[comp.ai] Simulation verus reality

fransvo@htsa.uucp (Frans van Otten) (04/07/89)

A lot of comp.ai writers seem to misunderstand the difference between
"reality" and "simulation".  Actually, both words are pointers to some
actual process, which has no name, I'm afraid.  Reality and simulation
are "relativity" concepts.

When we simulate a flying plain, it is (within the simulator) really
flying (in so far as the simulator simulates flying).  To us, it is a
simulation of a flying plane.  That is, in our reality the plane does
not fly, but in the reality inside the simulator it does fly !

Let's assume we made a computer system which can calculate the physics
of a person.  Let's assume we can communicate with this simulation.  Now
to us he is a simulation.  But if we asked him, he would say "Me ?  A
simulation ?  You must be out of your mind, I do really exist !"  Again,
in our reality the person is a simulation, but in the reality within the
computer system the person is real.

Our reality is not a "universal" reality, either.  The rules for our
existence are the chemical and physical rules, which are being executed
by the molecules.  The rules for the existence of molecules are being
executed by the constituting atoms.  The rules for the existence of
atoms are being executed by the constituting atoms.  Et cetera.  If we
would execute the rules for the molecules on a computer,  we would not
notice any difference except that nuclear fusion would not be possible.

The only problem is that a simulated reality is not physically in
contact with the simulating reality.  So I could never feed myself with
a simulated meal.  But that is also a very nice property of simulations:
whatever crashes a simulated plane makes, no real person dies !  And
nobody cares about all those killed simulated people, since we didn't
simulate their family and friends.
-- 
	Frans van Otten
	Algemene Hogeschool Amsterdam
	Technische en Maritieme Faculteit
	fransvo@htsa.uucp

ssingh@watdcsu.waterloo.edu ( SINGH S - INDEPENDENT STUDIES ) (04/09/89)

In article <827@htsa.uucp> fransvo@htsa.UUCP (Frans van Otten) writes:
>
>Our reality is not a "universal" reality, either.  The rules for our
>existence are the chemical and physical rules, which are being executed
>by the molecules.  The rules for the existence of molecules are being
>executed by the constituting atoms.  The rules for the existence of
>atoms are being executed by the constituting atoms.  Et cetera.  If we
>would execute the rules for the molecules on a computer,  we would not
>notice any difference except that nuclear fusion would not be possible.
>
>	Frans van Otten
>	Algemene Hogeschool Amsterdam
>	Technische en Maritieme Faculteit
>	fransvo@htsa.uucp


Very thought provoking!!! Since processes in the brain are chemical
reactions, I am wondering what models are the best we have to capture
the rules of chemical-chemical interaction that allows information 
processing of an intelligent sort to take place. Can the properties
of the chemicals be abstracted into something as imaginary as 
cellular automata? How WOULD we analyse the brain in such a way to
be able to decipher the dance of chemicals that is the esscence of
being human?

ssingh@watdcsu.waterloo.edu
 

lammens@sunybcs.uucp (Jo Lammens) (04/09/89)

In article <5790@watdcsu.waterloo.edu> ssingh@watdcsu.waterloo.edu ( SINGH S    - INDEPENDENT STUDIES    ) writes:
>Very thought provoking!!! Since processes in the brain are chemical
>reactions, I am wondering what models are the best we have to capture
>the rules of chemical-chemical interaction that allows information 
>processing of an intelligent sort to take place. Can the properties
>of the chemicals be abstracted into something as imaginary as 
>cellular automata? How WOULD we analyse the brain in such a way to
>be able to decipher the dance of chemicals that is the esscence of
>being human?
>

I wonder if there's any point in doing that. If you want to understand
how a car works, you don't analyze it in terms of chemistry and quantum
mechanics, although it is probably possible to do so - at least in
principle. If you want to achieve high-level understanding, you should
probably use high-level descriptions. That's basically why nobody
wants to use machine code any more to write a complex program,
although it is possible to do so - at least in principle.

Jo Lammens

BITNET: lammens@sunybcs.BITNET          Internet:  lammens@cs.Buffalo.EDU
UUCP: ...!{watmath,boulder,decvax,rutgers}!sunybcs!lammens

ssingh@watdcsu.waterloo.edu ( SINGH S - INDEPENDENT STUDIES ) (04/09/89)

In article <5106@cs.Buffalo.EDU> lammens@sunybcs.UUCP (Jo Lammens) writes:
>
>I wonder if there's any point in doing that. If you want to understand
>how a car works, you don't analyze it in terms of chemistry and quantum
>mechanics, although it is probably possible to do so - at least in
>principle. If you want to achieve high-level understanding, you should
>probably use high-level descriptions. That's basically why nobody
>wants to use machine code any more to write a complex program,
>although it is possible to do so - at least in principle.
>
You're right. There is no reason to analyse a car in terms of quantum
mechanics. That is carrying reductionaism too far. We know that in
the construction of the car, there are parts. It makes sense to analyse
this system of parts for a true understanding of what is going on.

The basic unit of information processing in the brain is the neuron.
Clearly tons of neurons put together will give us some form of
behaviour. It makes sense to abstract the properties of the neurons
into some sort of precise model. Then do simulations (soft or hardware)
that show us a system of N neurons. But the model MUST be consistent
with the actual properties of biological neurons. Other simulations
could be constructed with different unit properties.

>BITNET: lammens@sunybcs.BITNET          Internet:  lammens@cs.Buffalo.EDU
>UUCP: ...!{watmath,boulder,decvax,rutgers}!sunybcs!lammens

lammens@sunybcs.uucp (Jo Lammens) (04/09/89)

In article <5791@watdcsu.waterloo.edu> ssingh@watdcsu.waterloo.edu ( SINGH S    - INDEPENDENT STUDIES    ) writes:
>The basic unit of information processing in the brain is the neuron.
>Clearly tons of neurons put together will give us some form of
>behaviour. It makes sense to abstract the properties of the neurons
>into some sort of precise model. Then do simulations (soft or hardware)
>that show us a system of N neurons. But the model MUST be consistent
>with the actual properties of biological neurons. [...]

I think not even all connectionists would agree with your last
sentence. What I was really hinting at before is that a description at
the neural level *MAY* be too low to yield significant understanding,
even though it is tempting and certainly fascinating. It's a bit like
trying to understand how an operating system works by analyzing the
function of all the transistors in the machine it's running on. They
can be modeled more or less precisely, and for sure tons of them can
do some amazing things. But I doubt that this kind of analysis will
yield any significant understanding. Please convince me of the
opposite.

Jo Lammens

BITNET: lammens@sunybcs.BITNET          Internet:  lammens@cs.Buffalo.EDU
UUCP: ...!{watmath,boulder,decvax,rutgers}!sunybcs!lammens

ssingh@watdcsu.waterloo.edu ( SINGH S - INDEPENDENT STUDIES ) (04/10/89)

In article <5125@cs.Buffalo.EDU> lammens@sunybcs.UUCP (Jo Lammens) writes:
>
>I think not even all connectionists would agree with your last
>sentence. What I was really hinting at before is that a description at
>the neural level *MAY* be too low to yield significant understanding,
>even though it is tempting and certainly fascinating. It's a bit like
>trying to understand how an operating system works by analyzing the
>function of all the transistors in the machine it's running on. They
>can be modeled more or less precisely, and for sure tons of them can
>do some amazing things. But I doubt that this kind of analysis will
>yield any significant understanding. Please convince me of the
>opposite.
>
You analogy seems correct, but what alternative is there? We could
study simple brains, but we lose the idea of "emergence." There is 
not all THAT much difference between our brain and a monkey's. Why
are we so much more complex??? You could use automata with 
local communications properties that you define yourself and
run a simulation, but these are pure abstractions; there does
not seem to be a hope of physically realizing it, just as it was
not possible to physically create Von Neumann's self-reproducing
automaton machine. BY THE WAY, THE WORLD IS DISCRETE, NOT
CONTINUOUS (in response to past postings). Now, about the operating
system parallel. To me, it is more important to study the structure
of the computer running the operating system we call a MIND. How
does a neuron react to stimuli, how does it connect to others, how
does it change itself? If you want to lift the "algorithms of
thought" from a mind and transplant it elsewhere, GOOD LUCK.
What do you mean when you say "...any significant understanding?"

ssingh@watdscu.waterloo.edu ... a mind forever voyaging ...

arm@ihlpb.ATT.COM (Macalalad) (04/11/89)

In article <827@htsa.uucp> fransvo@htsa.UUCP (Frans van Otten) writes:
>A lot of comp.ai writers seem to misunderstand the difference between
>"reality" and "simulation".  Actually, both words are pointers to some
>actual process, which has no name, I'm afraid.  Reality and simulation
>are "relativity" concepts.

I always thought of those "actual processes" AS REALITY.  Whose concept
of relativity are you using?

>When we simulate a flying plain, it is (within the simulator) really
>flying (in so far as the simulator simulates flying).  To us, it is a
>simulation of a flying plane.  That is, in our reality the plane does
>not fly, but in the reality inside the simulator it does fly !

No, there is only ONE reality, not many separate realities.  The concept
behind relativity is that the MEASUREMENTS taken of reality, such as
time and distance, are relative to the observer.  This is quite different
from claiming that each observer is taking measurements of a different
reality.

Thus, it doesn't even make sense to talk of a separate reality within
a simulator.  Where is the observer within the simulator?  All of the
measuring and collapsing of quantum states take place at our level,
not the simulated level.

Sure, we can redefine what we mean by flying to encompass the concept
of flying on the simulator level, but remember that we are still talking
about two different concepts of flying.  (I think you do acknowledge as
much implicitly in your discussion of two "realities.")  Putting two
concepts under the same label does not make them the same.

I think that strong AI is making a stronger claim: to create an
intelligent machine not in some "simulated reality" but in our reality,
fully interacting with us and our environment.

We may be in the grips of an ideology, but let's not lose our grip
on reality.

-Alex

rapaport@sunybcs.uucp (William J. Rapaport) (04/13/89)

In article <827@htsa.uucp> fransvo@htsa.UUCP (Frans van Otten) writes:
>
>When we simulate a flying plain, it is (within the simulator) really
>flying (in so far as the simulator simulates flying).  To us, it is a
>simulation of a flying plane.  That is, in our reality the plane does
>not fly, but in the reality inside the simulator it does fly !

And I quote:

"It is often suggested that a simulation of a phenomenon is not an
instance of the p[henomenon being simulated.  For example, simulated
hurricanes are not real hurricanes.  After all, as people often point
out, simulated hurricanes don't get you wet.  I think it is wrong to
suppose that this shows that simulated Xs aren't Xs.  Simulated
huricanes won't get _you_ wet, but they _will_ get a simulated you
simulatedly wet; if they didn't they wouldn't be very good simulations
of hurricanes.  The proper way to look at it is that both simulated and
real hurricanes are implementations of an abstract notion of hurricane;
in this way, they can both legitimately be said to be hurricanes.  But
suppose that it is the case, _in general_, that simulated Xs aren't Xs.
Still, there might be _some_ values of X for which simulated Xs _are_
Xs.  In particular, simulated mentality seems to me to be a good
candidate for such an X.  If I have a conversation with a computer that
passes the Turing Test, it might very well be the case that I could
learn something from it.  To use the hurricane metaphor, it might indeed
get me "wet":  it might give me information in much the same way that a
Xerox copy of Searle's book can give me the same information that an
actual copy would.  Such a copy to perhaps all but certain
book-collectors, is the book itself."

From Rapaport, William J. (1988), ``To Think or Not to Think''
(critical study of Searle, _Minds, Brains & Science_), Nous 22:  585-609.

dmocsny@uceng.UC.EDU (daniel mocsny) (04/13/89)

In article <5227@cs.Buffalo.EDU>, rapaport@sunybcs.uucp (William J. Rapaport) writes:
> And I quote:
> 
> "It is often suggested that a simulation of a phenomenon is not an
> instance of the p[henomenon being simulated.  For example, simulated
> hurricanes are not real hurricanes.  After all, as people often point
> out, simulated hurricanes don't get you wet.

Why doesn't, or couldn't, a simulated hurricane get you wet? Because
we aren't so good at simulating things yet, or because that would
be "cheating?"

For us to detect the presence of a hurricane, we must absorb some sort
of sensory data (raindrops on skin, the view of the ground rushing by
as the gale carries us along, or perhaps we detect the hurricane
indirectly by reading reports from instruments). To detect the presence
of a _simulation_, we must also absorb some sort of sensory data. This
means that the simulating device must have some link with the physical
world for it to convey messages to our sensory organs. If a simulation
can't deliver some sort of sensory experience to an observer, then in
what sense does it exist? For a simulation to be a simulation, it must
first exist...one hand clapping, that sort of thing...

Thus any device that simulates things must have two essential parts:
the computing engine that performs what we ordinarily think of as a
simulation, and the I/O subsystem that pumps energy into the physical
world in a way that provides a convincing sensory experience to an
observer. The I/O subsystem can be as crude as a line printer that
hammers out line after line of numbers. It can be a high-fidelity
digital audio system that faithfully simulates the sounds of an
orchestra (...heard any CD's lately? Simulated hurricanes don't get
you wet yet, but simulated orchestras can move one to tears). It can
be the future successor to NASA's VIVED (VIrtual Visual Environment
Display) with stereoscopic LCD goggles and head-motion cancelling
panning, that delivers a convincing panoramic view of simulated
surroundings with depth cues. 

Someday it may be neural-interface implants that directly induce
signals on our sensory nerves indistinguishable from the "real" thing.
A really good simulation should saturate the observer's sensory
bandwidth, just like the "real" thing does. 

Certainly a hurricane simulator could include a fancy device to generate
raindrops and impart the correct velocity vectors to them. Spraying
water as an output is not different in principle from pounding ink
into a page--the simulating device has an expendable store of
material that it imparts energy to and exhausts over the course of
the simulation.

Dan Mocsny
dmocsny@uceng.uc.edu

rapaport@sunybcs.uucp (William J. Rapaport) (04/13/89)

In article <864@uceng.UC.EDU> dmocsny@uceng.UC.EDU (daniel mocsny) writes:
>
>Why doesn't, or couldn't, a simulated hurricane get you wet? Because
>we aren't so good at simulating things yet, or because that would
>be "cheating?"

I was thinking of the sort of computer simulation of a hurricane that
the weather service might construct, not a machine that produces a
hurricane artificially.  The latter ought to get you wet; the former
wouldn't.

lee@uhccux.uhcc.hawaii.edu (Greg Lee) (04/13/89)

From article <864@uceng.UC.EDU>, by dmocsny@uceng.UC.EDU (daniel mocsny):
" ... For a simulation to be a simulation, it must
" first exist...one hand clapping, that sort of thing...

Next you'll be asking what is the sound of one symbol clashing.

		Greg, lee@uhccux.uhcc.hawaii.edu

weltyc@cs.rpi.edu (Christopher A. Welty) (04/13/89)

In article <5106@cs.Buffalo.EDU> lammens@sunybcs.UUCP (Jo Lammens) writes:
>In article <5790@watdcsu.waterloo.edu> ssingh@watdcsu.waterloo.edu ( SINGH S    - INDEPENDENT STUDIES    ) writes:
>>Very thought provoking!!! Since processes in the brain are chemical
>>reactions, I am wondering what models are the best we have to capture
>>the rules of chemical-chemical interaction that allows information 
>>processing of an intelligent sort to take place....
>
>I wonder if there's any point in doing that. If you want to understand
>how a car works, you don't analyze it in terms of chemistry and quantum
>mechanics, although it is probably possible to do so - at least in
>principle. If you want to achieve high-level understanding, you should
>probably use high-level descriptions.

Perhaps I missed something by jumping in the middle of this, but it
seems to me that all the articles posted on this Simulation vs Reality
argument are talking about two fundamentally different concepts as if
they were the same.  Understanding and simulation are not the same
thing.  I don't know very many people, in fact I don't know any, who
could accurately simluate a car, although I do know many who understand
understand how it works.    I would argue that accurate simulation DOES
require a model from as low a level as possible in order to behave
exactly as the real thing being simulated.  Typically `high level'
descriptions of functional groups of low level objects are mere
generalizations of the function of the group, and thus only
incorporate the default knowledge of that function.


Christopher Welty  ---  Asst. Director, RPI CS Labs | "Porsche:  Fahren in
weltyc@cs.rpi.edu             ...!njin!nyser!weltyc |  seiner schoensten Form"

dmocsny@uceng.UC.EDU (daniel mocsny) (04/14/89)

In article <5244@cs.Buffalo.EDU>, rapaport@sunybcs.uucp (William J. Rapaport) writes:
> I was thinking of the sort of computer simulation of a hurricane that
> the weather service might construct, not a machine that produces a
> hurricane artificially.  The latter ought to get you wet; the former
> wouldn't.

The hurricane simulation that the weather service might construct
outputs a list of numbers representing the velocity field of the
hurricane. The velocity field is not the hurricane, but a formal
description of the hurricane that we can obtain directly by planting a
grid of instruments in the hurricane's path. So strictly speaking, I
would not call the weather service's simulation a simulation of THE
hurricane, but rather a simulation of some abstract measurements we
might take of the hurricane. Also, the artificial hurricane I
suggested need not reproduce every single effect of the hurricane on
the real world, but only those that lead directly to sensory
experience of the observer. If the observer inconveniently wants to
walk around and poke through the wreckage, then we have to include
more of those effects. If the observer is very persistent, we have to
generate a full-blown artificial hurricane.

I don't see a sharp distinction between a "simulation" and "a machine
that produces a hurricane artificially," but rather that they lie on a
continuum. Can we agree that a physical system has no reality outside
the sensory experience it conveys to an observer? If so, then a
"simulation" is the action of some artificial device that reproduces
some or all of the sensory experience we associate with the "real"
thing. If the simulation leaves something out, then it is incomplete.
If it doesn't leave anything out, then the observer cannot tell it
apart from the "real" thing. From the observer's standpoint, it IS the
real thing.

Every simulation must effect some change in the real world, because
the observer exists in the real world and can only detect things in
the real world. Two of our most important senses--vision and
audition--respond only to energy fluxes from the real world. The other
senses respond to both energy and material fluxes (or perhaps I should
say, energy fluxes mediated by material fluxes). Perhaps the
distinction we are trying to draw is that "simulating X" delivers
strictly energy-mediated sensations, while "reproducing X
artificially" includes whatever material fluxes are necessary to
deliver the full range of sensations. But I don't see this as
being a particularly natural division. Since every simulation must
have some detectable real-world effect, what is the difference
between an energy-only effect and an energy+material effect? They
differ only in the complexity of the output devices required.

Dan Mocsny
dmocsny@uceng.uc.edu

bwk@mbunix.mitre.org (Barry W. Kort) (04/15/89)

In article <5244@cs.Buffalo.EDU> rapaport@sunybcs.UUCP
(William J. Rapaport) writes:

 > I was thinking of the sort of computer simulation of a hurricane that
 > the weather service might construct, not a machine that produces a
 > hurricane artificially.  The latter ought to get you wet; the former
 > wouldn't.

And then there are the occasional storms projected by the weathermen
which fail to materialize.  In that case, one could say it's the
National Weather Service that gets wet.   :-)

--Barry Kort

bwk@mbunix.mitre.org (Barry W. Kort) (04/15/89)

In article <3752@uhccux.uhcc.hawaii.edu> lee@uhccux.uhcc.hawaii.edu
(Greg Lee) writes:

 > Next you'll be asking what is the sound of one symbol clashing.

Of course you meant "one cymbal crashing".  ;-)

--Barry Kort

sarima@gryphon.COM (Stan Friesen) (04/15/89)

In article <5791@watdcsu.waterloo.edu> ssingh@watdcsu.waterloo.edu ( SINGH S    - INDEPENDENT STUDIES    ) writes:
>You're right. There is no reason to analyse a car in terms of quantum
>mechanics. That is carrying reductionaism too far. We know that in
>the construction of the car, there are parts. It makes sense to analyse
>this system of parts for a true understanding of what is going on.
>
>The basic unit of information processing in the brain is the neuron.
>Clearly tons of neurons put together will give us some form of
>behaviour. It makes sense to abstract the properties of the neurons
>into some sort of precise model. Then do simulations (soft or hardware)
>that show us a system of N neurons. But the model MUST be consistent
>with the actual properties of biological neurons. Other simulations
>could be constructed with different unit properties.
>
	Good start. At least for a very low level understanding of mental
processes.  Such simulations could well give us a model of clusters of
neurons.  This knowledge could then be used to generate a simulation in
which the "parts" are tightly coupled clusters of neurons.

	The point?  Neurons are the basic unit of processing in the brain
only at one level, a rather low level at that.  It could be called the
mental equivalent of assembly language.  Most information processing in the
brain is performed by co-ordinated sets of neurons, called nuclei, tracts,
and columns.   For AI purposes I think this level might be more useful,
since it deals with coded information.
	By the way, there is also a lower level than the neuron, the synapse.
A remarkable amount of processing is done at the individual synapse.  And
even more is done in the dense clusters of interlocking synapses called
glomeruli.   We are talking about a remarkably complex structure when we
talk about the brain

-- 
Sarima Cardolandion			sarima@gryphon.CTS.COM
aka Stanley Friesen			rutgers!marque!gryphon!sarima
					Sherman Oaks, CA

jwi@lzfme.att.com (Jim Winer @ AT&T, Middletown, NJ) (04/18/89)

In article <50068@linus.UUCP>, bwk@mbunix.mitre.org (Barry W. Kort) writes:
> In article <3752@uhccux.uhcc.hawaii.edu> lee@uhccux.uhcc.hawaii.edu
> (Greg Lee) writes:
> 
>  > Next you'll be asking what is the sound of one symbol clashing.
> 
> Of course you meant "one cymbal crashing".  ;-)
> 
> --Barry Kort

The sound of one symbol clashing seems both more likely (since it
was stated), and more interesting. After all, everyone's heard one
cymbal crashing -- it happens all the time. You only get to hear one
symbol clashing if you subscribe to comp.ai.

Jim Winer ..!lzfme!jwi 

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