Reductionist Doubts by Julian Barbour

Julian,

I am suspecting that the angle you "measure" in ADM correlates somehow to a Lorentz Rotation angle? Recall that a Lorentz boost can be represented as a bonified rotation in the information space of Dirac. Does ADM build the "information space" of Einstein that provides the ultimate in a physical spatial scaling w/ "a measured Lorentz angle value" for each physical object possesing mass and having a rest frame to make measures within? If so, this sounds like the information we receive when we multiply by a complex #. Isn't this the information attained by conformal QED? ADS/CFT stuff with Alpha being the 5D symmetry having the 4D QFT "shapes" occupying a bounding surface?

Your analogy of the Alpha as the most uniform angle space yearned for by all different angle spaces (well you may not have exactly stated this ... ad lib by me here) may imply that the angle space of the ADS version of a QFT "desires" to become part of the 5 Dimentional informational space but has asymmetrically been broken off and given a series of angle measures that "precisely measure the asymmetric break-up" (maybe encoded in DNA for a "life" shape?)... like a conciousness in birth being the asymmetrical parting from a structure having a complete symmetry (like point symmetry of the electron. Hmmm, this may imply that the quantum field is created by nothing more then a correlation between the asymmetric "yearning - a projection on to Alpha" that drives all other shapes to entropically become more in line with the symmetric Alpha (an S matrix with a mission!) ... thus ... all shapes contain paths (maybe similar to the Feynman decision paths) that lead them them back to occupy the Alpha symmetry once again... ?

Afterall ... in ADM a living thing would have a shape space ... and like all shapes ...

My most enjoyable read, Thank you,

Tony

Dear Julian Barbour,

thank you very much for this essay. It does very clearly set out your ideas and the ideas of other that have been the foundation for them. Like your previous essays, it is accessible to non specialists, very well crafted and relevant to the essay question. I am sure there is still more I can learn from it. It is another fine essay.

You wrote "Using grand philosophical terms, the gap between epistemology - what can be observed - and ontology - what is assumed to exist - should be as small as possible. Ideally, there should be no gap at all....." That is where our views necessarily diverge. As I regard the observed output of data processing to be distinct from what existed unobserved as the source of the data.

Thank you once again for giving some time to discuss you work on your blog thread and your replies here. Good luck in the competition.

Thanks for your thoughtful reply! I suppose it is rather appropriate that when I wrote my thesis on Fundamental Theory that I included photographs of headstones from the graveyard where Eddington is buried. At any rate, I'm not sure I entirely agree regarding Fundamental Theory, but that's for another discussion over a drink sometime.

I still think I disagree about reductionism, though. As big a fan as I am of dictionaries, I find they do not always capture the subtleties in the actual usage of certain words. So nothing in the definition you posted is necessarily wrong, but I think the interpretation of that definition is almost too literal.

Consider a car, for example. I don't think anyone would disagree with the suggestion that a car can be easily understood via reductionist methods (in fact, Robert Pirsig demonstrates this, albeit with a motorcycle, as a beautiful demonstration of a reductionist scientific method in his Zen and the Art of Motorcycle Maintenance). But are there facets of a car that are meaningless outside of the whole? Absolutely! We could understand how every individual part works *and* how they work together to move the car, but the *purpose* of the car is entirely holistic.

Now consider a mechanic. Can a mechanic fix a car if he/she has a wholly holistic understanding of it, i.e. only knows its purpose? No because if the car fails the mechanic must still understand how the individual parts work in order to figure out how to fix the car! Yes, he/she needs to know how each of the parts is connected, but fixing the problem means isolating it.

As George pointed out in his essay, in many situations there are holistic issues that often enact a "top-down causation" effect where the "whole" somehow enacts restrictions on the parts. But that's really true of anything. For the car example, an accelerator peddle will go completely to the floor if the cable attaching it to the engine snaps (this actually happened to me). The limitations in the motion of the accelerator pedal are driven by a whole host of issues, many of which are "holistic" or even unrelated to the actual mechanisms of the car itself (e.g. laws may constrain design). Despite all of this, I can't see how a reductionist method could possibly be avoided here nor do I think reductionism itself excludes certain holistic notions such as "purpose" (incidentally, in order to determine the purpose of a car, if one is ignorant of such things, amounts to obtaining more information which is, in itself, a reductionist thing to do - the "whole" doesn't proclaim itself a car).

So the argument goes that there are certain phenomena that are simply either too complex or too abstract to be understood in the same way as a car. But this begs the question, how do we *know* these phenomena are too complex or abstract? Are we simply assuming they are since our usual reductionist methods haven't worked (yet)? If so, then we are a priori assuming there's a problem with reductionism. But this is a logically unprovable assumption. As Carl Sagan once said, "[y]our inability to invalidate my hypothesis is not at all the same thing as proving it true."

Or, what happens if we give up when we are just on the verge of understanding but don't realize it? Worse yet, what happens if this anti-reductionist movement takes on a life of its own and drives reductionism into obscurity? Because the argument that certain phenomena are too complex to be understood in this reductionist manner is the exact argument that is used by proponents of intelligent design and creationism. I find that a bit frightening.

At any rate, regarding shape dynamics, I agree that there absolutely is a huge conceptual difference between it and Newtonian dynamics. I understand precisely where you are coming from on this. However, I completely disagree with the idea that you can quantify the difference between two nearly identical wholes without appealing to something external to both (this is exactly what Eddington tried to do with Fundamental Theory). I mean, certainly at some point we get into some kind of recursiveness (even language is recursive since it is used to define itself). But with things like shapes, how does one quantify a difference without some reference? At some point one needs to define something which I say is reductionist. You may say this is still holistic, but at this point the argument has become one of semantics because the fact is that we need to define properties (which are inherently *not* holistic) by which we can compare the shapes. (I have more to say on this point, but I'll send you an e-mail about it.)

Now, in regard to my point about reductionism as a methodology versus reductionism as a formal structure to the universe, let me explain the latter by comparison to the former. While it might be possible that the universe contains structures whose function or purpose or nature simply cannot be understood by reductionist methods, this is *not* the same thing as saying that those structures' function or purpose or nature actually *is* independent of the behavior of its constituent parts. It may simply mean that there are limits to our *knowledge* of the universe. Part of this comes from the fact that we are *part* of the universe we are attempting to describe and thus naturally we will run into some problem of recursiveness. But taking a more holistic approach won't necessarily rid us of this problem.

So, reductionism doesn't obviate the need for holism, but fundamentally reductionism is still at the core of the scientific enterprise and must remain so if it is to remain science and not succumb to a lot of hokus pokus.

Julian, Ian,

I think it somewhat "reductionist" to say reductionism is a product of the last few hundred years of scientific thought. Knowledge is foundationally a process of extracting information from the whole.

There is a conceptual reductionism to math which obscures wholism. When we actually add things together, we get a larger whole, so what we are really adding, when we say one plus one equals two, are the sets, not the contents of the sets. So we have one larger set, not applesauce.

This then is a dynamic process, where we do not just have distinct states in sequence, but one state that changes. It's just that our minds see the distinctions, the angles, not the connections, the distances. This is because our minds function as a strobe like process of extracting frames of seemingly static perception from that dynamic. Which we then string together as a sequence of events. Yet the foundational reality is only the process, because duration is the state of the present between the occurrence of events, not a timeline external to the present.

Writing on a phone is a study in thought compression.

a sphere, interesting.:) revolution spherization !!!

John,

Well, to some extent, reductionism as we know it, vis-à-vis the scientific method, *is* largely a product of the last few hundred years of scientific thought. And, one of the points I've been trying to make is that nowhere does reductionism imply an anti-holism. Reductionism is merely a method for understanding the whole, but it does not deny that the whole may possess features that are unique.

Kudos on writing that on a phone, by the way. Most impressive.

Ian

So the question is: what constitutes a 'part'? There may well be different types, but, generically, I would suggest it is that which is physically existent as at any given point in time. In simple language, what is 'there' if we could 'stop the tape' (reality being analogous to a film).

Your car is no different from any other sequence of physical existence. The issue is that in that circumstance, we are defining physical reality at a level of differentiation significantly above that which occurs. The 'entity' is being defined by virtue of certain superficial physical features, and so long as they pertain, we know it as car. But the physical reality of this is much more complex. So long as the integrity of the physical sequence is maintained, and the explanation relates to that level of differentiation, then there is no problem. Indeed, apart from the fact that we could probably never define car (or any other entity) at the level of physically existent states, because of the sheer complexity involved, doing so will not assist understanding at a higher level in most cases. The 'purpose' of car is a sociological concept anyway. Issues arise when these higher levels of differentiation are deemed, incorrectly, to be physical reality, when actually they are sequences thereof (ie involve more than one physically existent state). Because then physical sequence can become confused (ie out of sequence), causal factors wrongly attributed, etc, etc.

For example: "enact a "top-down causation" effect where the "whole" somehow enacts restrictions on the parts. But that's really true of anything". Indeed so, but this is in the sense that what occurs next can only be a function of the previous occurrence. Any given physically existent state can only be the result of the immediate predecessor, both in terms of sequence and spatial location. Physical effects do not 'jump' circumstances. There is a implication in this type of thinking that the future is affected in some way. Ontologically, this is incorrect, as the future is non-existent. What actually happens is that a subsequent physically existent state occurs which is different from what otherwise would have occurred had the previous state been different. In the case of car, considerations are at a 'functional' level, in order to explain 'how it works'. It has not been differentiated to an physically existent level.

Paul

Ian,

I wasn't denying that science has codified conceptual reductionism, just pointing out the irony of imlying only science is reductionistic, ie, reductionism of reductionism. So to be wholistic about reductionism, it might be said that all knowledge is inherently reductionistic, since knowledge requires perspective and perspective is subjective.

Hello John, Paul, Mr Durham,

well said all that.

viva el revolution spherization.

Julian,

Not sure if you are reading my comments (no reply). I'll therefore make this my last "question" comment. Fermions are believed to form the structure of everything that has a measurable shape. Light (a boson) is the element that provides information regarding the shape (up to the Chandrasekhar limit). This implies that the information supplied by Shape Dynamics has to accomodate these facts (well, assuming they really are physical fact). This may then imply that Shape Dynamics can precisely describe information measured at the Fermi surface of virtually any manifold. Do the methods for obtaining information regarding the Fermi surface resemble Shape Dynamic methods - does this information correlate? One can envision the angle measures between atoms and molecules in solids (and especially atoms on the solid's surface) as being angle parameters in the Shape Dynamic representation. This would also bring forth band information as conduction (global information) and valence (local information). As the two bands part ways (conduction -> valence) global information (molecular levels) becomes local (atomic levels), periodic cellular, and increase in # of identical copies (all the atoms and molecules that makeup the solid). Can Shape dynamics accomodate anything like this? Characterizing band structure with a more simplified model could provide new horizons in the semiconductor business.

When a grad student, I went head to head with a person who insisted that the information regarding the 7x7 reconstruction of the Silicon surface was locked up in the measured angles and positions of the surface atoms .... that's it... and my argument was that the information was locked up in the hybridization of the atomic orbitals and forces generated (minimized energy, yadda, yadda). It would seem that from a shape dynamics perspective he may have had a good argument!

Regards,

Tony

Dear Julian:

I enjoyed reading your well-written and intuitive essay describing the weaknesses of the reductionist approach in representing the Natural physical reality.

My paper -" From Absurd to Elegant Universe" strongly vindicates the following conclusions of your paper especially related to the QM paradoxes and inconsistencies with GR -

"....it may be impossible to understand key features of the universe such as its pervasive arrow of time and remarkably high degree of isotropy and homogeneity unless we study it holistically - as a true whole. A satisfactory interpretation of quantum mechanics is also likely to be profoundly holistic, involving the entire universe. The phenomenon of entanglement already hints at such a possibility.."

The Reductionism literally means a pursuit of "Reduced" or truncated reality. The well-known Observer's Paradox of QM implies that the collapse of the wave function truncates the reality to the limits of the consciousness (or lack of it) of the observer. When this "Reduced" or truncated or incomplete view of reality is over-extrapolated to predict the universe or quantum behavior, paradoxes (multi-verses, multi-dimensions, black hole singularities, quantum gravity, quantum time, entanglement, dark matter, anti-matter, and dark energy etc.) and inconsistencies result leading to an Absurd universe.

My paper demonstrates that following a holistic approach wherein the whole universe is considered as a continuum of mass-energy-space-time, a very simple mathematical model of the missing physics (hidden variable) of the well-known spontaneous decay/birth of particles can be developed that explains the observed quantum as well as classical behaviors. The holistic model also successfully predicts the observed data at all scales from below Planck scale to beyond cosmological scales. The proposed model not only resolves black hole singularities but also the unresolved paradoxes of physics and cosmology. As you rightly said, the holistic model also explains the inner workings of QM and eliminates its paradoxes and inconsistencies with relativity. It also vindicates your conclusion that time is not a fundamental entity and is an illusion since the observed universe and galactic expansion can be predicted without any explicit consideration of a cosmic time.

I would greatly appreciate your comments on my paper. You can contact me at avsingh@alum.mit.edu.

Best Regards

Avtar Singh

You deleted all my comments because I did not read Shape Dynamics? The punishment is unproportional to the crime, Julian Barbour.

Pentcho Valev

You are "in the job of actually salvaging absolute simultaneity away from the clutches of Einstein", Julian Barbour. So Harvey Brown says. You confirm:

Aspects of Time, Julian Barbour, Warwick, August 24th 2011: "Was Spacetime Glorious Historical Accident? (...) ABSOLUTE SIMULTANEITY RESTORED!"

The problem is that, in textbooks, the relativity of simulteneity is derived from the principle of constancy of the speed of light (Einstein's 1905 light postulate). So if asked:

Can absolute simultaneity and the light postulate coexist in Einstein's relativity?

any textbook author would give a negative answer. Now my question:

Can absolute simultaneity and the light postulate coexist in Shape Dynamics?

Please don't delete the question, Julian Barbour. If your answer is "yes", then Shape Dynamics is a miraculous science, even more miraculous than relativity, and I promise to study it very carefully.

Pentcho Valev

Dear Mr Julian Barbour

Our intuition gives that Machian principle is foundation of physics, although it is not yet proved. Similar unproved intuition appears at fundamentality of consciousness and that gravitational force is different that other forces.

You wrote that time arrow is a holistic phenomenon. I wrote similarly in one old article: "Important time's arrow is also the cosmological time's arrow. It is very likely that all in our cosmos is connected, so it has the same direction of time's arrow. It is not possible to communicate with someone who travels in opposite time direction. Therefore, time's arrow at the collapse of a wave function can choose arbitrary plus or minus direction, but it is motivated by direction of time's arrow in the cosmos. (By the way, it is very likely that explanations of big-bang need improvement. For instance, why is entropy at big bang very low?! Low entropy does not happen spontaneously.) Hitoshi Kitada [15] wrote that absolute time of universe does not exist and that only time for local observers exists. This is true in principle, but time also exists as connection between local observers, local observers are connected and this gives one direction of time's arrow of cosmos."

I claim also that space-time is an emergent phenomenon caused by matter. Otherwise, interpretation of general relativity also claims, whether all matter is removed from universe, nothing remains - neither empty space. This is a holistic consequence of general relativity similarly as Machian principle is.

This is written in my essay: "SR gives also that space-time is emergent so time exists only in matter [8], although, formally, every point in space in SR has attributed time. This is rarely mentioned, but it is very important. Namely, if all matter had been removed from our universe, there would not remain anything, not even space-time. Otherwise, this is given also by GR by its "diffeomorphism invariance" and by the "background free space-time" [9, p. 138]. Similar conclusions are given also by Markopoulou, namely that space-time arises as a consequence of relations between the elementary particles (or other elements of matter) [10]."

Maybe you should mentioned in introduction that quantum field theory is also holistic principle where field is more important than single particles.

My speculation: Maybe all universe has also properties of a particle. Otherwise, I am sure that black holes are elementary particles, maybe also universe is one particle, that means that it shows some properties of elementary particles.

Because of clarity it should be mentioned that Machian principle is also generalization of relativization: relations between objects are more important than location in one inertial system or in one coordinate system - similarly is at relativity principle.

Maybe You should explicitly mentioned that because angular momentum of universe is zero and because universe is finite, the Newton's bucket is so explained as not contradictory with Machian principle.

You replace time with time of universe. This is a cunning and something grounded idea, maybe it will show as good.

You mentioned that only six components of metric tensor is physically important, this means one volume and five angles. I do not understand what means which component? Can you explain this on three and two dimensional metric tensor and on a four dimensional example of Schwarzschild Black hole. Here non-diagonal components are zero, thus angles are only 90°? Do You think also about angles between coordinate axes?

You write also about dimensionless quantities. Do you see any advantage of using Planck's distance.

I suspect in my essay, that interior of black holes does not exist, similarly as tahions do not exist. Is this in any accordance with Your theory? Do You propose and novelty about Big Bang?

Otherwise You write very clearly.

Dear Julian

Original, thoughtful and well explained. But is reductionism a 'mutually exclusive' methodology? Should the real solution to the workings of the universe not be valid on a macro as well as micro scale, deriving observed reality from a consistent mechanism applicable to both ends of the 'known' scales, quanta to universe? (both ends of course yet unconstrained).

I now better understand your shape dynamics, but wonder where evolution from relative motion lies within it, as it seems not at the centre. Am I wrong? I found myself desperately hoping for a 'success' to hang this new set of beliefs on, but despite incisive analysis nothing materialised. May I offer an ADM based option.

You'd need to read my essay, but what this does is derive the effects we term SR from a quantum mechanism, and the mechanism from the morphology and evolution of universes. It may be seen as defining and creating the boundaries of closed three-geometries, each a mutually exclusive but nested inertial frame, defined by relative kinetic states. These have real evolving shapes, but size is immaterial. From the foundational structure of truth function logic an ontologial construct is described in the essay entirely from epistemological elements. A pre big-bang (not really a 'bang') state emerges as logically as local CSL.

I quite understand how improbable this seems, it is none the less the case. As Feynman said it does at first look wrong, so fails the test of 'beliefs' most use, but it has passed all falsification. I hope you may give it a stern test, and look forward to your critique. http://fqxi.org/community/forum/topic/1330

Interestingly, the physical reality of the boundary mechanism is shown and correctly interpreted in the experimental findings in Rich Kingsley Nixey's essay Fig.2.; http://fqxi.org/community/forum/topic/1448

Yours is a more clearly written essay than my own, with perhaps too dense an Architecture of the components, though I do add a little superficial theatre for fun.

Best wishes and good luck in the competition.

Peter

Dear Dr. Barbour,

I just read your essay. The idea of shape dynamics appears to be a form of Regge calculus. I watched a video presentation of yours on the FQXi blog. The time evaluated from the Jacobi variational principle

δt = sqrt{m_iδx_iδx_i/(E-V)}

is related to a proper time, or an interval. This got me thinking about how you could describe this in a completely non-time manner.

It dawn on me how one could think about this according to light rays. In this way there is no matter of time involved with the "motion" of a shape, for null rays have no proper time. I illustrate this with two diagrams I attach to this post. The first is a flat spacetime description. This is also pictured in 2-space plus 1-time spacetime in 3 dimensions. Two points on a spatial surface emit light pulses. These converge on three points on a subsequent spatial surface. These then define a triangle on that spatial surface. The two points then emit subsequent light pulses and map the triangle onto a third spatial surface. In Minkowsk spacetime this continues indefinitely.

In the curved spacetime situation null rays are curved. Since the metric

ds^2 = g_{00}c^2dt^2 - g_{ij}dx^idx^j

is such that for ds = 0 we can have

U^iU^j = (g_{00}/g_{ij})c^2dt^2

And the optical path change due to curvature has a c^2 term. Hence we can assume the triangles on the spatial surface are flat. The deformation of null rays will then map the first triangle on the second diagram I attach into the second. The picture here is then completely described by null rays which have no proper time.

The time computed by the Jacobi variation is then an "emergent" or computed quantity. This is a parameter which emerges from the "motion" of the triangle, or the map from the first to the second.

On another vein I am not convinced that time is a complete illusion. Maybe I will go into this later, but I think that in quantum spacetime it may be that if you only have space then time is not defined. Conversely, if time is defined you have no space. I suspect the two are complements.

Cheers LCAttachment #1: light_rays_and_triangles.JPGAttachment #2: null_rays_and_triangles_in_curved_spacetime.JPG

This post above is mine; I forgot to include my name. My essay is on a different path.

Cheers LC

Lawrence Crowell wrote: "On another vein I am not convinced that time is a complete illusion. Maybe I will go into this later, but I think that in quantum spacetime it may be that if you only have space then time is not defined. Conversely, if time is defined you have no space. I suspect the two are complements."

How can one qualify this without facing deletion? "Not even wrong" seems to be a suitable euphemism. Brendan Foster? Is "not even wrong" too rude? Are you going to delete this comment?

Pentcho Valev