Vladimir you state
"I am conviced that if such a simple theory of everything were to be found, causation would be always local and linear at the smallest scales and the effects of large systems will be the resultant of effects transmitted locally and causally down to the local level and vice-versa simultaneously in a balanced way'
I agree with you completely. My more technical article on the way quantum theory works is based in precisely that premise. You will find it
here .
George
Dr. Ellis,
"In addition to contemplating relativistic and philosophical aspects of cosmology, he is now engaged in trying to understand how complex systems such as you and me can arise out of the underlying physics."
Could this be made to work without a thorough simulation, down to the particle interaction level, of the underlying physics -- in this case, of condensed matter physics?
One assumes the higher-level effects ("epiphenomena" seems to be a word to avoid) emerge as interactive constraints upon the substrate physics. (Let's not get into the contentious issue of substrate independence, which isn't a required topic at this point.) Whether or not their emergence is inevitable (and why shouldn't it be?) we know they wouldn't exist, at any rate to begin with, in the absence of the underlying physics. And the more complex the higher-level emergent phenomena, the more you need to know about the operational physics in order to map the emergence ... or is that a fallacious assumption?
Anyway, what about the fermion minus-sign problem? And thanks for your provocative and knowledgeable essay.
Thanks George
I just downloaded your paper and it will take me some time to read. My first impression is that it differs from my Beautiful Universe paper in scope and intention (and the presence of non-linearity it appears) as you will see if you read it. Another difference is that mine is the work of someone who has waded in deeper waters than he was trained for!
Cheers
Vladimir
You don't need simulation to establish effective laws at any particular level. For example you can establish the effective gas laws without using any simulations, through two routes: (a) experimentally, (b) by use of kinetic theory. The latter does not need to involve simulations, nor does it need quantum field theory, much less M-theory or string theory.
"One assumes the higher-level effects ... emerge as interactive constraints upon the substrate physics." I'd phrase it this way: the high level structure emerges somehow (it may be spontaneous, or may be manufactured, or may emerge through developmental processes) and then sets constraints on the underlying physics.
Yes, this emergence would not take place in the absence of the underlying physics. "The more complex the higher-level emergent phenomena, the more you need to know about the operational physics in order to map the emergence" - well not really. Digital computers are really good examples: they are the most complex things we have built. You don't need to know anything about the underlying physics to design the computer itself, you just need to know that it established the possibilities of existence of transistors and hence various kinds of gates. On that basis you can work out the logic of integrated circuits and make CPUs, memory banks, etc. Hence computer scientists are not taught quantum theory as part of their computer science courses. Someone else needs to know how the transistor works but you don't need to do so: you can take the transistors as the bottom level, for your purposes. And it's crucial that we are able to do so, for as I've already said we don't know what the bottom level is: we'd be unable to do most of present day physics if it was requisite that we understand the quantum gravity foundation layer first. The key question is, Which is the operational level? It's the one that is convenient for you to choose as the lowest level in your particular analysis.
The fermion minus-sign problem is to do with quantum Monte Carlo simulations; a technique for trying to understand specific types of emergent systems. I cannot meaningfully comment on that technique and problem, except to say that I don't think it helps understand systems such as the brain or a computer.
Thanks for the extended response. We'll simply have to disagree that manufactured artifacts are useful analogues of complex nonequilibrium systems -- complex natural processes -- to the extent I read you as believing them to be.
"Hence computer scientists are not taught quantum theory as part of their computer science courses."
Actually, that's not true in the case of quantum computation itself. And perhaps overly optimistic though it may seem, qcomp programming is taught on the theoretical level. You can't understand quantum algorithms without some fundamental knowledge of QM. Anyway, my own paradigm these days is the role of proton-coupled electron transfer (PCET) in photosynthesis. Now, to be sure, a plant doesn't need to understand anything at all about quantum tunneling in order to do its photosynthesizing thing, but if you're designing an artificial leaf (vide the Nocera team's ambitious project) you definitely do. Anyway you and I, a couple of complex systems, generate information no computer can, no matter how sophisticated its programming.
Note. Anticipating a possible objection here. An artificial leaf, albeit a manufactured artifact, doesn't stand in relation to a real leaf as a digital computer does to a brain. An artificial leaf reproduces a known process selected from a real leaf's repertoire of physics, whereas a computer can't be demonstrated to reproduce any process selected from the physics or systemic functionality of the brain.
An artificial leaf copies to some degree a real leaf. The computer is sui generis, a physically realized TM, as anyone familiar with Turing's papers from the 1930s realizes. Is the brain a TM? A lot of people seem to think so, but haven't proven it.
Dear George,
I agree with your point. It is also necessary to beware of linking unrelated events and so inventing a causation story when it didn't happen in that way. It can happen in science,( including social science), that correlation is mistaken for causation.It probably occurs more often than is realised. Particularly important and well known is the placebo effect, where getting better may be nothing to do with the treatment given.
I read an interesting item a long time ago about a study into the effect of high fat diets on rabbits. Rather than getting more unwell the badly fed rabbits remained healthy. Eventually it was found that the animal handler looking after the badly fed rabbits was giving them extra attention and fondling. Presumably reducing the animals stress level and making them better able to handle the bad diet ill treatment.
The book "Freakonomics" Steven D. Levitt and Stephen J. Dubner has many amusing stories of how correlation might be mistaken for causation. Fascinating.
"We'll simply have to disagree that manufactured artifacts are useful analogues of complex nonequilibrium systems -- complex natural processes -- to the extent I read you as believing them to be." Well I don't want to overdo the analogy, but for me a key similarity is they both are hierarchically structured modular systems with information hiding. This kind of structuring is very nicely described by Grady Booch in his book on object oriented programming. The mechanisms used in these two kinds of systems are quite different, but some of the logic is similar. And of course you can get the digital system to simulate many aspects of the physical system to high accuracy, basically because digital computers are universal computers (Turing).
Yes of course I agree about quantum computing. I should have added the caveat "classical computing" in all above.
Proton-coupled electron transfer seems fascinating. I'd be really interested to know how it relates to quantum state vector reduction. And I agree with you about the limitations of computers (though many don't).
"a computer can't be demonstrated to reproduce any process selected from the physics or systemic functionality of the brain." The physics functionality, I agree; the systemic functionality, perhaps not. The brain is an embodied brain certainly; but it also carries out pattern recognition and prediction processes that can be digitally simulated to some degree (indeed that's where Artificial Neural Nets came from). Furthermore computers can indeed learn to some degree, through adaptive programs such as genetic algorithms.
The brain is not a Turing Machine inter alia because emotion plays a key role in its functioning (see for example Damasio's writings). You can to some degree simulate those effects but I certainly don't believe you can reproduce them.
Dear Georgina,
yes indeed, in general separating out correlation from causation is very difficult, which is why I stated my definition of causation at the start of my essay in terms of the reliable consequences of an action. That makes clear what the initiating event is.
The placebo effect is fascinating; of course from my viewpoint it's a case of top-down action from beliefs (abstract entities) to physical systems (human bodies). Placebos are certainly effective, which is why drug treatments are compared to placebo treatments.
I like your story about the rabbits. The welfare of human children is similarly crucially affected by being given attention; it affects their bodily weight and even their survival.
Dear Avtar
I am glad we agree on top down causation.
George Ellis
"Proton-coupled electron transfer seems fascinating. I'd be really interested to know how it relates to quantum state vector reduction."
This topic has never been mentioned in any paper I've seen. The question for me has been to what extent is PCET a coherent quantum phenomenon. You don't even need to believe in wave function collapse to wonder about that, as one is interested also in the whole emerging discussion of room-temperature and high-temperature quantum coherence. (See Vlatko Vedral on the ubiquity of entanglement. Seth Lloyd on entanglement as crucial to ordinary bivalent bonds. And when you visited the IQOQI you were doubtless regaled with an account of the super-hot double-slit buckyball experiment.) Nocera & Co. are adamant that PCET's a coherent quantum tunneling effect, and appear to have established this contention to the satisfaction of those sectors of the scientific community that have paid attention.
Here's a now-defunct webpage from Daniel Nocera's MIT site, undoubtedly not technical enough for you but okay for most kibbitzers, which a friend of mine downloaded and converted to pdf a while back. It lays out the basic stuff:
http://www.dancing-peasants.com/Proton-Coupled_Electron_Transfer.pdf
I can cite deeper material if desired.
looked okay in the preview
http://www.dancing-peasants.com/Proton-Coupled_Electron_Transfer.pdf
Dear George Ellis,
In a comment above, you state, "Proton-coupled electron transfer seems fascinating. I'd be really interested to know how it relates to quantum state vector reduction."
I do invite you to read my current essay, The Nature of the Wave Function, as I address the issue of "quantum state vector reduction" and I would very much appreciate your thoughts on my approach.
Edwin Eugene Klingman
Dear George,
re the placebo I should have said; nothing to do with a pharmacological effect of the treatment, not nothing to do with the treatment. As the treatment might include the lengthy and concerned consultation, diagnosis and prescription which can make a person feel important, valued and cared about and so affect neurotransmitter levels, their balance and so psychology.
The brain has executive control of the body including maintenance of health. The function of the organs and tissues and biochemistry of the body can be affected by changes of activity within the very complex neural networks of the brain. Which is altered by changes in neurotransmitter availability and balance.It seems to me, the interaction of the complex external environment and social interaction upon the -complex organised brain- and its body interaction, causes the change in health and not the simple sugar pill and mere (abstract) belief in its power.
As you have pointed out the effect is relevant to your top down control concept.I think even more so than you have intimated- I think it is a good example of a specific effect (output) arising from complexity and organisation, not from very simple inputs. It can't be explained as the result of the simple "sugar pill" input.
Paul Davies and Sara Walker have put up two very useful papers on the internet that will interest those of you involved on the biology side. They are
Evolutionary Transitions and Top-Down Causation
The Algorithmic Origins of Life
Here is the abstract of the latter paper:
"Although it has been notoriously difficult to pin down precisely what it is that makes life so distinctive and remarkable, there is general agreement that its informational aspect is one key property, perhaps the key property. The unique informational narrative of living systems suggests that life may be characterized by context-dependent causal influences, and in particular, that top-down (or downward) causation -- where higher-levels influence and constrain the dynamics of lower-levels in organizational hierarchies - may be a major contributor to the hierarchal structure of living systems. Here we propose that the origin of life may correspond to a physical transition associated with a fundamental shift in causal structure. The origin of life may therefore be characterized by a transition from bottom-up to top-down causation, mediated by a reversal in the dominant direction of the flow of information from lower to higher levels of organization (bottom-up), to that from higher to lower levels of organization (top-down). Such a transition may be akin to a thermodynamic phase transition, with the crucial distinction that determining which phase (nonlife or life) a given system is in requires dynamical information and therefore can only be inferred by identifying causal relationships. We discuss one potential measure of such a transition, which is amenable to laboratory study, and how the proposed mechanism corresponds to the onset of the unique mode of (algorithmic) information processing characteristic of living systems."
Dear Georgina
nicely put.
George
The placebo effect and the rabbit story may also be explained in terms of hidden variables, may they not? Just as correlation is not necessarily causation, information is not necessarily knowledge.
At the end of the day, the questions we mean to answer -- Is treatment no better than a placebo? Does diet affect well being? -- depend on suppressing some information in order to validate contradictory information.
A self organized universe, on the other hand, does not demonstrably suppress information. It appears to be an uncontrolled experiment and infinitely creative. In terms of theory, then, a hierarchical structure (vice laterally distributed information) would seem to impose, a priori, a restriction on causality that leaves nature no choice. If conscious IGUS (information gathering and utilizing systems) are co-creative with self organized nature, however, their choices are co-variant with evolving nature and a hierarchical structure would seem to be superfluous.
Tom
Tom,
Information shouldn't be suppressed to add validity other information. To be valid it is necessary to have studies where as many parameters are controlled as possible and those that can not be controlled are pointed out. All of the rabbits had to be kept under identical conditions except for the dietary difference under consideration. As they were not the study was invalid.If the rabbits had not been expected to become unwell then it is unlikely the error would have been spotted.
The result of such a study shows what happens to rabbits under those conditions not what will happen to human beings living under very different and far more variable conditions. The answer to those questions "Is treatment no better than a placebo? Does diet affect well being?" has to be it depends. The answer is far more complex than many respectable scientific papers and pseudo science papers would suggest, IMO.
Tom, you said "A self organized universe, on the other hand, does not demonstrably suppress information". I'm probably not thinking about information as you are but if there is deposition or accumulation of material then couldn't the information within be considered as suppressed (even if not entirely hidden) because interaction happens mainly at surfaces, that is where the information is accessed. Surfaces are particularly important in biology.
I agree with George that some things can't happen if the organisation does not exist to give the output. Complex proteins such as enzymes are assembled within cells because there is the DNA code for them, the mRNA copies that are read and the ribosomes where the proteins are assembled. The complex enzyme proteins do not spontaneously assemble as an uncontrolled experiment.
I think I can understand what you mean about IGUS' being co-creative with nature and their choices co-varying as nature "evolves" but I don't understand what you mean about "the hierarchical structure" being superfluous in that case.
Hi Georgina,
"Information shouldn't be suppressed to add validity (to) other information."
Ah, but that's what a controlled experiment does, in principle. There's no way to tell that one has controlled for all possible variables. We can only do so to a reasonable certainty. Compare a controlled experiment to a theoretical prediction, e.g., Einstein's adjustment to the precessionary orbit of Mercury, or gravitational lensing.
"I think I can understand what you mean about IGUS' being co-creative with nature and their choices co-varying as nature 'evolves' but I don't understand what you mean about 'the hierarchical structure' being superfluous in that case."
I mean, that any hierarchy (such as a human being, the corporation of cooperating cells in which the brain has executive control, as you put it) may be undermined by an unexpected event. In Darwinian evolution, this might be a random mutation. A mutation may be beneficial, harmful or neutral -- however, we cannot know which except in the larger context of perfect information, to which we do not have access. I was impressed many years ago, in reading Kurt Vonnegut's *Breakfast of Champions* that the protagonist mused over a glass of champagne, wondering if the yeasts -- who consumed sugar and excreted alcohol until they drowned in their own excrement -- had any consciousness of what they were creating. (In the same respect, consider Emily Dickinson's poem: "My candle burns at both ends; it will not last the night. But oh my friends, and ah my foes, it makes a lovely light!")
Tom