The Case for Strong Emergence by Sabine Hossenfelder

quote

Effective field theories work with quantum field theories, that is the type of theory that we

presently use to describe nature at the highest resolution probed so far. The key equations of the

framework (the "renormalization group equations") connect a theory at high resolution with a

theory at low resolution. That is, the theory at low resolution is always weakly emergent. It can

be derived - at least in principle - from the theory at high resolution.

In practice the derivation of the low-resolution theory can only be done for simple systems,

but from a philosophical standpoint this isn't relevant. Relevant is merely that physicists do

have equations that define the theory on low resolution from the theory at high resolution.

Effective field theories can fail [9] in the sense of methods becoming inapplicable, and there

are certain theorems that can fail (such as the decoupling of scales), and there are some approximations

that might become invalid (such as weak coupling), and so on. These are practical

problems for sure. But in principle, none of this matters. Because even if we don't know how

to do a single calculation, the theory is still there. It doesn't go away

end of quote

Please describe how you would apply these criteria to the early universe, i.e. the pre Planckian to Plackian regime

I did an essay due to these considerations, too

You can review it, and I welcome your comments. I put it in December 21st

thanks for your essay. it was a good read

Andrew

Hi Sabine,

Nice essay! I'm a bit skeptical that anything we tend to call "free will" has anything to do with any of this, but you still make many interesting points about strong emergence and reductionism. (For a nice modern take on Free Will, I highly recommend Jenann Ismael's new book, "How Physics Makes us Free". )

Two questions for you:

1) The only vague overlap between our essays is the paragraph where you argue that boundary constraints aren't a counter-example, because in the case of a conducting plate you can replace the boundary constraint with the microscopic details of the plate. But you seemed to imply that the same argument would go through for *cosmological* boundaries. To me, this seems like a very different issue. It's not at all clear that one could talk about the microscopic details of the cosmological boundary in the same way. What would you say to a claim that the cosmological boundary is both fundamental and an example of top-down causation?

2) You finesse the question about the "size" of a quantum system by talking about center of mass energies, which I suppose is fine from an operational perspective. But near the end, when you try to dispute that entanglement is an example of top-down causation, you imply that there is such a thing as the "microscopic constituents" of two entangled particles. What do you have in mind here? We've recently had a conversation about this, and how there's often no way to come up with a spacetime representation of the pieces of an entangled state, so there's really no way to assess whether it's "microscopic" or not, living in a higher dimensional configuration space as it does. For example, for a two-qubit state, there are additional parameters (such as the "concurrence", a measure of entanglement) that don't seem to live anywhere at all, or have any size associated with them. So you might need to sharpen up this argument, using your operational language from before, if you don't want to have to defend and define the two "microscopic constituents" of an entangled state. (Or else help me figure out what those constituents might actually be! :-)

Cheers! -Ken

I have a query that concerns randomness and order in Nature. We find lot of logic in the design of universe we happen to belong. How come that all physical processes are governed by randomness rather than any order when one works the probabilty of occurence of the event in our sensors. We tried an experimnet where we mixed in smaller and smaller proportions of regular or ordered events to the normal random events. Our analysis showed that even when moxed regular pulses to a rather miniscular level, chi square test clearly indicated that we have done something not natural or purely random in nature. All this goes to show that we can not affect the Nature and its processes that we try to understand and explain using Physics or sciences in general. Also, i worry if the so-called constants we have designated like strenghts of four force fields/ velocity of light, etc.have changed in magnitude ever since the creation of the Universe billions of years back. Can we design an experiment where we look for an event in the far receeded universe and see if it follows a variation in the value of a physical constant?

May i make a request you and your friends on this site, to kindly visit our essay in the contest and critically examine our contention regarding the role of Consciousness in sciences! Can one talk about human consciousness as well as consciousness of the Universe itself too?

For 1), I meant something like a constraint at the Big Bang, but you'll probably have to slog through my essay to really understand what I'm getting at.

For 2), I don't see how configuration space helps you figure out what the "parts" even are. If there's no basis in which the entangled state separates out into parts, then I don't see how one can talk about parts at all, let alone assign a resolution to them. There is simply no standard answer to the question "how are the parts are entangled?" that doesn't simply list the entire nonlocal entangled state. It gets worse after 2 particles; in principle, if you take QM seriously, there are no "parts" whatsoever -- just a giant entangled structure, and that way lies Many Worlds. Really, one could make the case that GR talks about "smaller structures" than QM and QFT, because GR has a description that separates out into small parts, while QM and QFT don't.

Cheers! -Ken

Dear Sabine,

I thoroughly enjoyed your eloquent essay and agree with much of it. I also look forward to getting and studying your book when it comes out this summer. I wrote a fairly extensive reply to your comments on my essay, arguing that nonlinear dynamics, while in principle not incompatible with reductionism, for all practical purposes obviates it as a fundamental tool. My reply is too lengthy (and not all that relevant) for inclusion here, but you might like to read it.

Again, thanks for your comments and for a very thought-provoking essay.

Best,

Bill

Sabine,

I like your style. Your approach is clear and objective, showing what I consider real modesty about your approach, a healthy attitude that recognizes the need for objectivity in science. Your self-mocking statement concerning free will sets a playful tone that keeps readers interested to the end. Certainly we need to admit the failings of current theory, the inconsistency of dark matter, for example, and your recognition that fundamental depends on current knowledge something I mention about discoveries leading to evolution of that which we consider fundamental. My definition of fundamental is more general, that which is necessary for existence, yours applies to physical theories. And right away you recognize there are other approaches. You use QCD as an underpinning theory; I use ToE, recognizing tools and the coming together of forces to uncover the fundamental - LIGO thinking sensitivities can be enhanced to record the BB and LHC for less than a second after the BB. Hope you can check out my essay, Sabine.

Jim Hoover

Dear Sabine - I have to apologize, rather embarrassed, because I hadn't realized that you've devoted quite a bit of time to this debate over free will. Having looked now at several of your posts and papers, I think I understand why you care about this issue - because many other people do, and they also feel the need to defend themselves against science. I agree that's very bad.

Still, this debate perpetuates several misconceptions about, for example, reduction and emergence. Karen Crowther has an excellent essay in this contest, and has another paper on "decoupling" these concepts, which are often treated as mutually exclusive. But I question whether they're really useful concepts at all, since probably every case in which one layer of natural order is built on another has unique features. A notion like "phase transition" makes sense - different cases can be usefully compared. What useful comparison can we make between the emergence of chemistry and the emergence of life, or of literature?

If "strong emergence" means that the emergent properties of large systems do not derive from the nature of lower-level systems, there's no good reason to believe in it, and whether or not we can prove it's false, there's plenty of reason to assume it's true. That doesn't mean the behavior of a neural net has to be predictable, even in principle.

But the real question is - what could "free will" possibly mean, that's "undermined" by its dependence on many, many layers of physical and biological systems, not to mention our own language and culture? Clearly I'm the one making choices about what I do, for the most part. Certainly these choices aren't independent of my past, or of the situation in the world around me. Some of these dependencies I'm aware of, others not. Does that mean I'm not the one who's choosing? What does "I" mean, in that case? If it turned out that my consciousness runs on spirit-magic instead of neurons, would that make it more "free"?

So my sense is that the prevalence of a "free will" debate reveals something unsound in our collective mental state, but doesn't help cure it. If only philosophy - which was once such a grand intellectual adventure - could find something helpful to do in the modern world!

May I humbly thank you for your insightful contributions to every other topic you pick up, in your blog.

Conrad

Sorry, I meant to say -- whether or not we can prove strong emergence is false, there's plenty of reason to assume it is.

A thought provoking essay, Sabine.

On the issue of free will, I'm reminded that Quine said, "To be is to be the value of a (bound) variable." So I guess Hamlet was right about that fundamental question. :-)

Highest marks.

All best,

Tom

Dear Sabine

If you are looking for another essay to read and rate in the final days of the contest, will you consider mine please? I read all essays from those who comment on my page, and if I cant rate an essay highly, then I don't rate them at all. Infact I haven't issued a rating lower that ten. So you have nothing to lose by having me read your essay, and everything to gain.

Beyond my essay's introduction, I place a microscope on the subjects of universal complexity and natural forces. I do so within context that clock operation is driven by Quantum Mechanical forces (atomic and photonic), while clocks also serve measure of General Relativity's effects (spacetime, time dilation). In this respect clocks can be said to possess a split personality, giving them the distinction that they are simultaneously a study in QM, while GR is a study of clocks. The situation stands whereby we have two fundamental theories of the world, but just one world. And we have a singular device which serves study of both those fundamental theories. Two fundamental theories, but one device? Please join me and my essay in questioning this circumstance?

My essay goes on to identify natural forces in their universal roles, how they motivate the building of and maintaining complex universal structures and processes. When we look at how star fusion processes sit within a "narrow range of sensitivity" that stars are neither led to explode nor collapse under gravity. We think how lucky we are that the universe is just so. We can also count our lucky stars that the fusion process that marks the birth of a star, also leads to an eruption of photons from its surface. And again, how lucky we are! for if they didn't then gas accumulation wouldn't be halted and the star would again be led to collapse.

Could a natural organisation principle have been responsible for fine tuning universal systems? Faced with how lucky we appear to have been, shouldn't we consider this possibility?

For our luck surely didnt run out there, for these photons stream down on earth, liquifying oceans which drive geochemical processes that we "life" are reliant upon. The Earth is made up of elements that possess the chemical potentials that life is entirely dependent upon. Those chemical potentials are not expressed in the absence of water solvency. So again, how amazingly fortunate we are that these chemical potentials exist in the first instance, and additionally within an environment of abundant water solvency such as Earth, able to express these potentials.

My essay is attempt of something audacious. It questions the fundamental nature of the interaction between space and matter Guv = Tuv, and hypothesizes the equality between space curvature and atomic forces is due to common process. Space gives up a potential in exchange for atomic forces in a conversion process, which drives atomic activity. And furthermore, that Baryons only exist because this energy potential of space exists and is available for exploitation. Baryon characteristics and behaviours, complexity of structure and process might then be explained in terms of being evolved and optimised for this purpose and existence. Removing need for so many layers of extraordinary luck to eventuate our own existence. It attempts an interpretation of the above mentioned stellar processes within these terms, but also extends much further. It shines a light on molecular structure that binds matter together, as potentially being an evolved agency that enhances rigidity and therefor persistence of universal system. We then turn a questioning mind towards Earths unlikely geochemical processes, (for which we living things owe so much) and look at its central theme and propensity for molecular rock forming processes. The existence of chemical potentials and their diverse range of molecular bond formation activities? The abundance of water solvent on Earth, for which many geochemical rock forming processes could not be expressed without? The question of a watery Earth? is then implicated as being part of an evolved system that arose for purpose and reason, alongside the same reason and purpose that molecular bonds and chemistry processes arose.

By identifying atomic forces as having their origin in space, we have identified how they perpetually act, and deliver work products. Forces drive clocks and clock activity is shown by GR to dilate. My essay details the principle of force dilation and applies it to a universal mystery. My essay raises the possibility, that nature in possession of a natural energy potential, will spontaneously generate a circumstance of Darwinian emergence. It did so on Earth, and perhaps it did so within a wider scope. We learnt how biology generates intricate structure and complexity, and now we learn how it might explain for intricate structure and complexity within universal physical systems.

To steal a phrase from my essay "A world product of evolved optimization".

Best of luck for the conclusion of the contest

Kind regards

Steven Andresen

Darwinian Universal Fundamental Origin

Hi Sabine,

I enjoyed your essay and the dialogs that followed. As per:

"First I disagree that reductionism means that "Large things are made of smaller things", I would argue that more fundamental things can actually be bigger than less fundamental things, see my essay."

You may find my entry interesting in terms of your comment. Do take a look. Also see Enrico Prati's entry on deep learning.

So many essays, so little time...glad I got to yours,

Don Limuti

Hi Sabine,

Many thanks for the time and thought you put into your blog. More than a few jewels have come to light in my eyes from there.

Like that you number your essay. This is something several of the imo 'better' authors are doing in this forum, very helpful in the discussion threads.

1. Reductionism Works - really? how does emergence fit into reductionism?

2. What is Fundamental? - happy to see we (Michaele and I) define fundamental in what appears to be the same way as you, as that which cannot be taken to be emergent. As far as i know we and you are the only authors to do so. Do you know of any others? You elaborate on this with four points and some discussion, all pretty much well taken. No point to "...quibble about the use of words" here.

3. Weak vs Strong Emergence - The geometric wavefunction interaction (GWI) model we are working with appears to be fundamental without qualifier. It takes the enigmatic unobservable wavefunction and wavefunction interactions to be fundamental, and the lump-of-energy that emerges from wavefunction collapse, the amplitude, to be ummm... emergent.

GWI model is very simple. The vacuum wavefunction is taken to be comprised of fundamental geometric objects of the orientable eight component Pauli algebra - one scalar, three vectors, three bivector pseudovectors, and one trivector pseudoscalar. Point, line, plane, and volume elements of 3D space.

Five fundamental constants - speed of light, permittivity of space, electric charge quantum, Planck's constant, and electron mass (to define scale of space at the Compton wavelength) - are input by hand, needed to assign topologically appropriate quantized electric and magnetic fields to the eight wavefunction elements. There are no adjustable parameters.

Interactions are modeled by grade/dimension-changing geometric products of Clifford algebra, generate a 4D Dirac algebra of flat Minkowski spacetime, the particle physicist's S-matrix. Time (relative phase) emerges from the interactions.

As far as we know, such a model is not emergent from any existing theory, as it requires synthesis of the geometric wavefunction model with quantized impedance networks. Not easy to find that in the literature (except in vixra, bless Phil Gibbs), in folk's blogs,... radically new ideas, the paradigm shifters, are heavily filtered. Orthodoxy is a very stable system.

4. Strong Emergence Doesn't Work - Here we arrive where the essay has been heading for a while, at effective field theories. All well and good. But also well and good to keep in mind that the GWI approach is naturally finite, confined, and gauge invariant. Applies from IR boundary to UV Planck length, and beyond to the singularity. With that gonna jump to

5. Top Down Causation Doesn't Help - Agreed, with the caveat that in GWI approach the problem needing help does not exist.

6. The Loophole - No loophole in an electromagnetic model that is naturally finite, confined, and gauge invariant, a model that is 'effective' at all length/energy scales. And only one coupling constant.

Agree that the ball is back in court of physicists.

Hope you take a look, get some sense of what we're doing. Several of our fellow contributors have picked up on it.

Best regards,

Pete

Hi Sabine,

Thanks for letting me believe in free will!

Seriously, I never doubted it -- just like I did doubt strong emergence. Thanks for poking a hole into it -- it has been overused to say the least, ignoring that forests need to be made of trees to really be forests.

Ironically I did write exactly the type of essay you explicitly avoided: an essay directly answering this contest's question "what is fundamental?" Boring, maybe, but necessary, I think. It's super short, though, so it may not bore you too much to read it!

Best,

Luis Felipe Patino Cuadrado

Hi Sabine,

Your essay shows that you know where the problems are, but just like in the Star Trek movies, you're like Khan trying to kill Kirk... You keep missing the mark.

You say that reductionism worked in the past (and it did) but it has not worked recently - that is absolutely correct but the question is WHY has reductionism come to a screeching halt in advancing physics? The reason is because the scientific method is no longer useful in finding anything more fundamental. It is not possible because to do so would break the laws of physics (specifically the law of conservation of energy) to find the primordial building block entity that created everything. So smashing particles will not be fruitful.

https://www.academia.edu/27987699/_Why_Cant_the_LHC_Find_New_Math_

The other way the scientific method is used to advance theory is to derive a new theory from the already known base knowledge (advancing current math) and then prove it through experimentation. That cannot work to find "something" more fundamental because the moment you write a known mathematical equation, you are already passed the point of finding anything more fundamental in physics. Our math contains parameters such as distance, time dimensions, direction, charge...etc... These are all taken for granted - a fundamental theory must account for how each of these parameter came into existence.

In addition deriving "new math" from current math cannot work because all our current theories and math pertain to only 5% of the energy in the universe... While experiments suggest there is much more energy in our universe, there is NO mathematical representation of that energy nor can a mathematical representation of this energy be derived from our current math that does not include it.

Please consider reading my essay for this contest and these two papers also...

https://www.academia.edu/27987699/_Why_Cant_the_LHC_Find_New_Math_

https://www.academia.edu/30755282/Hidden_Dimensions_..._Not_So_Hidden_After_All

All the best to you as you seek knowledge and reality...

The secret lies with the hierarchy of energy... I'll be waiting for when it is finally realized.

These kind of essays are very useful because the expose the flaws of spacetime in a manner that mainstream science accepts. As usual, the author uses words that require further definition like naturalness and weak versus strong emergence.

Invoking new words to describe very old notions is a classic way to avoid addressing key notions like free will. Whenever there is trouble, simple invoke the notion of Landau poles and that will ease the pain of conflict. Does this make any sense at all?

"The argument that effective field theory proves reductionism even though no one is able to at least derive the properties of an atomic nucleus from QCD undeniably has an air of physicists' hubris to it."

The author is very smart and makes many good points...the points made in this essay are not really very good...