Re: why can't we erase information?

2006-05-10 Thread Russell Standish

On Sat, May 06, 2006 at 10:24:05PM -0400, [EMAIL PROTECTED] wrote:
 
 Russell,
 my apologies for the approximate typing. I don't assign to your not
 following my comments to that awful new keyboard I tried to use (light grey
 letters on a slightly less light grey base - not visible and I am not a good
 'blind'typist) with the YAHOO-mail spellchecker that garbles up the
 letters - I think your uncertainty stems from a different knowledge-base I
 use.

No doubt.

 
 Classical thermodynamics I learned in 1942 when I identified it as the
 science which tells us how things would go wouldn't they go the way they do
 go
 meaning the game of isotherm and reversible equational craze in closed
 systems.
 Then later Prigogine et al improved upon it, but I still hold the field
 within the limited model of our epistemic - ever changing, enriching -
 interpretation of the (obsolete) historical bases from very primitive
 knowledge level times and accordingly primitive measurements by
 unsophisticated instrumentation, subject to an all ingenious explanation on
 THAT level. (Think about the dozen+ (and still counting) changing views
 about the 'entropy' conceptS).

Indeed - you are thinking of the difference between equilibrium
thermodynamics (which is classical in the sense of being a mature
topic, but of extremely limited validity), and nonequilibrium
thermodynamics which applies to much of the rest of reality, but which
is very much an ongoing research topic. I have always eschewed
equilibrium physics in favour of the more exciting nonequlibrium
topics.

Nevertheless, the concept of closed system applies in both equilibrium
and nonequlibrium cases.

 *
 Singularity in my view is a no-system because there is no way we can
 extract any information about it - unless we give up the definition. This is
 how I view a 'closed' system, (not lawyerish: well, you can look at it as
 semi-closed, or even open, if you like,...) If it is closed, it is closed.
 Singularity is nice to speak about, I hold: there is no such thing only in
 sci-fi. We get usded to many sci-fi marvels and in the 15th step it looks
 like real.

Singularities are one of the features of General Relativity, but are
contradictory in the sense that GR is expected to break down (in the
sense of failing to describe reality) near them. So perhaps
singularities do or do not exist. In fact we really don't know much
about how they should behave assuming they do exist.

The business of event horizons (which would cloak singularities, as
well as other high density regions of space - collectively known as
black holes) and information flow is certainly a case in
point. Unitarity is tied up with information conservation, and some
studies indicate black holes violate unitarity. I'm personally
sceptical that unitarity is ever violated, except as a process of
observation (the creation of information).

But I have no plans to work in this area.

 
 Russell, when I said good bye to my polymer science (1987) and started to
 think I tried to throw out things to be 'believed' (axioms, paradoxes,
 emergence, chaos).  I retired with limited movablity and allowed myself to
 get away from conventional reductionism.  You are in the profession, books
 projects, responsibility for what you said yesterday: I don't want to
 persuade you to think differently, especially since I am fully aware of the
 embryonic level of the 'new ways' I still try to find. I have questions,
 very few answers and I doubt them.
 
 John
 

I'm well aware that you are following a deconstruction approach. A
little of this is healthy of course, but too much leads to one getting
lost. 

Is it not better to understand the language of science, to debate the
topics using understood terms of science, and occasionally lob in the
hand grenade that causes a radical change in understanding.

-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
Australiahttp://parallel.hpc.unsw.edu.au/rks
International prefix  +612, Interstate prefix 02


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Re: why can't we erase information?

2006-05-10 Thread jamikes

Thanks, Russell,
I really do not want to continue - seems side-line to you and side line to
me.
I just cannot keep my mouse shut.

1. The 'nonequilibrium' topics still identify a certain 'cut' within the
boundaries of them, neglecting wider - maybe unobserved/able - effects from
'unrelated' sides.
(see my '3' below) Pertinent to 'closed systems' as well. In (my) wholistic
view nothing is shut of of anything in an intereffectiveness that may
include unknown
elements at the level of our present cognitive inventory.
2. Suppose singularity is not - where does the (alleged) GR break down? It
is a 150th consequential idea from a questionable startup-figment and we
just continue to build logically, quantitatively, formally - call it
science. To be clear:
I appreciate and USE the technological marvels based on such questionable
theoretical background. I believe in human ingenuity even on wrong premises.
3.To your last par:
one cannot have it both ways. Einstein (what a comparison to myself!!!) did
not accept all Newton in his thinking and tackled only certain terms in a
new view.
Copernicus did not abide by the well proven Flat Earth and just 'included'
at some points his new ideas. You cannot keep creationism when you think in
evolution.
I may get lost - as you say - but it won't last long. I won't either. In the
meantime I have the luxury of tasting the new ideas. And I feel I am not
alone in these ways

John M

- Original Message -
From: Russell Standish [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Wednesday, May 10, 2006 2:01 AM
Subject: Re: why can't we erase information?



 On Sat, May 06, 2006 at 10:24:05PM -0400, [EMAIL PROTECTED] wrote:
 
  Russell,
  my apologies for the approximate typing. I don't assign to your not
  following my comments to that awful new keyboard I tried to use (light
grey
  letters on a slightly less light grey base - not visible and I am not a
good
  'blind'typist) with the YAHOO-mail spellchecker that garbles up the
  letters - I think your uncertainty stems from a different knowledge-base
I
  use.

 No doubt.

 
  Classical thermodynamics I learned in 1942 when I identified it as the
  science which tells us how things would go wouldn't they go the way they
do
  go
  meaning the game of isotherm and reversible equational craze in closed
  systems.
  Then later Prigogine et al improved upon it, but I still hold the field
  within the limited model of our epistemic - ever changing, enriching -
  interpretation of the (obsolete) historical bases from very primitive
  knowledge level times and accordingly primitive measurements by
  unsophisticated instrumentation, subject to an all ingenious explanation
on
  THAT level. (Think about the dozen+ (and still counting) changing views
  about the 'entropy' conceptS).

 Indeed - you are thinking of the difference between equilibrium
 thermodynamics (which is classical in the sense of being a mature
 topic, but of extremely limited validity), and nonequilibrium
 thermodynamics which applies to much of the rest of reality, but which
 is very much an ongoing research topic. I have always eschewed
 equilibrium physics in favour of the more exciting nonequlibrium
 topics.

 Nevertheless, the concept of closed system applies in both equilibrium
 and nonequlibrium cases.

  *
  Singularity in my view is a no-system because there is no way we can
  extract any information about it - unless we give up the definition.
This is
  how I view a 'closed' system, (not lawyerish: well, you can look at it
as
  semi-closed, or even open, if you like,...) If it is closed, it is
closed.
  Singularity is nice to speak about, I hold: there is no such thing only
in
  sci-fi. We get usded to many sci-fi marvels and in the 15th step it
looks
  like real.

 Singularities are one of the features of General Relativity, but are
 contradictory in the sense that GR is expected to break down (in the
 sense of failing to describe reality) near them. So perhaps
 singularities do or do not exist. In fact we really don't know much
 about how they should behave assuming they do exist.

 The business of event horizons (which would cloak singularities, as
 well as other high density regions of space - collectively known as
 black holes) and information flow is certainly a case in
 point. Unitarity is tied up with information conservation, and some
 studies indicate black holes violate unitarity. I'm personally
 sceptical that unitarity is ever violated, except as a process of
 observation (the creation of information).

 But I have no plans to work in this area.

 
  Russell, when I said good bye to my polymer science (1987) and started
to
  think I tried to throw out things to be 'believed' (axioms, paradoxes,
  emergence, chaos).  I retired with limited movablity and allowed myself
to
  get away from conventional reductionism.  You are in the profession,
books
  projects, responsibility for what you said yesterday: I don't want to
  persuade you

Re: why can't we erase information?

2006-05-10 Thread James N Rose

a simple question ... (which, if it cannot be
satisfactorally answered/rationalized/justified,
its unanswereability will indicate why any
creationist models versus 'science' models of
cosmology, are not reconcilable).


Q:  What conditions-of-state of the existing
functioning universe act as the boundary condition
which -prevents- the ZPE quantum foam from 
initiating at anytime/anyplce in the cosmos - 
a new 'ultimate singularity' from instigating 
(again and randomly and unrestrictedly)?


==


Collateral situational notion on whether G-contant
is +, 0, or -.   ...  in frame of reference of standard
thermodynamic concept of entropy.

One model for the 'final (mathematical) solution'
to the universe posits that all matter will 
uniformly distribute into all possible 'space'
uniformly, leaving no dis-equilibrium and therefore
- ultimately - no differential, such as is required
for any activity through which 'work' can be accomplished.

The 'final' thermodynamic picture is of a universe
maximally depleted in actionability -- at all possible
levels of 'energy'.



 ... the problem with that model however is that 
the current limiting definitional assignment of 
'energy' with qualia of -motion- and transference
or redistribution of motionenergy alone are patently
limiting, and contain a significant but fundamental
assignment error.


Consider a gedankenuniverse in which only two
motionless masses exist - no initial relative
motion between them and no other masses present.

Under conventional 'definition' they are 
thermodynamically depleted.  

Yet, their mutual spacetime is -not- 'uniform everywhere'.
And it is the unbalanced, non-uniform -spacetime- which
provides the source function for additional actionable
activities.

There is a character of spacetime which is not 'thermodynamic'
but which is a gradient source, significant enough to 
instigate anti-(thermodynamic)entropy motion. (!)

In the end-analysis of a UFT, it is gravity which trumps
all other action impelling gradients.  AND it is obligatory
that gravity be re-defined because of this reasoning,
to coordinate the qualia -of- energy thermodynamics with 
the non-energy definitions and qualia -of- gravity.


The question of erasability or not of information
involves absolute accessibility of all qualia with 
all other qualia.  Transducableness of any information
(form) into any other .. at least in essential
conversion.  Without such inter-translation capacity,
(some) information is effectively PRE-erased.

Non-accesibility isn't limited to erasure (now you
see it now you don't), but includes 'preclusion'
(exists but: never see it never will).

Bringing this inclusive logic to bear on gradients
means that trope-ic qualities must reside as concurrent
with -gradients- per se _irrespective_ of the format 
of system -- be it inertial, electromagnetic, -or-
gravitational.

That is the unifying informational linking 
qualia-primitive of -all- these formats ... what the
UFT wellsprings from and in-which it is discoverable
again.

Entropy and negentropy are characteristics of 
all gradients and are informational parameters of 
all gradients .. NOT of thermodynamic gradients
alone.   The exclusive linking of entropy with 
thermodynamics and thermodynamics alone is patently
hampering and incorrect and limiting.

The association of information with negentropy
is already indicative of this.  Whats required
is the association of information with
differential field structure and not just with
snap-shot 'content quantification' state-comparisons,
a with b and none else.

Jamie Rose


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Re: why can't we erase information?

2006-05-10 Thread Russell Standish

On Wed, May 10, 2006 at 09:28:44AM -0400, [EMAIL PROTECTED] wrote:
 
 Thanks, Russell,
 I really do not want to continue - seems side-line to you and side line to
 me.
 I just cannot keep my mouse shut.

Seems I'm the same :)

 
 1. The 'nonequilibrium' topics still identify a certain 'cut' within the
 boundaries of them, neglecting wider - maybe unobserved/able - effects from
 'unrelated' sides.

The cuts appear in models to make them tractable. Experiments testing
the models are set up to approximate the conditions of the model as
well as is able. This is science. The models are applicable to
describing reality only as far as how these conditions are
approximated by the real system. This is easier in some systems than
others - it fairly easy with respect to bridges and buildings, but
much more difficult when it comes to figuring out what happens when we
double atmospheric CO_2 concentration. In the latter system there are
many interconnections, and figuring out what can be cut without
invalidating the model is no easy task.

 3.To your last par:
 one cannot have it both ways. Einstein (what a comparison to myself!!!) did
 not accept all Newton in his thinking and tackled only certain terms in a
 new view.
 Copernicus did not abide by the well proven Flat Earth and just 'included'
 at some points his new ideas. You cannot keep creationism when you think in
 evolution.

Hence my comment about the hand grenade. Einstein was careful to
only change one or two things at a time - he still stayed within
scientific discourse.

 I may get lost - as you say - but it won't last long. I won't
 either. 

Well great, but your writings do give that impression...

 In the
 meantime I have the luxury of tasting the new ideas. And I feel I am not
 alone in these ways
 

So do I, and I really think most scientists do as well. It's probably
the teachers of science who miss out - and maybe that's what's missing
from science education, the buzz of the new.

I largely self-taught myself maths and science at school - I studied
quantum mechanics in year 11, and general relativity in year 12. Mind
you, I didn't have particularly good text books, so I had to unlearn some
stuff later on :(


-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
Australiahttp://parallel.hpc.unsw.edu.au/rks
International prefix  +612, Interstate prefix 02


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Re: why can't we erase information?

2006-05-06 Thread Russell Standish

On Thu, May 04, 2006 at 08:04:40AM -0700, John M wrote:
 
 Russell,
 thanks for your fime and effort to reply. 3 things:
 
 1. You picked my Hawkng typo, I have many more. I do
 recall that post and it gives me while writing, the
 subconscious vacillation: which version is the right
 and which the left? Very rarely do I wright his name.

Well I was having a little dig at you - not being at all serious
about it...

 
 2. You use usable (used) physics views in a topic way
 away from classical physics views, puting a systems
 talk into space-time measuring with a morphology I
 cannot (don't want to) follow in this thread. 
 

This is the usual definition and context of the term closed system.
Of course the term closed means many other things: a closed set for
instance, or closure in formal systems (which means the formal system
is complete). But I always thought we were talking about the
thermodynamic meaning.


 3. In your last par you said it: isolated from the
 rest of the unkiverse exactly the singularity I DO
 identify with Tom's description of a closed system. 
 

But I'm not sure a singularity is a closed system (the thermodynamics
meaning anyway).

 And 2Qs: 
 Yours:
  What is an unknowable closed system?
 If nothing (including information) comes out it must
 be pretty unknowable. In that ballgame ou suppose:
 it turns open from c;osed and then again closed,
 I assume it disappears from our observation. I see no
 indication that it keeps the same coordinates when
 dissappeared as we found kit at when it was open.
 The coordunates you want to find it at dissipate as
 well.

I don't see why this should happen - perhaps it happens sometimes, but
not to classical thermodynamics systems.

 Not to mention the changes or world ujndergoes to...
 Mine:
 RSt: Usually because it doesn't move :) Consider
  something inside a shielded container in a
 vacuum...
 How is move identified in connection with (my
 version of) closed system (singularity) with no
 interconnection in space lor time of OUR habiturl
 system? Assigning coordinates to no-info sounds
 funny. And the shielded vacuum container is Physics
 101. 
 
  I am on a different track...
 
 Regards
 
 John M
 

I suspect I don't follow you at all...

-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
Australiahttp://parallel.hpc.unsw.edu.au/rks
International prefix  +612, Interstate prefix 02


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Re: why can't we erase information?

2006-05-06 Thread Saibal Mitra

This thread is still alive! It seems that information can't be erased in
this thread either :)

I think that information can't be erased because of the way time is (or
should be) defined. If you take the observer moment approach to the
multiverse, then you have to define a notion of time. That definition will
then imply conservation of information.




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Re: why can't we erase information?

2006-05-06 Thread jamikes

Russell,
my apologies for the approximate typing. I don't assign to your not
following my comments to that awful new keyboard I tried to use (light grey
letters on a slightly less light grey base - not visible and I am not a good
'blind'typist) with the YAHOO-mail spellchecker that garbles up the
letters - I think your uncertainty stems from a different knowledge-base I
use.

Classical thermodynamics I learned in 1942 when I identified it as the
science which tells us how things would go wouldn't they go the way they do
go
meaning the game of isotherm and reversible equational craze in closed
systems.
Then later Prigogine et al improved upon it, but I still hold the field
within the limited model of our epistemic - ever changing, enriching -
interpretation of the (obsolete) historical bases from very primitive
knowledge level times and accordingly primitive measurements by
unsophisticated instrumentation, subject to an all ingenious explanation on
THAT level. (Think about the dozen+ (and still counting) changing views
about the 'entropy' conceptS).

The 'scientific view' does not fit into the interconnected and interactive
wholeness - it is topically boundaried (reduced?) into a model view.  It is
representative to our ongoing sciences, we cannot think including the
'totality'
using our matter-limited brainfunction, - only in a 'reduced-to-models' way,
which is pretty efficient as long as we do not want to explain them all by
the results drawn from within a limited model.
Our present view (totality, or wholeness) is far from know-it-all, but I
think it covers more information than had Ptolemy, Newton, Adam Smith or
Rousseau.
Brilliance of mind does not substitute for factual knowledge.
*
Singularity in my view is a no-system because there is no way we can
extract any information about it - unless we give up the definition. This is
how I view a 'closed' system, (not lawyerish: well, you can look at it as
semi-closed, or even open, if you like,...) If it is closed, it is closed.
Singularity is nice to speak about, I hold: there is no such thing only in
sci-fi. We get usded to many sci-fi marvels and in the 15th step it looks
like real.

Russell, when I said good bye to my polymer science (1987) and started to
think I tried to throw out things to be 'believed' (axioms, paradoxes,
emergence, chaos).  I retired with limited movablity and allowed myself to
get away from conventional reductionism.  You are in the profession, books
projects, responsibility for what you said yesterday: I don't want to
persuade you to think differently, especially since I am fully aware of the
embryonic level of the 'new ways' I still try to find. I have questions,
very few answers and I doubt them.

John



- Original Message -
From: Russell Standish [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Saturday, May 06, 2006 12:17 AM
Subject: Re: why can't we erase information?



 On Thu, May 04, 2006 at 08:04:40AM -0700, John M wrote:
 
  Russell,
  thanks for your fime and effort to reply. 3 things:
 
  1. You picked my Hawkng typo, I have many more. I do
  recall that post and it gives me while writing, the
  subconscious vacillation: which version is the right
  and which the left? Very rarely do I wright his name.

 Well I was having a little dig at you - not being at all serious
 about it...

 
  2. You use usable (used) physics views in a topic way
  away from classical physics views, puting a systems
  talk into space-time measuring with a morphology I
  cannot (don't want to) follow in this thread.
 

 This is the usual definition and context of the term closed system.
 Of course the term closed means many other things: a closed set for
 instance, or closure in formal systems (which means the formal system
 is complete). But I always thought we were talking about the
 thermodynamic meaning.


  3. In your last par you said it: isolated from the
  rest of the unkiverse exactly the singularity I DO
  identify with Tom's description of a closed system.
 

 But I'm not sure a singularity is a closed system (the thermodynamics
 meaning anyway).

  And 2Qs:
  Yours:
   What is an unknowable closed system?
  If nothing (including information) comes out it must
  be pretty unknowable. In that ballgame ou suppose:
  it turns open from c;osed and then again closed,
  I assume it disappears from our observation. I see no
  indication that it keeps the same coordinates when
  dissappeared as we found kit at when it was open.
  The coordunates you want to find it at dissipate as
  well.

 I don't see why this should happen - perhaps it happens sometimes, but
 not to classical thermodynamics systems.

  Not to mention the changes or world ujndergoes to...
  Mine:
  RSt: Usually because it doesn't move :) Consider
   something inside a shielded container in a
  vacuum...
  How is move identified in connection with (my
  version of) closed system (singularity) with no
  interconnection in space lor time of OUR habiturl

Re: why can't we erase information?

2006-05-04 Thread Jesse Mazer

Tom Caylor wrote:


Actually, in reviewing the definition of Turing machine (it's been over
2 decades since I studied it) I agree with you.  The Turing machine
leaves behind a memory of its past through its writes to the tape.
Maybe I don't understand what Wei Dai was saying with his setting of
the head back to the start of the tape.  In order to get back to the
exact beginning *state* the Turing Machine would have to be instructed
to do an inverse of all of the writes it has done and then go back to
the start of the tape.

But there is not always a unique inverse. There may be two distinct previous 
states A and B which would lead to the same state C on the next step--in 
this case the dynamics are not reversible.

Jesse



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Re: why can't we erase information?

2006-05-04 Thread Bruno Marchal


Le 03-mai-06, à 16:34, Tom Caylor a écrit :


 I am beside myself  ;)  Perhaps the interactive step-by-step approach
 that you've used in the past would be easier for you and more
 profitable for us.


Thanks for the suggestion. I will give it a try asap.






 Speaking of impasse with myself and diagonalization, a thought
 occurred to me that an instruction that erases information, like a
 Turing machine goto statement (e.g. Wei Dai's go to the beginning 
 of
 the tape instruction)


 ? Why a goto should erase anything ?


 Actually, in reviewing the definition of Turing machine (it's been over
 2 decades since I studied it) I agree with you.  The Turing machine
 leaves behind a memory of its past through its writes to the tape.
 Maybe I don't understand what Wei Dai was saying with his setting of
 the head back to the start of the tape.  In order to get back to the
 exact beginning *state* the Turing Machine would have to be instructed
 to do an inverse of all of the writes it has done and then go back to
 the start of the tape.


OK. Then it is not just a goto, it is a complete application of a 
reversible process. This will work only if you are using a reversible 
turing machine in the first place (like the one discover first by Hao 
Wang, Interesting work are those of Fredkin and Toffoli, and then the 
entire field of quantum computing).





 I believe that in the meta system, being open requires a paradigm
 shift in the meaning of understanding.


This is not entirely clear for me.



 If we just stick to our
 reductionist meaning of understanding, then we are still closed and we
 haven't really gone out of the system.  This new sense of understanding
 is what allows us to not go into an infinite or circular regress.  It
 is what allows us to assign *true* meaning in the first place.


I propose we come back on this after I (try to) explain a little bit 
more on diagonalization. I have a problem with the word reductionism. 
For some people number or machine are reductionist concepts, but I 
think that this opinion stems from a reductionist conception of number 
or machine.
Surely some new understanding of machine or number is needed.




 But now, I must confess (!) that I am discovering that if the Riemann
 critical zeros really describe a spectrum related to a quasi (?)
 classical chaotic regime---as it can be suspected from experimental
 (but still purely mathematical!) evidences---then I could imagine that
 the prime numbers could eventually describe not only a Universal Wave
 Function (even if only by pieces but the first person doesn't care as
 far as those pieces have a positive density) but would also describe a
 sort of universal wave reduction like if an absolutely external
 observer was included freely in the number's gift !
 So, recursion theory (computer science) allows internal metas, but
 primes, by their so much irregular behavior could still provide an
 apparent reduction justifying some external metas. Weird. I tend not 
 to
 believe in it, though.

 Who did invite the primes to the banquet?

 Just thinking aloud. Perhaps my Spring Riemann fever ...


 Wishful, but good, thinking in my view.  I take your I tend not to
 believe in it, though as saying that you don't think it's worth
 investing a lot of your resources in pursuing it.




I didn't say that. But we still don't know if Riemann hyp. is true and 
the field is technical. Clearly something happens there.






  I tend to think that
 pursuing anything is worth it if it allows us to see in a new way why
 it is closer or further away from reality.  The theory is that we can
 use these experiences to formulate a viewpoint of reality that is
 closer and closer to reality.


Maybe.




  Believing in this theory is actually an
 act of faith in the goodness of reality that goes beyond what evolution
 can explain.  I use the word goodness over and above
 understandability.  If reality is understandable *by us* in any way
 close to the aspirations of the Everything List, then I feel pulled to
 express this as, Someone out there is truly being good to us.


Plotinus says so but (from a 3 person point of view) I am not yet 
convinced. There are some evidences but we must try to be cold on 
this and to beware wishful thinking, and then we should also not to 
exaggerate in the opposite direction.
We can have doubt when seeing kind people suffering a lot, and remember 
that the Platonists link evil with matter, and this question is not 
entirely clear from the comp or lobian discussion.
We will not answer all this today, for sure.

Bruno




http://iridia.ulb.ac.be/~marchal/


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Re: why can't we erase information?

2006-05-04 Thread John M

Russell,
thanks for your fime and effort to reply. 3 things:

1. You picked my Hawkng typo, I have many more. I do
recall that post and it gives me while writing, the
subconscious vacillation: which version is the right
and which the left? Very rarely do I wright his name.

2. You use usable (used) physics views in a topic way
away from classical physics views, puting a systems
talk into space-time measuring with a morphology I
cannot (don't want to) follow in this thread. 

3. In your last par you said it: isolated from the
rest of the unkiverse exactly the singularity I DO
identify with Tom's description of a closed system. 

And 2Qs: 
Yours:
 What is an unknowable closed system?
If nothing (including information) comes out it must
be pretty unknowable. In that ballgame ou suppose:
it turns open from c;osed and then again closed,
I assume it disappears from our observation. I see no
indication that it keeps the same coordinates when
dissappeared as we found kit at when it was open.
The coordunates you want to find it at dissipate as
well.
Not to mention the changes or world ujndergoes to...
Mine:
RSt: Usually because it doesn't move :) Consider
 something inside a shielded container in a
vacuum...
How is move identified in connection with (my
version of) closed system (singularity) with no
interconnection in space lor time of OUR habiturl
system? Assigning coordinates to no-info sounds
funny. And the shielded vacuum container is Physics
101. 

 I am on a different track...

Regards

John M

--- Russell Standish [EMAIL PROTECTED] wrote:

 
 On Tue, May 02, 2006 at 01:33:37PM -0700, John M
 wrote:
  
  Russell, you 'opem' and 'close' a system? Why
 woulod
  you close it, once it is already open? and how
 would
  you find it again, when it is closed?
 
 Usually because it doesn't move :) Consider
 something inside a
 shielded container in a vacuum - many physics
 experiments are like
 this.
 
 Closedness, of course is an idealisation of the real
 system.
 
  
  And how do you assess those closed system laws,
 if
  no info goes in or out? (need an intelligent
 design?)
  
 
 As I said - by measuring the system at two points,
 in between which
 the system is closed. How the system evolves between
 those points in
 time will be closed system evolution.
 
  Is OUR time-scale valid to the inside of an
 unknowable
  closed system? You decide as you need - see below,
 
 What is an unknowable closed system?
 
  
  I segregated the black-hole type phantasms which
 allow
  action INTO them - and Hawkins had to make
 allowance
 
 Caution - misspelling Stephen Hawkings' name is
 considered a sure sign
 of a crank (I can't seem to lay my hands on the ref
 here...)
 
  even for them to 'release' SOME information as I
  understand. Well, these things are our
 brainchildren,
  not 'ntaure's' so we identify them as we need it.
  
  John M 
  
 
 Are you saying black holes are meant to be closed
 systems? I would
 have thought otherwise, unless it is isolated from
 the rest of the
 universe in some way.
 
 -- 


 A/Prof Russell Standish  Phone 8308
 3119 (mobile)
 Mathematics  0425
 253119 ()
 UNSW SYDNEY 2052  
 [EMAIL PROTECTED] 
 Australia   
 http://parallel.hpc.unsw.edu.au/rks
 International prefix  +612, Interstate
 prefix 02


 

 
 


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Re: why can't we erase information?

2006-05-03 Thread Kim Jones

How many angels can you fit on a drawing pin?  ;)

Kim J

On 03/05/2006, at 6:17 AM, John M wrote:

 Does that entire topic really make sense? Or is it
 just a straw-man debate to get it right? Sometimes I
 wonder.

 John M

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Re: why can't we erase information?

2006-05-03 Thread Bruno Marchal


Le 02-mai-06, à 00:18, Tom Caylor a écrit :



 Bruno Marchal wrote:
 Le 25-avr.-06, à 17:37, Tom Caylor a écrit :


 In fact, closed system and meta element seem to be contradictory.

 Not necessarily. It could depend of what you mean exactly by closed.
 Closure for the diagonalization procedure is the key. Diagonalization
 is the key of the heart of the matter. I will come back on this
 later.


 Closed system (Principia Cybernetica): An isolated system having no
 interaction with an environment.  A system whose behavior is entirely
 explainable from within, a system without input...

 Mathematically, a closed system contains its boundary, or it contains
 its limit points.  In other words, anything expressable with the given
 axioms/language is itself a member the system.



All right. Topologically they are closure systems, and they provide 
natural models for both first person and S4 type of modal knowledge 
theory. A set is included in its closure, the closure of a closure is a 
closure, etc. Example: a theory (set of formula closed for the 
application of the inference rules), a closed subset of a topological 
space (not necessarily Hausdorff), closed subpace of Hilbert spaces.







 And, back to the original question, closed system and erasing
 information seem to be contradictory.

 Why?


 I'm at an impasse with myself in trying to explain my intuition
 further.


OK.


 Meanwhile I'm studying up on diagonalization, waiting for
 your heart of the matter (which I take as just a pun and not
 referring to physical matter, heaven forbid).


Heaven forbid? Comp forbids!  ;-)

About the heart of the matter I have begun a post but I realize it will 
be far too long and technical, and I am still searching a way to 
present that heart of the matter  in some swallowable way 
Of course heart of the matter is an allusion to a section in 
Smullyan's Forever Undecided which got that name.


 Speaking of impasse with myself and diagonalization, a thought
 occurred to me that an instruction that erases information, like a
 Turing machine goto statement (e.g. Wei Dai's go to the beginning of
 the tape instruction)


? Why a goto should erase anything ?



 seems to be a *self-referential* instruction.
 Maybe this has something to do with the original question and (I
 maintain) the need for a meta viewpoint, or an open system, to
 understand it.


But then how will you explain how that meta-open system understand 
anything. You take a risk of being lead to infinite regress (but then 
see for a case below).
The heart of the matter, which will really be the closure of some set 
for the diagonalization procedure will make it possible to find some 
fixed point for the meta operation itself, so that it will be 
possible for a system belonging to a closed system to refer to itself 
in a relatively correct way, with some probability (normally determined 
from inside).

But now, I must confess (!) that I am discovering that if the Riemann 
critical zeros really describe a spectrum related to a quasi (?) 
classical chaotic regime---as it can be suspected from experimental 
(but still purely mathematical!) evidences---then I could imagine that 
the prime numbers could eventually describe not only a Universal Wave 
Function (even if only by pieces but the first person doesn't care as 
far as those pieces have a positive density) but would also describe a 
sort of universal wave reduction like if an absolutely external 
observer was included freely in the number's gift !
So, recursion theory (computer science) allows internal metas, but 
primes, by their so much irregular behavior could still provide an 
apparent reduction justifying some external metas. Weird. I tend not to 
believe in it, though.

Who did invite the primes to the banquet?

Just thinking aloud. Perhaps my Spring Riemann fever ...

Bruno

http://iridia.ulb.ac.be/~marchal/


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Re: why can't we erase information?

2006-05-03 Thread Tom Caylor


Bruno Marchal wrote:
 Le 02-mai-06, à 00:18, Tom Caylor a écrit :

 
 
  Bruno Marchal wrote:
  Le 25-avr.-06, à 17:37, Tom Caylor a écrit :
 
 
  In fact, closed system and meta element seem to be contradictory.
 
  Not necessarily. It could depend of what you mean exactly by closed.
  Closure for the diagonalization procedure is the key. Diagonalization
  is the key of the heart of the matter. I will come back on this
  later.
 
 
  Closed system (Principia Cybernetica): An isolated system having no
  interaction with an environment.  A system whose behavior is entirely
  explainable from within, a system without input...
 
  Mathematically, a closed system contains its boundary, or it contains
  its limit points.  In other words, anything expressable with the given
  axioms/language is itself a member the system.



 All right. Topologically they are closure systems, and they provide
 natural models for both first person and S4 type of modal knowledge
 theory. A set is included in its closure, the closure of a closure is a
 closure, etc. Example: a theory (set of formula closed for the
 application of the inference rules), a closed subset of a topological
 space (not necessarily Hausdorff), closed subpace of Hilbert spaces.



Bruno, thanks for understanding what I mean by closed.
John, I shouldn't have mentioned the closed definition that allows
output from the system, because this is not what I mean by closed.  My
meaning of closed does not allow knowledge from the outside.


 
 
  And, back to the original question, closed system and erasing
  information seem to be contradictory.
 
  Why?
 
 
  I'm at an impasse with myself in trying to explain my intuition
  further.


 OK.


  Meanwhile I'm studying up on diagonalization, waiting for
  your heart of the matter (which I take as just a pun and not
  referring to physical matter, heaven forbid).


 Heaven forbid? Comp forbids!  ;-)

 About the heart of the matter I have begun a post but I realize it will
 be far too long and technical, and I am still searching a way to
 present that heart of the matter  in some swallowable way 
 Of course heart of the matter is an allusion to a section in
 Smullyan's Forever Undecided which got that name.


I am beside myself  ;)  Perhaps the interactive step-by-step approach
that you've used in the past would be easier for you and more
profitable for us.

 
  Speaking of impasse with myself and diagonalization, a thought
  occurred to me that an instruction that erases information, like a
  Turing machine goto statement (e.g. Wei Dai's go to the beginning of
  the tape instruction)


 ? Why a goto should erase anything ?


Actually, in reviewing the definition of Turing machine (it's been over
2 decades since I studied it) I agree with you.  The Turing machine
leaves behind a memory of its past through its writes to the tape.
Maybe I don't understand what Wei Dai was saying with his setting of
the head back to the start of the tape.  In order to get back to the
exact beginning *state* the Turing Machine would have to be instructed
to do an inverse of all of the writes it has done and then go back to
the start of the tape.



  seems to be a *self-referential* instruction.
  Maybe this has something to do with the original question and (I
  maintain) the need for a meta viewpoint, or an open system, to
  understand it.


 But then how will you explain how that meta-open system understand
 anything. You take a risk of being lead to infinite regress (but then
 see for a case below).
 The heart of the matter, which will really be the closure of some set
 for the diagonalization procedure will make it possible to find some
 fixed point for the meta operation itself, so that it will be
 possible for a system belonging to a closed system to refer to itself
 in a relatively correct way, with some probability (normally determined
 from inside).


I believe that in the meta system, being open requires a paradigm
shift in the meaning of understanding.  If we just stick to our
reductionist meaning of understanding, then we are still closed and we
haven't really gone out of the system.  This new sense of understanding
is what allows us to not go into an infinite or circular regress.  It
is what allows us to assign *true* meaning in the first place.

 But now, I must confess (!) that I am discovering that if the Riemann
 critical zeros really describe a spectrum related to a quasi (?)
 classical chaotic regime---as it can be suspected from experimental
 (but still purely mathematical!) evidences---then I could imagine that
 the prime numbers could eventually describe not only a Universal Wave
 Function (even if only by pieces but the first person doesn't care as
 far as those pieces have a positive density) but would also describe a
 sort of universal wave reduction like if an absolutely external
 observer was included freely in the number's gift !
 So, recursion theory (computer science) allows internal metas, but
 

Re: why can't we erase information?

2006-05-03 Thread John M

Kim,
you picked a side-remark, although an important one.
In the heat of the debates it seems healthy somtimes
to rake a breather and look at the topics with an oprn
and unbiased (strangers'? outsiders'?) eye to restore
some sanity lost to emotional discourse.
Otherwise it is easy to get carried away. I do it all
the time.

In all lack of 'sanity'

John Mikes

 
--- Kim Jones [EMAIL PROTECTED] wrote:

 
 How many angels can you fit on a drawing pin?  ;)
 
 Kim J
 
 On 03/05/2006, at 6:17 AM, John M wrote:
 
  Does that entire topic really make sense? Or is it
  just a straw-man debate to get it right? Sometimes
 I
  wonder.
 
  John M
 

 
 


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Re: why can't we erase information?

2006-05-03 Thread Tom Caylor


Tom Caylor wrote:
 I am beside myself  ;)  Perhaps the interactive step-by-step approach
 that you've used in the past would be easier for you and more
 profitable for us.

Bruno,

My beside myself statement was a punny reference to self-reference.
I meant that I am looking forward to your post(s) with positive
eagerness.

Tom


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Re: why can't we erase information?

2006-05-03 Thread Russell Standish

On Tue, May 02, 2006 at 01:33:37PM -0700, John M wrote:
 
 Russell, you 'opem' and 'close' a system? Why woulod
 you close it, once it is already open? and how would
 you find it again, when it is closed?

Usually because it doesn't move :) Consider something inside a
shielded container in a vacuum - many physics experiments are like
this.

Closedness, of course is an idealisation of the real system.

 
 And how do you assess those closed system laws, if
 no info goes in or out? (need an intelligent design?)
 

As I said - by measuring the system at two points, in between which
the system is closed. How the system evolves between those points in
time will be closed system evolution.

 Is OUR time-scale valid to the inside of an unknowable
 closed system? You decide as you need - see below,

What is an unknowable closed system?

 
 I segregated the black-hole type phantasms which allow
 action INTO them - and Hawkins had to make allowance

Caution - misspelling Stephen Hawkings' name is considered a sure sign
of a crank (I can't seem to lay my hands on the ref here...)

 even for them to 'release' SOME information as I
 understand. Well, these things are our brainchildren,
 not 'ntaure's' so we identify them as we need it.
 
 John M 
 

Are you saying black holes are meant to be closed systems? I would
have thought otherwise, unless it is isolated from the rest of the
universe in some way.

-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
Australiahttp://parallel.hpc.unsw.edu.au/rks
International prefix  +612, Interstate prefix 02


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Re: why can't we erase information?

2006-05-02 Thread Tom Caylor

In a general sense, if we (the observer) are outside of the system,
there is a definition of closed system which allows output from the
system, even though there is no input into the system, *if such a
configuration is possible*.  If there is no output, I agree with you
that the system is unknowable.

If the observer is inside (part of) the closed system, that's when
things get very mystifying.  In this case there are non-trivial limits
to what we can know about the system, even though we are in it, since
our framework of knowing is also part of the system.  (For instance,
I maintain that in this case we cannot know if information is being
erased.)  But I don't think that's what your question was referring to.

Tom

John M wrote:
 Tom: one excerpt I try to address:

 Closed system (Principia Cybernetica): An isolated
 system having no
 interaction with an environment.  A system whose
 behavior is entirely
 explainable from within, a system without input...
 (I skip the rest, including the mathematical closure
 as irrelevant for my reply).

 How do you know about such system?
 What I mean is: if NO interaction reaches or leaves
 the 'system', (it includes 'information as well) it
 does
 not even 'exist' for us. It is more than a 'black
 hole' which is said to be receptive. A 'closed
 no-thing'?

 John M


 - Original Message -
 From: Tom Caylor [EMAIL PROTECTED]
 To: Everything List
 everything-list@googlegroups.com
 Sent: Monday, May 01, 2006 6:18 PM
 Subject: Re: why can't we erase information?




 Bruno Marchal wrote:
  Le 25-avr.-06, à 17:37, Tom Caylor a écrit :
 
  
   In fact, closed system and meta element seem
 to be contradictory.
 
  Not necessarily. It could depend of what you mean
 exactly by closed.
  Closure for the diagonalization procedure is the
 key. Diagonalization
  is the key of the heart of the matter. I will come
 back on this
  later.
 

 Closed system (Principia Cybernetica): An isolated
 system having no
 interaction with an environment.  A system whose
 behavior is entirely
 explainable from within, a system without input...

 Mathematically, a closed system contains its boundary,
 or it contains
 its limit points.  In other words, anything
 expressable with the given
 axioms/language is itself a member the system.
 ...SKIP
 Tom


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Re: why can't we erase information?

2006-05-02 Thread John M

Tom, yhou are right: my remark was not aiming AT YOUR
implied situation of 'from inside' of the system.
The outside case YOU DID ACCEPT AS OK, but you play
with words.
If  n o  interaction can leave the system (you are
outside) then it cannot allow output whatsoever.
None. If there aint, there aint. No bargain in favor
of one's opinion to hold nevertheless.
 
I left open the 'game' to 'measure' along where the
system is and find a hiatus in the contenue, it is
not feasible, because in our space measurement the
closed system (-I equate it with singularity - no
relaxed or 2nd rate one) the hypothetic 'volume' does
not show, so it won't be missed in our measurement. 
No 'buts'.

I wonder why don't we think about the mind as in a
relaxed self referential (=inside view) system, like: 
mindcontent, knowledgebase, ideation, mentality etc.
which, however indirectly receives info from outside
its (closed) system? {{that would give some new
meaning of a CLOSED MIND ha ha)

Does that entire topic really make sense? Or is it
just a straw-man debate to get it right? Sometimes I
wonder.

John M



--- Tom Caylor [EMAIL PROTECTED] wrote:

 
 In a general sense, if we (the observer) are outside
 of the system,
 there is a definition of closed system which
 allows output from the
 system, even though there is no input into the
 system, *if such a
 configuration is possible*.  If there is no output,
 I agree with you
 that the system is unknowable.
 
 If the observer is inside (part of) the closed
 system, that's when
 things get very mystifying.  In this case there are
 non-trivial limits
 to what we can know about the system, even though we
 are in it, since
 our framework of knowing is also part of the
 system.  (For instance,
 I maintain that in this case we cannot know if
 information is being
 erased.)  But I don't think that's what your
 question was referring to.
 
 Tom
 
 John M wrote:
  Tom: one excerpt I try to address:
 
  Closed system (Principia Cybernetica): An
 isolated
  system having no
  interaction with an environment.  A system whose
  behavior is entirely
  explainable from within, a system without
 input...
  (I skip the rest, including the mathematical
 closure
  as irrelevant for my reply).
 
  How do you know about such system?
  What I mean is: if NO interaction reaches or
 leaves
  the 'system', (it includes 'information as well)
 it
  does
  not even 'exist' for us. It is more than a 'black
  hole' which is said to be receptive. A 'closed
  no-thing'?
 
  John M
 
 
  - Original Message -
  From: Tom Caylor [EMAIL PROTECTED]
  To: Everything List
  everything-list@googlegroups.com
  Sent: Monday, May 01, 2006 6:18 PM
  Subject: Re: why can't we erase information?
 
 
 
 
  Bruno Marchal wrote:
   Le 25-avr.-06, à 17:37, Tom Caylor a écrit :
  
   
In fact, closed system and meta element
 seem
  to be contradictory.
  
   Not necessarily. It could depend of what you
 mean
  exactly by closed.
   Closure for the diagonalization procedure is the
  key. Diagonalization
   is the key of the heart of the matter. I will
 come
  back on this
   later.
  
 
  Closed system (Principia Cybernetica): An isolated
  system having no
  interaction with an environment.  A system whose
  behavior is entirely
  explainable from within, a system without input...
 
  Mathematically, a closed system contains its
 boundary,
  or it contains
  its limit points.  In other words, anything
  expressable with the given
  axioms/language is itself a member the system.
  ...SKIP
  Tom
 
 

 
 


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Re: why can't we erase information?

2006-05-02 Thread John M

Russell, you 'opem' and 'close' a system? Why woulod
you close it, once it is already open? and how would
you find it again, when it is closed?

And how do you assess those closed system laws, if
no info goes in or out? (need an intelligent design?)

Is OUR time-scale valid to the inside of an unknowable
closed system? You decide as you need - see below,

I segregated the black-hole type phantasms which allow
action INTO them - and Hawkins had to make allowance
even for them to 'release' SOME information as I
understand. Well, these things are our brainchildren,
not 'ntaure's' so we identify them as we need it.

John M 

--- Russell Standish [EMAIL PROTECTED] wrote:

 
 We can observe a closed system at two points in time
 t0, t1 say. The
 system is closed in between, but not at the point of
 observation,
 obviously.
 
 The evolution of the system between the two
 observation points must
 follow closed system laws.
 
 Cheers
 
 On Mon, May 01, 2006 at 06:42:26PM -0700, John M
 wrote:
  
  
  Tom: one excerpt I try to address:
  
  Closed system (Principia Cybernetica): An
 isolated
  system having no
  interaction with an environment.  A system whose
  behavior is entirely
  explainable from within, a system without
 input...
  (I skip the rest, including the mathematical
 closure
  as irrelevant for my reply).
  
  How do you know about such system?
  What I mean is: if NO interaction reaches or
 leaves
  the 'system', (it includes 'information as well)
 it
  does
  not even 'exist' for us. It is more than a 'black
  hole' which is said to be receptive. A 'closed
  no-thing'?
  
  John M
  
  
  - Original Message -
  From: Tom Caylor [EMAIL PROTECTED]
  To: Everything List
  everything-list@googlegroups.com
  Sent: Monday, May 01, 2006 6:18 PM
  Subject: Re: why can't we erase information?
  
  
  
  
  Bruno Marchal wrote:
   Le 25-avr.-06, à 17:37, Tom Caylor a écrit :
  
   
In fact, closed system and meta element
 seem
  to be contradictory.
  
   Not necessarily. It could depend of what you
 mean
  exactly by closed.
   Closure for the diagonalization procedure is the
  key. Diagonalization
   is the key of the heart of the matter. I will
 come
  back on this
   later.
  
  
  Closed system (Principia Cybernetica): An isolated
  system having no
  interaction with an environment.  A system whose
  behavior is entirely
  explainable from within, a system without input...
  
  Mathematically, a closed system contains its
 boundary,
  or it contains
  its limit points.  In other words, anything
  expressable with the given
  axioms/language is itself a member the system.
  ...SKIP
  Tom
  
  
  
  
  
 -- 


 A/Prof Russell Standish  Phone 8308
 3119 (mobile)
 Mathematics  0425
 253119 ()
 UNSW SYDNEY 2052  
 [EMAIL PROTECTED] 
 Australia   
 http://parallel.hpc.unsw.edu.au/rks
 International prefix  +612, Interstate
 prefix 02


 

 
 


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Re: why can't we erase information?

2006-05-01 Thread Tom Caylor


Bruno Marchal wrote:
 Le 25-avr.-06, à 17:37, Tom Caylor a écrit :

 
  In fact, closed system and meta element seem to be contradictory.

 Not necessarily. It could depend of what you mean exactly by closed.
 Closure for the diagonalization procedure is the key. Diagonalization
 is the key of the heart of the matter. I will come back on this
 later.


Closed system (Principia Cybernetica): An isolated system having no
interaction with an environment.  A system whose behavior is entirely
explainable from within, a system without input...

Mathematically, a closed system contains its boundary, or it contains
its limit points.  In other words, anything expressable with the given
axioms/language is itself a member the system.


  And, back to the original question, closed system and erasing
  information seem to be contradictory.

 Why?


I'm at an impasse with myself in trying to explain my intuition
further.  Meanwhile I'm studying up on diagonalization, waiting for
your heart of the matter (which I take as just a pun and not
referring to physical matter, heaven forbid).

Speaking of impasse with myself and diagonalization, a thought
occurred to me that an instruction that erases information, like a
Turing machine goto statement (e.g. Wei Dai's go to the beginning of
the tape instruction) seems to be a *self-referential* instruction.
Maybe this has something to do with the original question and (I
maintain) the need for a meta viewpoint, or an open system, to
understand it.

Tom


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Re: why can't we erase information?

2006-05-01 Thread Tom Caylor

I notice that erasure of information on a goto instruction occurs
only for goto instructions which send the Turing machine to an
instruction already executed.  Thus the self-reference is a reference
to the *past* self of the Turing machine, which in a sense is the only
self the Turing machine knows.

Tom

Tom Caylor wrote:
 Bruno Marchal wrote:
  Le 25-avr.-06, à 17:37, Tom Caylor a écrit :
 
  
   In fact, closed system and meta element seem to be contradictory.
 
  Not necessarily. It could depend of what you mean exactly by closed.
  Closure for the diagonalization procedure is the key. Diagonalization
  is the key of the heart of the matter. I will come back on this
  later.
 

 Closed system (Principia Cybernetica): An isolated system having no
 interaction with an environment.  A system whose behavior is entirely
 explainable from within, a system without input...

 Mathematically, a closed system contains its boundary, or it contains
 its limit points.  In other words, anything expressable with the given
 axioms/language is itself a member the system.

 
   And, back to the original question, closed system and erasing
   information seem to be contradictory.
 
  Why?
 

 I'm at an impasse with myself in trying to explain my intuition
 further.  Meanwhile I'm studying up on diagonalization, waiting for
 your heart of the matter (which I take as just a pun and not
 referring to physical matter, heaven forbid).

 Speaking of impasse with myself and diagonalization, a thought
 occurred to me that an instruction that erases information, like a
 Turing machine goto statement (e.g. Wei Dai's go to the beginning of
 the tape instruction) seems to be a *self-referential* instruction.
 Maybe this has something to do with the original question and (I
 maintain) the need for a meta viewpoint, or an open system, to
 understand it.
 
 Tom


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Re: why can't we erase information?

2006-05-01 Thread John M


Tom: one excerpt I try to address:

Closed system (Principia Cybernetica): An isolated
system having no
interaction with an environment.  A system whose
behavior is entirely
explainable from within, a system without input...
(I skip the rest, including the mathematical closure
as irrelevant for my reply).

How do you know about such system?
What I mean is: if NO interaction reaches or leaves
the 'system', (it includes 'information as well) it
does
not even 'exist' for us. It is more than a 'black
hole' which is said to be receptive. A 'closed
no-thing'?

John M


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Sent: Monday, May 01, 2006 6:18 PM
Subject: Re: why can't we erase information?




Bruno Marchal wrote:
 Le 25-avr.-06, à 17:37, Tom Caylor a écrit :

 
  In fact, closed system and meta element seem
to be contradictory.

 Not necessarily. It could depend of what you mean
exactly by closed.
 Closure for the diagonalization procedure is the
key. Diagonalization
 is the key of the heart of the matter. I will come
back on this
 later.


Closed system (Principia Cybernetica): An isolated
system having no
interaction with an environment.  A system whose
behavior is entirely
explainable from within, a system without input...

Mathematically, a closed system contains its boundary,
or it contains
its limit points.  In other words, anything
expressable with the given
axioms/language is itself a member the system.
...SKIP
Tom




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Re: why can't we erase information?

2006-04-26 Thread Bruno Marchal


Le 25-avr.-06, à 17:37, Tom Caylor a écrit :


 Tom Toffoli's paper, Nothing makes sense in computing except in the
 light of evolution, gives support to the idea that there needs to be
 some meta element to give meaning or design to this whole swirl of
 information we see around us.  I think this is also why we keep 
 feeling
 the need to appeal to anthropic thoughts.

 Tom

 I'd like to add that I don't think that evolution in a closed system
 actually supplies a meta element.  I'm just pointing out that
 Toffoli's paper is an example of recognizing that there needs to be a
 meta element.

OK.



 In fact, closed system and meta element seem to be contradictory.

Not necessarily. It could depend of what you mean exactly by closed.
Closure for the diagonalization procedure is the key. Diagonalization 
is the key of the heart of the matter. I will come back on this 
later.


 And, back to the original question, closed system and erasing
 information seem to be contradictory.

Why?

Bruno


http://iridia.ulb.ac.be/~marchal/


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Re: why can't we erase information?

2006-04-13 Thread Tom Caylor

Any conclusion about information erasure, or entropy, in a given system
seems to depend on the particular meaning assigned to the information.
Note that assigned is a verb.  What I mean when I say this is that
I'm pointed to the fact that it takes someone to do it.

There's a recurring thought in this thread about information's
dependency on an observer (Russell Standish), a language (Hal Finney).
Bruno suggests entropy is a 1st person phenomenon.  In other words, the
assigning of meaning to the information (or variables, constraints,
states) requires a person.  From a certain point of view it may look
locally like an increase in information, but do a change of variables
(albeit maybe a horrific one) and viola, information is decreasing.

On the other hand, when we talk about information erasure, it seems
that we are talking about something different from entropy.  Saiba
Mitra says that it could be that internal observers can't see
information erasure.  Ben Udell appealed to the need for a meta
viewpoint.  Total information erasure has to be in the global context
of the whole universe, or Everything.  Otherwise you can't be sure
you're dealing with information erasure, or if it's simply negative
entropy.  So you have to be omniscient about the whole universe.  Hence
my previous reference to the assumption of reductionism and a closed
system, i.e. assume you are God.

Wei Dai's Turing machine, which acts on instructions to erase
information, has to interpret the instructions using a certain
language.  The command to erase could be interpreted as having a
different meaning in another language.

Tom Toffoli's paper, Nothing makes sense in computing except in the
light of evolution, gives support to the idea that there needs to be
some meta element to give meaning or design to this whole swirl of
information we see around us.  I think this is also why we keep feeling
the need to appeal to anthropic thoughts.

Tom


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Re: why can't we erase information?

2006-04-13 Thread Tom Caylor

My first sentence looks like I was equating information erasure with
entropy, but further down I hope it's clear that I'm treating them as
two different concepts.

Tom


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Re: why can't we erase information?

2006-04-11 Thread Wei Dai

Jesse Mazer wrote:
 As for the question of why we live in a universe that apparently has this
 property, I don't think there's an anthropic explanation for it, I'd see 
 it
 as part of the larger question of why we live in a universe whose
 fundamental laws seem to be so elegant and posess so many symmetries, one 
 of
 which is time-symmetry (or to be more accurate, CPT-symmetry, which means
 the laws of physics are unchanged if you switch particles with 
 antiparticles
 and flip the 'parity' along with reversing which direction of time is
 labeled 'the future' and which is labeled 'the past'). Some TOEs that have
 been bandied about here say that we should expect to live in a universe
 whose laws are very compressible, so maybe this would be one possible way 
 of
 answering the question.

Let me be more explicit about the point I was trying to make. Most of the 
TOEs that try to explain why our laws are so elegant (for example 
Schmidhuber's) do so by assuming that all possible computations exist, with 
our universe being in some sense a random selection among all possible 
computations. Elegant universes with simple laws have high algorithmic 
probability (i.e., high probability of being produced by a random program), 
thus explaining why we live in one.

The problem I was trying to point out with this approach is that the 
standard Turing machine we usually use to define computations is not 
reversible, meaning it includes instructions such as set the current tape 
location to 0 (regardless of what's currently on it) that erase 
information. Most programs that we (human beings) write use these kinds of 
instructions all the time, and thus are not reversible. A random program on 
such a machine could only avoid irreversibility by chance. But our universe 
apparently does avoid them, so this observation seems to require further 
explanation under this kind of approach.

Of course we can use a reversible Turing machine, or a quantum computer 
(which is also inherently reversible), to define algorithmic probability, in 
which case we would expect a random program to be reversible. But that seems 
like cheating...



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Re: why can't we erase information?

2006-04-11 Thread Wei Dai

Ti Bo wrote:
 On reversibility, there is the observation (I think acredittable to Tom
 Toffoli)
 that most/all irreversible systems have a reversible subsystem and the
 dynamics arrive in that
 subsystem after some (finite) time. Thus any system that we observe a
 while
 after it has started will, with high likelihood, be reversible. In some
 sense the
 irreversibility dissipates and leaves a reversible core.

That's an interesting observation, but are you suggesting that it can 
explain why our universe is reversible? If so, how? Do you have a reference 
to a fuller explication of the idea? 



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Re: why can't we erase information?

2006-04-11 Thread Wei Dai

Saibal Mitra wrote:
 How would an observer know he is living in a universe in which information
 is lost? Information loss means that time evolution can map two different
 initial states to the same final state. The observer in the final state 
 thus
 cannot know that information really has been lost.

If the universe allows two different states to evolve into the same final 
state, the second law of thermodynamics wouldn't hold, and we would be able 
to (in principle) contruct perpetual motion machines.

I don't know why you say this can't be detected by an observer. In theory 
all we have to do is prepare two systems in two different states, and then 
observe that they have evolved into the same final state. Of course in 
practice the problem is which two different states? And as I suggest 
earlier, it may be that for anthropic reasons one or both of these states is 
very difficult to access.



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Re: why can't we erase information?

2006-04-11 Thread Jesse Mazer

From: Wei Dai [EMAIL PROTECTED]
Reply-To: everything-list@googlegroups.com
To: everything-list@googlegroups.com
Subject: Re: why can't we erase information?
Date: Mon, 10 Apr 2006 16:11:28 -0700


Jesse Mazer wrote:
  As for the question of why we live in a universe that apparently has 
this
  property, I don't think there's an anthropic explanation for it, I'd see
  it
  as part of the larger question of why we live in a universe whose
  fundamental laws seem to be so elegant and posess so many symmetries, 
one
  of
  which is time-symmetry (or to be more accurate, CPT-symmetry, which 
means
  the laws of physics are unchanged if you switch particles with
  antiparticles
  and flip the 'parity' along with reversing which direction of time is
  labeled 'the future' and which is labeled 'the past'). Some TOEs that 
have
  been bandied about here say that we should expect to live in a universe
  whose laws are very compressible, so maybe this would be one possible 
way
  of
  answering the question.

Let me be more explicit about the point I was trying to make. Most of the
TOEs that try to explain why our laws are so elegant (for example
Schmidhuber's) do so by assuming that all possible computations exist, with
our universe being in some sense a random selection among all possible
computations. Elegant universes with simple laws have high algorithmic
probability (i.e., high probability of being produced by a random program),
thus explaining why we live in one.

The problem I was trying to point out with this approach is that the
standard Turing machine we usually use to define computations is not
reversible, meaning it includes instructions such as set the current tape
location to 0 (regardless of what's currently on it) that erase
information. Most programs that we (human beings) write use these kinds of
instructions all the time, and thus are not reversible. A random program on
such a machine could only avoid irreversibility by chance. But our universe
apparently does avoid them, so this observation seems to require further
explanation under this kind of approach.

Of course we can use a reversible Turing machine, or a quantum computer
(which is also inherently reversible), to define algorithmic probability, 
in
which case we would expect a random program to be reversible. But that 
seems
like cheating...

I have a vague memory that there was some result showing the algorithmic 
complexity of a string shouldn't depend too strongly on the details of the 
Turing machine--that it would only differ by some constant amount for any 
two different machines, maybe? Does this ring a bell with anyone?

Jesse



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Re: why can't we erase information?

2006-04-11 Thread Ti Bo


Hi All,

   I feel like a Toffoli disciple. I cannot recreate the argument right 
now,
but he argues that an increase in entropy is compatible with reversible 
and irreversible
processes, but a decrease in entropy is only compatible with reversible 
dynamics.

   The argument is interesting and the book where it appears (he was 
talking at
the Data Ecologies 05 event last year) is due out some time soon...

cheers,

tim



On Apr 11, 2006, at 4:26 AM, Jesse Mazer wrote:
 Likewise, I think the second law is interpreted as the destruction of
 information needs a bit of clarification--as entropy increases, there 
 are
 more and more microstates compatible with a given macrostate so the 
 observer
 is losing information about the microstate, but information is not 
 really
 being lost at a fundamental level, since *in principle* it would 
 always be
 possible to measure a system's exact microstate.





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Re: why can't we erase information?

2006-04-11 Thread Ti Bo


I think that this observation could explain why we see a reversible 
universe:
all the irreversibility has already happened. If we think of a dynamics 
with
discrete time then we have a collection of points with directed arcs
between them. As a graph, this has the structure of several cycles with
trees connected to some of the points. The trees correspond to the 
irreversible
part of the dynamics, the cycles to the reversible part.

If the largest tree is of height h, then after h time steps, the system
must be in a state on one of the cycles. Thus the dynamics is 
reversible.

Of course this argument requires a finite state system, which is usually
assumed in such discussions. An uncountably infinite counterexample to 
this idea
is an infinite tree, with every node branching to two predecessors. At 
every
state and every time step there is an irreversible transition.

A countable counterexample can be assembled by grafting a copy of the 
natural numbers
onto the integers with the system state transition taking n to n-1. 
Then 0
has two predecessors. Because there is no bound on the time taken for a 
pair of
distinct states (the same positive integer on the two branches) to be 
mapped together,
the reversibility does not dissipate.

I thought I had a copy of the paper here, but I cannot locate it. If 
memory
serves me right, it was one of a series of papers that Toffoli wrote in 
the
last half of the 90s dealing with computation and physics. Most of them 
are
good reading anyway, so have a dive into:
http://pm1.bu.edu/~tt/publ.html

Tim




On Apr 11, 2006, at 1:19 AM, Wei Dai wrote:


 Ti Bo wrote:
 On reversibility, there is the observation (I think acredittable to 
 Tom
 Toffoli)
 that most/all irreversible systems have a reversible subsystem and the
 dynamics arrive in that
 subsystem after some (finite) time. Thus any system that we observe a
 while
 after it has started will, with high likelihood, be reversible. In 
 some
 sense the
 irreversibility dissipates and leaves a reversible core.

 That's an interesting observation, but are you suggesting that it can
 explain why our universe is reversible? If so, how? Do you have a 
 reference
 to a fuller explication of the idea?



 

-Tim Boykett  TIME'S UP::Research Department
  \ /   Industriezeile 33b A-4020 Linz Austria
   X+43-732-787804(ph)   +43-732-7878043(fx)
  / \  [EMAIL PROTECTED]http://www.timesup.org
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http://www.timesup.org/fieldresearch/setups/index.html


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Re: why can't we erase information?

2006-04-11 Thread Wei Dai

Jesse Mazer:
 I have a vague memory that there was some result showing the algorithmic
 complexity of a string shouldn't depend too strongly on the details of the
 Turing machine--that it would only differ by some constant amount for any
 two different machines, maybe? Does this ring a bell with anyone?

That is correct, but the constant is a multiplicative one, and could be made 
arbitrarily large. 



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Re: why can't we erase information?

2006-04-11 Thread Saibal Mitra

Yes, I agree. But it could be that information loss is a bit ambiguous. E.g.
't Hooft has shown that you can start with a deterministic model exhibiting
information loss and end up with quantum mechanics.

Saibal

- Original Message - 
From: Jesse Mazer [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Monday, April 10, 2006 03:22 AM
Subject: Re: why can't we erase information?



 Saibal Mitra wrote:

 
 
 How would an observer know he is living in a universe in which
information
 is lost? Information loss means that time evolution can map two different
 initial states to the same final state. The observer in the final state
 thus
 cannot know that information really has been lost.

 If he is able to figure out the fundamental laws of physics of his
universe,
 then he could see whether or not they have this property of it being
 possible to deduce past states from present ones (I think the name for
this
 property might be 'reversible', although I can't remember the difference
 between 'reversible' and 'invertible' laws). For example, the rules of
 Conway's Game of Life cellular automaton are not reversible, but if it
 were possible for such a world to support intelligent beings I don't see
why
 it wouldn't be in principle possible for them to deduce the underlying
 rules.

 As for the question of why we live in a universe that apparently has this
 property, I don't think there's an anthropic explanation for it, I'd see
it
 as part of the larger question of why we live in a universe whose
 fundamental laws seem to be so elegant and posess so many symmetries, one
of
 which is time-symmetry (or to be more accurate, CPT-symmetry, which means
 the laws of physics are unchanged if you switch particles with
antiparticles
 and flip the 'parity' along with reversing which direction of time is
 labeled 'the future' and which is labeled 'the past'). Some TOEs that have
 been bandied about here say that we should expect to live in a universe
 whose laws are very compressible, so maybe this would be one possible way
of
 answering the question.

 Jesse



 

-
Defeat Spammers by launching DDoS attacks on Spam-Websites:
http://www.hillscapital.com/antispam/


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Re: why can't we erase information?

2006-04-11 Thread Bruno Marchal


Le 11-avr.-06, à 01:11, Wei Dai a écrit :


 Jesse Mazer wrote:
 As for the question of why we live in a universe that apparently has 
 this
 property, I don't think there's an anthropic explanation for it, I'd 
 see
 it
 as part of the larger question of why we live in a universe whose
 fundamental laws seem to be so elegant and posess so many symmetries, 
 one
 of
 which is time-symmetry (or to be more accurate, CPT-symmetry, which 
 means
 the laws of physics are unchanged if you switch particles with
 antiparticles
 and flip the 'parity' along with reversing which direction of time is
 labeled 'the future' and which is labeled 'the past'). Some TOEs that 
 have
 been bandied about here say that we should expect to live in a 
 universe
 whose laws are very compressible, so maybe this would be one possible 
 way
 of
 answering the question.

 Let me be more explicit about the point I was trying to make. Most of 
 the
 TOEs that try to explain why our laws are so elegant (for example
 Schmidhuber's) do so by assuming that all possible computations exist, 
 with
 our universe being in some sense a random selection among all possible
 computations. Elegant universes with simple laws have high algorithmic
 probability (i.e., high probability of being produced by a random 
 program),
 thus explaining why we live in one.


Except that I done understand what you mean by our universe, due to 
the 1/3 person pov distinction. Adding that ourselves are the result of 
a long (deep) computations could help here (cf Bennett's work on 
computational depth), but will be enough only if you allow the result 
of the deep computation to remains stable on some dovetailing on the 
reals, to explain away the first person rabbits!




 The problem I was trying to point out with this approach is that the
 standard Turing machine we usually use to define computations is not
 reversible, meaning it includes instructions such as set the current 
 tape
 location to 0 (regardless of what's currently on it) that erase
 information.


To my knowledge, Hao Wang (a expert on Godel) has been the first to 
program a universal turing machine which never erase its tape. Much 
work has been done (cf Toffoli). Abramski has written a compiler 
transforming irreversible programs into reversible one.
In term of combinators, a quantum world lacks Kestrels (capable of 
eliminating information) and Warbler or Starling or any combinators 
capable of duplicating information. I explain this in my last paper 
(the one which is not yet on my web page).




 Most programs that we (human beings) write use these kinds of
 instructions all the time, and thus are not reversible. A random 
 program on
 such a machine could only avoid irreversibility by chance. But our 
 universe
 apparently does avoid them, so this observation seems to require 
 further
 explanation under this kind of approach.

 Of course we can use a reversible Turing machine, or a quantum computer
 (which is also inherently reversible), to define algorithmic 
 probability, in
 which case we would expect a random program to be reversible. But that 
 seems
 like cheating...


Certainly. Note that a kripke multiverse with a symmetric accessibility 
relation (good for reversibility), needs to obey to the modal law LASE: 
p - BDp. I got it with the interview of the lobian machine but only 
for the atomic p. This means that true irreversibility is still an open 
problem with comp, but there is some evidence at the bottom.

Apparently information, at the bottom, cannot be created, cannot be 
erased, and cannot in general be duplicated. Quite unlike classical 
bits. But with comp this is just due to our ignorance about the 
infinite set of computations which emulate us. I think it is the same 
with Everett, information is never lost at the bottom, but when we 
measure bottom states, we entangle ourselves with all possible 
alternative results and the information dissipates through parallel 
histories. The increase of entropy could be a local and a first person 
(plural) phenomenon.

Bruno


http://iridia.ulb.ac.be/~marchal/


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Re: why can't we erase information?

2006-04-11 Thread Saibal Mitra


- Original Message - 
From: Wei Dai [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Tuesday, April 11, 2006 01:46 AM
Subject: Re: why can't we erase information?



 Saibal Mitra wrote:
  How would an observer know he is living in a universe in which
information
  is lost? Information loss means that time evolution can map two
different
  initial states to the same final state. The observer in the final state
  thus
  cannot know that information really has been lost.

 If the universe allows two different states to evolve into the same final
 state, the second law of thermodynamics wouldn't hold, and we would be
able
 to (in principle) contruct perpetual motion machines.

 I don't know why you say this can't be detected by an observer. In theory
 all we have to do is prepare two systems in two different states, and then
 observe that they have evolved into the same final state. Of course in
 practice the problem is which two different states? And as I suggest
 earlier, it may be that for anthropic reasons one or both of these states
is
 very difficult to access.


Yes, in principle you could observe such a thing. But it may be that generic
models exhibiting information loss look like model that don't have
information loss to internal observers. 't Hooft's deterministic models are
an example of this.

I'm also skeptical about observers being able to make more efficient
machines. The problem with that, as I see it (I haven't read Lloyd's book
yet) is as follows.

Consider first a model without information loss, like our own universe. What
is preventing us from converting heat into work with 100% efficiency is lack
of information. If we had access to all the information that is present then
you could make an effective Maxwell's Daemon.

Lacking such information, Maxwell's Deamon has to make measurements, which
it has to act on. But eventually it has to clear it's memory, and that makes
it ineffective.

To get rid of this problem Maxwell's Daemon would have to be able to reset
its memory without changing the state of the rest of the universe. This
could possibly be done in an universe with information loss, but that could
only work if the Daemon has control over the information loss process. If
information loss interferes with the actions of the Daemon, then it isn't
much use.

You could also think of the possiblity of some ''physical process'' which
would be sort of a ''passive Maxwell's Deamon'' that could reduce the
entropy in such universe. Using that you could create a temperature
difference between two objects. To extract work you now need to let heat
flow between the two objects. So, at that stage you need an entropy to
increase again.

So, to me this doesn't seem to be a generic world in which you have
information loss, rather a world in which it is preserved but where it can
be overruled at will. The benefits come from that magical power.


Saibal


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Re: why can't we erase information?

2006-04-11 Thread daddycaylor

I'm not a physicist, so I'm asking a question.  How much of this we 
have no information loss in this universe prinicple are we simply 
assuming at the outset?  I know that a lot of it is unverified theory, 
like in the case of Stephen Hawking's black hole vs. no black hole from 
infinity argument, etc.  For instance, are we simply assuming, by the 
sacred laws of thermodynamics, that in the quantum background there is 
always an antiparticle for each particle in order to annihilate each 
other?  Or could it be that particles and antiparticles appear and 
disappear asymmetrically on their own, under our observational radar, 
even though that wouldn't be elegant?  Perhaps all these undetectable 
asymmetries add up to cancel out any observable asymmetries.  Weirder 
things have happened in quantum physics.  Are we assuming by elegance 
that there is no information loss?  You can just tell me to go back to 
my math if you want.

Tom


 Saibal Mitra wrote:
  How would an observer know he is living in a universe in which
information
  is lost? Information loss means that time evolution can map two
different
  initial states to the same final state. The observer in the final 
state
  thus
  cannot know that information really has been lost.

 If the universe allows two different states to evolve into the same 
final
 state, the second law of thermodynamics wouldn't hold, and we would be
able
 to (in principle) contruct perpetual motion machines.

 I don't know why you say this can't be detected by an observer. In 
theory
 all we have to do is prepare two systems in two different states, and 
then
 observe that they have evolved into the same final state. Of course in
 practice the problem is which two different states? And as I suggest
 earlier, it may be that for anthropic reasons one or both of these 
states
is
 very difficult to access.


Yes, in principle you could observe such a thing. But it may be that 
generic
models exhibiting information loss look like model that don't have
information loss to internal observers. 't Hooft's deterministic models 
are
an example of this.

I'm also skeptical about observers being able to make more efficient
machines. The problem with that, as I see it (I haven't read Lloyd's 
book
yet) is as follows.

Consider first a model without information loss, like our own universe. 
What
is preventing us from converting heat into work with 100% efficiency is 
lack
of information. If we had access to all the information that is present 
then
you could make an effective Maxwell's Daemon.

Lacking such information, Maxwell's Deamon has to make measurements, 
which
it has to act on. But eventually it has to clear it's memory, and that 
makes
it ineffective.

To get rid of this problem Maxwell's Daemon would have to be able to 
reset
its memory without changing the state of the rest of the universe. This
could possibly be done in an universe with information loss, but that 
could
only work if the Daemon has control over the information loss process. 
If
information loss interferes with the actions of the Daemon, then it 
isn't
much use.

You could also think of the possiblity of some ''physical process'' 
which
would be sort of a ''passive Maxwell's Deamon'' that could reduce the
entropy in such universe. Using that you could create a temperature
difference between two objects. To extract work you now need to let heat
flow between the two objects. So, at that stage you need an entropy to
increase again.

So, to me this doesn't seem to be a generic world in which you have
information loss, rather a world in which it is preserved but where it 
can
be overruled at will. The benefits come from that magical power.


Saibal


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Re: why can't we erase information?

2006-04-11 Thread Hal Finney

A few years ago I posted a speculation about Harry Potter universes,
from the Schmidhuber perspective.  Schmidhuber argues that the reason
we don't see such a universe is that its program would be more complex,
hence its algorithmic-complexity measure would be less.  Such a universe
would basically have natural laws identical to what we see, but in
addition it would have exceptions to the laws.  You wave a wand and say
Lumino! and light appears.  (Here I am taking the Harry Potter name
rather literally, but the same thing applies to the more general concept
of universes with magical exceptions to the rules.)

You could also argue, as Wei does, on anthropic grounds that in such a
universe the ease of exploiting magic would reduce selection pressure
towards intelligence.  Indeed in the Harry Potter stories there are
magical animals but it is never explained why their amazing powers did
not allow them to dominate the world and kill off mundane creatures long
before human civilization arose.

I suggested that the Schmidhuber argument has a loophole.  It's true that
the measure of a simple universe is much greater than a universe with
the same laws plus one or more exceptions.  But if you consider the set
of all universes built on those laws plus exceptions, considering all
possible variants on exceptions, the collective measure of all these
universes is roughly the same as the simple universe.  So Schmidhuber
gives us no good reason to reject the possibility that our universe may
have exceptions to the natural laws.

If we do live in an exceptional universe, we are more likely to live in
one which is only slightly exceptional, i.e. one whose laws are among
the simplest possible modifications from the base laws.  Unfortunately,
without a better picture of the true laws of physics and an understanding
of the language that expresses them most simply, we can't say much about
what form exceptions might take.  We know that they would be likely
to be simple, in the same language that makes our base laws simple,
but since we don't know that language it is hard to draw conclusions.

Here is where the anthropic argument advanced by Wei Dai sheds some
light; one thing we could say is that these simple exceptions should not
be exploitable by life and make things so easy as to remove selection
pressure.  So this would constrain the kinds of exceptions that could
exist.

Ironically, waving a wand and speaking in Latin would indeed be the
kind of exception that would not likely be exploited by unintelligent
life forms.  So purely on anthropic principles we could not fully rule out
Harry Potter magic.  But the complexity of embedding Latin phrases in the
natural laws would argue strongly against us living in such a universe.

Hal Finney

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Re: why can't we erase information?

2006-04-11 Thread Russell Standish

On Mon, Apr 10, 2006 at 09:45:50PM -0700, Brent Meeker wrote:
 
 Russell Standish wrote:
  On Mon, Apr 10, 2006 at 12:03:47AM -0700, Brent Meeker wrote:
  
 Russell Standish wrote:
 
 Unitary evolution preserves information. It is only through
 measurement by an observer that information can be created or
 destroyed. Usually, the second law is interpreted as the destruction
 of information (anyone observing a closed system will over time know
 less information about the system), so it puzzles me that you have the
 sign the other way.
 
 What?  You're saying that if I observe a system, then I know less about it. 
  You 
 must be using some non-standard meaning of know.
 
 Brent Meeker
 
  
  
  Yes - in the case of milk being stirred into coffee. Strange as it may
  seem, you know more information when the system is initially
  structured than after that initial structure  has dispersed.
 
 What's that have to do with observing it?  Stirring milk into coffee isn't 
 observing it - and as you point out below, entropy depends on observation, 
 i.e. on some coarse grained constraint.
 
 Your answer seems to consist of non-sequiturs.  ISTM that my knowledge is 
 increased when I observe something.  Physically this corresponds to some 
 small 

Your total knowledge increases, assuming perfect memory (which is
itself debatable, but beside the point). But your knowledge of the
current state of the system decreases. The information content of the
system decreases (exactly offset by the rise in entropy). 

My point is that this is precisely because it is observed.  If it
weren't observed, one simply has a quantum superposition undergoing
unitary evolution.

Cheers
-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
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Re: why can't we erase information?

2006-04-11 Thread Russell Standish

On Mon, Apr 10, 2006 at 10:26:17PM -0400, Jesse Mazer wrote:
 
 As I understand it, you don't need exactly need an observer, you just need 
 to identify various macro-variables (like pressure and temperature) which 
 can be used to coarse-grain the phase space of the system, with entropy 
 being proportional to the logarithm of the number of possible detailed 
 microstates (detailed descriptions of the positions and momenta of all the 
 particles, within the limits of the uncertainty principle) compatible with a 
 given macrostate (descriptions of the system which only tell you the value 
 of the macro-variables). Once you have chosen your set of macro-variables, 
 they should have well-defined values for any system, regardless of whether 
 it's being observed by anyone or not. Of course, the choice of variables is 
 based on what properties we human observers are actually capable of 
 measuring in practice, so I don't necessarily disagree with your statement, 
 but I think it needs a little clarification.

That is precisely my point. However, observers are needed to specify
the thermodynamic variables (as otherwise these things are
meaningless). I try to make this somewhat provocatively, sure, but
denying the role of the observer is bit like sweeping it under the carpet.

 
 Likewise, I think the second law is interpreted as the destruction of 
 information needs a bit of clarification--as entropy increases, there are 
 more and more microstates compatible with a given macrostate so the observer 
 is losing information about the microstate, but information is not really 
 being lost at a fundamental level, since *in principle* it would always be 
 possible to measure a system's exact microstate.
 
 Jesse
 

Information also needs an observer. Information is lost from the
observer. I would argue it is not hidden, unless you believe in the
possibility of Laplace's daemon actually existing. (Which I suspect
you are saying with your *in principle* clause).

Also note that exact measurements of microstates is *in principle*
incompatible with the Heisenberg Uncertainty Principle.

-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
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Re: why can't we erase information?

2006-04-11 Thread Russell Standish

There would have to be some pretty major conditions and caveats on
this. A system undergoing thermodynamic stress (ie is nonequilibrium)
will exhibit a lowering of entropy compared with its state at
equilibrium. However, the process is decidedly nonreversible...

Cheers. 

On Tue, Apr 11, 2006 at 09:18:01AM +0200, Ti Bo wrote:
 
 
 Hi All,
 
I feel like a Toffoli disciple. I cannot recreate the argument right 
 now,
 but he argues that an increase in entropy is compatible with reversible 
 and irreversible
 processes, but a decrease in entropy is only compatible with reversible 
 dynamics.
 
The argument is interesting and the book where it appears (he was 
 talking at
 the Data Ecologies 05 event last year) is due out some time soon...
 
 cheers,
 
 tim
 
 
 
 On Apr 11, 2006, at 4:26 AM, Jesse Mazer wrote:
  Likewise, I think the second law is interpreted as the destruction of
  information needs a bit of clarification--as entropy increases, there 
  are
  more and more microstates compatible with a given macrostate so the 
  observer
  is losing information about the microstate, but information is not 
  really
  being lost at a fundamental level, since *in principle* it would 
  always be
  possible to measure a system's exact microstate.
 
 
 
 
 
 
-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
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Re: why can't we erase information?

2006-04-11 Thread Jesse Mazer

Russell Standish wrote:


Also note that exact measurements of microstates is *in principle*
incompatible with the Heisenberg Uncertainty Principle.

Well, that's why I defined microstates as detailed descriptions of the 
positions and momenta of all the particles, within the limits of the 
uncertainty principle. My memory is that in the quantum version of 
statistical mechanics, the phase space is partititioned into finite regions 
so that the uncertainty principle does not prevent you from measuring which 
region the system is in (and the regions are made as small as possible while 
still having that be true). I wonder if there'd be a natural way to look at 
statistical mechanics in the MWI interpretation though--I would think the 
maximal information about a system, analogous to the microstate, would be 
the system's exact quantum state (which only assigns amplitudes to different 
values of noncommuting variables like position and momentum), and the 
evolution of the system's quantum state over time should be completely 
deterministic, and also information-preserving in the sense that knowing 
the quantum state at a later time would tell you the quantum state at an 
earlier time. But I can't think what macrostates you'd use, since a 
particular quantum state can involve a superposition of different possible 
temperatures, pressures and so forth.

Jesse



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Re: why can't we erase information?

2006-04-10 Thread Russell Standish

Unitary evolution preserves information. It is only through
measurement by an observer that information can be created or
destroyed. Usually, the second law is interpreted as the destruction
of information (anyone observing a closed system will over time know
less information about the system), so it puzzles me that you have the
sign the other way.

Because of the action of the second law, it actually takes a
thermodynamic flux to preserve information - which is why you need to
read your old backup tapes an make copies every few years if you want
to retain access to your data.

Cheers

On Sun, Apr 09, 2006 at 12:11:52AM -0700, Wei Dai wrote:
 
 If we consider our observable universe as a computation, it's rather 
 atypical in that it doesn't seem to make use of the erase operation (or 
 other any operation that irreversibly erases information). The second law of 
 thermodynamics is a consequence of this. In order to forget anything 
 (decrease entropy), we have to put the information somewhere else (increase 
 entropy of the environment), instead of just making it disappear. If this 
 doesn't make sense to you, see Seth Lloyd's new book Programming the 
 Universe : A Quantum Computer Scientist Takes On the Cosmos for a good 
 explanation of the relationship between entropy, computation, and 
 information.
 
 Has anyone thought about why this is the case? One possible answer is that 
 if it were possible to erase information, life organisms would be able to 
 construct internal perpetual motion machines to power their metabolism, 
 instead of competing with each other for sources of negentropy, and perhaps 
 intelligence would not be able to evolve in this kind of environment. If 
 this is the case, perhaps there is reason to hope that our universe does 
 contain mechanisms to erase information, but they are not easily accessible 
 to life before the evolution of intelligence. It may be a good idea to look 
 out for such mechanisms, for example in high energy particle reactions.
 
 However I'm not sure this answer is correct because there would still be 
 competition for raw material (matter and energy) where intelligence can 
 still be an advantage. Anyone have other ideas?
 
 
 
 
-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
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Re: why can't we erase information?

2006-04-10 Thread Brent Meeker

Russell Standish wrote:
 Unitary evolution preserves information. It is only through
 measurement by an observer that information can be created or
 destroyed. Usually, the second law is interpreted as the destruction
 of information (anyone observing a closed system will over time know
 less information about the system), so it puzzles me that you have the
 sign the other way.

What?  You're saying that if I observe a system, then I know less about it.  
You 
must be using some non-standard meaning of know.

Brent Meeker


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Re: why can't we erase information?

2006-04-10 Thread Ti Bo



On reversibility, there is the observation (I think acredittable to Tom 
Toffoli)
that most/all irreversible systems have a reversible subsystem and the 
dynamics arrive in that
subsystem after some (finite) time. Thus any system that we observe a 
while
after it has started will, with high likelihood, be reversible. In some 
sense the
irreversibility dissipates and leaves a reversible core.

Tim


On Apr 10, 2006, at 3:22 AM, Jesse Mazer wrote:


 Saibal Mitra wrote:



 How would an observer know he is living in a universe in which 
 information
 is lost? Information loss means that time evolution can map two 
 different
 initial states to the same final state. The observer in the final 
 state
 thus
 cannot know that information really has been lost.

 If he is able to figure out the fundamental laws of physics of his 
 universe,
 then he could see whether or not they have this property of it being
 possible to deduce past states from present ones (I think the name for 
 this
 property might be 'reversible', although I can't remember the 
 difference
 between 'reversible' and 'invertible' laws). For example, the rules of
 Conway's Game of Life cellular automaton are not reversible, but if 
 it
 were possible for such a world to support intelligent beings I don't 
 see why
 it wouldn't be in principle possible for them to deduce the underlying
 rules.

 As for the question of why we live in a universe that apparently has 
 this
 property, I don't think there's an anthropic explanation for it, I'd 
 see it
 as part of the larger question of why we live in a universe whose
 fundamental laws seem to be so elegant and posess so many symmetries, 
 one of
 which is time-symmetry (or to be more accurate, CPT-symmetry, which 
 means
 the laws of physics are unchanged if you switch particles with 
 antiparticles
 and flip the 'parity' along with reversing which direction of time is
 labeled 'the future' and which is labeled 'the past'). Some TOEs that 
 have
 been bandied about here say that we should expect to live in a universe
 whose laws are very compressible, so maybe this would be one possible 
 way of
 answering the question.

 Jesse



 

-Tim Boykett  TIME'S UP::Research Department
  \ /   Industriezeile 33b A-4020 Linz Austria
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Re: why can't we erase information?

2006-04-10 Thread Russell Standish

On Mon, Apr 10, 2006 at 12:03:47AM -0700, Brent Meeker wrote:
 
 Russell Standish wrote:
  Unitary evolution preserves information. It is only through
  measurement by an observer that information can be created or
  destroyed. Usually, the second law is interpreted as the destruction
  of information (anyone observing a closed system will over time know
  less information about the system), so it puzzles me that you have the
  sign the other way.
 
 What?  You're saying that if I observe a system, then I know less about it.  
 You 
 must be using some non-standard meaning of know.
 
 Brent Meeker
 

Yes - in the case of milk being stirred into coffee. Strange as it may
seem, you know more information when the system is initially
structured than after that initial structure  has dispersed.

And yes you need to observe it. Entropy is undefined without an
observer.

Cheers

-- 

A/Prof Russell Standish  Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED] 
Australiahttp://parallel.hpc.unsw.edu.au/rks
International prefix  +612, Interstate prefix 02


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Re: why can't we erase information?

2006-04-10 Thread Jesse Mazer




From: Russell Standish [EMAIL PROTECTED]
Reply-To: everything-list@googlegroups.com
To: everything-list@googlegroups.com
Subject: Re: why can't we erase information?
Date: Mon, 10 Apr 2006 18:34:42 +1000


On Mon, Apr 10, 2006 at 12:03:47AM -0700, Brent Meeker wrote:
 
  Russell Standish wrote:
   Unitary evolution preserves information. It is only through
   measurement by an observer that information can be created or
   destroyed. Usually, the second law is interpreted as the destruction
   of information (anyone observing a closed system will over time know
   less information about the system), so it puzzles me that you have the
   sign the other way.
 
  What?  You're saying that if I observe a system, then I know less about 
it.  You
  must be using some non-standard meaning of know.
 
  Brent Meeker
 

Yes - in the case of milk being stirred into coffee. Strange as it may
seem, you know more information when the system is initially
structured than after that initial structure  has dispersed.

And yes you need to observe it. Entropy is undefined without an
observer.

Cheers

As I understand it, you don't need exactly need an observer, you just need 
to identify various macro-variables (like pressure and temperature) which 
can be used to coarse-grain the phase space of the system, with entropy 
being proportional to the logarithm of the number of possible detailed 
microstates (detailed descriptions of the positions and momenta of all the 
particles, within the limits of the uncertainty principle) compatible with a 
given macrostate (descriptions of the system which only tell you the value 
of the macro-variables). Once you have chosen your set of macro-variables, 
they should have well-defined values for any system, regardless of whether 
it's being observed by anyone or not. Of course, the choice of variables is 
based on what properties we human observers are actually capable of 
measuring in practice, so I don't necessarily disagree with your statement, 
but I think it needs a little clarification.

Likewise, I think the second law is interpreted as the destruction of 
information needs a bit of clarification--as entropy increases, there are 
more and more microstates compatible with a given macrostate so the observer 
is losing information about the microstate, but information is not really 
being lost at a fundamental level, since *in principle* it would always be 
possible to measure a system's exact microstate.

Jesse



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Re: why can't we erase information?

2006-04-10 Thread Brent Meeker

Russell Standish wrote:
 On Mon, Apr 10, 2006 at 12:03:47AM -0700, Brent Meeker wrote:
 
Russell Standish wrote:

Unitary evolution preserves information. It is only through
measurement by an observer that information can be created or
destroyed. Usually, the second law is interpreted as the destruction
of information (anyone observing a closed system will over time know
less information about the system), so it puzzles me that you have the
sign the other way.

What?  You're saying that if I observe a system, then I know less about it.  
You 
must be using some non-standard meaning of know.

Brent Meeker

 
 
 Yes - in the case of milk being stirred into coffee. Strange as it may
 seem, you know more information when the system is initially
 structured than after that initial structure  has dispersed.

What's that have to do with observing it?  Stirring milk into coffee isn't 
observing it - and as you point out below, entropy depends on observation, 
i.e. on some coarse grained constraint.

Your answer seems to consist of non-sequiturs.  ISTM that my knowledge is 
increased when I observe something.  Physically this corresponds to some small 
decrease in the entropy of a few neural connections in my brain.  This is 
accompanied by a relative large increase in entropy of my body which I have to 
make up for by consuming some low entropy organic material.

Whether the entropy the thing I observe is increased or decreased by the 
observation is a different question.

Brent Meeker

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why can't we erase information?

2006-04-09 Thread Wei Dai

If we consider our observable universe as a computation, it's rather 
atypical in that it doesn't seem to make use of the erase operation (or 
other any operation that irreversibly erases information). The second law of 
thermodynamics is a consequence of this. In order to forget anything 
(decrease entropy), we have to put the information somewhere else (increase 
entropy of the environment), instead of just making it disappear. If this 
doesn't make sense to you, see Seth Lloyd's new book Programming the 
Universe : A Quantum Computer Scientist Takes On the Cosmos for a good 
explanation of the relationship between entropy, computation, and 
information.

Has anyone thought about why this is the case? One possible answer is that 
if it were possible to erase information, life organisms would be able to 
construct internal perpetual motion machines to power their metabolism, 
instead of competing with each other for sources of negentropy, and perhaps 
intelligence would not be able to evolve in this kind of environment. If 
this is the case, perhaps there is reason to hope that our universe does 
contain mechanisms to erase information, but they are not easily accessible 
to life before the evolution of intelligence. It may be a good idea to look 
out for such mechanisms, for example in high energy particle reactions.

However I'm not sure this answer is correct because there would still be 
competition for raw material (matter and energy) where intelligence can 
still be an advantage. Anyone have other ideas?



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Re: why can't we erase information?

2006-04-09 Thread Benjamin Udell

It does seem a little confusing how to quantify information when the universe 
itself is regarded as a computation.

Some flies buzzing around the horses may make a difference in the horse race. 
If the flies are erased, then that issue is settled, which seems to count as 
a decrease of uncertainty and therefore as an _increase_ of info. How does one 
arrive at a result for net change of info?

The settlement of questions by imaginary erasure of all 'extraneous' factors, 
elimination of 'details,' reductive abstraction, etc., seems to be a basic 
working step for treating a scenario under a probability-theoretic viewpoint. 
Would the real erasure of those factors count in the same way as an increase 
of information? It seems like an increase of info at least in the case where we 
do remember the real things that we've erased or annihilated. Anyway, trying to 
arrive at a result for net change of information seems to require adopting some 
meta viewpoint, though I don't know, I'm not well versed in information 
theory.

On the other hand, when we treat things as being samples  surfaces of more 
opaque things even when we do know somewhat about what is or isn't under those 
surfaces, then factors/details which have been settled tend to get put into 
question or veiled such that it's uncertain what difference they make, and 
that's a decrease in info which seems to be a basic working step for treating a 
scenario under a statistical-theoretic viewpoint. When we feign ignorance about 
how things will be affected, that's an imaginary addition possible factors. 
Would a real adding of possible factors, uncertainty, count as a decrease in 
info? It seems like a decrease of info at least in the case where we do 
remember that those factors weren't previously there.

Are these problems real? Maybe a universe doesn't allow for change of 
information that requires some sort of meta viewpoint to calculate. On the 
other hand, maybe I just don't know what I'm talking about.

Best regards, Ben Udell


- Original Message - 
From: Wei Dai [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Sunday, April 09, 2006 3:11 AM
Subject: why can't we erase information?



If we consider our observable universe as a computation, it's rather 
atypical in that it doesn't seem to make use of the erase operation (or 
other any operation that irreversibly erases information). The second law of 
thermodynamics is a consequence of this. In order to forget anything 
(decrease entropy), we have to put the information somewhere else (increase 
entropy of the environment), instead of just making it disappear. If this 
doesn't make sense to you, see Seth Lloyd's new book Programming the 
Universe : A Quantum Computer Scientist Takes On the Cosmos for a good 
explanation of the relationship between entropy, computation, and 
information.

Has anyone thought about why this is the case? One possible answer is that 
if it were possible to erase information, life organisms would be able to 
construct internal perpetual motion machines to power their metabolism, 
instead of competing with each other for sources of negentropy, and perhaps 
intelligence would not be able to evolve in this kind of environment. If 
this is the case, perhaps there is reason to hope that our universe does 
contain mechanisms to erase information, but they are not easily accessible 
to life before the evolution of intelligence. It may be a good idea to look 
out for such mechanisms, for example in high energy particle reactions.

However I'm not sure this answer is correct because there would still be 
competition for raw material (matter and energy) where intelligence can 
still be an advantage. Anyone have other ideas?


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Re: why can't we erase information?

2006-04-09 Thread Brent Meeker

Wei Dai wrote:
 If we consider our observable universe as a computation, it's rather 
 atypical in that it doesn't seem to make use of the erase operation (or 
 other any operation that irreversibly erases information). The second law of 
 thermodynamics is a consequence of this. In order to forget anything 
 (decrease entropy), we have to put the information somewhere else (increase 
 entropy of the environment), instead of just making it disappear. If this 
 doesn't make sense to you, see Seth Lloyd's new book Programming the 
 Universe : A Quantum Computer Scientist Takes On the Cosmos for a good 
 explanation of the relationship between entropy, computation, and 
 information.
 
 Has anyone thought about why this is the case? One possible answer is that 
 if it were possible to erase information, life organisms would be able to 
 construct internal perpetual motion machines to power their metabolism, 
 instead of competing with each other for sources of negentropy, and perhaps 
 intelligence would not be able to evolve in this kind of environment. If 
 this is the case, perhaps there is reason to hope that our universe does 
 contain mechanisms to erase information, but they are not easily accessible 
 to life before the evolution of intelligence. It may be a good idea to look 
 out for such mechanisms, for example in high energy particle reactions.
 
 However I'm not sure this answer is correct because there would still be 
 competition for raw material (matter and energy) where intelligence can 
 still be an advantage. Anyone have other ideas?

I guess you have in mind some kind of local (micrsoscopic) mechanism for 
erasing 
information.  The Copenhagen intepretation of QM assumed this, but couldn't 
solve the problem of the Heisenberg cut.  At a large scale, it is not yet 
settled whether black holes erase information.  With a few exceptions, like 
t'Hooft, physicist assume that the unitary evolution of QM is fundamental.  If 
that's the case, the only place information gets erased is by expansion of 
the 
universe.

Brent Meeker

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Re: why can't we erase information?

2006-04-09 Thread Saibal Mitra

How would an observer know he is living in a universe in which information
is lost? Information loss means that time evolution can map two different
initial states to the same final state. The observer in the final state thus
cannot know that information really has been lost.



- Original Message - 
From: Wei Dai [EMAIL PROTECTED]
To: everything-list@googlegroups.com
Sent: Sunday, April 09, 2006 09:11 AM
Subject: why can't we erase information?



 If we consider our observable universe as a computation, it's rather
 atypical in that it doesn't seem to make use of the erase operation (or
 other any operation that irreversibly erases information). The second law
of
 thermodynamics is a consequence of this. In order to forget anything
 (decrease entropy), we have to put the information somewhere else
(increase
 entropy of the environment), instead of just making it disappear. If this
 doesn't make sense to you, see Seth Lloyd's new book Programming the
 Universe : A Quantum Computer Scientist Takes On the Cosmos for a good
 explanation of the relationship between entropy, computation, and
 information.

 Has anyone thought about why this is the case? One possible answer is that
 if it were possible to erase information, life organisms would be able to
 construct internal perpetual motion machines to power their metabolism,
 instead of competing with each other for sources of negentropy, and
perhaps
 intelligence would not be able to evolve in this kind of environment. If
 this is the case, perhaps there is reason to hope that our universe does
 contain mechanisms to erase information, but they are not easily
accessible
 to life before the evolution of intelligence. It may be a good idea to
look
 out for such mechanisms, for example in high energy particle reactions.

 However I'm not sure this answer is correct because there would still be
 competition for raw material (matter and energy) where intelligence can
 still be an advantage. Anyone have other ideas?



 


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Re: why can't we erase information?

2006-04-09 Thread Jesse Mazer

Saibal Mitra wrote:



How would an observer know he is living in a universe in which information
is lost? Information loss means that time evolution can map two different
initial states to the same final state. The observer in the final state 
thus
cannot know that information really has been lost.

If he is able to figure out the fundamental laws of physics of his universe, 
then he could see whether or not they have this property of it being 
possible to deduce past states from present ones (I think the name for this 
property might be 'reversible', although I can't remember the difference 
between 'reversible' and 'invertible' laws). For example, the rules of 
Conway's Game of Life cellular automaton are not reversible, but if it 
were possible for such a world to support intelligent beings I don't see why 
it wouldn't be in principle possible for them to deduce the underlying 
rules.

As for the question of why we live in a universe that apparently has this 
property, I don't think there's an anthropic explanation for it, I'd see it 
as part of the larger question of why we live in a universe whose 
fundamental laws seem to be so elegant and posess so many symmetries, one of 
which is time-symmetry (or to be more accurate, CPT-symmetry, which means 
the laws of physics are unchanged if you switch particles with antiparticles 
and flip the 'parity' along with reversing which direction of time is 
labeled 'the future' and which is labeled 'the past'). Some TOEs that have 
been bandied about here say that we should expect to live in a universe 
whose laws are very compressible, so maybe this would be one possible way of 
answering the question.

Jesse



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