I interpret that as saying that we are not terribly used to correlating observations with strange relationships, like a spin in one direction of one particle to a spin in some 45 degree direction of the other particle. If we were used to doing that, and had lots of entangled systems in our environment, then we would be used to the problems with imagining that observational values pre-exist. When all we deal with is simple diagonal density matrices, we of course build an intuition that we can imagine the outcomes pre-existed, but we forget that just because a given picture usually works well for us, it doesn't require this is what is really happening. I might go so far as to say the entire history of science is trying to tell us, loud and clear, that all uses of ontology, all attempts to say what is really happening, simply falls into this "fallacy of oversimplification." It's fine to simplify, we always imagine cannon balls fly in an absence of air resistance, but we don't have to tell ourselves the simplification is the truth. Idealization is epistemology; believing the idealization is ontology.stevendaryl said:Right. That's the frustrating (for me) thing about quantum measurements. On the one hand, whatever it is that we measure, it's as if it always had that value, and we're just discovering it. On the other hand, Bell's theorem shows that it can't be the case that every quantity that we might measure has a pre-existing value. (Or at least, it's impossible to make sense of such a thing using standard reasoning about probabilities).
You don't have to imagine that observational values pre-exist to run into the problems with entanglement. It's enough to imagine observation results as factual and that observations are independent from non local affairs.Ken G said:I interpret that as saying that we are not terribly used to correlating observations with strange relationships, like a spin in one direction of one particle to a spin in some 45 degree direction of the other particle. If we were used to doing that, and had lots of entangled systems in our environment, then we would be used to the problems with imagining that observational values pre-exist. When all we deal with is simple diagonal density matrices, we of course build an intuition that we can imagine the outcomes pre-existed, but we forget that just because a given picture usually works well for us, it doesn't require this is what is really happening.
Yes, we know. The map is not the territory.Ken G said:I might go so far as to say the entire history of science is trying to tell us, loud and clear, that all uses of ontology, all attempts to say what is really happening, simply falls into this "fallacy of oversimplification." It's fine to simplify, we always imagine cannon balls fly in an absence of air resistance, but we don't have to tell ourselves the simplification is the truth. Idealization is epistemology; believing the idealization is ontology.
Yet all the problems stem from insisting that observations are not just information, they are information about something. Get rid of the "something" and all the problems go away, yet you still have what you actually use: the information.zonde said:You don't have to imagine that observational values pre-exist to run into the problems with entanglement. It's enough to imagine observation results as factual and that observations are independent from non local affairs.
Actually, what I'm saying is that the territory is a map too. It's all maps, at least in science.Yes, we know. The map is not the territory.
Ken G said:Yet all the problems stem from insisting that observations are not just information, they are information about something. Get rid of the "something" and all the problems go away, yet you still have what you actually use: the information.
Ken G said:Yet all the problems stem from insisting that observations are not just information, they are information about something. Get rid of the "something" and all the problems go away, yet you still have what you actually use: the information.
I just don't think information works like that-- it makes no difference "what it is about", it's information, that's all that matters. Let's take an example. A deer sees a car coming, and has the sense to leap out of the way. It makes no difference at all if the deer knows "what a car is", say from the perspective of what a human thinks a car is, all that matters to the deer is the information that matters to the deer: jump out of the way. The act that saves the deer has nothing to do with what that information is "about", the information is that there is danger and the deer must leap or die. The deer doesn't need to know anything else, and anything else that it might imagine it knows is most likely a form of self delusion.ddd123 said:No, this can't be right. Information without an object is like saying: I have the following information "10001011101101". And you ask "what is it about?" And I say "nothing". You have no problem but no information either.
I would say that it doesn't matter if I regard it as information about physical systems, or information about experimental outcomes, what matters is that it is information. Yes, the concept of an experiment is crucial to science, so that's just more information-- the information that what we regard as an experiment is happening, I'm going to process that information too. But it doesn't matter what an experiment is "about", it only matters how I relate to the information that an experiment is happening. All we ever use is what we make of that information, it never needs to be "about" anything other than that, like the deer.Maybe what you mean is: you don't have information about physical entities, but about experimental procedures (i.e. outcomes of measurements).
I think I understand, you are trying to generate a working ontology. That's a perfectly normal thing to do, the deer probably does it too-- but what the deer thinks a car is is probably nothing at all like what we think it is, and neither are at all like what a car is in some absolute sense because the "territory" that is a car has meaning only as another map.I don't know if I'm making sense though :)
We probably need to refine what we mean by "information." I think if we do that, we will find that it is not important to be "about" something. Information is something like a culling process, where you get answers to yes/no questions that allow you to reduce the possibilities of what you expect to happen. Let's say you are playing bridge, and your partner bids something-- that's information to you, it narrows down the possibilities for their hand. So it would be natural to say that means it is information "about" their hand, but what if the bridge game is being played online, and there is no hand-- it's just digital 1s and 0s. You can play as if the information is "about" a hand, but it doesn't matter that there is no hand, it's just information. You don't play any differently, none of the strategies change-- that should tell us the "about" part is very optional.stevendaryl said:Well, information is pretty useless if it's not about something (I would say that it's not information if it's not about something).
I'm fine with that, but that's not an "about" in the sense of an ontology., because there is no need to think the measurements have an ontology either-- they are information. Information does have to relate to something, it must allow you to cull your expectations somehow, so it is "about" culling expectations. But what I mean is that it doesn't need to be "about" an observation in the sense that the observation is anything more than just additional information. We never use anything except information, so it needs no other "object" than itself.For quantum mechanics, at the minimum, the information is about future measurement results.
Yet that makes perfect sense if the "aboutness" is just how we think about things. It's not surprising we deal more effortlessly with "aboutnessess" that we are already used to from a lifetime of ontological idealizations that we have come to expect more from than we really have any right to.And that's the problem I have with it; it gives a reality to macroscopic objects and processes that it denies (or seems to) for microscopic objects and processes. Since macroscopic objects are (presumably) made up out of microscopic objects, it's hard to see how the former can have more reality than the latter.
Ken G said:Yet that makes perfect sense if the "aboutness" is just how we think about things. It's not surprising we deal more effortlessly with "aboutnessess" that we are already used to from a lifetime of ontological idealizations that we have come to expect more from than we really have any right to.
secur said:Science provides only quantitative information from experiments and observations. It tells you nothing about underlying reality. It's epistemological, not ontological. All these "endless debates" concern ontology and can't be decided scientifically - which, of course, is why they're endless.
Anyway all this is mere philosophy. Epistemology vs. Ontology just as much as Copenhagen vs. MWI. A certain amount of such discussion is valuable and necessary. But remember it's not science and will never furnish any new scientific information.
It's not the general concept of "aboutness" that I mean-- I agree that information has to change our expectations in some way, so it's "about" that-- changing expectations. But what I'm talking about is the need to think that the "aboutness" of the information has some existence beyond the way we are using the information to alter our expectations. When that is demonstrably all we ever use information for, why do we have to believe it is something more than that, in order to use that information? Why does a deer need to think it knows what a car is in order to have the sense to jump out of the way of it?stevendaryl said:I really don't understand what you can mean by "information" that lacks "aboutness". As ddd123 says, a string of numbers is not information (or at least, is not meaningful information) unless the numbers are about something: the number of fish caught in a certain pond over the last few days, for example.
But look at what you just said there-- ontology is necessary to make sense. But isn't all making sense epistemology? The core idea of ontology is that it needs to be true or else it wouldn't work to help us make sense, but if all we are using the ontology for is to make sense, then why does it need to be true? If all we are doing is making sense, then it's all epistemology, the ontology part is a pretense-- what we are telling ourselves in the process of making sense. It's a voice inside our own heads. Have you referred to anything else? That's what I mean that is you look at what we use ontology for, you can see that it is epistemology in a convincing disguise. It makes the epistemology easier to swallow, somehow.Measurement results are part of an ontology that is necessary to make sense of quantum mechanics.
It's not solipsism, let's be clear on that. Solipsism is another form of ontology, because it claims that what exists is what is inside our heads. I'm saying something different-- I'm saying that all we are doing is processing information, so there isn't even solipsistic ontology. It's all epistemology, because that's all we ever use. It's all you are using too-- you are saying that it is not to your taste. What is to your taste is epistemology-- why should ontology be to someone's taste?You can't actually do quantum mechanics, at least in the usual interpretation, without talking about measurement results. My complaint, as I said, is that measurement results are about us. Having a physics whose only ontology is observations by physicists is way too narrow and solipsistic for my tastes.
stevendaryl said:... because nobody can come up with a sensible ontology for quantum mechanics, people like to say that that was not a worthwhile goal. And people like to engage in revisionism and say that it was never a goal for science.
I mostly agree with the previous post, and this somewhat less. There is no need to mention physicists, only how they prepare states and what the probable states of the measuring apparata will be.stevendaryl said:To me, there is a very different character to a theory that posits "there is a tensor-valued field [itex]F_{\mu \nu}[/itex] that obeys such-and-such equation of motion..." and a theory that posits "if you do such-and-such, you will get such-and-such result with probability such-and-such". The first seems to be about reality, while the second seems to be about ME (or about physicists). I think it's weird for people to say that physics is always about the latter (what happens when you do certain things), and is never about the former (what exists, and how does it behave). Every theory before quantum mechanics was the former type, so it seems like revisionism to say that only the latter counts as "science".
Actually I agree with that-- the scientist must be agnostic about reality. But that's all I'm saying-- if we don't use something, then it's not in our science. So I'm saying reality (as in, ontology) is not in science, because we never use it, what we do is picture it, while we are actually using information. People will create ontologies, I do it too, the difference is I don't take them seriously. I am even more than agnostic about ontology, I'm skeptical of it. I don't think any human ontology will really matter much, except as a kind of epistemological crutch for us. Which is fine-- that's what ontology is, an epistemological crutch. So that's all I'm saying-- our ontologies are epistemologies in disguise. I have no idea if there is actually a territory-- but if there is, it isn't what we mean by the word, because we are using territory to mean just another kind of map for us to picture.secur said:Where you go too far, Ken G, is asserting that there really is no reality. Instead, we must be agnostic about ontology, scientifically.
There might be some value in parsing the difference between knowledge and intuition, but they both sound like ways that we think-- neither sounds like what is, independent of those ways we think.You try to reject all ontology by claiming that science constitutes all of our knowledge; but that's not so. There's also what we can loosely call intuition, or whatever. Intuitively we all know there's something real which the measurements are measuring, and the observations are observing.
Yes, that is very much the purpose of recognizing that our ontology is just epistemology. We don't actually get any new scientific information by taking the information we do have, and picturing some kind of "real" scaffolding that supports it. That is the self delusion-- that we can bootstrap our way to reality by imagining there is a "territory" there, when what we have actually found to be the case is that the only way to learn about reality is by looking for new information. That's epistemology, not ontology. Is this not the lesson of history?Anyway all this is mere philosophy. Epistemology vs. Ontology just as much as Copenhagen vs. MWI. A certain amount of such discussion is valuable and necessary. But remember it's not science and will never furnish any new scientific information.
stevendaryl said:I think it's weird for people to say that physics is always about the latter (what happens when you do certain things), and is never about the former (what exists, and how does it behave).
Of course we don't know if there actually is a territory but ... some maps simply don't work and if we ask why they don't work assuming that there actually is a territory gives explanation why they don't work. In that sense there is simply no point in assuming that there is no territory.Ken G said:I have no idea if there is actually a territory-- but if there is, it isn't what we mean by the word, because we are using territory to mean just another kind of map for us to picture.
I suppose that the second type of theory is called "phenomenological". And I think that this type of theory has utility but it does not directly advance our understanding of reality. However it can advance our understanding indirectly as it shows what fundamental models are not going to work.stevendaryl said:To me, there is a very different character to a theory that posits "there is a tensor-valued field [itex]F_{\mu \nu}[/itex] that obeys such-and-such equation of motion..." and a theory that posits "if you do such-and-such, you will get such-and-such result with probability such-and-such". The first seems to be about reality, while the second seems to be about ME (or about physicists). I think it's weird for people to say that physics is always about the latter (what happens when you do certain things), and is never about the former (what exists, and how does it behave). Every theory before quantum mechanics was the former type, so it seems like revisionism to say that only the latter counts as "science".
Surely the burden in science is on the claim that there is a territory. You say we need it to explain why some maps don't work, but it seems to me that is something that needs no explanation.zonde said:Of course we don't know if there actually is a territory but ... some maps simply don't work and if we ask why they don't work assuming that there actually is a territory gives explanation why they don't work. In that sense there is simply no point in assuming that there is no territory.
I can propose non scientific test for the first statement: all valid descriptions of reality can be joined in one consistent system.Ken G said:On the general topic of realism, there are two ways to state what realism is in physics, one which is perfectly attuned to the goals of science, and the other, the more standard way, which I claim has nothing to do with science at all:
1) standard way: physics is the study of what is real, independent of our physics. Reality thus gives meaning to the notion of doing physics. (How would we ever know that? How does that help us do physics, when we can just do the physics anyway?)
2) workable way: physics is a tool that we use to decide what we will regard as real. Physics thus gives meaning to the notion of reality. (Here we have an operational meaning of real that is accessible and useful.)
Notice how the first is ontological, useless, and untestable, while the second is epistemological, useful, and is all about how we test our concept of reality constantly.
You have proposed a test, but you have not supplied evidence that the test is ever passed. Isn't that a problem-- a test that is not passed?zonde said:I can propose non scientific test for the first statement: all valid descriptions of reality can be joined in one consistent system.
Yes, I take the epistemological approach of simply asserting that I seek mutually consistent descriptions. Notice how easily I handle the failure to achieve the goal, it is simply a goal whether I achieve it or not!So can you justify requirement that descriptions should be mutually consistent without claiming that there is reality?
Pilot wave theory consistently unifies particle and wave descriptions.Ken G said:You have proposed a test, but you have not supplied evidence that the test is ever passed. Isn't that a problem-- a test that is not passed?
You haven't provided justification for that assertion. And the ease with which you give up the goal I see as a drawback of your approach.Ken G said:Yes, I take the epistemological approach of simply asserting that I seek mutually consistent descriptions. Notice how easily I handle the failure to achieve the goal, it is simply a goal whether I achieve it or not!
Ken G said:So how we use information is helped by imagining that the information is "about" something, I've no problem with that. But it only matters to how we process and use that information, what we think the information is "about" is not, itself, information, it's more like a kind of crutch that supports our information processing without adding anything to that information. It's how we think, so it's just more epistemology, disguised as what the epistemology is "about."
I think I understand, you are trying to generate a working ontology.
Mentz114 said:I mostly agree with the previous post, and this somewhat less. There is no need to mention physicists, only how they prepare states and what the probable states of the measuring apparata will be.
If the same scenario happened accidentally we would expect the same distribution of outcomes, surely ?
(Or replace the Physicist by an equivalence class ...)
This is nonsense. In QT nothing, really nothing, depends on whether a human being is looking at something. Nature doesn't care about humans very much.stevendaryl said:Well, I would certainly be more comfortable with quantum mechanics if it could be formulated without mentioning "preparation" and "measurement". Surely, on a star billions of miles from any humans, nuclear fusion works perfectly fine without anybody preparing anything, and without anybody measuring anything. The standard minimalist interpretation of quantum mechanics would seem to say that it requires a human looking at the star before nuclear fusion in the star has any meaning.
vanhees71 said:This is nonsense. In QT nothing, really nothing, depends on whether a human being is looking at something. Nature doesn't care about humans very much.
stevendaryl said:Don't call it nonsense when you're agreeing with me. I agree that physics doesn't depend on humans. But the formulation of the minimalist interpretation in terms of "preparation procedures" and "measurements" is not appropriate for physics without humans. So the minimalist interpretation is not adequate.
Real life seldom follows the idealized preparation-observation pattern presented throughout this book. Astronomers, for instance, observe spectral lines (i.e., detect photons) which they interpret as due to the presence of atoms or molecules in interstellar space. Obviously, the atoms were there a long time ago in an excited state; they decayed to their ground state, emitting photons which we can now observe, considerably later. These excited atoms were not prepared by us, nor our research assistants. We can only observe them passively. We also observe bigger objects, such as the Moon moving around the Earth, or various planets, without ever having prepared them.
This would cause no conceptual difficulty with quantum theory if the Moon, the planets, the interstellar atoms, etc., had a well defined state ρ. However, I have insisted throughout this book that ρ is not a property of an individual system, but represents the procedure for preparing an ensemble of such systems. How shall we describe situations that have no preparer? […] why should we expect A and B to agree that there is, objectively, a star somewhere in the sky? The reason is that any macroscopic object, such as a star, involves an enormous number of identical subsystems with almost identical properties, in particular identical positions, within the accuracy of our instruments. Thus, a macroscopic object effectively is assembly, which mimics, with a good approximation, a statistical ensemble. Measurements performed on such an assembly have a huge redundancy. In particular, different apparatuses can be used for probing disjoint subassemblies, each one of which is large enough to mimic an infinite ensemble. We can thereby measure, with little dispersion, the expectation values of noncommuting operators.
You must have noted the difference between the present pragmatic approach and the dogmas held in the early chapters of this book. It was then asserted that any operator which can be written by a theorist can also be measured in the laboratory. This fiction was needed in order to establish a formal framework for quantum theory. Now, our goal is different: we want to use a classical language for describing, with a good approximation, macroscopic phenomena.
stevendaryl said:I'm not sure whether the irony is intentional, or not, but proclamations about what science is and is not is philosophy, rather than science.
I completely agree that science requires semantics, but I don't agree with the association of ontology with semantics. Meaning is modeling, yes, but ontology is not modeling-- ontology is believing the model. That's my whole point here. When the ancient Greeks pictured the universe as geocentric, that was a model. If they could have just said "we choose to model the universe as geocentric for reasons X,Y and Z", that is 100% pure epistemology, and it would have given the world zero problems when Galileo came along and said "actually, a heliocentric model does better with observations A, B and C." That's science. But no, Galileo had to recant his claims, because of ontology, which is never scientific. Ontology is the statement that the universe either really is geocentric, or it really is heliocentric, which turns "geocentric" and "heliocentric" into "geocentrism" and "heliocentrism." But the shift from "ic" to "ism" is a category error in scientific thinking, because geocentric and heliocentric are attributes of models, not attributes of universes. Science models, and judges models-- that means science uses "ics" not "isms." Epistemology, not ontology.ddd123 said:If we want to get this philosophical, we might as well do it right. You are confusing information and epistemology: what is beyond information (which you assert, for science, is everything) is semantics (in the actual sense, not the usual ironic figure of speech). Science needs information and semantics, at a minimum.
If you are trying to generate an epistemology, then you are agreeing with me-- an epistemology is all about modes of creating expectations toward outcomes, and then testing those expectations. Notice the crucial role of thought in all that. An ontology is a claim about what is, independent of thought-- so it's not at all about expectations and modes of thinking to get some result. I certainly agree that we use pictures to help us process information-- it's not ontology until you claim your picture is what is, when the "ic" of a model, a way of thinking, becomes the "ism" of what is, independent of thought.No, I was trying to generate a working epistemology, but again, I'm not sure about it.
vanhees71 said:Yes, read Peres's book. That's the best to prevent one from getting into these esoterics by trying to provide ontology from science. That's the realm of religion/philosophy, not science!