Information (Theory)

A

Archaea

Guest
Thanks for posting :)

I had a quick read through of the constructor theory paper from constructortheory.org

Here are some highlights:

2.14 Abstract constructors
The classic philosophical puzzle of the ‘ship of Theseus’ concerns the legend that after Theseus’s adventure in Crete, the Athenians made his ship a monument, replacing any plank that decayed. Eventually, none of the original planks were left. Was it still the same ship, and if not, when did it stop being so?

Though the original puzzle has little substance (being hardly more than an essentialist exercise about the meaning of ‘same’), it does illustrate a fact about the physical world which, in the prevailing conception, is counter-intuitive. Let us approximate the ship as a substrate on which a constructor, the city of Athens, is repeatedly performing the task of restoring it to its original state. To prevent it from gradually changing shape with successive renovations, some blueprint must exist, specifying the correct shape. So Athens must be a programmable constructor, with the blueprint in a program whose physical representation (say, on a scroll) is a additional substrate that Athens must keep from deteriorating. Another part of the program would be the ideas that cause generations of Athenians to keep doing that. And since different Athenians perform the task in each generation, they, too, are among the substrates on which the task is being repeatedly performed.

So, since the ship, the scroll, and Athens are all substrates, what is the constructor? By hypothesis, none of the physical objects effecting the repair survives unchanged for many generations. Only the program does: the abstract information expressed in the scroll and the ideas. So that information meets the definition of a constructor more closely than anything else in the situation. It is an abstract constructor.

There seem to be constructor-theoretic laws, such as the interoperability principle for information (Section 2.6 above), that refer directly to abstract constructors. If there are such laws, then abstract constructors cannot be omitted from fundamental physics in the constructor-theoretic conception. Readers who baulk at the idea of an abstraction causing something physical need only substitute a weaker term for ‘can cause’ in the definition of a constructor in Section 1.1, such as ‘can cause, or codes for’.

2.15 Knowledge
The most important kind of abstract constructor is knowledge. Knowledge is information which, once it is physically instantiated in a suitable environment, tends to cause itself to remain so: it survives criticism, testing, random noise, and errorcorrection. (Here I am adopting Popper’s (1972) conception of knowledge, in which there need be no knowing subject.) For example, the knowledge encoded in an organism’s DNA consists of abstract genes that cause the environment to transform raw materials into another instance of the organism, and thereby to keep those abstract genes, and not mutations or other variants of them, physically instantiated, despite the mutation and natural selection that keep happening. Similarly, the ideas constituting the abstract constructor for preserving the ship of Theseus would have had to include not only some relatively arbitrary information about the historical shape of the ship, but also knowledge of how to cause Athenians to preserve those ideas themselves through the generations, and to reject rival ideas.

Now consider again the set of all physically possible transformations. For almost every such transformation, the story of how it could happen is the story of how knowledge might be created and applied to cause it. Part of that story is, in almost all cases, the story of how people (intelligent beings) would create that knowledge, and of why they would retain the proposal to apply it in that way while rejecting or amending rival proposals (so a significant determinant is moral knowledge). Hence, from the constructor-theoretic perspective, physics is almost entirely the theory of the effects that knowledge (abstract constructors) can have on the physical world, via people. But again, the prevailing conception conceals this.

[...]

3.9 Wealth
In constructor theory it is natural to define the wealth of an entity in a nonanthropocentric way as the set of transformations that the entity would be capable of performing without generating new knowledge. Wealth has always consisted fundamentally of knowledge, even though it has been limited by the capacity of relatively fixed installations for harnessing naturally occurring resources. Once universal constructors exist, it will consist almost entirely of knowledge.

[...]

3.15 Are we universal constructors?
I guess that neither a typical human nor human civilisation as a whole approximates a universal constructor – not because we are something less but because, I hope, we are something more: we cannot be programmed – and especially not programed to carry out arbitrary instructions for an arbitrarily long time – because we may not want to.

Since we do not have hardware to upload arbitrary information into our brains as programs, the issue comes down to this: for each possible task A , does there exist information M(A) such that if we received a message instantiating M(A) , from space, followed by the substrates of A in a legitimate input state, and a supply of naturally-occurring raw materials, we would reliably transform the substrates to the corresponding output states, and then be ready to do so again for another possible task? What would M(A) have to say, to cause us to do this?

Presumably the effective part of M(A) would be in its preamble. Could it be a threat: ‘we are immensely powerful and will destroy you unless you obey the following instructions faithfully…’? Or a trade: ‘we offer you the secret of immortality if you pass this test…’? Presumably neither would be sufficient to cause us to be just as capable of performing A again afterwards in response to another instance of M(A) . Among other things, M(A) would have to cause changes in our civilisation that prevented our ideas from moving in directions that would make us disinclined to obey future commands. Perhaps there exists some way of fooling us into making something that would destroy us after causing us to build a more straightforward universal constructor. But again, could that be done with high reliability? I think that in reality, our creativity makes it implausible that we approximate a universal constructor very closely, despite our presumed ability to build one.

If a universal constructor is possible, there must be a smallest one. It would be interesting to know what it is, and how it works. Is it at the scale of molecules? If so, it may become the centrepiece of nanotechnology. If it is much larger, then generalpurpose nanotechnology will never be independent of macroscopic control and support systems. Will it just be a curiosity (like the simplest Turing machine)? Or will it rapidly become the commonest pattern of matter in the universe, the vehicle by which knowledge comes to dominate everything that happens?
 

Laura

Administrator
Administrator
Moderator
FOTCM Member
Pierre's book is out! It includes a discussion on Information Theory and whole bunch of other stuff.

ECHCC_front_low_def_CoverBook_.jpg


http://www.amazon.com/Changes-Human-Cosmic-Connection-Secret-History-ebook/dp/B00KI8KKWW/ref=sr_1_1?ie=UTF8&qid=1400964663&sr=8-1&keywords=earth+changes+and+the+human+cosmic

Hard copy available within days.
 

Siberia

Ambassador
Ambassador
FOTCM Member
Thanks, Laura, after I've read yesterday's article on SoTT by Pierre, I will definitely put this book on the top of my reading list. I was absolutely shocked to learn all this: http://www.sott.net/article/279645-Mummy-why-is-Daddy-wearing-a-dress-Daddy-why-does-Mummy-have-a-moustache. I didn't know that things are SO BAD :shock:
 

Laura

Administrator
Administrator
Moderator
FOTCM Member
Siberia said:
Thanks, Laura, after I've read yesterday's article on SoTT by Pierre, I will definitely put this book on the top of my reading list. I was absolutely shocked to learn all this: http://www.sott.net/article/279645-Mummy-why-is-Daddy-wearing-a-dress-Daddy-why-does-Mummy-have-a-moustache. I didn't know that things are SO BAD :shock:

Yes, and that was just a thread that got pulled on after the book was finished and that particular study was brought up in the context of Information Theory. When I came across that during the editing I said to myself "What???!!!" and then Pierre and I began discussing it and off he went to do more research (poor guy never gets any rest with me cracking the whip!)

I've opened a thread on this new book: https://cassiopaea.org/forum/index.php/topic,34835.new/topicseen.html and I hope we can get to discussing the host of things in there as soon as others can read it. It's a clean and easy read with lots of graphics and I can guarantee you won't be able to put it down.
 

eleusis

Jedi Master
Great job Pierre. Congratulations on your book and may it fly off the shelves. But I'm not sure I've heard of your coauthor. Perhaps you could recommend something she's written. :D (Lightning strikes) :shock:

Based on your article, and hearing you speak on SOTT talk radio, I'm sure there is going to be quite a bit that is digestible and nourishing in your book even though it may be a bit gnarly going down.
 

eleusis

Jedi Master
Pierre, I know I was a bit jokey or breezy in my prior post but truly want you to know that I do know all the hard work and effort that went into your work. Laura as well. And that's not something I ever want to make light of. I really can't wait to get your book because I know it's going to get my mind whirling and give me so much to consider and apply.

Every time I see the cover of a book written by someone here like Ark's or Laura's or yours (and Approaching Infinity's too) I can't describe the feelings of happiness that wash over me. Find myself wishing I was in a different more sane world where works like these are truly appreciated, studied and disseminated widely and that the author or author's receive the proper compensation for their efforts.
 

Laura

Administrator
Administrator
Moderator
FOTCM Member
Not to worry Pegasus - I thought it was clever and I chuckled!

And yes, I'm not sure that everyone realizes that running as a constant drumbeat behind all the other stuff we do is our constant research and connecting the dots.
 

RGG

Jedi Master
Laura said:
Pierre's book is out! It includes a discussion on Information Theory and whole bunch of other stuff.

ECHCC_front_low_def_CoverBook_.jpg


http://www.amazon.com/Changes-Human-Cosmic-Connection-Secret-History-ebook/dp/B00KI8KKWW/ref=sr_1_1?ie=UTF8&qid=1400964663&sr=8-1&keywords=earth+changes+and+the+human+cosmic

Hard copy available within days.

Wow! Great topics and really cool cover too.

Being a "big picture" kind of person this kind of compilation really appeals to me but I can see and appreciate how all of the small pieces of the puzzle and references will appeal to those who are at the other end of the spectrum and work their way up starting with facts and details too. Exactly the perfect kind of balance this organization excels at and it makes for exciting AND insightful reading. Could be the kind of book that those people hovering around the periphery of waking up could read and get wise to the goings on of this planet quickly with. That would make it quite invaluable in a world where we have become used to being fed short, sexed-up news bites instead of doing any kind of real research or data collection ourselves. It is unfortunate that humanity generally is that way but you gotta work with you got or the message will never get through! The house is burning down after all and it's time to shout out to anyone who will listen to wake the hell up. After I've read it myself, I'll be lending it out immediately to those I know who might like it.


Congrats on your book Pierre :) I'm looking very forward to it!
 

Muxel

Dagobah Resident
I like the cover art of Pierre's new book. Nice!

[quote author=Reconstructing physics: The universe is information]And it has a "counterfactual" character: a message cannot carry information unless a different message is also possible.[/quote]
Is this "Free Will"? (or an analogue of it?)
 

darksai

Jedi Master
Muxel said:
I like the cover art of Pierre's new book. Nice!

[quote author=Reconstructing physics: The universe is information]And it has a "counterfactual" character: a message cannot carry information unless a different message is also possible.
Is this "Free Will"? (or an analogue of it?)
[/quote]

No, at least I don't think so. I think free will relates closer to the sending of a message and it's interpretation. The sender chooses what to send, and the receiver chooses how to interpret. Theoretically, then, the message itself is objectively static while it travels from sender to receiver, though in real life a message can pass through several receiver-sender pairs, or mediums, which may alter how the message is received for the "intended" receiver.

What he's saying is about messages is easier to explain with an example. If you get an missed call your phone that from someone you don't know that you weren't expecting, there is no information from the sender; it could indicate that someone wanted to talk to you and phoned from a different number, or it could be that the caller had the wrong number. For a missed call to carry meaning (without any further messages being sent) you would have had to agree on the meaning/information beforehand which means you've made a selection of some set of possibilities, which means there must be more than one possible message. I hope this makes it clearer, as it's kinda hard to explain, but it helps to try and think of few examples yourself if you're not convinced :)
 

rs

Dagobah Resident
I just saw a Scientific American web article about this. I'm curious as to Ark's take on the paper.

Constructor Theory of Information
David Deutsch & Chiara Marletto

Centre for Quantum Computation, The Clarendon Laboratory, University of Oxford
Materials Department, University of Oxford
May 2014

We present a theory of information expressed solely in terms of which transformations of physical systems are possible and which are impossible – i.e. in constructor - theoretic terms.
Although it includes conjectured laws of physics that are directly about information, independently of the details of particular physical instantiations, it does not regard information as an a priori mathematical or logical concept, but as something whose nature and properties are determined by the laws of physics alone. It does not suffer from the circularity at the foundations of existing information theory (namely that information and distinguishability are each defined in terms of the other). It explains the relationship between classical and quantum information, and reveals the single, constructor - theoretic property underlying the most distinctive phenomena associated with the latter, including the lack of in - principle distinguishability of some states, the impossibility of cloning, the existence of pairs of variables that cannot simultaneously have sharp values, the fact that measurement processes can be both deterministic and unpredictable, the irreducible perturbation caused by measurement, and entanglement (locally inaccessible information).

http://arxiv.org/ftp/arxiv/papers/1405/1405.5563.pdf
 

Pierre

SuperModerator
Moderator
FOTCM Member
pegasus said:
Pierre, I know I was a bit jokey or breezy in my prior post but truly want you to know that I do know all the hard work and effort that went into your work.

Don't worry. I liked your joke (especially the lightning part) :)
 

monotonic

The Living Force
I recently came across an engineer who wrote that noise is just missing information. I thought that was an interesting idea to contemplate.
 
Top Bottom