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Originally Posted by Ivan Viehoff
(1) No I'm not. Particles have been observed. To assert otherwise is either to argue for a nontestable theory of existence such as "reality doesn't exist, it's all a dream", or else is vexatious.
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Neither one, actually. Particles are models. What makes that obvious enough is that if you ask ten theoretical physicists in different subfields what a particle is, you will likely get 10 very different answers. This is what I mean when I say that you are assuming your argument when you assume a meaning for "particle", as if your own images around that word are the same thing as the reality. Your concept unifies your familiarities, someone else's unifies theirs. This is why I say that we can never unify everything that is real, because we will never have access to total familiarity.
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(2) So you don't like what I say because it's a mouthful. What kind of an argument is that?
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That wasn't the argument part. The meaning of "mouthful" is that there is a lot behind the words that is being glossed over. What is being glossed over was the argument part.
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Quantum theory is described probabilistically, so I am saying nothing unusual or novel here.
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My point is that one of the great efforts at unification that occurs is the effort to unify what appears to be a random outcome with underlying causal factors. If you are willing to leave that step out, as most quantum mechanics is formulated to do, then you have not unified everything and cannot use it in an argument that everything is unifiable. Personally, I have no problem with leaving the probabilistic aspects ununified, but then I'm arguing that complete unification is as impossible as walking north to Polaris.
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I didn't really need to say it, given that our existing theories are probabilistic, but I was predicting a common but fallacious objection before someone made it.
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Our "existing theories" are ununified! Ergo, citing aspects of current theories is not an argument for unifications that have not yet been achieved.
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If we haven't yet discovered Pythagoras and I say that in principle geometry must exist, then I am saying "it exists because it is there to be found".
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But how do you know what is there to be found until you find it? Again you are simply imposing your philosophy on your argument, and then extracting as conclusions what you put in as assumptions. You define "what exists is what is there to be found", then argue from that definition of existence that everything that exists is there for us to find. It's circular reasoning. Science normally differentiates what exists from our best descriptions of it, and for good reason, especially if one is wondering what is unifiable.
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You say "ah but if we don't find it then it doesn't exist for us", well, I don't think that is the kind of non-existence OP is interested in.
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Actually, I say
neither that we what don't find doesn't exist,
nor that everything that exists is there for us to find. Either claim would beg the issue at hand, which is what we can find and unify out of what exists. I am using words that leave the question open, you are using words that simply assume your conclusions and then use them to reach those conclusions.
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Obviously it is unknowable whether we will ever find something, even if we can prove it is there to be found. Rather like the well-ordering of the reals that is predicted by an existence argument based upon the Axiom of Choice, but which no one thinks can ever be exhibited.
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Axiomatic systems are the perfect example of finding the ramifications of your own assumptions. The effort to understand reality is not like that, because reality is not subject to our choice of axioms, but rather the other way around. Mathematicians are not used to that state of affairs!
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(4) I said "complete and consistent", ie no cracks. Electro-weak-strong unification which sticks 3 laws together without cracks.
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There are always cracks, which have to do with connecting the axiomatic structures to reality. This is the part of physics that a lot of people don't seem to recognize. The way it works is, we form an axiomatic structure of some kind to be able to draw on its consistency and provability. This is generally called "idealization", and there is no axiomatic structure for choosing idealizations, that's the art of physics (that often gets overlooked even though it is always the first step.) We then confront that axiomatic system with observations to see how useful that consistency and provability are in practice. That process involves all kinds of "cracks", because it has the "fingerprints of the practitioner" all over it. The first, and most important, fingerprint is the choice of the axioms in the first place. The meaning of "particle" is a perfect example of this-- different practitioners with different goals will adopt different axioms around the meaning of a particle, from classical descriptions, to the way the term is used in elementary quantum mechanics, to how it is used in field theory, string theory, or even abstract mathematical formulations. All different, involving different idealizations, different accuracy, and requiring different information to analyze.
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If there are actually cracks in reality, then there are situations when the particle doesn't "know" what to do. Which I think is nonsense, and that is the only real point I am making here.
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The cracks I refer to are not in reality, they are in our understanding about reality. We cannot discuss the unification of the former directly, as unification exists in the latter and extends by implication to the former. Hence our discussion is not about reality, it is about the axiomatic systems we invent to describe reality. The distinction is usually ignorable, but only at our peril in discussions that try to get to the heart of what science can achieve.
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Edit: In (3) the Axiom of Choice suggestion is not a good analogy on second thoughts. A better one is the Navier-Stokes equations, which we have found but can't solve. So we have a theory but can't use it. But the theory is still there.
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We have no disagreement that the theory is there.