Water has emergent properties?

[arildno]

I think it is meaningless to bandy about with terms purporting to describe some aspect of reality but that cannot be checked whether they hold true or not.

Come up with an example where this theoretical "in principle" emergence will have different detectable results than my practical "in principle" emergence concept.

And no, my emergence concept is the precise one, not yours.

 

[atyy]

(1) at least 2 water molecules
(2) particles and laws; hydrogen atoms, oxygen atoms and relevant physical laws
(3) the abstract addition of particles and laws

If I understand you correctly, then water and all other phenomena in everyday life are not emergent in that sense. We believe that the fundamental laws (Schroedinger's equation for the interaction of hydrogen and oxygen) describe what we see everyday.

In physics, "emergent" usually means a relation between two theories. A more "fundamental" theory which is a good approximation over a "bigger" domain, and an "emergent" theory with different dynamical variables which is a good approximation over a "smaller" domain. An example of a fundamental theory would be one in which there are things like wood blocks, nails etc, and the emergent theory would be one in which there are tables and chairs. If you are arranging the furniture in a room, you can use the emergent theory of tables and chairs. But if you are a carpenter making a table then you use the fundamental theory of nails and wood.

One subtlety is that the carpenter must also know the relation between the theories, and part of the relation between a fundamental theory and an emergent theory is the concept of a good approximation over a smaller domain, where "good" depends on the user (the assumption that user is going to arrange furniture in a room, and not chop the tables up).

 

[Diderot]

atyy,

If I understand you correctly, then water and all other phenomena in everyday life are not emergent in that sense. We believe that the fundamental laws (Schroedinger's equation for the interaction of hydrogen and oxygen) describe what we see every day.

Ergo, the so-called emergent properties of water, e.g. wetness, can be deduced from the most complete knowledge of hydrogen atoms and oxygen atoms and fundamental laws (Schroedinger's equation for the interaction of hydrogen and oxygen).
People who tell us that water has ‘emergent’ properties - properties which are in principle not deducible from the most complete knowledge of a lower level - are ill-informed. Water molecules are not more than the sum of its parts.

 

[Pythagorean]

even for a single hydrogen atom, modelling it with Schrödinger requires some liberties to be taken.

Talking about whether an ensemble of water molecules are "more than the sum of their parts" isn't meaningful. More what? Why are you summing their parts? What qualities do you measure to quantify that statement. It sounds quantifiable but it lacks quality.

You could find some properties of water for which it is true vs. not (probably something to do with extensive vs. intensive properties.)

And again, I have to agree with arildno that deducibility is a poor measure.

 

[Diderot]

Pythagorean,

Talking about whether an ensemble of water molecules are "more than the sum of their parts" isn't meaningful.

Not meaningful as in nonsensical?

More what?

Emergent properties! According to the theory of emergence water has emergent properties that are in principle not deducible from even the most complete knowledge of a lower level. These emergent properties emerge from nothing, they cannot be explained – at least not from a lower level -. These emergent properties therefor constitute the ‘more’. Due to these in-deducible (unexplainable) properties there is a whole that is more than the sum of its parts.

Why are you summing their parts?

In order to compare it to the ‘whole’ which is – according to emergence – the sum of the parts + *poof* emergent properties.

 

[Pythagorean]

Emergent properties! According to the theory of emergence water has emergent properties that are in principle not deducible from even the most complete knowledge of a lower level. These emergent properties emerge from nothing, they cannot be explained – at least not from a lower level -. These emergent properties therefor constitute the ‘more’. Due to these in-deducible (unexplainable) properties there is a whole that is more than the sum of its parts.

I don't really think that's a question about water, or the universe, so much as about models. This seems like a pure philosophy question, really; it appears ontology-dependent.

In order to compare it to the ‘whole’ which is – according to emergence – the sum of the parts + *poof* emergent properties.

Water does have emergent properties in this sense, though. Without bringing deducibility into it. Clearly, there's no way to talk about the (classical) wave properties of a small number of water molecules so when you put enough together, new properties emerge.

 

[Diderot]

Pythagorean,

Water does have emergent properties in this sense, though. Without bringing deducibility into it.

By wiki's definition of emergent properties (see OP) one cannot separate 'emergence' and 'deducibility'. Emergent is synonymous for in-deducible. Emergent properties *poof* into existence. Properties which we can deduce (explain) from a lower level are not emergent properties by definition.

 

[Pythagorean]

And do you realize the fundamental issue with that making it an ontology-dependent question? It means it's purely philosophical, not scientific. I don't think most scientists will share that definition of emergent, so it smells kind of like equivocation.

 

[atyy]

atyy,

Ergo, the so-called emergent properties of water, e.g. wetness, can be deduced from the most complete knowledge of hydrogen atoms and oxygen atoms and fundamental laws (Schroedinger's equation for the interaction of hydrogen and oxygen).
People who tell us that water has ‘emergent’ properties - properties which are in principle not deducible from the most complete knowledge of a lower level - are ill-informed. Water molecules are not more than the sum of its parts.

Either they are ill-informed, or they are using a different definition of "emergent".

Have you seen Shalizi's thoughts (not sure I'll buy everything he says, but it looks like he's not ignorant)? http://vserver1.cscs.lsa.umich.edu/~crshalizi/notabene/emergent-properties.html

 

[arildno]

To make it VERY simple:
Suppose you have something you can call 2 points, A and B. In addition, you have a single RELATION that can be made between them, we call that a STRAIGHT LINE.

Now, add one more point to your system, which is now A, B, C.

The particular configuration we call a TRIANGLE is an emergent property in the three-point system, it is IMPOSSIBLE in the two-point system to create it.

But:
Even though the triangle is a totally new phenomenon for our new system, it is STILL in accordance with the basic laws of interaction governing the two-point system.

Huge collections of basic interactions bring about possibilities that cannot exist in smaller collections of basic interactions. Because those possibilities simply require for their existence a sufficiently huge number..

 

[Diderot]

Atyy,
your link to Cosma Rohilla Shalizi's website is a great find. Prof Shalizi goes to the heart of the issue.

"An emergent is a higher-level property, which cannot be deduced from or explained by the properties of the lower-level entities." This is almost troubling. The key is in "properties." Reductionists --- sane ones, anyhow --- don't deny that things interact; we spend a great deal of time worrying about those interactions. If by "properties" is meant just properties in the logical sense, then of course there are emergents, but so what? In this sense, pressure and volume are emergents.

On the other hand, if we are allowed both our properties and our relations, then "emergence" is a notion with teeth. The existence of any emergent properties, in this strong sense, would mean that universal reductionism is false. (Though it might be true locally, or for all other properties, or still be the most useful means of guiding inquiry, etc.) But, as above, I don't see how "X is an emergent property (strong sense)" could be established. At best we could say "X may be an emergent, since we have been unable to deduce it from the lower-level properties {Y}."

Does anyone know of any good candidates for this kind of emergent?

 

[Diderot]

Arildno,

To make it VERY simple:

I love very simple. Thank you, I enjoyed your very clear reasoning. It is in accordance with what philosopher Chalmers wrote:

One sometimes hears it suggested that emergence is the existence of properties of a system that are not possessed by any of its parts. However, this phenomenon is too ubiquitous for our purposes. Under this definition, file cabinets and decks of cards, and even XOR gates, have many ‘emergent’ properties. So this surely not what theorists generally mean by ‘emergence’.

 

[arildno]

Well, whatever this or that philosopher means,..
a) I can't see why a property of "wetness" couldn't be just the type of emergent phenomenon I talk about, rather than this mysterious ontological feature he wishes it to be
b) Such "trivial" emergences I talk about are quite self-evidently extremely difficult to deduce at the outset, just given a bundle of basic laws of interactions to play around with.
c) I see absolutely ZERO advantage of the philophical ontological viewpoint, not the least because it seems impossible to derive any sort of predictions that could distinguish itself from the viewpoint I have.
d) It seems a lot more advantageous to establish basic laws of interactions, and then we see how far we can get with them. If we end up in a dead-end, one might look upon the issue once again.

 

[Diderot]

From talking to you physicists I have come to the conclusion that emergent properties, in the strong sense (see OP and Shalizi’s quote in post #41), is not considered a meaningful or even truthful concept. This is what I expected and hoped for.

Off topic: This subject relates to the thesis of emergentism in philosophy of mind. The emergentist reasons like this: "emergent properties (in the strong sense) are ubiquitous in physics, take for instance the emergent properties of water. Now after establishing the reality of in principle unexplainable emergent properties, I've cleared the road for the core idea of emergentism: consciousness is an emergent property of the brain."

 

[arildno]

I often find that it is people like historians and philosophers who are most eager to use words such as "unexplainable" rather than "unexplained", rather than physicists.

 

[Pythagorean]

"explained" is a pretty loaded term anyway. We can't "explain" gravity in a complete way either. We can model and predict the actions of gravity... but we can do that with the mind too.

 

[Q_Goest]

Hi Diderot. You might want to look into separability first. Healey is well known for his work on separability and especially for the nonseparability of quantum mechanics.

It has sometimes been suggested that quantum phenomena exhibit a characteristic holism or nonseparability, and that this distinguishes quantum from classical physics.

...

Classical physics presents no definitive examples of either physical property holism or nonseparability. As section 6 explained, almost any instance of physical property holism would demonstrate nonseparability.

Ref: http://plato.stanford.edu/entries/physics-holism/

I think you need to grasp the concepts of separability and nonseparability first, then look at definitions of emergence. It's always best to go directly to the source. There are various types of emergence including "weak emergence" and "strong emergence" as defined for example by Bedau and Emmeche.

Weak emergence is applicable to "connectionist modelling, non-linear dynamics" and other classical mechanical phenomena as Bedau points out. I think separable systems best characterize weak emergence. Note that Beau talks about microstates of a system result from microstates of nearby parts of the system at preceding times, such that the microdynamic is local. He uses as an example, the game of life which is a game that has local rules governing the evolution of the system. So generally, I’d say weak emergence best fits separable systems or phenomena that can be described using classical mechanics. Strong emergence on the other hand, requires something other than local interactions. It requires a system as a whole be able to causally influence or over-ride local interactions within the system. This influence is also called "downward causation" as described by Emmeche for example. So strong emergence is an example of a type of holistic behavior in the way Healey defines “holistic”. Strong emergence requires a nonseparable system so phenomena produced by quantum mechanical interactions might exhibit strong emergence in some form.

I think a better way of thinking about nonseparable ‘emergent’ properties however, is given by Humphreys, "How Properties Emerge" who talks about there being a fusion of properties, and I think that gets to the point of water having new properties when hydrogen and oxygen combine. See also Kronz, "Emergence and Quantum Mechanics". In order for water to exhibit new properties, it has to be nonseparable so those properties have to come out of quantum mechanical interactions.

Regarding p-consciousness, that’s something beyond what PF wants to discuss here. These concepts are applicable to p-consciousness but that topic ignites too many flame wars.

 

[arildno]

Q_Guest:
Are any of these people you refer to practising physicists, to be deemed competent at discussing matters physical?
I looked at Kronz' educational background; he had just a few credit hours in maths&physics within his philosophical education from the early 1980s.
Similarly, this Humphreys seems to have a B.A in "maths and physics" back from 1971.
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To be blunt:
I do not see, at the outset, that these guys really have much relevant to contribute to the developing understanding of physics. In contrast to physicists.

 

[Diderot]

Arildno,

I often find that it is people like historians and philosophers who are most eager to use words such as "unexplainable" rather than "unexplained", rather than physicists.

It should be no surprise to anyone that physicists object to a concept of a universe which is inhabited by in principle unexplainable emergent properties. Obviously they don't want the universe to be like that; 'emergent properties' - in this strong sense - goes against everything that physics and science in general stand for.

 

[Pythagorean]

"Don't want"? Are you implying that physicist's judge based on desire rather than observation?

 

[arildno]

The Grand Declamation of Unexplainability from the Philosopher sort of justifies his professional existence, doesn't it?
The physicist's justification for his professional existence is trivial and undoubted, whereas the philosopher??

 

[arildno]

Why do you think physicists work with basic laws of interactions, rather than fighting over unverifiable ontological claims and counter-claims?

Perhaps they have the dastardly attitude that they wish to check their predictions?

 

[Q_Goest]

Q_Guest:
Are any of these people you refer to practising physicists, to be deemed competent at discussing matters physical?
I looked at Kronz' educational background; he had just a few credit hours in maths&physics within his philosophical education from the early 1980s.
Similarly, this Humphreys seems to have a B.A in "maths and physics" back from 1971.
---------------------------------------------------------------------
To be blunt:
I do not see, at the outset, that these guys really have much relevant to contribute to the developing understanding of physics. In contrast to physicists.

Hi arildno,
I’ve read a few hundred papers and numerous books that cover this topic and I would say these are solid references that help define the terms being discussed here. The papers help clarify what is meant by words like emergence and in fact, they provide the BEST examples of those definitions. I think it’s clear from reading these papers that the authors have a solid background in the natural sciences and are very familiar with what they are writing about.

In comparison, I’ve seen quite a number of papers written by physicists and others who should be qualified to discuss things like emergence and downward causation who are utterly ignorant of the most fundamental concepts that they write about. A perfect example is Dr. Robert Bishop who writes papers about downward causation in fluid mechanics (here here). Those papers espouse that there are “nonlocal, global forces” which emerge during Rayleigh Benard convection that exhibit influences over the convective cells above and beyond anything explained by the Navier Stokes equations, Van Der Waal forces or gravitational forces. These are unexplained forces which organize and conduct the fluid into cells. Bishop is one of those I put in a minority category of people who feel that new, unexplained forces emerge from nonlinear physical systems that can’t be explained by the local interactions nor by any molecular interactions that have already been identified. But Bishop is only one of a vocal handful. Note that Bishop also teaches at Wheaton University where they teach “For Christ and His Kingdom”. In my opinion, that explains his interest in downward causation.

The papers I’ve provided are solid and help provide definitions for people who want to understand the arguments surrounding emergence. I think if you read through the articles, you’ll find they are consistent with our present understanding of nature and physics.

 

[arildno]

Thank you for the details, Q-Goest!

I do not go as far as saying it is "impossible" for some ontological emergence to be present, one way or other. That would be rather metaphysical of me, wouldn't it?

Furthermore, since sufficiently complex axiomatic systems may "generate" sentences within that are true, but cannot be proven in terms of the axiomatic proof structure within that system, might not I make a hand-waving analogy that something like that might be present in Reality as well?

But NOW, I am well and truly speculative...

 

[Pythagorean]

I agree with Q Goest that "weak emergence" is an appropriate description of what we accept as emergence in physics (particularly the nonlinear sciences) and "strong emergence" is closer to what Diderot seems to be asking (though I haven't read "hundreds of papers" on the subject).

"The whole is more than the sum of the parts" is a rather confusing and ambiguous statement, though. Especially to mathematicians and physicists for which sum has a precise meaning. We can describe a function such that:

F(a+b+c) ≠ F(a) + F(b) + F(c)

and such functions are common in descriptions of reality. This is, of course, any system that does not obey superposition, which is typical of nonlinear systems; also this can end up in the whole being less than the sum of the parts. But if "whole is more than the sum of parts" just means "whole system is not deducible from elements of the system" then we've already covered that.

 

[arildno]

It seems that for some, "deduction" is equated to "summation".
That is one source of confusion with the "The whole is no more than the sum of its parts".

 

[Diderot]

Q_Goest #47, #53

Thank you for the summary and links, I have to read up. One quick response:
New nonseperable fused properties, which come out of quantum mechanical interactions (Q_Goest#47), do not support the thesis of strong emergence – as defined in the OP. Obviously if these properties are deducible from quantum mechanical interactions they are not ‘in principle not deducible from the most complete knowledge of a lower level’.

 

[Q_Goest]

Q_Goest #47, #53

Thank you for the summary and links, I have to read up. One quick response:
New nonseperable fused properties, which come out of quantum mechanical interactions (Q_Goest#47), do not support the thesis of strong emergence – as defined in the OP. Obviously if these properties are deducible from quantum mechanical interactions they are not ‘in principle not deducible from the most complete knowledge of a lower level’.

Yes and no…. Strong emergence requires some kind of downward causation which is the “not deducible” part you are thinking of. Zz mentioned Laughlin who talks about this kind of “not deducible” bit in his ftp://www.phy.pku.edu.cn/pub/Books/%CE%EF%C0%ED/%BE%AD%B5%E4%D6%F8%D7%F7/nobel%20lectures/Nobel%20Phy98/nobelphy1998-1.pdf (as well as some of http://www.pnas.org/content/97/1/28.full.pdf). Laughlin generally refers to nonsepararable systems. But others have suggested there is something nonreductive and therefore not deducible about much larger systems such as societies. I don’t think anyone is suggesting there is downward causation at play in societies.

The concept of deducibility isn’t really specific enough in my opinion. I see arildno and Pythagorean have both already said as much and I’d agree. In fact, different philosophers use the term to either mean something is strongly emergent (ex: Chalmers) or something that might be weakly emergent such as societies. Deducibility needs to be clarified before you can use it in discussions about emergence. I think the way you want to use it is as Chalmers does, “That is, if there are phenomena whose existence is not deducible from the facts about the exact distribution of particles and fields throughout space and time (along with the laws of physics), then this suggests that new fundamental laws of nature are needed to explain these phenomena.” So where does that leave us when it comes to phenomena that can’t be reduced mathematically such as solving the Navier Stokes equations, the n body problem or societies? If the equations governing a system are not deducible, even in principal, that's not proof of downward causation.

 

[Pythagorean]

So where does that leave us when it comes to phenomena that can’t be reduced mathematically such as solving the Navier Stokes equations, the n body problem or societies? If the equations governing a system are not deducible, even in principal, that's not proof of downward causation.

Yes, and furthermore when we do eventually get around to making new mathematics to describe something that was elusive before, it often turns out that it's a matter of assumptions in language and interpretation, not a matter of it being "not deducible".

For instance, Ito Calculus was invented as one interpretation of stochastic systems, but it turns out the Stratonovich's interpretation is more appropriate (at least for classical physical systems). And essentially the difference is that Stratonovich says "ok... Gaussian noise isn't really Gaussian in the real world so we can actually use the old tricks if we just assume that the Gaussian noise is only almost Gaussian" whereas Ito took the Gaussian noise to be literally Gaussian (even though we don't observe true Gaussian noise in nature) and changed the calculus itself to get a meaningful result.

So, here, it's a matter of assumptions becoming ingrained in symbols that we use in mathematics and those assumption turn out being ideals that don't really fit the natural world.