Register to reply

Ultimate question: Why anything at all?

by bohm2
Tags: ultimate
Share this thread:
Albuquerque
#163
Dec18-11, 04:34 AM
P: n/a
...how come speaking on potential can be related with not having constrains ? How come increasing the spectrum from set to power set is said to be related with vagueness ? Either there is causality in place and mechanic relation from the beginning or the whole foundation goes down the drain as magic, no matter what direction you choose to approach the problem be it holistic or not...
...as for time, one can easily extend the concept from the "classical" relativist perspective of space time and apply it to any kind of change process who proves to be more fundamental...motion does n´t appeal to me either, but such is beside the point of what time ends up standing for in practical terms which again is change...one must be careful on how one stacks words together or we end up creating words to address the same phenomena needlessly...as I see it time cannot be removed out of the equation nor some sort of meta space call it what you will...there must exist an axis of order for whatever meta substance there is with a simple rule as simple as present not present relating the discrete bits of such axis...("not present" would stand for null rather then absent...meaning null as being countered by an opposite direction of a mirrored nature or something similar...absence is more a matter of ilusion then a matter of fact the way I see it...)
Albuquerque
#164
Dec18-11, 04:47 AM
P: n/a
If you find the time and the appeal, I would like you to clarify as most as possible your notion of "vagueness" as I may be missing some fundamental idea in your view which would be unfortunate...maybe you could start by defining some model for freedom at large....my dull imagination cannot wrap my head around any concept of pure freedom no matter how much I try...in that sense your wise input would be greatly appreciated !
apeiron
#165
Dec18-11, 04:52 AM
PF Gold
apeiron's Avatar
P: 2,432
Quote Quote by Albuquerque View Post
If you find the time and the appeal, I would like you to clarify as most as possible your notion of "vagueness"...
I collected some grounding ideas and literature references in this thread....

http://www.physicsforums.com/showthread.php?t=301514
Maui
#166
Dec19-11, 03:00 PM
P: 724
Quote Quote by bohm2 View Post
I agree. I'm not sure what to call it though but it seems to have some properties similar to the same "stuff" that gave birth to our universe, in that it defies spatio-temporal explanation.

Space, matter(chairs, cars, etc.), time and motion are classical concepts, they are derivative(and secondary) and comprized of the momentary excitation of the respective field(this - the field ontology - is by far the single and only ontology that stands all evidence thrown at it). There is no other ontology and there are no particles('particles' are the classical momentary state of the field - sorry, language fails me here). Matter is a state of the field, why reality is like that, would be a very good question for philosophers to answer. Perhaps fields have a mind of their own(joking ).

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet - N. Bohr
apeiron
#167
Dec19-11, 03:19 PM
PF Gold
apeiron's Avatar
P: 2,432
Quote Quote by Maui View Post
Matter is a state of the field, why reality is like that, would be a very good question for philosophers to answer.
Fields are just another modelling concept. They have the advantage in that they are both local and global, so do offer a holistic approach.

A field can define a space by filling it, while locally specifying its material content. Local particles can be described as excitations and so given a contextual definition. Etc.

So if reality is holistic and systematic in its causality, we should expect a field ontology to be good at capturing that essential local~global organisation.

Of course, like any analogy, there are then shortcomings. Fields have no memory, no persistence. All is flux. So it is hard to represent history or gradients.

So classical wave mechanics has been a useful mental concept for modelling material reality. But note that soliton modelling and superconductor modelling from condensed matter physics are now also common mental concepts being employed in fundamental physics, along with network theory (as in loop quantum gravity).

And also, the essence of a "field" in any of these descriptions is that it preserves locality. Whereas QM creates a problem in that regard.
Maui
#168
Dec19-11, 03:36 PM
P: 724
Quote Quote by apeiron View Post
Fields are just another modelling concept. They have the advantage in that they are both local and global, so do offer a holistic approach.

They are the only consistent model of reality there is.



A field can define a space by filling it, while locally specifying its material content. Local particles can be described as excitations and so given a contextual definition. Etc.


No, a field doesn't fill space, space is relative and e.g. the gravitational field defines space-time as per GR. Fields define and make up spacetime


So if reality is holistic and systematic in its causality, we should expect a field ontology to be good at capturing that essential local~global organisation.

My long standing gripe with causality has always been that it's a secondary(derivative) concept(like matter, space and time). You are looking for the organizing principles where they don't exist.


Of course, like any analogy, there are then shortcomings. Fields have no memory, no persistence. All is flux. So it is hard to represent history or gradients.

Memory is a secondary, emergent concept as well(a property of the field?). Classical realism of objects as a fundamental characteristic of reality has been dead for a while.


And also, the essence of a "field" in any of these descriptions is that it preserves locality. Whereas QM creates a problem in that regard.
QFT doesn't pressupose realism, so no problem in that respect with QM.
apeiron
#169
Dec19-11, 04:14 PM
PF Gold
apeiron's Avatar
P: 2,432
Quote Quote by Maui View Post
Classical wave mechanics had some success in mimicing reality. But it's still a spectacular failure at high speeds, energies and small scales. Philosophically, it's dead.

QFT doesn't pressupose realism, so no problem in that respect with QM.
But what is a "relativistic quantum field" then? We have various formal descriptions for making calculations, but no single mental image of what we are talking about.

If you are talking classically, then you can claim that particles are just local excitations. But what you are talking about with QFT is precisely what people complain they cannot imagine in terms of "just waves", or "just particles" either.

So your use of the word "field" here is a placeholder for that hoped-for deeper appreciation of what may be the ontological reality. And as such, it does not actually rule out a more particle-based approach as you want to claim.

For example this is a good discussion of the problems for both camps: http://plato.stanford.edu/entries/qu...ld-theory/#Ont

Many of the creators of QFT can be found in one of the two camps regarding the question whether particles or fields should be given priority in understanding QFT. While Dirac, the later Heisenberg, Feynman, and Wheeler opted in favor of particles, Pauli, the early Heisenberg, Tomonaga and Schwinger put fields first (see Landsman 1996). Today, there are a number of arguments which prepare the ground for a proper discussion beyond mere preferences...
So even quantum field theory is not with any certainty a "field theory".

And then there is the issue of what a quantum gravity theory would be. Would it look even less like a classical notion of a field (as with a spin foam, or a string condensate, or whatever)?

So OK, you can call the ultimate concept of reality "a field". But how are you actually now defining a field? What does the word mean concretely here?

If we cannot spell this out, then the concept is simply a placeholder and carries no ontological weight. It becomes another way of saying "we don't know". Or perhaps, we don't know, but we are sure it means particles are not real, locality isn't fundamental, etc.
Maui
#170
Dec19-11, 04:47 PM
P: 724
Quote Quote by apeiron View Post
But what is a "relativistic quantum field" then? We have various formal descriptions for making calculations, but no single mental image of what we are talking about.

If we leave physics and return to philosophy - fields would be the Ultimate Reality as far as we know(and probably can know). That which exists and is real in the sense that it's the substrate of being.


If you are talking classically, then you can claim that particles are just local excitations. But what you are talking about with QFT is precisely what people complain they cannot imagine in terms of "just waves", or "just particles" either.

So your use of the word "field" here is a placeholder for that hoped-for deeper appreciation of what may be the ontological reality. And as such, it does not actually rule out a more particle-based approach as you want to claim.

For example this is a good discussion of the problems for both camps: http://plato.stanford.edu/entries/qu...ld-theory/#Ont

That is a good article and it very well portraits why a particle explnation of QFT is untenable.



And then there is the issue of what a quantum gravity theory would be. Would it look even less like a classical notion of a field (as with a spin foam, or a string condensate, or whatever)?

To my knowledge - all appraoches of QG involve a variant of emergence/symmetry breaking.


So OK, you can call the ultimate concept of reality "a field". But how are you actually now defining a field? What does the word mean concretely here?

If we cannot spell this out, then the concept is simply a placeholder and carries no ontological weight. It becomes another way of saying "we don't know". Or perhaps, we don't know, but we are sure it means particles are not real, locality isn't fundamental, etc.

I won't let you push me off the cliff on this (there's literature about Wheeler's beliefs, Bohm's beliefs, etc. on this issue in particular, they wrote extensively and would be more appropriate for a forum with more relaxed rules, i'd rather keep my points at their maximum). Otherwise, the field ontology is the triumph of human thought over reality(don\t ask if they are different, i don't know)
apeiron
#171
Dec19-11, 05:08 PM
PF Gold
apeiron's Avatar
P: 2,432
Quote Quote by Maui View Post
If we leave physics and return to philosophy - fields would be the Ultimate Reality as far as we know(and probably can know). That which exists and is real in the sense that it's the substrate of being.
My argument here is that when examined closely, the notion of a "field" has long become a notion about a simple potential - ie: a vagueness.

The substrate of being now has properties such as "infinite degrees of freedom", which then get "collapsed" due to the emergence of global constraints.

To my knowledge - all appraoches of QG involve a variant of emergence/symmetry breaking.
Precisely. They presume a fundamental unoriented potential, a vagueness, and then the actual world emerges via symmetry breaking.

So this is no longer a "field" concept, because fields are what emerge. But an unlimited potential of infinite dimensions is perhaps a little "field-like" when we try to imagine it. It is an uber-field possibly.

But by definition, a vagueness lacks locality and other definite features. These actual properties of fields have to emerge via development, or symmetry breaking.
bohm2
#172
Dec19-11, 07:58 PM
PF Gold
bohm2's Avatar
P: 691
I think a lot of this hinges on what the wave function means. Given Bell's and now PBR, it seems that our best model of "reality" at least at the microscale can no longer be directly interpretable as a local beable. If one wants to use some dualistic "cut" as in Copenhagen, there are difficulties as Maudlin points out:

The reason that this problem does not come up in practice is because the ‘standard’ interpretation is a legacy of the Copenhagen view, and the Copenhagen view does not postulate wavefunction monism. Copenhagenism insisted on the necessity of having a classical description somewhere, the description of the ‘measurement situation’: the infamous Copenhagen ‘cut’ was exactly between a quantum realm and a classical realm. And the classical description would, of course, be in terms of local beables, so there is no problem applying a spacetime transformation to it. Within this sort of a dualistic picture the problem of spacetime transformations of the wavefunction can be approached. The problem, of course, is that this sort of dualistic ontology is impossible to take seriously: no one ever thought that there were really two different sorts of physical systems, the classical and the quantum, that somehow interact. If that were the view, then the ‘cut’ would be a matter of physical fact: somewhere the classical and quantum bits of ontology would actually meet. Furthermore, it is evident that the ‘classical objects’, measuring apparatus and so on, are composed out of ‘quantum stuff’ (electrons, protons, and so on), so this cannot really be a dualistic ontology. In the confused morass of Copenhagenism, the observation that the ‘cut’ could, For All Practical Purposes, be moved about at will within a large range was taken to show that the cut itself corresponded not to a physical fact but to a convention, or something like that. But if the theory can be formulated without a cut at all, let it be so formulated. Having removed the cut and put everything in the quantum ontology, one would evidently remove all the local beables, and all the problems we have been discussing would return.
And the problem is also nobody seems to know the meaning of this larger space (3N dimensions)where the wave function lives. But it is at clearly at odds with the local classical field as Einstein notes:

It is further characteristic of these physical objects that they are thought of as arranged in a space-time continuum. An essential aspect of this arrangement of things in physics is that they lay claim, at a certain time, to an existence independent of one another, provided these objects ‘are situated in different parts of space’. Unless one makes this kind of assumption about the independence of the existence (the ‘being-thus’) of objects which are far apart from one another in space—which stems in the first place from everyday thinking— physical thinking in the familiar sense would not be possible. It is also hard to see any way of formulating and testing the laws of physics unless one makes a clear distinction of this kind. This principle has been carried to extremes in the field theory by localizing the elementary objects on which it is based and which exist independently of each other, as well as the elementary laws which have been postulated for it, in the infinitely small (four-dimensional) elements of space.
Thus, "Einstein notes that in classical field theory all of the beables are local, and local in the strongest sense: the entire physical situation is nothing but the sum of the physical situations in the infinitely small regions of space-time."
apeiron
#173
Dec19-11, 10:34 PM
PF Gold
apeiron's Avatar
P: 2,432
Quote Quote by bohm2 View Post
I think a lot of this hinges on what the wave function means. Given Bell's and now PBR, it seems that our best model of "reality" at least at the microscale can no longer be directly interpretable as a local beable. If one wants to use some dualistic "cut" as in Copenhagen, there are difficulties as Maudlin points out:
This is again re-stating the fact that locality is not fundamental and at best an emergent feature of reality. So now we move on to consider what is fundamental, and how things like locality might emerge?

Or should we instead keep going back to try to make locality work?

The conversation keeps returning to a point where you are either presuming "something exists fundamentally" or that "everything is emergent".

What is it, in the face of a good understanding of QM, that maintains a faith in the first option?
Maui
#174
Dec20-11, 03:17 AM
P: 724
Quote Quote by apeiron View Post
My argument here is that when examined closely, the notion of a "field" has long become a notion about a simple potential - ie: a vagueness.

The substrate of being now has properties such as "infinite degrees of freedom", which then get "collapsed" due to the emergence of global constraints.

Modern physics - turning physicists into philosophers and (at least some) philosophsers into physicists. I'm lovin' it



Precisely. They presume a fundamental unoriented potential, a vagueness, and then the actual world emerges via symmetry breaking.

So this is no longer a "field" concept, because fields are what emerge. But an unlimited potential of infinite dimensions is perhaps a little "field-like" when we try to imagine it. It is an uber-field possibly.


I would not say that it's easy to categorize fields as either real or unreal. There are good arguments that they are both(at the same time). Again, classical baggage(concepts) seem to stand in the way of a better understanding.

But by definition, a vagueness lacks locality and other definite features. These actual properties of fields have to emerge via development, or symmetry breaking.


I applauded you earlier in another thread about introducing ancient thinkers into the discussion with vagueness and potential development(vaguely resembles a wavefunction evolution and 'collapse').
apeiron
#175
Dec20-11, 03:26 AM
PF Gold
apeiron's Avatar
P: 2,432
Quote Quote by bohm2 View Post
I think a lot of this hinges on what the wave function means.
Further, if you were reading that Kastner paper on a possibilist transactional interpretation of QM, you will have noted that it too takes an "everything emerges from potential" approach to ontology.

Shimony (2009) has similarly suggested that relativistic spacetime can be considered as a domain of actuality emergent from a quantum level of possibilities:

“There may indeed be “peaceful coexistence” between Quantum nonlocality and Relativistic locality, but it may have less to do with signaling than with the ontology of the quantum state. Heisenberg's view of the mode of reality of the quantum state was ... that it is potentiality as contrasted with actuality. This distinction is successful in making a number of features of quantum mechanics intuitively plausible — indefiniteness of properties, complementarity, indeterminacy of measurement outcomes, and objective probability. But now something can be added, at least as a conjecture: that the domain governed by Relativistic locality is the domain of actuality, while potentialities have careers in space-time (if that word is appropriate) which modify and even violate the restrictions that space-time structure imposes upon actual events....” (2009, Section 7, item 2.)

Shimony goes on to note the challenges in providing an account of the emergence of actuality from potentiality, which amounts to ‘collapse.’ PTI suggests that transactions are the vehicle for this process ; and therefore at least part of it must involve processes and entities transcending the spacetime construct.
Maui
#176
Dec20-11, 03:30 AM
P: 724
Quote Quote by apeiron View Post
What is it, in the face of a good understanding of QM, that maintains a faith in the first option?

Our observations - you, me, the beauty of nature, love, the relentless human spirit for understanding how things work...

It's obvious at this point that the inner workings of reality are inaccessible to us, things happen, what the heck(ice-cream still tastes good, cold beer too)
bohm2
#177
Dec20-11, 09:49 AM
PF Gold
bohm2's Avatar
P: 691
I enjoyed reading Kastner's paper but I don't know exactly why but I just don't buy the whole concept of a 'collapse' process. I think any theory that has collapse in it, just seems wrong. I really found the video below (including a double-slit type of experiment) really useful in getting a "picture" of what may be happening. Still, the major problem is the wave can't be that type of guiding wave (e.g. existing in our familiar space-time). But at least, one can get an intuitive sense of how emergence of our familiar space-time may come from this configuration space stuff (whatever it is). Of course, the problem is that a direct mapping from configuration space to the more familiar space-time can't be done in any unique way, as others have argued, because when one tries to do it, the structure of the 3-N space can underwrite more than one set of emergent 3-spaces.The MWI doesn't have a problem with this view because they argue that more than one set of emergent 3-spaces exist at the same time. But I just don't buy MWI, either. But I still like the picture of those silicone drops in the video being our familiar objects in space-time whereas "below" there is some other stuff that defies locality/separability (something unlike the guiding wave depicted in Couder experiments). This is in line with some of Bohm's metaphysics which I'm biased toward.



One paper tries to get a wave to exist in the physical space we are familiar but the model seems really complicated:

This is admittedly a complicated, ugly, and highly contrived theory. (And although it is straightforward to generalize from 2 particles moving in 1 spatial dimension to N particles moving in 3 spatial dimensions, the complexity and ugliness in that more serious context is surely much worse!)...

It is sometimes raised as an objection against pilot-wave theory that, in the theory, the wave function causally influences the particles, but the particles exert no influences back on the wave. (This, it is apparently thought, suggests that the particles are some kind of mere epiphenomenon, which might as well be dropped-a bizarre suggestion, for anyone who understands the crucial role the particles play in making the theory empirically adequate, but still a suggestion one hears sometimes.) To whatever extent one takes such an objection seriously, then, it is of interest to point out its inapplicability to the pilot-wave theory (of exclusively local beables) sketched here: each particle’s motion is dictated just by its own associated pilot-wave field, but the evolution of each pilot-wave field is influenced by all the other particles. Not only, then, do the particles influence the pilot-wave fields, but the particles can quite reasonably be understood as (indirectly) affecting each other (through the various fields). Perhaps those who dislike the causality posited by the usual pilot-wave theory, then, will find the theory sketched here more tolerable...

The theory presented in Section III contains an infinite number of interacting fields on physical space and causal influences from particles onto the fields associated with other particles – but is mathematically equivalent to standard pilot-wave theory in which there is just one wave, on configuration space, and no causation from the particles onto the pilot-wave.
The Theory of (Exclusively) Local Beables
http://lanl.arxiv.org/PS_cache/arxiv...909.4553v3.pdf
bohm2
#178
Dec21-11, 07:51 PM
PF Gold
bohm2's Avatar
P: 691
Edit: I thought I'd mention that Bohm (at least in his metaphysics) didn't appear to believe in the "reality" of particles:

We have frequently been asked the question “Didn’t Bohm believe that there was an actual classical point-like particle following these quantum trajectories?" The answer is a definite No! For Bohm there was no solid 'particle' either, but instead, at the fundamental level, there was a basic process or activity which left a ‘track’ in, say, a bubble chamber. Thus the track could be explained by the enfolding and unfolding of an invariant form in the overall underlying process.
Zeno Paradox for Bohmian Trajectories: The Unfolding of the Metatron
http://www.freewebs.com/cvdegosson/ZenoPaper.pdf
ryan7585
#179
Jan2-12, 08:31 AM
P: n/a
Quote Quote by JordanL View Post
In that sense, what you are describing is a justification or reasoning for nihilism, as the discussion about "something vs. nothing" eventually leads towards existential nihilism in the form of a logical conclusion of the argument being presented: if everything is nothing, no thing can have inherent meaning.

It is ultimately, from my perspective, a discussion about what the difference is between ideas and reality.
Nihilism is so ridiculous to me... Regardless of whether everything is nothing, we all have an objective experience which is affected in definite ways by how we interact. A search for "inherant meaning" will ALWAYS yield fruitless results. But contextual meaning can be found in absolutely everything in the universe. It is our experience of it which gives it meaning

How is this not obvious?
bohm2
#180
Feb18-12, 01:22 PM
PF Gold
bohm2's Avatar
P: 691
Here’s some interesting arguments against the probabilistic argument presented in original post:
Van Inwagen, while not himself a cosmologist, addresses a cosmological question. He proposes to answer the question that is “supposed to be the most profound and difficult of all questions”: “Why is there anything at all?” The argument is elaborate, so I shall jump to the essential step. Van Inwagen presents the premises that there is only one possible world in which there are no beings but there are infinitely many possible worlds in which there are beings. The latter is arrived at by arguing that there are many ways for beings to be but only one way for them not to be. He then urges that the probability of being actual for each possible universe is the same. (I set aside the problem that this instantly conflicts with the requirement that probability measures normalize to unity.) It now follows that the probability “of there being nothing is 0.” It is “as improbable as anything can be” . Hence, no doubt, we are to infer that there being anything at all is as probable as anything can be. Van Inwagen prudently admits that he is “unhappy about the argument...No doubt there is something wrong with it...but I should like to be told what it is”. What is wrong is that it is an instance of the inductive disjunctive fallacy. Our background assumptions are near vacuous and provide completely neutral support for the actuality of each possible world; therefore, they provide completely neutral support for any disjunction of these possibilities. What van Inwagen has done is to represent this neutrality incorrectly by a widely spread probability measure, thereby committing himself fallaciously to the conclusion that a disjunction of all but one of them is strongly supported.
Cosmic Confusions: Not Supporting versus Supporting Not
http://www.pitt.edu/~jdnorton/papers...sion_final.pdf

If one applies probabilities thoughtlessly, one might try to represent the state of complete ignorance by a broadly spread probability distribution over the outcomes. Then the probability of the disjunction can be brought close to unity merely by adding more outcomes. Hence one would infer fallaciously to near certainty for a sufficiently large contingent disjunction of outcomes over which we are individually in complete ignorance. The fallacy is surprisingly widespread. A striking example is supplied by van Inwagen [1996] in answer to the cosmic question “Why is there anything at all?” There is, he asserts, one way for no thing to be, but infinitely many ways for different things to be. Distributing probabilities over these outcomes fairly uniformly, we infer that the disjunction representing the infinitely many ways things can be must attract all the probability mass so that we assign probability one to it.
Challenges to Bayesian Confirmation Theory
http://www.pitt.edu/~jdnorton/papers...nges_final.pdf

Zinkernagel summarizes this:
From the perspective of Norton’s critique, it is not hard to see what is wrong with the analogy. When you win the lottery ticket it may be reasonable to infer that other people bought a ticket but, in any case, the very idea of winning a lottery presupposes that other tickets exist and that the winning ticket has been drawn more or less randomly from the collection of tickets. By contrast, our universe being the way it is (“winning the lottery”) does not presuppose that other universes (with different properties) exist-our evidence is simply neutral in this respect. Furthermore, we have no a priori right to presuppose that the values of the parameters characterizing our universe are bestowed on it by some random process-and so no right to presuppose a probability distribution (uniform or otherwise) of the outcomes. Therefore, a judgment of what is natural to infer from our universe being as it is (with us in it) hangs in the air.
Some trends in the philosophy of physics
http://philsci-archive.pitt.edu/8761/


Register to reply

Related Discussions
The Ultimate Question Chemistry 11
Ultimate Question General Discussion 10
The ultimate question General Math 1