Thanks for that. I am also not sure if your paper really relates to my view.

Let me ask you the following: does your approach (a) somehow embody Mach's principle? (b) somehow relate to the arrow of time?

If yes, then yes!

George Ellis

Well for me the issue is whether algebra can sensibly describe a modular hierarchical structure. If so, it might work, If not, then not. As you say, it's all in the structure.

We really need graph theory. I am a novice in that area.

George

Dear Cristi

" I think there are strong parallels between how causation may "propagate" from "top" toward "down", and the relation between quantum measurements and reality."

yes indeed. I think this is an area that will eventually be illuminated by this approach.

And yes a key to it all relates to constraints: this is how top down actin takes place, in physical terms. But as I state, they have very powerful properties: they can create, modify, and delete lower level entities. That is a key reason why a purely bottom up approach won't work.

Ah, singularities in GR: haven't worked on those for a long time. Will try to get time to look.

George

Dear Jeffrey

"that random (symmetric) processes sometimes become concatenated into more complex processes which are capable of controlling their own foundations to ensure their own continued existence" - nicely stated. Yes. But that is possible because the possibility space for such processes includes structures that have properties (e.g. crystal symmetries, molecular folding) that enables such top-down causation to happen. And this not only allows their own continued existence: it allows their building up of higher levels of complexity. This is possible via adaptive selection, choosing the higher level entities that work from those that don't.

George

Hi, you are giving exactly the same arguments over again. And my reply remains the same.

"As I argued, if when there is a cause, to rationally understand it, we must be able to reduce it a previous cause, then this chain of cause-and-effect goes on ad infinitum, or it stops at some primordial cause which, as it cannot be reduced to a preceding cause, cannot be understood by definition, then nothing has any meaning since we cannot find its ultimate cause. You still haven't pointed out what is wrong with this reasoning." As I stated before, you don't have to understand ultimate meaning in order to understand local meaning. For example, we can carry out this discussion without knowing if God exists or if random chance underlies all.

I am simply not debating ultimate causation in this paper. Please see "Is There "Ultimate Stuff" and Are There "Ultimate Reasons"?" by David Rousseau and Julie Rousseau for that debate, which is not the topic of my essay. If you are not willing to look at how causation works in local situations such as daily life, my essay is obviously of no interest to you and you should debate with them.

"I'm afraid that the bigbang hypothesis a fairy tale." Ok so present day cosmology goes out the window.

"In contrast, as I argue here (or, in this study), a self-creating universe has no cause and nor does it violate conservation laws as it has no physical reality as a whole: since in this universe particles create, cause one another, it can be understood rationally." So how do particles come into being that can create themselves? If that has any meaning, it has nothing to do with this essay. take it up with David Rousseau and Julie Rousseau.

George

DearIan,

thanks for that. Multiple issues to deal with!

"the ultimate example of top-down causation also happens to be the ultimate boundary condition: the universe itself (even within the context of the multiverse - indeed, one could argue that physical laws are constrained by the universe for, if they were different, it wouldn't be the same universe). On the other hand, you say at one point that no real system is truly isolated (and, in principle, I tend to agree), but what about the universe as a whole? If there is no multiverse (an open question), then the universe truly is an isolated system."

Well one is there starting to deal with issues of existence of the laws of physics that underlie how things behave in our universe. If one extends the hierarchy from one of scale to one of causation (as one needs to do on the life sciences side) then the laws of physics causally lie above the largest scales of the universe (alternatively, whatever laws govern multiverses lie above the physical existence of multiverses).

These laws - which are not themselves physical entities - somehow intrude down on the physical levels (see e.g. Roger Penrose' writings on the large, the small, and the complex). IN this sense the physical universe is not closed: it is controlled by a causally higher level of non-physical entities such as laws of physics, with their mysterious basis in mathematics.

This takes us far from my essay, so I won't pursue it. I'll answer your other issues in another posting.

george

continued:

"1. I think the computing example with Word and Photoshop is a bit oversimplified."

- not sure why. It was Turing's genius to see that any application could be implemented by the same hardware, by changing its operating context; in this case, by loading different high level software. That software then determines the (data) ==> (output) relation.

"2. You mentioned "uncaused changes" at one point. Are you saying there is no such thing as randomness or do you accept that random outcomes can still be causal (just not deterministic)?"

- quantum physics tells us - if we believe the standard view - there is stuff out there which is neither causal nor deterministic. I find it strange that this fundamental discovery is still not accepted (at least implicitly) by many physicists today.

3. Regarding logic, one could argue that physics partly emerges from logic itself in which case it would not be particularly unusual to have higher-level logic dictating physical processes since, in some sense, logic may be even more fundamental and universal.

- I completely agree.

"4. Why can't multiple processes/paths lead to the same conclusion? I fail to see why this is a bad thing. (This question/comment refers to point D on pp. 5-6)."

- I'm not saying its a bad thing: on the contrary, it`s very positive because that is what underlies emergence of higher level entities that are independent of their lower level representations.

"5. You suggest that interactions are necessarily higher-level phenomena from particles themselves, but one could fairly easily argue that quantum field theory says that they are, in some sense, *more* fundamental than particles (or, at the very least, *as* fundamental)."

- well they arise from interactions of effective particles: however those arise.

"6. I'm still unconvinced by argument 6e on p. 7."

- I agree its debatable. But there is lots of evidence of the importance of random processes in microbiology and in brain microprocesses. It is a hypothesis that this might relate to quantum uncertainty. Needs development and testing.

"Finally, while I agree that there is most definitely some top-down causality in the universe, I tend to think that, in general, it tends to "drift" upward, if you will, i.e. if you were to model causal flow as a process, it would be like a random walk with drift with the drift going from the simple to the more complex."

- it starts off as a random walk, But then it is crucial that some outcomes of that random process get selected and others get rejected. It is that selection process (locally going against the grain of entropy growth) that underlies the growth of true complexity, and lifts causation from physical to biological. In physical terms, it is a non-unitary process, and it is not random: it is directed by the selection criteria. In biological terms, it is where useful information originates.

George

George,

Thanks for the reply. Regarding, the computing example, on the one hand I see your point (and Turing's), but the reason I thought it was a bit oversimplified is because the program that one chooses to run is ultimately constrained by the underlying physics of the machine you're running it on. In quantum computing, for example, D-Wave's system (which Lidar's group at USC has shown has coherence times consistent with it being truly quantum) can really only run certain types of tasks (e.g. it happens to be best suited to machine-learning tasks). This is precisely because it is an adiabatic quantum computer. The way the adiabatic aspect of its implementation limits what it can do.

Sorry for leading us off-topic with the comments about universes, but it is something intriguing to consider at any rate.

Cheers,

Ian

Hi Ian

You say "the program that one chooses to run is ultimately constrained by the underlying physics of the machine you're running it on." This is a crucial claim you are making, and it's not true of Universal Turing machines - that is the whole point of Turing's discovery of this concept (unless you are talking about how long it will take to complete the job - that is indeed physically dependent).

Just for the record - when Turing developed his idea, "computers" were usually *people* who performed a specified task on data and then passed a slip of paper on to the next person down the line. That's the implementation context he had most in mind! (it was common in astronomy round the turn of the last century) The point of an algorithm is it does not matter how it is implemented, by people or electronics, the result is the same: and it can be any algorithm whatever, as long as it is well defined.

So if there are limits to what an adiabatic quantum computer can do, so much the worse for them: there are non-quantum computers that can do better. You can run *any* algorithm on a classical digital computer. Whether it will halt or not is another issue, but that's got nothing to do with the choice of physical implementation.

Cheers

George

Addendum:

"Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm .... The model of computation that Turing called his "universal machine"--"U" for short--is considered by some (cf Davis (2000)) to have been the fundamental theoretical breakthrough that led to the notion of the Stored-program computer."

From wikipedia

George

Hi George,

Oh yes, a universal Turing machine should be able to run *any* program since all such programs boil down to a finite set of logic functions. What I meant was, they won't all run the same programs equally well. In the case of an adiabatic quantum computer (and other quantum computers) this is at least in part a direct result of the underlying physical implementation. So it's a matter of efficiency which, while not a flat-out restriction, is still an effect produced by the underlying physics.

Ian

  • [deleted]

You start your amusing essay with the outdated thinking of Dirac: "chemistry is just an application of quantum physics." But as the Nobel laureate in physics P.W. Anderson wrote in his famous paper "More is different", published in Science, "Chemistry is not applied physics and biology is not applied chemistry."

You then present your belief that bottom-up causation is wrong and promise us that you find many examples of top-bottom causation. You write that "There is nothing new in all this: it's just that we don't usually talk about this as top-down effects."

The problem here is not only that there is nothing new, but that you only provide examples of bottom-up causation. No need to review all your examples, but I will comment on the arrow of time in cosmology and the Caldeira-Leggett model in quantum physics. As is well-known, the cosmological arrow of time can be derived by applying the usual cosmological approximations to the arrow of time at macroscopic scale. There is nothing fundamental in an approximation of the fundamental microscopic description. The same criticism about the Caldeira-Leggett model. This is a well-known approximated model which is derived from the microscopic description (check the section "microscopic derivations" of the same book that you cite). Again there is nothing fundamental in an approximation of the fundamental microscopic description.

The conclusion here is that your top-down causation hypothesis is nothing but the bottom-up causation in disguise.

    "As the Nobel laureate in physics P.W. Anderson wrote in his famous paper "More is different", published in Science, "Chemistry is not applied physics and biology is not applied chemistry." Well yes, that's reference [16] in my essay. Guess you failed to notice I'd referred to it.

    "You then present your belief that bottom-up causation is wrong". Incorrect. I did not say its wrong, just that it's not the whole story. Of course it occurs.

    "You only provide examples of bottom-up causation". Incorrect. You choose to ignore all but two of the examples I give.

    "The cosmological arrow of time can be derived by applying the usual cosmological approximations to the arrow of time at macroscopic scale. There is nothing fundamental in an approximation of the fundamental microscopic description." Actually the causation is the other way round. It's the *macroscopic* arrow of time that derives from conditions at the cosmological scale. At the microscopic scale that there is no preferred arrow of time, and approximating those interactions at the micro scale won't give you an arrow of time when there is none there to begin with. You have to get it from large scale properties of the distribution of matter in the distant past.

    "The Caldeira-Leggett model.. is a well-known approximated model which is derived from the microscopic description." Well yes of course it's well known: I referred to it by name, with references. The question is how introduction of the "counter term" is justified. One of the standard physics texts phrases it "this term is added in for convenience". But you can't just add in a term for convenience: you have to derive it from the interactions in the problem. All the bottom up interactions are already covered by the other three terms in the Lagrangian. You have to add it in to account for the affects that are *not* derivable in a bottom up way from those interactions alone.

    "The conclusion here is that your top-down causation hypothesis is nothing but the bottom-up causation in disguise." Well I choose to side with Nobel prize winner Bob Laughlin's analysis (reference [12]) rather than yours.

    • [deleted]

    The O.P. didn't read the same essay as I. I saw a complex system model in which top down causation is linked to laterally distributed causality. Self organized order with feedback.

    Tom

    Hi Tom

    Agreed. It's a world away from the way fundamental physicists usually think, because they are unfamiliar with all that literature and with that way of thinking, so they find it difficult to relate to this viewpoint. The problem is that their restricted view, which excludes these effects, is supposed by them to encapsulate all forms of causation that occur in the real world. Not true.

    Condensed matter physicists such as Anderson and Laughlin understand the crucial causal connections, which is why they take a broader view than this anonymous commentator (and win Nobel prizes in consequence). But their ideas are crucial to fundamental physics too: vide the key role Anderson's ideas on broken symmetries played in the development of the Higgs mechanism.

    George

    Sure I agree on that. Efficiency is determined by both the underlying physics, and how it is deployed (design issues enter here); possibility is not.

    George

    George, I hope you find time to get involved with one of the several institutes devoted to complex system research, such as NECSI or SFI. I think you'd find the highly interdisciplinary climate very comfortable.

    Tom

    • [deleted]

    I introduced the quote from the Science paper, because this important quote cannot be found in your essay.

    You have truncated part of what I wrote and then missed my point. *All* the examples that you believe show that bottom-up causation "is wrong" are compatible with ordinary bottom-up causation and invalidate your hypothesis.

    The macroscopic arrow of time can be obtained from the microscopic description. The cosmological description is a coarse-grained approximation to the microscopic description. This is all well-known and explained in many excellent textbooks although ignored by some cosmologists.

    The "counter term" in the Caldeira-Leggett model is an ordinary renormalization term. In the same textbook that you use as reference, the Caldeira-Leggett model is introduced in the section on quantum Brownian motion. As everyone knows quantum Brownian motion is compatible with ordinary bottom-up causation. You would also check the section "microscopic derivations" of the cited textbook before continuing posting such incorrect thoughts.

    "I introduced the quote from the Science paper, because this important quote cannot be found in your essay." There are numerous important quotes I could not include because of the length limits on the essay. I have no obligation to include any particular one that you prefer.

    "*All* the examples that you believe show that bottom-up causation "is wrong" are compatible with ordinary bottom-up causation and invalidate your hypothesis." I deny this claim of yours. In particular it does not apply for example to the way that abstract algorithms control computerised robots. There is no way you can derive those algorithms from the underlying physics in a bottom up way. The relevant variables are not coarse grained versions of lower level variables, or derivable from them in any other way. It also does not apply to the physiology of the heart, as explained by Denis Noble in his writings on physiology, or to epigenetics, as explained by Gilbert and Epel.

    "The macroscopic arrow of time can be obtained from the microscopic description. The cosmological description is a coarse-grained approximation to the microscopic description. This is all well-known and explained in many excellent textbooks although ignored by some cosmologists." Of course the cosmological description is a coarse grained approximation to the microscopic description; see my GR10 lectures from 1984 for a clear description of how this works. This feature is incapable of explaining the arrow of time, as there is no arrow of time in the micro level physical laws. This was known already to Loschmidt and Boltzmann (the key point is that Boltzmann's derivation of the H-theorem works equally well for both directions of time). It is for this reason that authors such as Roger Penrose and Sean Carroll relate the arrow of time to a global low entropy state in the early universe. That is a macro state that has to be described at a macro level of description.

    "The "counter term" in the Caldeira-Leggett model is an ordinary renormalization term. In the same textbook that you use as reference, the Caldeira-Leggett model is introduced in the section on quantum Brownian motion. As everyone knows quantum Brownian motion is compatible with ordinary bottom-up causation." I will reconsider this when I have the chance, the issue being whether renormalisation can be regarded as representing a purely bottom up effect or not. It is conceivable this review could lead me to change my opinion in this particular case. But your claims of a purely bottom up explanation won't work for example in the case of superfluidity, as is carefully explained by Robert Laughlin in his Nobel lecture.

    Dear George, you agrue that causation is top down with those who argue it is bottom up. But even with feedback loops, either way, it is still a linear, one-dimensional view on things. Have you considered that it may be neither? (I know from your essay that you considered it could be both).

    What if causation is a multidimentional, convoluted, worse yet, fractal thingie that defies all methodologies trying to trace it with a finger like a crack on the wall?

    It so happens that all things in life and in physics are interconnected; nothing is ever a single, naked point in spacetime. Everything has many different causes, large and small, near and far, that converge into making that particular thing manifest. And it, in turn, also causes so many other things manifest, large and small, near and far -- after colliding, merging and parting ways with so many other things and causes, large and small, near and far..

    Ah?