Goals emerge in macroscopic descriptions of the world by Stefan Keppeler

Hi Stefan,

A coherent, logical and interesting paper.

A pleasure to read.

Don Limuti

What I was trying to say is that a law that explains, say behaviour, is not the same as a law that explains the orientation to behave.

The former is a law explaining a objective observation. The latter is a law explaining something that underlies the observation itself... whatever that might be.

The criticisms of behaviourism kind of come to the same thing. The criticism is that however clever the observation and the laws explaining them, the underlying nature of their existence are not addressed...

Hi Stefan! Well I finally got around to it, and I agree about as much as I expected to. Rather than offer criticisms of your argument, since I basically agree with it, I think I would suggest places where we might extend and add further detail to the argument. I think Mark mentioned this but it would be nice to be able to say a little more about under what conditions "aims and intentions" do emerge from microscopic dynamics and when they dont. The glass of water vs the human body example is an excellent starting point, and I like the concept of rigidity in describing the 'many degenerate macrostates' of something like the configuration space of the human body. That's a great point, but can we actually give a mathematical criteria for when the amount of macrostate degeneracy leads an "aims and intentions" desciption to be more efficient than a thermodynamic description? If it does somehow scale with the number of macrostates which for which we can't assign probabilities from inspection of the observables of microstates, what is the actual scaling relationship? I'm definitely not criticizig because I don't think I know the answer either, but it seems like it would be fun to think about.

Finally, great job describing Boltzmann's ideas. You hear people get Boltzmann wrong so often it's really refreshing to see it done well! :)

--Joe Brisendine

Dear Stefan Keppeler

I invite you and every physicist to read my work "TIME ORIGIN,DEFINITION AND EMPIRICAL MEANING FOR PHYSICISTS, Héctor Daniel Gianni ,I'm not a physicist.

How people interested in "Time" could feel about related things to the subject.

1) Intellectuals interested in Time issues usually have a nice and creative wander for the unknown.

2) They usually enjoy this wander of their searches around it.

3) For millenniums this wander has been shared by a lot of creative people around the world.

4) What if suddenly, something considered quasi impossible to be found or discovered such as "Time" definition and experimental meaning confronts them?

5) Their reaction would be like, something unbelievable,... a kind of disappointment, probably interpreted as a loss of wander.....

6) ....worst than that, if we say that what was found or discovered wasn't a viable theory, but a proved fact.

7) Then it would become offensive to be part of the millenary problem solution, instead of being a reason for happiness and satisfaction.

8) The reader approach to the news would be paradoxically adverse.

9) Instead, I think it should be a nice welcome to discovery, to be received with opened arms and considered to be read with full attention.

11)Time "existence" is exclusive as a "measuring system", its physical existence can't be proved by science, as the "time system" is. Experimentally "time" is "movement", we can prove that, showing that with clocks we measure "constant and uniform" movement and not "the so called Time".

12)The original "time manuscript" has 23 pages, my manuscript in this contest has only 9 pages.

I share this brief with people interested in "time" and with physicists who have been in sore need of this issue for the last 50 or 60 years.

Héctor

Hi, Stefan,

thanks for the good read, I truly enjoyed your essay! And I agree, our ideas are very much aligned. Let me list a few thoughts that have crossed my mind while reading your essay. By all means, don't take this as a critique, I just want to share with you what you generate:

1- The second law of thermodynamics seems to be both weaker and stronger than the more fundamental laws. Weaker, because (even if its fans will hate me for saying this) it is approximate. One cannot deduce it from microscopic dynamics, precisely because when reversing all velocities (and parity, or whatever else QM may need) the backward trajectory exists, so no mechanistic deduction is possible. Bolzmann derived irreversibility assuming particles had independent positions and velocities after each collision, which is ultimately not true. He thereby introduced irreversibility. If one discards this assumption, irreversibility does not arise. I do not want to be hard on the 2nd law, however. If we accept that it emerges (overwhelmingly!) from a probabilistic (as opposed to mechanistic) reasoning, it is extremely powerful. In fact, it is in a way stronger than the fundamental laws because, as you point out, it is independent of the nature of the underlying laws, it just emerges from large numbers. It would also arise in many other universes composed of many particles obeying different fundamental laws - probably not all such universes, but a good fraction of them.

2- I do think we have some mathematical models of goals, I should look them up to be sure. But I know that people working on insect behavior, for example, can reproduce their actions to a remarkable precision, they truly behave as tiny robots. I also believe that the whole topic of neural networks, where local plasticity rules give rise to global oriented behavior are good examples. One can argue that these are just simulations, but that brings me to the third thought.

3- I liked your search for conditions about rigidity and fluidity. I would be very curious to know how far these concepts can be pushed. One class of systems that clearly exhibits goal-directed behavior is artificial intelligence (including neural networks), with or without some hardware (robot) performing the actions. So even if I can picture your conditions of rigidity and fluidity in biological images, I am sure one can frame those conditions in a substrate-independent fashion, which you have started to do: I have the impression that your comments about the relation between a larger-scale structure, and the lower-level components are relevant in this regard. But I do not quite know whether there needs to be a sharp distinction between these two scales, or something more or less gradual would suffice. What is, ultimately, a sharp distinction? What exactly is a macro-structure? I need to think more about it ...

So, again, thanks a lot for putting my brain into motion!

inés.

Hi Stefan - your essay is eminently clear and sensible... I entirely agree that macroscopic theories are needed to describe the emergent features of larger-scale entities, and that they're fully compatible with microscopic descriptions from which these same features are absent. In fact, as I suggest in my essay, even classical physics is such a macroscopic theory, containing important features that are absent from the quantum description. Evidently the two are compatible, though the relationship is a bit more mysterious than in the Boltzmann case, which you present very well.

Is classical physics then in some sense goal-directed? Not as we usually think of it. But I argue that empirically, we know that the determinacy of macroscopic physics depends on the possibility of physical measurement (not necessarily by human observers). And I argue that physics is indeed structured just so as to keep on making more measurements possible.

If that makes sense, then the physical world might reasonably by described as having the "goal" of measuring and communicating itself, somewhat as living organisms have the goal of reproducing, and species the goal of evolving. This isn't to ascribe any mysterious source of agency... rather, in each case there's a "mindless" recursive process that operates because it keeps on generating the conditions for its own success, subject to natural selection when it fails. (This isn't at all obvious in the case of physics, because we tend to take it for granted that things are measurable. But I argue that that the physics of our universe has to be quite complex and finely-tuned to make any kind of measurement possible.)

Sorry, this wanders from the theme of your essay. You quite rightly point out that the emergence of higher-level behavior is only possible if there's a degree of flexibility in the higher-level structure... but not so much that relevant information can't be maintained over time. Beyond that, I would say the important thing is to be able to keep on repeating the same information and making it relevant in new contexts - which we see happening in very different ways in both physics and biology.

Thanks for contributing - Conrad

Stefan,

Clear and sensible connection between micro and macro worlds, a conclusion that "if the macroscopic entities under question are sufficiently flexible and sufficiently rigid,mindless mathematical laws can give rise to aims and intention"

In my essay I feature the mindless physical law of entropy operating at many levels in the universe with an interesting theory built on the second law of dynamics by Jeremy England. Without making your clear micro-macro connection I try to show that human decisions sometimes speculate theories putting together complex arrangements of life's elements.

Hope you can provide your ideas on my essay.

Regards,

Jim Hoover

I liked the discussion of rigidity, it is an interesting observation. Buckminster Fuller would say that you need both tension and integrity. In my essay I hinted at interactions between solidity and liquidity.

Stefan,

Did you read my essay and give it a rating? During this contest, there are more partisan strikes piggy-backing on comments or providing no comments.

Jim

You thought it was that bad.

hi Stefan,

Good article, I am very interesting and thank you for this article. Very happy to read this article.

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