'we' - collectively the whole human species - must have asked questions about everything we already have beliefs about. The formal and systematic way of checking out answers to practical questions of fact is through the assertion of an explanation which is able to make specific predictions because we assume causality, then someone sets up experimental situation to test the predictions. Now the experiment will either falsify the assertions of the explanation because the predictions were not correct, or the predictions will turn out to be correct in which case the assertions will gain strength as explanatory tools and become linked, in the minds of ever more people, with all the other assertions that didn't get falsified. The more this happens, the more the universe is constrained to comply with our explanations. 'So what?' you say.
Well, as curious people keep asking questions about their world, so more and more pervasive and detailed application of scientific theory occurs. Curious kids grow up to be curious adults, and some are always going to refuse to be fobbed off with the 'because it IS' response. And the ways of asking questions are potentially infinite because answers get re-input as new questions, which more or less guarantees non-linear results. So newer experiments get created which just by the by incorporate new juxtapositions of previously accepted results as part of the experimental set up. Over time this effectively demands that the accepted theories have to be 100% correct because any slight errors will be multiplied over time. Now I realise this is a rather informal way of asserting this but, as I said before, plain-English is what I want and yes I know this does seem to make things long winded. But the bottom line here is that, over time, scientific theories are constrained to be ever more exactly correct with less and less margin for error. In effect the human species will test just about all significant and practically useful theories to vanishingly small tolerances so whatever might be 'simulating' the universe as seen from planet Earth has ever less margin for error. Simply put the 'universe in the bottle' has to be perfectly consistent and ontologically complete.
So the conspiratorial simulators must have 'computers' that are able to increase their representational power to infinite precision when needed. And can the conspirators predict before they start the simulation running just precisely what tests and outlandish ideas the humans will come up with? I think not.
I think this means that Stathis's 'no matter how powerful the computer?' is a bit of a cheat [nothing personal you understand; what I am saying is that I think the whole project of Mathematical universe and 'Comp' may be just a very sophisticated house of cards.] I believe that either all of our universe as seen on, at and from planet Earth is being simulated perfectly or none of it is being simulated at all.
God or an advanced civilization could make an actual universe by gathering raw material (whatever that might mean), setting starting parameters and laws of physics, then letting it all unfold: Big Bang, planets, evolution, the US invading Iraq, etc. Alternatively, God or an advanced civilization could build a simulated universe on a big computer by starting with virtual raw material, setting starting parameters and laws of physics, then clicking "run". Is there any way from the inside of determining whether we are more likely living in one than the other?
Stathis Papaioannou
Mark Peaty
Which scientists...ours of theirs?'MP: Ours. The situation is not static; they would have to KEEP responding to our scientists' unpredictable forays into basic science, unpredictable a-priori either to them or to us.
John Mikes
John
John M
----- Original Message -----From: Brent MeekerSent: Saturday, February 24, 2007 5:35 PMSubject: Re: Evidence for the simulation argument(Brent wrote):"....The point is that the simulation doesn't have to simulate the whole complicated universe, only the part we can investigate and understand." -----(End of his post below)---WE???WHO????---"We" as Einstein or Feinstein, or John Doe?or even Mbamba Kruit from the forests of New Guinea?Does every one of us simulate(!) (into?) his personalized universe with understandability levels PERSONALLY adjusted?(and why simulate?)John-------------------------------
(John Mikes wrote:--skip--)BM:
Stathis Papaioannou
From: Brent MeekerSent: Saturday, February 24, 2007 5:35 PMSubject: Re: Evidence for the simulation argument(Brent wrote):"....The point is that the simulation doesn't have to simulate the whole complicated universe, only the part we can investigate and understand." -----(End of his post below)---WE???WHO????---"We" as Einstein or Feinstein, or John Doe?or even Mbamba Kruit from the forests of New Guinea?Does every one of us simulate(!) (into?) his personalized universe with understandability levels PERSONALLY adjusted?(and why simulate?)John
Stathis Papaioannou
Bruno Marchal
Le 26-févr.-07, à 11:57, Stathis Papaioannou a écrit :
>
>
> On 2/26/07, John M <jam...@prodigy.net> wrote:
>>> From: Brent Meeker
>>> To: everyth...@googlegroups.com
>>> Sent: Saturday, February 24, 2007 5:35 PM
>>> Subject: Re: Evidence for the simulation argument
>>> (Brent wrote):
>>> "....The point is that the simulation doesn't have to simulate the
>>> whole complicated universe, only the part we can investigate and
>>> understand." -----(End of his post below)
>>>
>>> ---WE???WHO????---
>>>
>>> "We" as Einstein or Feinstein, or John Doe?
>>> or even Mbamba Kruit from the forests of New Guinea?
>>> Does every one of us simulate(!) (into?) his personalized universe
>>> with understandability levels PERSONALLY adjusted?
>>> (and why simulate?)
>>> JohnThe discussions so far seem to assume that as inhabitants of a
>>> possibly simulated world we have some reliable knowledge of what a
>>> "real" world would look like, so that we can gather scientific data
>>> and thereby determine whether it is a sham. But it's unlikely that
>>> we are going to run into a Microsoft logo or bump their heads
>>> against a huge planetarium screen. How do we know that the limits of
>>> the simulation we might be in are not represented by the speed of
>>> light or the granularity of matter/energy, both limits on how much
>>> we can possibly observe? Maybe in the "real" world the speed of
>>> light is much larger or infinite, or matter/energy is continuous or
>>> more finely granular. How would we know?
>
> Stathis Papaioannou
Of course we cannot *know*. But if we assume the comp Hypothesis, then
we *can* "know" (relatively to the comp hyp).
Indeed, if comp is true, then we "belong" to all simulations of us
possible at once. All the simulations are generated by the DU. And the
physical appearances are (first person) sum on all relative
computations. And if "I" is different from "Universe/God", then comp
predicts "Universe/God", as it can appear to me or us, is NOT Turing
emulable. QM confirms this fact, but it is an open problem if comp
generates to too much white rabbit or not. If QM is the only
comp-physics possible, then indeed first and third person white rabbits
would disappear.
Remember just this: if I am turing emulable then the observable
universe cannot be. This follows from UDA.
Cf my previews explanation:
http://www.mail-archive.com/everyth...@eskimo.com/msg05272.html
Bruno
Stathis Papaioannou
Le 26-févr.-07, à 11:57, Stathis Papaioannou a écrit :
>
>
> On 2/26/07, John M <jam...@prodigy.net> wrote:
>>> From: Brent Meeker
>>> To: everyth...@googlegroups.com
>>> Sent: Saturday, February 24, 2007 5:35 PM
>>> Subject: Re: Evidence for the simulation argument
>>> (Brent wrote):
>>> "....The point is that the simulation doesn't have to simulate the
>>> whole complicated universe, only the part we can investigate and
>>> understand." -----(End of his post below)
>>>
>>> ---WE???WHO????---
>>>
>>> "We" as Einstein or Feinstein, or John Doe?
>>> or even Mbamba Kruit from the forests of New Guinea?
>>> Doesevery one of us simulate(!) (into?) his personalized universe
The UDA is an argument about ultimate reality. We can still speculate as to whether we are simulated in one level relative to another level.
Stathis Papaioannou
Bruno Marchal
Le 26-févr.-07, à 12:58, Stathis Papaioannou a écrit :
Locally, this makes sense. What UDA shows (I think Mark Peaty has the
right intuition here) is that if we are simulated at some relative
level, then we can know it (like in a lucid dream). If we are 100%
correctly simulated, this is equivalent as saying we are already
simulated by the UD, because if the simulation is physically correct,
then it makes no sense to attach our mind to just that simulation. We
are infinitely distributed in the whole UD* (static block-execution of
the UD). OK?
If the simulation is not correct, then we can know it, if it last
enough, and if there is no "malin genie" killing his creature each time
when they discover the fake nature of they neighborhood (like in
totalitarian system).
Must go. I am not sure when I can go back to my office this week.
Teaching duties.
Bruno
John M
scerir
(1) The universe is more complex than current physics
makes it out and may not be computable, and in comparison,
(2) Our ability to comprehend things is quite limited.
But these two together imply that is quite possible
that we live in a simulation.
In a n-dimensional Hilbert space, one needs n^2 -1
real parameters to specify the information content,
that is to say a density matrix, hermitean,
with tr(rho)=1.
Since human measurements, within a specific basis set,
give n-1 independent probabilities, one needs n+1
unbiased basis sets to provide the required
number n^2 - 1. (Note that n+1 unbiased basis sets
exist if n is _prime_, as far as I remember).
Are the great simulators number theorists?
:-)
Stathis Papaioannou
Bruno - thanks.Stathis did not address my "why simulation at all" main question, you did by an "IF" followed by "then" and another 'if' (already assumed) and it goes on and on.At the end we are in a virtual reality what could bring Hollywood a $billion and the teens would kill all the aliens in the video-games.It is not far from the Gedankenexperiment to shortcut something we do not understand by fantasy and keep it repeating so many times that people get used to it. That happened with the EPR, the Big Bang, (oops: indeed the expanding universe), etc. leading to 'complementarities' in which I really do not know: is our mental faculty not wide enough to comprehend it, or we just misunderstand some readings on our instruments. When people "get used" to the 'if'-s: comes the statement of a physicist on another list: "I can live with paradoxes".I feel sometimes somebody somehow somewhere should recall a 'reasonable' (original?) question.
Mark Peaty
> That is one thing. Another thing is that no entity or set of entities
> could know if their 'simulation' attempt was doing what they wanted in
> every detail because to attempt to find this out would interfere
> irreversibly with the unfolding of the world.
This assumes that the simulation must be quantum mechanical - but I think that would defeat the whole point of assuming a simulation. If the world can be simulated classically, then it can be monitored without interference.
My concern is much more a pronounced sceptical disbelief in the ability of sentient creatures at any order of magnitude to be able to control all the variables in a system they wish to impose. I think the basic condition is always going to be that we and they CANNOT. My usual expression of this, said in the context of working at a low level in a bureaucracy, is that in any given situation there are always more things which can occur than we want to occur, and usually there are more things which can occur than we can possibly know about. This is a long winded way of expressing 'Murphy's Law', but it is also a precise way of stating in plain-English how entropy manifests at the level of our work-a-day lives.
The thing is, setting up a simulation or emulation of something requires giving up some degree of control over the process. I mean that's what we have machines for isn't it,to do the work for us? And as far as I can see, despite what Bruno says, the numbers have got to BE somewhere. So the cosmic Boffins have got to have systems which are at least to some degree autonomous. [As I write this it seems to me I am cutting at the root of Bishop Berkeley's concept of being in the mind of God, or some such.] In fact considering the scale of what is being contemplated I would assume that at least some parts of the system would be interacting in recursive self-referential ways that guaranteed unpredictability. And if it is unpredictable then you are not controlling it; it is simply happening, and it is non-QM randomness.
I can see I have rambled on here a bit too much, but I have to say I think the issue of testing to see if what you predicted is really happening, must involve some interference in the simulation process itself, either that or the measurement is estimation with significant error margins.
I also think there is a strong argument from ethics that we are NOT in a simulation and furthermore that that sort of thing just doesn't happen. My argument is very presumptuous of course but, what the heck, if there IS a conspiracy of ET, pan-dimensional experimenters out there somewhere tweaking their coding to make our world ever more 'realistic', well they NOW have a moral duty to show themselves and give account for what they have done. Why? Because if they are smart enough to do such a thing then they are also smart enough to realise that they are causing avoidable harm and suffering to people here on Earth and this has been going on for a long time. [and it's gotta stop!]
If they don't show themselves and give account then they are just a bunch of moral wimps who do not deserve our respect, let alone adoration. This will be true even only if there is only The One. It is the question that has to be directed at all those who wield power: If you are so smart, why aren't you kind?
It's like Terry Pratchett says: There is only one sin, and that is to treat another person like a thing.
Brent Meeker wrote:
<<snipped>>Mark Peaty wrote:
Bruno Marchal
Le 01-mars-07, à 17:14, Mark Peaty a écrit :
>
>
> MP: .....
> > That is one thing. Another thing is that no entity or set of entities
> > could know if their 'simulation' attempt was doing what they wanted
> in
> > every detail because to attempt to find this out would interfere
> > irreversibly with the unfolding of the world.
I agree.
>
> Brent:
> This assumes that the simulation must be quantum mechanical - but I
> think that would defeat the whole point of assuming a simulation. If
> the world can be simulated classically, then it can be monitored
> without interference.
I disagree, or I agree. The multi-words, or multi-computations, can be
simulated classically. Then the interference between world/computations
appears from the fact that we are ourselves in the simulations, and
that we cannot know in which computational histories we are, and that
we suffer from unavoidable self-limitations.
>
> MP: well actually I wasn't thinking about QM at all; I guess most of
> my thinking is 'classical' although I realise of course that QM
> principles impose minimum sizes for basic components of all
> information processing systems.
>
> My concern is much more a pronounced sceptical disbelief in the
> ability of sentient creatures at any order of magnitude to be able to
> control all the variables in a system they wish to impose.
I agree.
> I think the basic condition is always going to be that we and they
> CANNOT. My usual expression of this, said in the context of working at
> a low level in a bureaucracy, is that in any given situation there are
> always more things which can occur than we want to occur, and usually
> there are more things which can occur than we can possibly know about.
> This is a long winded way of expressing 'Murphy's Law', but it is also
> a precise way of stating in plain-English how entropy manifests at the
> level of our work-a-day lives.
Yes. And a reading of Godel's second incompleteness theorem is exactly
that "Murphy law": Shit happens of may happen" (is it english?).
Well modally: Bf v DBf, i.e. the false is provable or it is consistent
that the false my be provable. We are insane or, if we are sane, we may
well loose sanity.
>
> The thing is, setting up a simulation or emulation of something
> requires giving up some degree of control over the process.
Yes, and that is why, in the spirit of this list, we never consider the
problem of emulating something, which is indeed near the impossible,
but we simulate everything. With comp, there is a notion of
"everything" completely captured by Church thesis. If comp is true,
although you cannot and will never been able to emulate a particular
individual and, at the same time, knowing that your emulation is
correct, you can trivially emulate all individuals, by running the
Universal Dovetailer, for example.
> I mean that's what we have machines for isn't it,to do the work for
> us?
Err... locally yes, but most machine introduced in this list are run
for theoretical purpose only.
> And as far as I can see, despite what Bruno says, the numbers have got
> to BE somewhere.
I think you are doing a category error. A particle can be somewhere
(and even this is only relative to some other particles). I don't see
at all why a number should be somewhere, except when the number
manifests itself to you in some context, but even here I would take
such localization as not being entirely serious. If your bank account
is empty, saying zero is in your bank would only be a way to speak.
Numbers are not the type of entity capable of being somewhere. You will
never say: guess who I met in Tokyo last week, the number 666!
> So the cosmic Boffins have got to have systems which are at least to
> some degree autonomous. [As I write this it seems to me I am cutting
> at the root of Bishop Berkeley's concept of being in the mind of God,
> or some such.] In fact considering the scale of what is being
> contemplated I would assume that at least some parts of the system
> would be interacting in recursive self-referential ways that
> guaranteed unpredictability. And if it is unpredictable then you are
> not controlling it; it is simply happening, and it is non-QM
> randomness.
I agree. I think it is a fundamental point. But we have to distinguish
between
1) simulating everything (easy with comp, in Platonia (by which I mean
with no bounded time nor bounded space or memory).
2) simulating a thing (and not necessarily knowing it): possible, by
chance.
3) simulating a thing and knowing it (most of the time impossible with
comp)
>
> I can see I have rambled on here a bit too much, but I have to say I
> think the issue of testing to see if what you predicted is really
> happening, must involve some interference in the simulation process
> itself, either that or the measurement is estimation with significant
> error margins.
I think so. In a nutshell, this is how I try to extract physics
(interference and non classical logic) from comp (classical
truth/logic).
>
>
> I also think there is a strong argument from ethics that we are NOT
> in a simulation and furthermore that that sort of thing just doesn't
> happen. My argument is very presumptuous of course but, what the heck,
> if there IS a conspiracy of ET, pan-dimensional experimenters out
> there somewhere tweaking their coding to make our world ever more
> 'realistic', well they NOW have a moral duty to show themselves and
> give account for what they have done. Why? Because if they are smart
> enough to do such a thing then they are also smart enough to realise
> that they are causing avoidable harm and suffering to people here on
> Earth and this has been going on for a long time. [and it's gotta
> stop!]
Most probably we are not in *such* a simulation, desired by other
person-being. If we are in such a simulation then we can know it, soon
or late. But with comp, we are in a natural simulation handled by the
usual (but very rich) relation among numbers. Like in Plotinus, the
ultimate simulator is not a thinking person.
>
> If they don't show themselves and give account then they are just a
> bunch of moral wimps who do not deserve our respect, let alone
> adoration. This will be true even only if there is only The One. It
> is the question that has to be directed at all those who wield power:
> If you are so smart, why aren't you kind?
There is no sense to say the One is smart or whatever quality you want
attribute to It/Him/her.
True, Plotinus and Plato call it "Good", but it means only that it acts
as a universal attractor for all soul.
>
> It's like Terry Pratchett says: There is only one sin, and that is to
> treat another person like a thing.
I agree completely, as I have already told you. But this is a reason
for appreciating comp, if only to understand (either intuitively
through thought experiments, or formally by listening to a
self-observing universal machine) why most machine are lead to the
distinction between third-person notions and first person notions. Of
course the person that you describe as not being a thing is the *first*
person. The one who can have pleasure and pain. Even Peano Arithmetic
can prove that a first person is not a thing.
Regards,
Bruno
Danny Mayes
“I've no idea why we might be being simulated if we are being simulated. It is actually very arrogant to assume that we are somehow the centre of the simulation at all, like bacteria in my gut assuming that the universe, the solar sysstem, humans were made for their benefit. “
Stathis Papaioannou
I have a problem with the very premise of asking why we are being simulated. Having been a member of this list for years, I have seen objections to the simulation argument raised repeatedly that are along the lines of “it is presumptuous to assume anyone would want to simulate us,” or “it is entirely speculative and not based in science”, etc. I have also seen a fair amount of discussion about how the simulation could be done.
To me, the logical chain is straightforward. If you accept a MWI interpretation or some other ensemble theory, then everything that can happen does happen. There is maybe a little wiggle room here, as perhaps you can have a MWI with an enormous number of universes versus and infinite number, depending on the nature of the underlying implementation, but as I understand it from earlier discussions and from my reading, most interpret MWI as requiring an actual infinity.
Now, after you have the MWI as the underlying foundation, there is really only one additional question that needs to be answered. Is there something fundamentally primitively “physical” and non-reproducible about my existence that would forever prohibit any attempt at reproduction? When I say “my existence” you have to include two possibilities. First, if you want to hold onto the “primitive physical” viewpoint you have to assume that there is something about the nature of our apparent reality in the third person that is simply not capable of emulation or simulation. Second, you ALSO have to assume there is something about our first person experience that is also not capable of emulation or simulation. This is where the “primitive physical” proponents lose me. I have thought about this a great deal, and just can’t figure out why I should assume there is something so special about my experiences, memories, and thought process that it under no circumstances could ever be capable of reproduction anywhere else in existence (other than the “naturally” occurring copies of myself in other parts of the multiverse, which are of course under this line of thinking occurring at a “primitive physical” level).
I am an attorney, so I guess I look at this at a little different perspective than most on here with science related backgrounds. I think once you get to a certain level, whether it be with MWI, or string theory or any other concept that can not be directly tested or observed, science loses its ability to take you further and you have to look into other areas such as logic and philosophy to finish the journey. However, there is a circumstantial case to be made for things even beyond strict science. For instance, I believe the circumstantial case for our universe being emulable or simulable is strong given what we know about how our universe works so far. The reasons for this have probably been discussed around here extensively, for instance the close relationship between math and physics, and our ability to describe the things we observe in mathematical terms.
To my way of thinking, the opponents to a simulation viewpoint are basically left arguing a concept that there is something “magical” or “spiritual” about human thought. That it is a supernatural function that is forever beyond the realm of science. Either that or they do not accept an ensemble theory. I could not disagree more with your statement that it is “arrogant to assume that we are somehow the center of the simulation.” On the contrary, what is arrogant is to assume that in a universe in which it is possible to simulate environments and universes (and this we know, just check out a Playstation 3 game I will say only partially tongue in cheek), is that we occupy a special location at the very top (or bottom depending on how you look at it) of this hierarchy of natural and artificial creations.
I think one thing that hangs a lot of people up on this concept is the idea that somewhere there IS a primitive, physical universe, and that we are just a digital simulation being run in that “more real” universe. This is NOT necessary nor is it part of my thinking on the subject. Maybe there is some “more real” or “primitive physical” reality out there that is simulating our entire quantum mechanical multiverse, but this is entirely speculative and presumably beyond the realm of any potential scientific discussion. When I refer to our being simulated, I am assuming the simulation is occurring in every way that is logically and physically possible in the multiverse, just as every other part of the multiverse is being likewise simulated in every way that is logically and physically possible in some other part. This is required, in fact is logically necessary if you assume it is capable of simulation.
That is as far as I think logic can take us. All the different theoretical ways that we can be emulated or simulated or of course interesting discussion. Why some intelligent beings in some other part of the multiverse may want to simulate or emulate our part of the multiverse is interesting as well, but is entirely unrelated to the logic of whether the entire entity is at least in part a simulation as set forth above.
Danny Mayes
Jason
> Why some intelligent beings in some other part of the
> multiverse may want to simulate or emulate our part of the multiverse is
> interesting as well, but is entirely unrelated to the logic of whether the
> entire entity is at least in part a simulation as set forth above.
>
> Danny Mayes
I think such simulation will be the ultimate goal of technology for
any intelligent and curious species. Simulation is the ultimate form
of exploration as it allows connections to be made between otherwise
unreachable universes. If every possible universe exists and each is
non-interacting, the only way to "explore" the other possibilities for
existance would be simulation. Any universes where a Turing machine
can be built can discover all Turing emulable universes. New
universes are not being created when a simulation is conducted, rather
a connection is made to a possible existance which has always been
there.
Douglas Jones wrote a very interesting hypothetical conversation
between a human and a highly advanced alien who lives in "cyberspace"
where not only can any imaginable environment or universebe be
simulated, but all beings like him had thier minds uploaded and are
also simulated. It is available at http://www.station1.net/douglasjones/aconvers.htm
and is well worth the read. Mind uploading and simulation I think
would be desirable to any intelligent and sufficently advanced race.
It offers unlimited freedom, immortality (or at least greatly extended
existance), and the ability to participate in fully immersive "game
worlds" which are subjectively indistingushable from any other
reality.
I believe there may even be a statistical argument for our existance
in such a "game world" now. Consider that in human history, about 60
billion humans have ever lived. If humanity reaches a technological
singularity in the near future, and the majority of the human race
uploaded their minds into computers, it would only take each person on
average playing 10 lifetimes (600-700 years) worth of these immersive
games before the bulk of human experience has been simulated as
opposed to physical. Considering such a civilization could last many
billions of years if not longer, the simulated human experiences would
greatly outweigh the physics-based ones.
Jason
Mark Peaty
very clever and thoughtful person.
One interesting thing about "A Conversation" [and I didn't read all of
it because it is LONG as the author warns us] is how it balances the
extremes of optimism and pessimism. The pessimism is expressed in Bob's
hints and descriptions of the ugliness that people can create in
their/our treatment of each other. The optimism is in the infinity of
potential of the 'cyberspace' where Bob /actually/ lives.
As I said I didn't read all of it, but dipped in and out, may be read
30% of it. My complaint about it, for want of a better word, is that it
does not seem to deal with entropy or the distinction between digital
versus analogue universes, or indeed a patentable design for an
interface. Bob' one-way 'Door' is of course a read-and-destroy
teleporter station, and therefore a form of suicide machine; cyberspace
is the 'promised land', the good news that comes after the bad news.
Overall it makes quite happy reading, though I really do think Douglas
Jones has paid far too much attention to the claims of people who say
they have been abducted by Aliens. I personally have only experienced
the 'paralysis' that accompanies night terrors a few times and I chanced
to wake up each time within 20 or 30 seconds of the onset of the
experience. I think I was very fortunate in that respect because at the
time, about 30 years ago, I was much more 'open minded' than I am now
and could well have ended up believing a complete load of old cobblers
that might have been very hard to escape.
I'll say no more to that because it is off topic
On-topic however, is my assertion that >> the human universe is always
potentially infinite, so long as it exists and we believe it to be so <<.
In bygone eras people were confined to saying things like: "Where
there's life, there's hope!". That is still true, and appropriate for
many circumstances but it is a bit low-tech for the modern era. The
potential infinity of the human universe is based on our subjective
ability to imagine things being other than they are, and on our
objective ability to change the world around us. The first involves
simulation within the mind, the second involves implementation of the
results of mental simulation. And of course these processes are
potentially recursive to an extent limited ultimately by our
intelligence, loosely speaking, and our desire to maximise the survival
prospects of our descendants and their contemporaries.
I don't think it is 'moralising' to point out that every thing we do has
an opportunity cost, including speculation concerning simulations and
replications of universes.
Regards
Mark Peaty CDES
http://www.arach.net.au/~mpeaty/
Stathis Papaioannou
"I've no idea why we might be being simulated if we are being simulated. It is actually very arrogant to assume that we are somehow the centre of the simulation at all, like bacteria in my gut assuming that the universe, the solar sysstem, humans were made for their benefit. "
Stathis Papaioannou
I have a problem with the very premise of asking why we are being simulated. Having been a member of this list for years, I have seen objections to the simulation argument raised repeatedly that are along the lines of "it is presumptuous to assume anyone would want to simulate us," or "it is entirely speculative and not based in science", etc. I have also seen a fair amount of discussion about how the simulation could be done.
To me, the logical chain is straightforward. If you accept a MWI interpretation or some other ensemble theory, then everything that can happen does happen. There is maybe a little wiggle room here, as perhaps you can have a MWI with an enormous number of universes versus and infinite number, depending on the nature of the underlying implementation, but as I understand it from earlier discussions and from my reading, most interpret MWI as requiring an actual infinity.
Now, after you have the MWI as the underlying foundation, there is really only one additional question that needs to be answered. Is there something fundamentally primitively "physical" and non-reproducible about my existence that would forever prohibit any attempt at reproduction? When I say "my existence" you have to include two possibilities. First, if you want to hold onto the "primitive physical" viewpoint you have to assume that there is something about the nature of our apparent reality in the third person that is simply not capable of emulation or simulation. Second, you ALSO have to assume there is something about our first person experience that is also not capable of emulation or simulation. This is where the "primitive physical" proponents lose me. I have thought about this a great deal, and just can't figure out why I should assume there is something so special about my experiences, memories, and thought process that it under no circumstances could ever be capable of reproduction anywhere else in existence (other than the "naturally" occurring copies of myself in other parts of the multiverse, which are of course under this line of thinking occurring at a "primitive physical" level).
I am an attorney, so I guess I look at this at a little different perspective than most on here with science related backgrounds. I think once you get to a certain level, whether it be with MWI, or string theory or any other concept that can not be directly tested or observed, science loses its ability to take you further and you have to look into other areas such as logic and philosophy to finish the journey. However, there is a circumstantial case to be made for things even beyond strict science. For instance, I believe the circumstantial case for our universe being emulable or simulable is strong given what we know about how our universe works so far. The reasons for this have probably been discussed around here extensively, for instance the close relationship between math and physics, and our ability to describe the things we observe in mathematical terms.
To my way of thinking, the opponents to a simulation viewpoint are basically left arguing a concept that there is something "magical" or "spiritual" about human thought. That it is a supernatural function that is forever beyond the realm of science. Either that or they do not accept an ensemble theory. I could not disagree more with your statement that it is "arrogant to assume that we are somehow the center of the simulation." On the contrary, what is arrogant is to assume that in a universe in which it is possible to simulate environments and universes (and this we know, just check out a Playstation 3 game I will say only partially tongue in cheek), is that we occupy a special location at the very top (or bottom depending on how you look at it) of this hierarchy of natural and artificial creations.
I think one thing that hangs a lot of people up on this concept is the idea that somewhere there IS a primitive, physical universe, and that we are just a digital simulation being run in that "more real" universe. This is NOT necessary nor is it part of my thinking on the subject. Maybe there is some "more real" or "primitive physical" reality out there that is simulating our entire quantum mechanical multiverse, but this is entirely speculative and presumably beyond the realm of any potential scientific discussion. When I refer to our being simulated, I am assuming the simulation is occurring in every way that is logically and physically possible in the multiverse, just as every other part of the multiverse is being likewise simulated in every way that is logically and physically possible in some other part. This is required, in fact is logically necessary if you assume it is capable of simulation.
That is as far as I think logic can take us. All the different theoretical ways that we can be emulated or simulated or of course interesting discussion. Why some intelligent beings in some other part of the multiverse may want to simulate or emulate our part of the multiverse is interesting as well, but is entirely unrelated to the logic of whether the entire entity is at least in part a simulation as set forth above.
Mohsen Ravanbakhsh
When we're talking about a machine with an infinite power of computation, we're considering a TM which has a countable number of states, even if it's running an undecidable problem to produce the infinite possible outputs and even we're considering time to be infinitely compressed to allow for the infinity of the power of our machine, at the end the possible states of a TM is Countably infinite.
But as one might notice we have some continuous and therefore Uncountable parameters in our universe, like the measures of distance which are not reducible to countable ones even considering the concept of precision. They are naturally Uncountable.
Now the question is: can that kind of infinitely powerful machine simulate this infinite reality?
Am I missing a point?
--
Mohsen Ravanbakhsh,
Mark Peaty
I think it is a very good question, and succinctly put.
I have been trying to ask the same question and get a plain-English
answer, but without success. Of course, I could be missing 'the point'
too, and it wouldn't be the first time by a long shot. :-)
If there was simply nothing, utterly and absolutely nothing, well that
would be the end of it: 'No problemas!' as the cool dudes say. But there
seems to be something, because I seem to be here, at the moment anyway,
and I have this distinct belief that I was here yesterday living in this
same house with all these recalcitrantly individualistic people who all
play along with a story about being my wife and children. Appeals to
solipsism degenerate into incoherent babbling; I really am here, even
though my grasp of the facts about my existence gets shaken loose every
so often. And you are here too, except you are over there. In short
there IS a universe and it seems to be remarkably self-consistent.
I, like you, am confronted by the manifest existence of an objective
reality. Being educated and impressed by the successes of the
application of scientific method we are quite well equipped to accept
certain problematic statements about the parts of the world we normally
take for granted as 'real'. We have learned that the *appearances* of
solidity, power, enduring nature, and so forth, which we experience as
*qualities* of those things, are not the full story; that in fact the
'*true* nature of things is that if you try and find absolute objective
boundaries to things you can't and if you try to make any other kind of
measurement, you have to make do with an approximation. Indeed, the more
you wish to precisely specify anything about the location or motion of
anything then the more you must accept a complex statistical description
about the rest of its characteristics.
Well and good; normally we don't have to worry about this too much. It
is only when we start persistently asking *How does it all work?* that
the seemingly intractable problems begin. And for each of us there is
some kind of recursive process: we read and interact with others
[indeed some lucky people can apparently just wander into the next room
and straight away *talk* on the topic with someone who is interested!],
and then we cogitate and imagine things and some of you scribble arcane
arithmetic and run mathematical 'what-ifs' on computers; finally we
reach some kind of internal stability of viewpoint that allows a
reassessment of things previously held to be clear, or problematic
perhaps. But after some time, doubt sets in, we think something far
enough through and see a problem or, more likely, we read of some new
viewpoint which challenges what we believe and we feel we must take it
seriously because of its apparent validity, consistency, etc, or it is
presented by someone we respect. Either way we have to work to either
assimilate it or uncover valid reasons for rejecting it.
The mathematicians who contribute here seemingly have no problems with a
totally 'insubstantial' existence of numbers. Unlike me who has
*ultimate* problems wrapping my head around the idea. I have not yet
succeeded. You asked about 'assumptions' in you 'Joining' thread, but
here by definition the only one is the existence of Many Worlds, which
is hugely problematic because nobody really knows what it means. In my
case it is obvious why, but in the case of those who *espouse* the
Many-Worlds hypothesis, I have absolutely know idea how they can account
for the purely logical - and therefore mathematically necessary, yes? -
consequence of the problem you have so succinctly put. As I reason it,
this 'continuous' aspect of location, even if it is only 'virtual'
guarantees that the Many Worlds are always proliferating at a rate which
must effectively be an infinity times an infinity of infinities. [I fear
I might have underestimated the speed there, but as I say, my maths is
not all that good!] In other words it seems to make no sense at all!
Why? [Grin!] well because *my* world seems to be just one story. What
keeps it together? It can't be any inherent smartness on my part! [Grin
again; no false modesty there mate!] So *IT*, what I call 'The Great
IT', is just doing IT'S thing.
Nobody here has yet explained in plain-English why we have entropy. Oh
well, surely, in the Many Worlds, that's just one of the universes that
can happen! Except that, for plain-English reasons stated above, there
are *and always have been* infinity x infinity x infinity of entropic
universes.
It doesn't make sense. Call me a heretic if you like, but I will 'stick
to my guns' here: If it can't be put into plain-English then it probably
isn't true!
:-)
Regards
Mark Peaty CDES
http://www.arach.net.au/~mpeaty/
Bruno Marchal
Le 05-mars-07, à 15:03, Mark Peaty a écrit :
> Nobody here has yet explained in plain-English why we have entropy. Oh
> well, surely, in the Many Worlds, that's just one of the universes that
> can happen!
Not really. That would make the comp hyp or the everything idea
trivial, and both the "everything hyp" and the "comp hyp" would loose
any explicative power. (It *is* the problem with Schmidhuber's comp,
*and* with Tegmark's form of mathematicalism: see older posts for
that).
> Except that, for plain-English reasons stated above, there
> are *and always have been* infinity x infinity x infinity of entropic
> universes.
>
> It doesn't make sense. Call me a heretic if you like, but I will
> 'stick
> to my guns' here: If it can't be put into plain-English then it
> probably
> isn't true!
I will try. I will, by the same token, answer Mohsen question here:
Mohsen:
> I don't know if in the hypothesis of simulation, the conflict of
> Countable and Uncountable has been considered.
1) I assume the comp hyp, if only for the sake of the reasoning. The
comp hyp is NOT the hypothesis of simulation, but it is the hypothesis
that we are in principle self-simulable by a digital machine.
2) Then we have to distinguish the first person points of view (1-pov)
from third person points of view (3-pov), and eventually we will have
to distinguish all Plotinus' hypostases. With comp, we are duplicable.
I can be read and cut (copy) in Brussels, and be "pasted" in Washington
and Moscow simultaneously. This gives a simple example where:
a) from the third point of view, there is no indeterminacy. An external
(3-pov) observer can predict Bruno will be in Washington AND in Moscow.
b) from a first person point of view, there is an indeterminacy, I will
feel myself in washington OR in Moscow, not in the two places at once.
3) Whatever means I use to quantify the first person indeterminacy, the
result will not depend on possible large delays between the
reconstitutions, nor of the virtual/material/purely-mathematical
character of the reconstitution.
4) There exist a universal dovetailer (consequence of Church thesis,
but we could drop Church thesis and define comp in term of turing
machine instead).
5) Never underestimate the dumbness of the universal dovetailer: not
only it generates all computational histories, but it generates them
all infinitely often, + all variations, + all "real" oracles (and those
oracles are uncountable).
6) this means that if I take the comp hyp seriously, then, to predict
the results of any experiment/experience, I have to "localize" all the
infinitely many instantiations of my current state in the UD, look at
the uncountable comp histories going through that states, and compute
the statistics bearing on all consistent first person
self-continuation.
7) A naive reading of this leads to predict white rabbits (indeed the
lewis Carroll one) and perhaps white noise, that is too much entropy
... This leads to a cheap refutation of comp, ...
8) ... except that the math shows this is a bit too cheap. Now if comp
is correct, AND if the physical laws are (approximately) correct, then
we have to extract the physical laws
a) without assuming the existence of a physical universe,
b) from the comp statistics.
My (more technical) result is that computer science and mathematical
logics gives already clues that indeed we can recover the physical laws
from computer science, once we get the relevant description of the
different points of view.
In particular, for Mohsen's question, the conflict between countable
and uncountable appears to be an unavoidable conflict between first and
third person points of view. The first person is bound up to interact
with uncountable physical apparent reality.
But all self-referentially correct universal machine introspecting
herself can discover the unavoidability of that conflict, and somehow
"meta-solve" it, indeed by distinguishing explicitly those points of
view again. When she does this, she discover a more subtle tension
between recursively countable and non recursively countable. This
tension is creative and can be proposed as a beginning of explanation
of life and local neguentropy.
All this makes comp, and its related "theology" (theory of everything
including persons, say), empirically testable: derive the comp-physics
and compare with empirical nature.
Must go. Hope this helps, (see papers in my url for more, or just ask)
Bruno
Brent Meeker
I quite agree with you about Many Worlds - it's not even an hypothesis; it's a whole class of hypotheses. And I don't think numbers exist either in the way that I exist, though I'm open to defining different kinds of existence. But I think I can explain why we have entropy.
The short answer is that we have entropy for the same reason we have number and distance and duration and energy and temperature, etc. We invented them. They are variables in our model of the world. Usually in our model we, through ignorance or disinterest, only include a rough description of how things can be, the possible states we will consider significant. For example, we don't care where every molecule of air is in the room, just the density. So in such a model there are a lot of different possible states at the microscopic level that map into one state at the level of our model. If we assign a number to each macro state proportional to the logarithm of the number of micro states that map into it, then that number will be additive: if we put two different macro states together the number of micro states mapping into the sum state is the sum of those logs. Further, if we assume in our model that the system will occupy the microstates with equal probability of bei
ng in any one of them, this correctly predicts the equilibrium behavior of the system in terms of its macrostates. If we consider this logarithm, call it S, in the case of a system modeled in terms of it's internal energy, Q, and its temperature, T, we find that it satisfies an equation for small changes dS=dQ/T. This quantity, S, is called "the entropy". By extension the analogous quantity was called the entropy of a possible message by Shannon.
>Oh
> well, surely, in the Many Worlds, that's just one of the universes that
> can happen!
The problem is to get from "anything can happen" to "this is more probable than that".
>Except that, for plain-English reasons stated above, there
> are *and always have been* infinity x infinity x infinity of entropic
> universes.
"Entropic universes" doesn't convey anything to me. Our universe, because of its expansion, is very far from equilibrium: its entropy density is very small compared to its maximum possible value.
>
> It doesn't make sense. Call me a heretic if you like, but I will 'stick
> to my guns' here: If it can't be put into plain-English then it probably
> isn't true!
I commend to you the book "The Comprehensible Cosmos" by my friend Vic Stenger. It's pretty much in plain English, with equations confined to the appendices.
Brent Meeker
John Mikes
completely misunderstood so far. As i wrote to Brent, my vocabulary is not your
vocabulary and the meanings mix up. Simulation emerged to me as 'copying', while
you lit up the little lamp to consider it as 'forming a simulacron' (sort of), a way to
make - what I call - a "model" including those characteristics which we might find
relevant. Which is a way of examining our topic in ' certain' detailing.
Thanks, it is interesting.
John M
Russell Standish
>
> I will try. I will, by the same token, answer Mohsen question here:
>
>
>
>
> Mohsen:
> > I don't know if in the hypothesis of simulation, the conflict of
> > Countable and Uncountable has been considered.
>
>
...
>
> In particular, for Mohsen's question, the conflict between countable
> and uncountable appears to be an unavoidable conflict between first and
> third person points of view.
Bruno's answer is right, but not necessarily the easiest to
understand. A very simple way of putting it is to consider sampling a
random bitstream. Every time a bit is sampled, the Multiverse branches
with the observed bit being 0 or 1 depending on your branch. If you
were to continue for an infinite amount of time, each observer will
have observed a real number. However after any finite amount of time,
all the observers have are rational approximations to real numbers.
Just so in our real world. You can either think of each of us as
sampling multiple random bitstream, or alternatively weaving together
all of the data streaming into our senses into a single bitstream. Its
mathematically equivalent, of course. All of our physical measurements
are rational approximations, and are continually refined as we
continue our measurements.
Cheers
--
----------------------------------------------------------------------------
A/Prof Russell Standish Phone 0425 253119 (mobile)
Mathematics
UNSW SYDNEY 2052 hpc...@hpcoders.com.au
Australia http://www.hpcoders.com.au
----------------------------------------------------------------------------
Stathis Papaioannou
Bruno's answer is right, but not necessarily the easiest to
understand. A very simple way of putting it is to consider sampling a
random bitstream. Every time a bit is sampled, the Multiverse branches
with the observed bit being 0 or 1 depending on your branch. If you
were to continue for an infinite amount of time, each observer will
have observed a real number. However after any finite amount of time,
all the observers have are rational approximations to real numbers.
Russell Standish
Yes, of course.
Mohsen Ravanbakhsh
Thank you for welcoming me Mark,
I agree with you about the problem with the concept of entropy, but not all your points. Actually I like this hypothesis, and as Bruno put it we might be able to describe the Why question about physical laws, which is very interesting.
4) There exist a universal dovetailer (consequence of Church thesis,
but we could drop Church thesis and define comp in term of turing
machine instead).
5) Never underestimate the dumbness of the universal dovetailer: not
only it generates all computational histories, but it generates them
all infinitely often, + all variations, + all "real" oracles (and those
oracles are uncountable).
1.We are referring to one (actually an infinitely long sub-sequence of that) history of such universal dovetailer, as some state of our world.
2.Because that machine is a TM, a history has to be countable, regardless of compression or expansion of time to allow infinite power.
3.So we're referring to some state of our universe as a countable one.
4.A universal state is not countable.
Every time a bit is sampled, the Multiverse branches
with the observed bit being 0 or 1 depending on your branch. If you
were to continue for an infinite amount of time, each observer will
have observed a real number. However after any finite amount of time,
all the observers have are rational approximations to real numbers.
What you are saying just proves that we have uncountable number of universes.
--
Mohsen Ravanbakhsh,
Brent Meeker
All actual measurements yield rational values. Using real numbers in the equations of physics is probably merely a convenience (since calculus is easier than finite differences). There is no evidence that defining an instantaneous state requires uncountable information.
Brent Meeker
Mark Peaty
Thank you Bruno!
You and Russell between you have managed to strike some sparks of
illumination from the rocky inside of my skull. There is no beacon fire
to report but I start to get a glimmering of why you want to *assume*
comp and see where it leads.
It seems that self-reference and recursion are fundamental properties of
anything that is "interesting" in all this, which rather seems to be the
flavour of the new millennium.
Just in thinking superficially about the Many Worlds though, it seems to
pose a 'binding problem'. Now, I know that might sound like a leakage of
concept from objections to identity theory in brain and mind theory. But
what I am thinking about is this bit:
6) this means that if I take the comp hyp seriously, then, to predict
the results of any experiment/experience, I have to "localize" all the
infinitely many instantiations of my current state in the UD, look at
the uncountable comp histories going through that states, and compute
the statistics bearing on all consistent first person
self-continuation.
A human life must be a compilation of all these including the creation
of internal [synaptic change, etc] structure/record which endow the
ability to *be* the story. But when looking at this as a/n
[infinity^infinity] Many Worlds affair, none of the worlds could 'know'
that they are like or identical to others, surely? So I am puzzled. What
holds 'my lot' together? We seem always to be confronted by yet another
infinite regression.
******
A quick aside, hopefully not totally unrelated: Am I right that a valid
explanation of the zero point energy is that it is impossible *in
principle* to measure the state of something and therefore *we* must
acknowledge the indeterminacy and so must everything else which exists
because we are nothing special, except we think we know we are here, and
if we are bound by quantum indeterminacy, so is everything else [unless
it can come up with a good excuse!]?
[Perhaps this is more on Stathis's question to Russell: Is a real number
an infinite process?]
******
Regards
Mark Peaty CDES
http://www.arach.net.au/~mpeaty/
Stathis Papaioannou
A human life must be a compilation of all these including the creation
of internal [synaptic change, etc] structure/record which endow the
ability to *be* the story. But when looking at this as a/n
[infinity^infinity] Many Worlds affair, none of the worlds could 'know'
that they are like or identical to others, surely? So I am puzzled. What
holds 'my lot' together? We seem always to be confronted by yet another
infinite regression.
Brent Meeker
>
>
> On 3/6/07, *Mark Peaty* <mpe...@arach.net.au
>
>
> A human life must be a compilation of all these including the creation
> of internal [synaptic change, etc] structure/record which endow the
> ability to *be* the story. But when looking at this as a/n
> [infinity^infinity] Many Worlds affair, none of the worlds could 'know'
> that they are like or identical to others, surely? So I am puzzled.
> What
> holds 'my lot' together? We seem always to be confronted by yet another
> infinite regression.
>
>
> How do you know that you are the same person from moment to moment in
> ordinary life? The physical processes in your brain create psychological
> continuity; that is, you know you are the same person today as yesterday
> because you have the same sense of personal identity, the same memories,
> woke up in the same environment, and so on. It is necessary and
> sufficient for survival that these psychological factors are generated,
> but it doesn't matter how this is achieved.
How so? The Many Worlds idea seems to imply that you survive no matter what. The consequences of natural selection obtain only within worlds which are law-like - and we're back to the white rabbit problem.
Brent Meeker
Stathis Papaioannou
> How do you know that you are the same person from moment to moment in
> ordinary life? The physical processes in your brain create psychological
> continuity; that is, you know you are the same person today as yesterday
> because you have the same sense of personal identity, the same memories,
> woke up in the same environment, and so on. It is necessary and
> sufficient for survival that these psychological factors are generated,
> but it doesn't matter how this is achieved.
How so? The Many Worlds idea seems to imply that you survive no matter what. The consequences of natural selection obtain only within worlds which are law-like - and we're back to the white rabbit problem.
Russell Standish
Well there is a reason we don't observe them, due to observational
selection effects tied to Occam's razor. This is written up in my "Why
Occams Razor" paper. Nobody has shot down the argument yet, in spite
of it being around on this list since 1999, and in spite of it being
published since 2004.
Jesse Mazer
>
>Well there is a reason we don't observe them, due to observational
>selection effects tied to Occam's razor. This is written up in my "Why
>Occams Razor" paper. Nobody has shot down the argument yet, in spite
>of it being around on this list since 1999, and in spite of it being
>published since 2004.
The basic problem I have with this proposal is the starting assumption,
where you say that the "natural measure induced on the ensemble of bitstring
is the uniform one." This sort of assumption is made by a number of TOEs
including Schidhuber's, but it always seemed fairly arbitrary to me, not
much different in principle from assuming that the measure produced by the
laws of physics in our universe (which, under the MWI, will probably include
some instances of every possible finite computation in some branch or
another) should be taken as a starting point. I posted on this issue in one
of my first posts on this list:
Jesse
_________________________________________________________________
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Stathis Papaioannou
Russell Standish wrote:
>
>Well there is a reason we don't observe them, due to observational
>selection effects tied to Occam's razor. This is written up in my "Why
>Occams Razor" paper. Nobody has shot down the argument yet, in spite
>of it being around on this list since 1999, and in spite of it being
>published since 2004.
The basic problem I have with this proposal is the starting assumption,
where you say that the "natural measure induced on the ensemble of bitstring
is the uniform one." This sort of assumption is made by a number of TOEs
including Schidhuber's, but it always seemed fairly arbitrary to me, not
much different in principle from assuming that the measure produced by the
laws of physics in our universe (which, under the MWI, will probably include
some instances of every possible finite computation in some branch or
another) should be taken as a starting point. I posted on this issue in one
of my first posts on this list:
http://groups.google.com/group/everything-list/browse_thread/thread/0d5915764b7f3e08/fc56caf79ce58750?#fc56caf79ce58750
If a uniform measure leads to the world we see, isn't that empirical evidence that it is the correct one? A uniform measure, or no measure at all (which seems to me equivalent), isn't really as arbitrary as some specific measure from physics, which as you imply is what the whole everything idea is trying to avoid. Could the question in theory be settled by experiment, running the UD and counting the relative number of structures?
Stathis Papaioannou
Russell Standish
True, and this was the sense in which I adopted it for the
paper.
However, I think there is an even better argument. By interposing
another suitable onto function (f:{0,1}*->{0,1}* say) between the
observer and the ensemble of strings, one can make the ensemble of
bitstrings have any measure one likes.
So by composing the observer function O(x) with f(x), we can perform
the treatment for an arbitrary measure as though the we had an
observer O(f(x)) observing strings selected from a uniform measure.
In short terms, one can write "Without loss of generality, assume a
uniform measure over the strings".
Whichever way you cut it, structure is still in the eye of the
observer :)
Mohsen Ravanbakhsh
Mohsen Ravanbakhsh.
Russell Standish
\aleph_{\aleph_0}.
On the other hand, one set of cardinality 2^\aleph_0 appears to be big
enough to explain all of observed reality.
Maybe Tegmarkism is going too far...
On Wed, Mar 07, 2007 at 11:19:03AM +0330, Mohsen Ravanbakhsh wrote:
> *All actual measurements yield rational values. Using real numbers in the
> equations of physics is probably merely a convenience (since calculus is
> easier than finite differences). There is no evidence that defining an
> instantaneous state requires uncountable information.*
>
> What about the realizability of mathematical concepts. Real numbers are
> mathematical, so they should have a counterpart in real world. What ever
> that counterpart is, it's toils the problem of uncountability.
> But I think your answer is the best shot.
>
> Mohsen Ravanbakhsh.
>
> >
--
Mark Peaty
incredibly succinct 'bit stream' summary of universal-dovetailer
ontology. [Though only a vocational mathematician would seriously call
it 'very simple' even if it does have less than 1% of Bruno's word count
for his essay on the subject.] Having the two approaches to the problem
at hand has allowed me to get a bit of purchase on the beasty.
Thanks also to Stathis for that simple and lovely, 'obvious', question
from left-field. I am now convinced that, no matter what others might
say, each number is in fact a process. Bruno referred to some kind of
Platonia, some unspeakably not-anywhere place as the source of numbers
and other mathematical objects or relationships. That is all well and
good but as far as I can see - still - the numbers and other
mathematical objects that people use are words in the strictest sense.
They arise in human minds through inter-subjective induction, empathic
copying [mirror neurons], interaction with the world, etc. But they are
created anew in each brain that learns them, same as all other
constructs. Their fantastic power comes about because they reflect -
emulate and simulate - emergent properties of the rest of the universe.
That this happens so successfully in so many people leads me to infer
that the underlying principle organising the human mind, just as that
organising the Great IT, the Multiverse, what ever, is harmonic resonance.
**************
Meanwhile -
SP: 'How do you know that you are the same person from moment to moment
in ordinary life? The physical processes in your brain create
psychological continuity; that is, you know you are the same person
today as yesterday because you have the same sense of personal identity,
the same memories, woke up in the same environment, and so on. It is
necessary and sufficient for survival that these psychological factors
are generated, but it doesn't matter how this is achieved.'
MP: Yep! I am a story! I am not like a story, I *am* a story. It is *my*
story and I'm sticking to it, except when I find there are aspects of it
I don't like. The problem [or a problem] is that this does not take away
any of the intrinsic paradox of our experience. As I have said many
times our experience is what it is like to be the portrayal of self in
the world created within one's brain. The rendition in its details is
effectively *about* being a person in his/her world, moment by moment.
The experience we argue about, and other, possibly less benighted,
persons write poetry and songs about, is simply what it is like to be
this rendition. The primary practical paradox for each of us is that
unless this distinction is pointed out repeatedly, we mistake the
rendition, the story, for the world itself. We are doomed to live ever
like this. From the recesses of my dark corner it looks as if Bruno can
show us conclusively that this subjective-objective distinction is an
inherent feature of any kind of universe that we humans have any real
hope of understanding.
and as per the first part above, I think that the answer to the binding
question in each domain is harmonic resonance. As far as I can see it
accounts for why the pure gasses like to form molecular pairs; there
have been reports recently that our sense of smell relies on inter and
intra molecular vibrations as the fundamental [pun unintended] mechanism
for detection and recognition of minuscule amounts of thousands of
different airborne molecules; Steven Lehar has been banging his head
against the wall for many years trying to point out to people how
harmonic resonance can easily explain a huge range of Gestalt type
capabilities clearly effected within the brain; correlations of brain
wave frequencies have been discovered marking temporally related
activities of the hippocampus and cortical regions shown through MR
imaging to be involved in the creation or activation of memories. And
the list goes on.
NB: I hope that my imaginary destination in your speculation of possible
post mortem exploits for my erstwhile sceptical soul is not a
post-Freudian slip. I know that many of my contributions to this and
other lists have lacked the erudite succinctness of those with greater
talents; failure of concentration [AKA 'ADD'] has been a characteristic
of life for me, but I think that 'awaking' to the innards of a black
whole would do more than wonderfully concentrate the mind: concentration
itself would become the major problem even for a ghost! =-O
Regards
Mark Peaty CDES
http://www.arach.net.au/~mpeaty/
Stathis Papaioannou wrote:
>
>
> On 3/6/07, *Mark Peaty* <mpe...@arach.net.au
Stathis Papaioannou
NB: I hope that my imaginary destination in your speculation of possible
post mortem exploits for my erstwhile sceptical soul is not a
post-Freudian slip. I know that many of my contributions to this and
other lists have lacked the erudite succinctness of those with greater
talents; failure of concentration [AKA 'ADD'] has been a characteristic
of life for me, but I think that 'awaking' to the innards of a black
whole would do more than wonderfully concentrate the mind: concentration
itself would become the major problem even for a ghost! =-O
Stathis Papaioannou
Mark Peaty
SP:' You wouldn't necessarily be squashed if you were inside the event
MP: Two thoughts come to my suspicious mind.
1/ [Not far from the post-Freudian speculation :-] ... Attendance
within the event horizon of a common or garden galactic variety black
hole would seem to incorporate a one-way ticket *to* the singularity,
would it not?
2/ I once heard someone on the Australian Broadcasting Corporation's
Radio National Science Show [on every Saturday after the midday news]
describing our universe in these terms. His point was that whatever we
might think about what was 'beyond' the bounds of 'our' universe,
nothing from here can escape to 'there'. As I understand it this is in
line with Einstein's concept of the universe being closed in upon
itself, the key cause of which is gravity, the curvature of space-time.
MP: Going off at a tangent, I have a question which is quite possibly a
dumb question that just needs to be asked because it CAN be asked.
Preamble: The expansion of the universe, characterised by the Hubble
Constant I believe, is usually explained non-mathematically by analogy
with the stretching of the surface of a balloon as the balloon is
inflated. The balloon surface is stretched uniformly, pretty much, by
its having everywhere the same tensile strength and elasticity and by
the force which causes the deformation being applied equally all over
because it is the averaged effect of all the gas particles within the
contained volume. That much makes sense, and the overall effect is to
cause point locations on the surface of the balloon to recede from one
another at a rate which is proportional at any given moment to the
distance between the points, measured along the surface.
Question: Would it be mathematically equivalent, or significantly
different, to consider the measured change in size and in distances as
a uniform *contraction* of the metric, ie the measuring system, rather
than an expansion of the location, so to speak. In particular, why is it
not feasible to consider the Big Bang and subsequent Inflationary epoch
as being in effect a collapse?
Regards
Mark Peaty CDES
mpe...@arach.net.au
http://www.arach.net.au/~mpeaty/
Stathis Papaioannou wrote:
>
>
> On 3/8/07, *Mark Peaty* <mpe...@arach.net.au
John M
Stathis Papaioannou
MP: Two thoughts come to my suspicious mind.
1/ [Not far from the post-Freudian speculation :-] ... Attendance
within the event horizon of a common or garden galactic variety black
hole would seem to incorporate a one-way ticket *to* the singularity,
would it not?
Stathis Papaioannou
Stathis:your starting the argument: "IF" the M-W-I(dea) is valid, it it seems to imply"...which is a bit shaky (what if not?) - the "law-like" is a breakable compromise between confro nting arguments. Do I read some denigration of the White Rabbit? (coming from a wide interpretation of "all possible")
Now to the meat of it:have you ever tried to outline the 'mind' of the early hiominid to survive? Before Immanuel Kant and even the Mother Goddess? Maybe with some notion of the most advanced and best weaponry 'ever': the hand--ax? or the 'mind' of an amoeba?Just asking questions in extension of ourselves.
John Mikes
I would not go further than "according to what is said about them, they may
wash off whatever got into and turn into - sort of - a singularity".
Galaxies, whatever, fall into those hypothetical BHs and who knows how much
Dark Matter (the assumed), we just "don't know" - it all may be neatly stuffed
in and escape from the habitual description of the 'singularity' as an indiscernible
structural view, - or - as seemingly you assume: they homogenize (paste?)
it all into a - well - singularity-content.
Whoever KNOWS more about singularities, BHs, Dark Matter, should
speak up - please: NO assumptions ('it got to be's) or deductions of such!
John M
Quentin Anciaux
Singularity is just a name that means that the solutions of the equations
describing the BH gives infinity... It's what is a singularity. Does
the "infinity" is "real" (we must still be in accordance about what it means)
is another question, but accepting GR as a true approximation of reality,
singularity existence is a real question.
Quentin
Stathis Papaioannou
i ENVY YOU, guys, to "know" so much about BHs to speak of a singularity.
I would not go further than "according to what is said about them, they may
wash off whatever got into and turn into - sort of - a singularity".
Galaxies, whatever, fall into those hypothetical BHs and who knows how much
Dark Matter (the assumed), we just "don't know" - it all may be neatly stuffed
in and escape from the habitual description of the 'singularity' as an indiscernible
structural view, - or - as seemingly you assume: they homogenize (paste?)
it all into a - well - singularity-content.
Whoever KNOWS more about singularities, BHs, Dark Matter, should
speak up - please: NO assumptions ('it got to be's) or deductions of such!
Stathis Papaioannou
John M
Jesse Mazer
>
>Cher Quentin,
>let me paraphrase (big):
>
>so someone had an assumption: BH. OK, everybody has the right to fantasize.
>Especially if it sounds helpful.
Well, the basic assumption was more broad than that: it was that general
relativity is a trustworthy theory of gravity. There's plenty of evidence
that supports various predictions of GR which differ from Newtonian gravity,
like the precession of the perihelion of Mercury's orbit, the gravitational
lensing of light near stars and galaxies, and gravitational time dilation
which can be measured at different altitudes on Earth (and it also needs to
be taken into account when programming the clocks on board the orbiting GPS
satellites). One of GR's predictions is that a sufficiently large collapsing
star will form a black hole (another is that the universe must be either
expanding or contracting, which lead to the Big Bang theory once redshift
was observed). Black holes were theorized for a while, then in the last two
decades they found observational evidence for a large number of likely black
holes with telescopes.
Most physicists believe general relativity's predictions will cease to be
accurate at the "Planck scale" of very short distances and times and very
high energy densities, and that at these scales it will need to be replaced
by a quantum theory of gravity. So although they are fairly confident that
GR is correct about large collapsing stars forming a black hole with an
"event horizon" and a size proportional to its mass (given by the
'Swarzschild radius'), they think that the prediction of a singularity of
infinite density at the center could be wrong, and that we'll need a theory
of quantum gravity to understand what's really going on there.
Jesse
_________________________________________________________________
The average US Credit Score is 675. The cost to see yours: $0 by Experian.
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John Mikes
thanks for the cool and objective words.
I take it back (not what I said: I mean the topic) further. Our edifice of physical science
is a wonderful mental construct, balanced by applied math, all on quantities fitting the reduced models of historical observations from the hand-ax on. Explanations grew out from all consecutive levels of our epistemic enrichment and served as indisputable basis for later explanations (even if they 'corrected' them, like the more than a dozen entropies and still counting). Assumptions make good basis for thousands of level in consecutive build-up we still use 'atoms', 'molecules' 'gravity' 'electricity', 'photon' etc. etc. as our basis. Then comes your judgement that one theory in this building looks finer than another. The learned
(brainwashed) scientist-mind finds them as natural as fish the nonexistence of water. The huge amount of knowledge blocks any naive (elementary) scrutiny of the basics.
I do not argue with your learned examples; within the system matches are found especially quantitative ones, visualizing our select domain and scale-restrictions.
'Observational evidence' is a belief in our up-to-date instrumental readings explained INTO the theoretical faith as evidence. Wilson found the "background radiation" because he had readings they were fitable and he new about the idea of such possibility in view of the Big Bang (- assumption - as we believe it today in our present cosmology). Eric Lerner's book (90s?) presented some doubts (The Big Bang Never Was (title approximate) -) I added some more upon my feeble thinking. How many "ether"s and "phlogista" do we still have?
We got rid of "elan vitale" - but did we really?
I do not start a crusade against conventional science and understand the reluctance of the practitioners to accept the endangerment of their wisdom. Reductionist thinking (science) is the only one our mind is capable of exercising (mine included), but I feel it is time to take a breath and a wider view to elevate from the age-old concepts to the acceptance of something else, without paradoxes, givens, axioms, in interconnection of them all and ready for a change. Human science went through changes over the millennia, even fundamental ones at times, there are more to come. I remember the time when tachyon-observation was denied as false, because they seemed FTL and this was prohibited. Theory over observed. I do not claim that 'my views' are the call for a future, I did not invent them, just picked up changing views (not so few on this list) and opened my mind to let them in. Since I was not committed to the 'old' I had no problem. I allow myself to be wrong and argue cautiously:
you may be right, I may be wrong, but I have to see that in a view broader than the conventional physical teaching. I don't believe today my own 'macromolecules' I made and got patented, they are good within the old theory. I saw 'effects' and applied the 'wisdom' to explain them without scrutiny. They worked. Not perfectly, as all we have has flaws ( e.g. airplanes fall out from the sky, medicines fail, buildings collapse, etc.,) but we are very confident in our science. Well, I am not without scrutiny.
I love assumptions: they push forward our advancement. Just do not allow them to become facts and basis for many levels of consecutive conclusions without a grain of salt.
Your expressions ("Most physicists believe", "they are fairly confident", or: "general
relativity is a trustworthy theory of gravity" and I do not go into 'gravity'. nor into the words of curvature of spacetime) are carefully chosen. Religious people talk more straightforward in their religious argumentation.
Excuse my lengthy reply, I enjoyed your argument.
Regards
John M
Mark Peaty
SP: ' ... it could take a long time to get there ... '
MP: But is that according to the time frame of the laughing devil who
threw me in there and who remains safely out of reach of
acceleration-induced time dilation, or my wailing ghost which/who's mind
and sensoria will be ever more wonderfully concentrated on 'what it is
like to be' a piece of spaghetti, unable to see anything except *the
destination*?
Regards
Mark Peaty CDES
mpe...@arach.net.au
http://www.arach.net.au/~mpeaty/
Stathis Papaioannou wrote:
>
>
> On 3/9/07, *Mark Peaty* <mpe...@arach.net.au
Stathis Papaioannou
SP: ' ... it could take a long time to get there ... '
MP: But is that according to the time frame of the laughing devil who
threw me in there and who remains safely out of reach of
acceleration-induced time dilation, or my wailing ghost which/who's mind
and sensoria will be ever more wonderfully concentrated on 'what it is
like to be' a piece of spaghetti, unable to see anything except *the
destination*?
I'm not the best person on this list to answser, but I think the tidal forces as you pass the event horizon of a very massive black hole would not be enough to destroy you, since tidal forces are proportional to M/r^3 while the Schwarzschild radius is proportional to M. Tidal forces will increase as you approach the singularity, which is inevitable once you pass the event horizon, but the time for this to happen is proportional to M. This refers to your time frame: for the devil who threw you in, it would appear that you never reach the event horizon.
Stathis Papaioannou
Bruno Marchal
Le 10-mars-07, à 18:42, John M a écrit :
> I don't deny the usefulness of science (even if it is reductionist) ...
How could science be reductionist? Science is the art of making
hypotheses enough clear so as to make them doubtable and eventually
testable.
No scientist will ever say there is a primitive physical universe or an
ultimate God, or anything like that. All theories are hypothetical,
including "grandmother's one when asserting that the sun will rise
tomorrow. The roots of our confidence in such or such theories are
complex matter.
Don't confuse science with the human approximation of it. Something
quite interesting per se, also, but which develops itself.
Lobian approximations of it are also rich of surprise, about "oneself".
"Science" or better, the scientific attitude, invites us to listen to
what the machine can say and dream of, nowadays. How could such an
invitation be reductionist?
I would say science is modesty. It is what makes faith necessary and
possible.
With comp, when science or reason grows polynomially (in a trip from G
to G* for example), then faith "has to" grow super-exponentially.
Bruno
Stathis Papaioannou
John M
----- Original Message -----From: Bruno MarchalSent: Sunday, March 11, 2007 10:45 AMSubject: Re: Evidence for the simulation argument - and Thanks and a dumb question.
Le 10-mars-07, à 18:42, John M a écrit :
I don't deny the usefulness of science (even if it is reductionist) ...
How could science be reductionist? Science is the art of making hypotheses enough clear so as to make them doubtable and eventually testable.
My take on "reductionist" is to 'reduce' the observation to a boundary-enclosed "model" as our choice. It is a necessity for us, because we are not capable to encompass the totality and all its ramifications into our mind's work at once. Reduced (reductionist ) view is the way how humanity gathered our knowledge of the world. (Probably other animals do the same thing at their mind-level).What I see here - and thank you, Bruno, for it, - you are using a more advanced view of science than what I referred to as the conventional - historic, topically fragmented "sciences" of old. Where e.g. physics is based on the 'primitive' physical (material) worldview and biology is what Darwin visualized.Reductionist sciences established our technology. You use it, I use it. We just start to 'think' beyond it.
*
No scientist will ever say there is a primitive physical universe or an ultimate God, or anything like that. All theories are hypothetical, including "grandmother's one when asserting that the sun will rise tomorrow. The roots of our confidence in such or such theories are complex matter.
I wish we had more of "your" scientists. Academia as a general establishment is not so advanced yet.
Don't confuse science with the human approximation of it. Something quite interesting per se, also, but which develops itself.
Lobian approximations of it are also rich of surprise, about "oneself".
Now this is exactly what I mean. I would like to read a definition of 'science' as you formulate it. Then again: how many 'scientists' have ever heard of a Lobian m?We are living here (list) in a vacuum and I was talking non-vacuum.
*
"Science" or better, the scientific attitude, invites us to listen to what the machine can say and dream of, nowadays. How could such an invitation be reductionist?
Here we go again: is the 'machine' superhuman? does it tell us things beyond our comprehension? How? "We" (Loeb etc.) invented and outlined it and its functionality. How can it be beyond those limits?*
I would say science is modesty. It is what makes faith necessary and possible.
"Faith" in what? Not in 'hearsay', not in Alice-land, not in (really) reduced models of age-old worldviews. The 'supernatural' is a cop-out for the modesty to say:"I know not" .*
With comp, when science or reason grows polynomially (in a trip from G to G* for example), then faith "has to" grow super-exponentially.
I hope you have (Mark's) PLAIN ENGLISH TRANSLATION to that in non-mathematico lingo.
Bruno Marchal
Le 11-mars-07, à 17:56, Stathis Papaioannou a écrit :
> Reductionism means breaking something up into simpler parts to explain
> it. What's wrong with that?
Because, assuming comp, neither matter nor mind (including perception)
can be break up into simpler parts to be explained. That is what UDA is
all about. First person expection (both on mind and matter) are already
global notion relying on the whole UD*.
And empirical physics, currently quantum mechanics, confirms that
indeed, we cannot explain matter by breaking it into parts. That is
what "violation of bell's inequality" or more generally "quantum
information " is all about. This has been my first "confirmation of
comp by nature": non-locality is the easiest consequence of comp.
A good (and actually very deep) analogy is provided by the structure of
knots (see the table of knots:
http://www.math.utoronto.ca/~drorbn/KAtlas/Knots/index.html
A knot is closed in its mathematical definition (unlike shoe tangle).
You cannot break a knot in smaller parts, so that the whole structure
is explained by the parts. Knots, like many topological structure,
contains irreductible global information. The same for the notion of
computations (and indeed those notions have deep relationship, see the
following two impressive papers:
http://web.comlab.ox.ac.uk/oucl/work/samson.abramsky/tambook.pdf
http://arxiv.org/abs/quant-ph/0606114
I know that Derek Parfit call "comp" the reductionist view". this is a
very misleading use of vocabulary. Comp is the simplest destroyer of
any reductionist attempt to understand anything, not just humans.
Bruno
Stathis Papaioannou
Only if God issues everyone with immaterial souls at birth, so that reproducing the material or functional structure of the brain fails to reproduce consciousness, would I say that reductionism does not work... unless you add the soul as an element in the reduction.
Stathis Papaioannou
Brent Meeker
> /All actual measurements yield rational values. Using real numbers in
> calculus is easier than finite differences). There is no evidence that
>
> What about the realizability of mathematical concepts. Real numbers are
> mathematical, so they should have a counterpart in real world.
Why? "Mathematical" means nothing but not self-contradictory. Sherlock Holmes stories are mathematical. That doesn't mean Sherlock Holmes exists in some Platonic realm.
Brent Meeker
Mohsen Ravanbakhsh
Mohsen Ravanbakhsh,
Stathis Papaioannou
Not necessarily. If you draw a diagonal on a square on a computer screen, it will be made up of a discrete number of pixels despite what Pythagoras' theorem calculates. Irrational in the real world may just be an illusion.
Stathis Papaioannou
Bruno Marchal
Le 12-mars-07, à 12:37, Stathis Papaioannou a écrit :
> OK, but it seems that we are using "reductionism" differently.
Perhaps. I am not so sure.
> You could say that a hydrogen atom cannot be reduced to an electron +
> proton because it exhibits behaviour not exhibited in any of its
> components;
Nor by any juxtaposition of its components in case of some prior
entanglement. In that case I can expect some bits of information from
looking only the electron, and some bits from looking only the proton,
but an observation of the whole atom would makes those bits not
genuine. It is weird but the quantum facts confirms this QM prediction.
> or you could say that it can be reduced to an electron + proton
> because these two components appropriately juxtaposed are necessary
> and sufficient to give rise to the hydrogen atom.
In general this is not the case.
> And if the atom is just a part of UD*, well, that's just another, more
> impressive reduction.
But just comp, without the quantum, makes it implausible that an atom
can be individuated so much that it makes sense to say it is just a
part of the UD. And QM confirms this too. To compute the EXACT (all
decimal) position of an electron in an hydrogen atom, soon or later you
have to take into account of white rabbit path, where the electron
will, for going from position x to the position y you are computing,
follow the path x too earth, reacts locally and transforms itself into
a white rabbit running for the democrat election in the US, loose the
election and come back to y. Same with the UD, the object "atom of
hydrogen" is only defined relatively to an infinity of first person
plural expectation dependong on the WHOLE UD*. There is no sense to say
an atom is part of the UD. It is "part" of the necessary discourse of
self-observing machine. Recall comp makes physics branch of machine's
psychology/theology.
> As for knots, can't any particular physical knot be described in a 3D
> coordinate system? This is similar to describing a particular physical
> circle or triangle.
Not really because the knot is a topological object. Its identity is
defined by the class of equivalence for some topological transformation
from your 3D description. If you put the knot in your pocket so that it
changes its 3D shape (but is not broken) then it conserve its knot
identity which is only locally equivalent with the 3D shape. To see the
global equivalence will be tricky, and there is no algorithm telling
for sure you can identify a knot from a 3D description.
People can look here for a cute knot table:
http://www.math.utoronto.ca/~drorbn/KAtlas/Knots/index.html
>
> Only if God issues everyone with immaterial souls at birth, so that
> reproducing the material or functional structure of the brain fails to
> reproduce consciousness, would I say that reductionism does not
> work...
OK, but then you identify reductionism with comp. I identify
reductionism with the idea that something is entirely explainable in
some finitary theory. From this I can explain that comp can be used to
refute all reductionist theory of both matter and mind (and their
relation).
I am aware it is a subtle point, but if you understand the Universal
Dovetailer Argument (UDA) from step 1 to 8, in the version:
http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHAL.htm
then you should, I think, understand that the idea that there is
anything made of something, although locally true and useful for many
practical purpose, is just wrong, globally. Even with just comp, but
this is also entailed by the quantum empirical facts (even with the
many-worlds view: if not they would not interfere). People can ask if
they are not yet convinced by this. I have refer this by saying that if
comp is true, physics is a branch of bio-psycho-theo-logy. matter
emerges (logico-arithmetically, not "temporally") from mind and number.
You can attach a mind to a body, like children does with dolls, but you
cannot attach a body to a mind, you can and must attach an infinity of
"relative bodies" to a mind. "relative bodies" are only defined by
infinity of arithmetical relationships, not by sub-bodies.
(I know this contradicts Aristotle notion of Matter, but see Plotinus
for old platonist reasons, a priori independent of comp and QM, to
already suspect that Aristotle was wrong).
> unless you add the soul as an element in the reduction.
Of course, but *that* would make any explanation a reductionism.
Bruno
Mohsen Ravanbakhsh
Mohsen Ravanbakhsh.
Mark Peaty
Brent: 'doesn't mean Sherlock Holmes exists in some Platonic
realm ...'
MP: For those who occasionally like a clever and entertaining
read unencumbered by deep social comment can I recommend the
adventures of Ms Thursday Next in 'The Eyre Affair' a novel by
Jasper FForde, and in the sequels, the names of which I have
forgotten at the moment. The author shows what could happen if
Platonia started really getting out of hand.
Regards
Mark Peaty CDES
http://www.arach.net.au/~mpeaty/
Brent Meeker
> /Why? "Mathematical" means nothing but not self-contradictory.
> Holmes exists in some Platonic realm.
>
> Brent,
>
> What do you mean by that?
Mathematics is just assuming some axioms and rules of inference and then proving theorems that follow from those. There's no restriction except that it should be consistent, i.e. not every statement should be a theorem. So you can regard a game of chess as a mathematical theorem or even a Sherlock Holmes story. You may suppose these things "exist" in some sense, but clearly they don't exist in the same sense as your computer.
>I do not get your point.
> Anyway I do not insist that it should be realizable. But I have examples
> in which we need them!
> Consider the use of Pythagoras theorem in nature. There are many cases
> in which the distance between two points should be irrational.
Only under the assumption that space has a Euclidean metric - which is begging the question. From the operational viewpoint, all measurements yield integers (in some units). Real numbers are introduced in the Platonic realm to insure that some integer equations have solutions. Similarly imaginary numbers are introduced to complete the algebra. They are all our inventions - except some people think the integers are not.
Brent Meeker
Brent Meeker
>
>
> Le 12-mars-07, à 12:37, Stathis Papaioannou a écrit :
>
>
>
> OK, but it seems that we are using "reductionism" differently.
>
>
>
>
>
> Perhaps. I am not so sure.
>
>
> You could say that a hydrogen atom cannot be reduced to an electron
> + proton because it exhibits behaviour not exhibited in any of its
> components;
>
>
>
> Nor by any juxtaposition of its components in case of some prior
> entanglement. In that case I can expect some bits of information from
> looking only the electron, and some bits from looking only the proton,
> but an observation of the whole atom would makes those bits not genuine.
> It is weird but the quantum facts confirms this QM prediction.
Not only that, but QM admits of negative information, so some of the information you get from observing the parts may be cancelled out in a more comprehensive measurement.
>
>
>
>
>
> or you could say that it can be reduced to an electron + proton
> because these two components appropriately juxtaposed are necessary
> and sufficient to give rise to the hydrogen atom.
>
>
> In general this is not the case.
>
>
>
> And if the atom is just a part of UD*, well, that's just another,
> more impressive reduction.
>
>
>
> But just comp, without the quantum, makes it implausible that an atom
> can be individuated so much that it makes sense to say it is just a part
> of the UD. And QM confirms this too. To compute the EXACT (all decimal)
> position of an electron in an hydrogen atom, soon or later you have to
> take into account of white rabbit path, where the electron will, for
> going from position x to the position y you are computing, follow the
> path x too earth, reacts locally and transforms itself into a white
> rabbit running for the democrat election in the US, loose the election
> and come back to y.
Of course this is assuming that QM (which was discovered by applying reductionist methods) is the correct EXACT theory - which is extremely doubtful given its incompatibility with general relativity.
Brent Meeker
Mohsen Ravanbakhsh
Now I got it.
Mohsen Ravanbakhsh.
Brent Meeker
> Mathematics is just assuming some axioms and rules of inference and then
> proving theorems that follow from those. There's no restriction except
> that it should be consistent, i.e. not every statement should be a
> theorem. So you can regard a game of chess as a mathematical theorem or
> even a Sherlock Holmes story. You may suppose these things "exist" in
> some sense, but clearly they don't exist in the same sense as your
> computer.
>
>
> Now I got it.
>
> assuming the same to oppose/)- which is begging the question. From the
Yes, but if they are not operational it is not clear how they relate to our world of experience. Generally they are taken to be idealized models.
>all
> measurements yield integers (in some units (If you want to keep the same
> unit for two measurements as I said you'd encounter the irrational
> numbers)).
No. For example the most accurate measurement to confirm Pythogora's theorem now possible would be to use ultraviolet light and count the number of wavelengths along each side and the diagonal. Those counts would all be integers. At present this is a practical experimental limit and so one can imagine using shorter wavelengths and making more accurate measurements - which will still come out as integers. But according to current theories of general relativity and quantum mechanics there is also a limit to how short the wave length can be; an in-principle limit. Measurements never yield numbers that are not integers (or ratios of integers).
Brent Meeker
Stathis Papaioannou
Not necessarily. If you draw a diagonal on a square on a computer screen, it will be made up of a discrete number of pixels despite what Pythagoras' theorem calculates. Irrational in the real world may just be an illusion.I was trying to mark a distance in real world which is irrational according to a rational unit(Width of pixels), and for such diagonal the distance is an irrational number, although it might be made up of rational numbers of another irrational unit (diagonal pixels)I mean there's some irrational distance out there!
Stathis Papaioannou
> You could say that a hydrogen atom cannot be reduced to an electron +
> proton because it exhibits behaviour not exhibited in any of its
> components;
Nor by any juxtaposition of its components in case of some prior
entanglement. In that case I can expect some bits of information from
looking only the electron, and some bits from looking only the proton,
but an observation of the whole atom would makes those bits not
genuine. It is weird but the quantum facts confirms this QM prediction.
Quantum weirdness is an observed fact. We assume that it is, somehow, an intrinsic property of subatomic particles; but perhaps there is a hidden factor or as yet undiscovered theory which may explain it further.
> or you could say that it can be reduced to an electron + proton
> because these two components appropriately juxtaposed are necessary
> and sufficient to give rise to the hydrogen atom.
In general this is not the case.
You could get a neutron at high enough energies, I suppose, but I don't think that is what you mean. Is it possible to bring a proton and an electron appropriately together and have them just sit there next to each other?
> And if the atom is just a part of UD*, well, that's just another, more
> impressive reduction.
But just comp, without the quantum, makes it implausible that an atom
can be individuated so much that it makes sense to say it is just a
part of the UD. And QM confirms this too. To compute the EXACT (all
decimal) position of an electron in an hydrogen atom, soon or later you
have to take into account of white rabbit path, where the electron
will, for going from position x to the position y you are computing,
follow the path x too earth, reacts locally and transforms itself into
a white rabbit running for the democrat election in the US, loose the
election and come back to y. Same with the UD, the object "atom of
hydrogen" is only defined relatively to an infinity of first person
plural expectation dependong on the WHOLE UD*. There is no sense to say
an atom is part of the UD. It is "part" of the necessary discourse of
self-observing machine. Recall comp makes physics branch of machine's
psychology/theology.
Isn't that the *ultimate* reduction of everything?
> As for knots, can't any particular physical knot be described in a 3D
> coordinate system? This is similar to describing a particular physical
> circle or triangle.
Not really because the knot is a topological object. Its identity is
defined by the class of equivalence for some topological transformation
from your 3D description. If you put the knot in your pocket so that it
changes its 3D shape (but is not broken) then it conserve its knot
identity which is only locally equivalent with the 3D shape. To see the
global equivalence will be tricky, and there is no algorithm telling
for sure you can identify a knot from a 3D description.
People can look here for a cute knot table:
http://www.math.utoronto.ca/~drorbn/KAtlas/Knots/index.html
I was thinking of a physical knot, which is not the same as the Platonic ideal, even if there is no such thing as a separate physical reality.
The term is most commonly used in a pejorative sense against scientists, eg. "you can't reduce the mind to neurophysiology". Perhaps "physical reductionism" would be a better term for this criticism.
Stathis Papaioannou
Mohsen Ravanbakhsh
Brent Meeker
How are you going to circumnavigate the Earth when it's intuitively flat? Maybe you can't arrange such a triangle for the smallest units. The metric that gives x^2 + y^2 = r^2 only one possibility (and one we think doesn't apply near matter because of general relativity).
Brent Meeker
Torgny Tholerus
--
Torgny Tholerus
Stathis Papaioannou
I don't see that "discrete" and "finite" necessarily go together. The integers are discrete, but not finite.
Stathis Papaioannou
Torgny Tholerus
On 3/14/07, Torgny Tholerus <tor...@dsv.su.se> wrote:
Stathis Papaioannou skrev:How can you be sure? Maybe space is discrete.
Yes, space (and time) is discrete. Everything in the universe is finite, and the universe itself is finite. Infinity is a logically impossible concept.
I don't see that "discrete" and "finite" necessarily go together. The integers are discrete, but not finite.
No, the integers are finite. There exists only a finite numer of integers. There exists a biggest integer N. It is true that you can construct the integer N+1, but this integer is not a member of the set of all integers.
Because everything is finite, you can conclude that the space-time is discrete.
--
Torgny Tholerus
Brent Meeker
> Stathis Papaioannou skrev:
>>
>> Stathis Papaioannou skrev:
>>> How can you be sure? Maybe space is discrete.
>> Yes, space (and time) is discrete. Everything in the universe is
>> finite, and the universe itself is finite. Infinity is a
>> logically impossible concept.
>>
>>
>> I don't see that "discrete" and "finite" necessarily go together. The
>> integers are discrete, but not finite.
> No, the integers are finite. There exists only a finite numer of
> integers. There exists a biggest integer N. It is true that you can
> construct the integer N+1, but this integer is not a member of the set
> of all integers.
This must be computer arithmetic (modulo N?) - not Peano's. :-)
>
> Because everything is finite, you can conclude that the space-time is
> discrete.
That doesn't follow. The universe could be finite and closed, like the interval [0,1] and space could still be a continuum.
But these ideas illustrate a problem with "everything-exists". Everything conceivable, i.e. not self-contradictory is so ill defined it seems impossible to assign any measure to it, and without a measure, something to pick out this rather than that, the theory is empty. It just says what is possible is possible. But if there a measure, something picks out this rather than that, we can ask why THAT measure?
Brent Meeker
Mark Peaty
Your elementary unit SU will have more of a logical existence
than a 'physical' existence. There is no reason to suppose that
Pythagoras's theory will apply because Pythagoras's theory
entails ideas of straight lines, a right angle, and so forth but
your elementary units are too simple to know about that stuff
:-) How do they even know where their ends are? Ie what makes
the difference between the 'length' of the elementary unit and
the 'end' where it joins another.
In fact though, I think it is more exciting to contemplate the
possibility that space-time is a process. Certainly this is what
is being asserted by the proponents of "Process Physics". I
cannot pretend to understand the mathematical formalisation they
put forward. I like the idea very much though so I play around
with my mental picture version and see where it takes me.
The story so far looks like this:
* existence [all that which is] consists of nodes and connections
* the nodes can be called a 'quorum' when talking about one,
and 'quora' for plural
* the connections can be called a 'janus' when talking about
one, and 'jani' for plural
* the janus is named after the Roman god Janus, the god of
doors and name sake of the month of January, the common feature
being that Janus had two faces one for each opposite direction,
and two natures one being that of connecting and the other being
that of dividing
* the quorum is so named because there must be at least three
jani facing together and bound together [how so bound is a
mystery] because if there were only two their condition would be
indistinguishable from there just being one janus connecting two
real quora, and this in effect is how jani 'disappear'
* my assumption, which reflects some aspects of what I think
the process physics people are on about, is that the plenitude
constituted by these jani and their quora [connections and
nodes], is fundamentally unstable such that whenever it is
possible for a janus to slip out of a quorum this will happen,
as for example it MUST happen if two jani find themselves both
to be facing into the same two quora; they will become one janus
- one connection, and if this means that there would otherwise
only be two jani left at one or both of the quora they face,
then [by definition almost] such a quorum ceases to exist
* the net effect of this is that the plenitude is always
simplifying and 'collapsing' in the direction of smallwards and
this is the basis of gravity, so it is true to say that gravity
IS space-time and vice versa
* it has to be remembered that jani and their quora ARE
space-time, and ARE everything which exists, there is nothing else
* for brevity and clarity, we can call this conception of the
plenitude "JQspacetime"
* for reasons not clear to me, regions of JQspacetime can
become knotted and self-entangled such that the in-falling drift
in the direction of smallwards cannot normally destroy the
tangle which thus takes on something of the nature of a
permanent vortex; these regions of JQspacetime are what people
call 'particles'
* there are all sorts of characteristic JQspacetime vortices
and quite a few of them have the ability to create simple
'glider' type vortices - much like the glider factories of the
cellular automata *Game of Life* which, being essentially
complex wave forms in the plenitude travel about at a
characteristic velocity which reflects their complexity and some
aspect of the intrinsic rate of evolution of the in-falling
JQspacetime
* distance within JQspacetime is first and foremost a question
of connection; there is essentially NO distance at all between
the two faces of a janus; it has no 'body' and is simply a
connection between two quora
* thus it is possible, indeed very common, that the two faces
of a janus look into quora which are only otherwise connected
[and here we could say 'next most closely connected'] indirectly
via a pathway composed of a whole sequence of other jani
* because the two faces of a janus simply ARE a connection
between two quora, if the 'next most closest connection' between
the two quora entails a sequence of umpteen billions of billions
of other jani so that a NASA space probe would take decades to
go the long way round [by the shortest feasible path none the
less], well that is just the way it is
Now I realise that all that is a lot of words but, if you care
to look closely, you will see that it is all plain-English and
goes a fair way to informally explaining quite a lot of things.
* so-called Dark matter may simply be vortex knots that neither
generate nor receive gliders
* the generation and receipt of gliders may be the basis of
electromagnetic, weak nuclear, and strong nuclear forces
* the various kinds of charge may be the manifestations of
chirality, fractal dimensionality, other aspects of topology,
and wave interactions such as harmonic resonance and interference
* none of the above relies on any concepts of 'particle' or
'solidity' but points to all aspects of existence manifesting a
wave nature, so talk of particles is out of place, 'wavicles'
might be a word we have to use :-)
That is enough for now. I will leave for another posting my
question about the apparent scandal of Michelson/Morley
interferometry NOT actually falsifying the aether concept, and
Dayton Miller is it? Not only not falsifying it but actually
providing support for a clear sidereal drift of some cosmic
velocity.
Regards
Mark Peaty CDES
http://www.arach.net.au/~mpeaty/
John Mikes
*:
I hate when people create a new vocabulary to be learned for appropriate use. I made MY vocabulary and the rest of the world should learn it. Adolf Hitler.
*
Then again I like your 'plain English' of Latin words, grammar and mythology.
*
We like to mix features of reductionist (conventional) "science" with more advanced ideas, it is an excellent way to secure endless discussions. Like e.g. the "SU"..
I rather spread my 'I dunno' into the vagueness of my narratives, suggest what we might find (out?) in the future and scratch those assumptions that *in my views* serve only the purpose to make model-theories better believable (calculable?).
*
If I got it right, your 'ianus' is sometimes called relation and the quorum may be referred to as (network) nodes or hubs in some other vocabulary. (quorum, btw. looks to me as a plural genitive of the pronoun qui quae quod in masculine or neutral (quarum being the feminine), also used pars pro toto for the existing total construct mostly in human assemblages. Accordingly my Latin disallows to form a simple plural of it, since it is not a noun within the neutral o-based conjugation. (Yet, you may say: 'quorums').
(I learned this 74-75 years ago, so please do correct me if someone has more recent and unmatching memories).
You start well with " * so-called Dark matter may simply be vortex knots that neither
generate nor receive gliders..." but continue within the subatomic 'particle' lingo,( of which Enrico Fermi quipped: If I knew that much Greek, I could be a botanic. )
Best regards
John M