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No.Does bohemian mechanics for instrumentalists also take into account consciousness?
No.Does bohemian mechanics for instrumentalists also take into account consciousness?
Bohmian mechanics offers a clear explanation why naive realism is wrong: http://de.arxiv.org/abs/quant-ph/9601013Only if you insist on a "naive realism" you have quibbles with quantum theory.
It has all to say about the outcome of a single measurement event that can be said about it: If the system is not prepared in a state, for which the measured observable takes a determined value, then the outcome of the single measurement is indetermined (which is a tautology!). Than all QT says and up to the knoweldge we have can be said are probabilities for the possible outcomes of such measurements given the state the system is prepared in. This prediction can be tested (imho only) by preparing a sufficiently large ensemble of equally prepared systems and statistical analysis of the outcomes of measurements on each member of the ensemble. Whether or not you find this satisfactory from some metaphysical or philosophical point of view, physics doesn't care about.The mathematical formalism of quantum theory has nothing to say regarding the actual outcome of a single measurement event; such questions are not answerd by the minimal statistical interpretation as long as one doesn't confuse the minimal statistical interpretation with the ensemble interpretation: There is no mechanism which can be proposed for the occurrence of an actual outcome of a single measurement event, no algorithm for it can be given and no causal description is possible. Thus, in order to relate the mathematical formalism of quantum theory to our perceived reality – actual outcomes of single measurement events – the wave-packet reduction postulate has to be put in “by hand” as part and parcel of quantum physics. Period!
By "physics", do you mean Nature or community of physicists? If you mean the latter, then a significant part of it actually cares. If you mean the former, then physics also doesn't care about our incomplete effective theories (such as standard QFT).Whether or not you find this satisfactory from some metaphysical or philosophical point of view, physics doesn't care about.
Hi DarMM:Yes, that's the state reduction postulate.
By incomplete, I mean an effective theory which describes only what we, the human beings with limited abilities, can observe in practice with current technology.I'm not so clear about, what you mean by "incomplete".
Obviously - but I feel I'm being led into a trap. Soon you will argue that not all the dof in the preparation can have values - which I will deny and we'll get nowhere.What are these initial conditions if not a wavefunction? The preparation set up?
I'm not sure why you think I'm trapping you rather than just discussing things.Obviously - but I feel I'm being led into a trap.
Soon you will argue that not all the dof in the preparation can have values - which I will deny and we'll get nowhere.
The problem is that in QM the initial preparation, ##\rho## and the dynamics ##U(t)## do not give the outcomes in experiments. Thus it is not only the initial conditions and the dynamics that seem to govern experiments. Doesn't the Kochen-Specker theorem block all the dofs having values?This is inevitable in a theory that only gives probabilities. It is of no importance because every instance in a repeated experiment is governed by the dynamics of the system and the initial conditions, not the wave function.
It's commonly used in textbooks as an alternative name for wave function collapse as you said. It's a common element of the practical application of the theory, so all interpretations have it. They just don't agree on its status (i.e. is it fundamental) and nature (i.e. is it a physical process or a calculational aid)I tried to find an authoritative explanation of the state reduction postulate online, but the best I could find is
Is this postulate an alternative name for "wave function collapse"?
The dead apparati do not interpret what they are measuring. Investigating probabilities experimentally involves repeated measurements of similar events. It's human's who judge that a series of actions repeats "the same" experiment. Two repetitions of literally "the same" experiment wouldn't be two repetitions of something, it would be just that single self-same experiment. So interpreting the statistical significance of measurements involves a decision to classify different things as being alike.What should the "consciousness of the observer" have to do with quantum measurements, which you can just let dead apparati do fully automatically without interference of any living being.
Told you so. I knew you would bring that up.I'm not sure why you think I'm trapping you rather than just discussing things.
The problem is that in QM the initial preparation, ##\rho## and the dynamics ##U(t)## do not give the outcomes in experiments. Thus it is not only the initial conditions and the dynamics that seem to govern experiments. Doesn't the Kochen-Specker theorem block all the dofs having values?
I referenced DOFs because you mentioned them in a way that seem to run counter to the Kochen-Specker theorem. I didn't originally intend to comment on them. I only did so in response to what you said in #33. It's odd to introduce a topic and then claim I brought it up. Of course it will now come up since you introduced it.Told you so. I knew you would bring that up.
What theorems do you have in mind here?QM is a theory that predicts the probabilities of outcomes. It has nothing to say about the underlying dynamics. Theorems that claim otherwise are mathematically true but prove nothing except that such statements have no physical import.
It seems that many scientists have still not become aware that what we call "nature" appears to us first of all through our consciousness. A consequence is for example :By incomplete, I mean an effective theory which describes only what we, The human beings with limited abilities, can observe in practice with current technology.
The correlation between wavelength and perceived color is imperfect. Similar perceptions of color can be associated with various mixtures of light of different wavelengths and intensities.Timothy H. Goldsmith said:http://www.ler.esalq.usp.br/aulas/lce1302/visao_aves.pdf
It is true, as many youngsters learn in school, that objects absorb some wavelengths of light and reflect the rest and that the colors we perceive “in” objects relate to the wavelengths of the reflected light. But color is not actually a property of light or of objects that reflect light. It is a sensation that arises within the brain.
I mentioned dof's in the hope you might realize the futility of quoting theorems to persuade me of your point.I referenced DOFs because you mentioned them in a way that seem to run counter to the Kochen-Specker theorem. I didn't originally intend to comment on them. I only did so in response to what you said in #33. It's odd to introduce a topic and then claim I brought it up. Of course it will now come up since you introduced it.
I wasn't aware I had a point I was arguing in favor of. I certainly was not advocating the wave function as real. I don't know a single place where I invoked this.I mentioned dof's in the hope you might realize the futility of quoting theorems to persuade me of your point.
All your arguments contradict this and therefore have no weight for me.
Sorry about that. But you accept it as a premise, which is nearly as badI wasn't aware I had a point I was arguing in favor of. I certainly was not advocating the wave function as real. I don't know a single place where I invoked this.
I admit that I have not tried to understand the theorem.The Kochen Specker theorem doesn't even rely on nor is concerned with the wave function being real. What's your issue with it or why do you think you can ignore its implications considering they seem to run counter to what you have said? You seem to be saying all the values prexisted the measurement, but this seems impossible in light of the theorem and the theorem isn't about wave function reality. In fact it's a theorem about the observable algebra not the state.
Where did I accept it as a premise?Sorry about that. But you accept it as a premise, which is nearly as bad
That was the classic Kochen Specker theorem. The modern one in the ontological models framework can be proven directly as a contradiction between pre-existing values and observations, just as Bell's theorem does not rely on the mathematical structure of QM.You make my point with the words I've emphasised. For the theorem to have physical import the 'operator algebra' must be physical. But it is a mathematical object. The theorem makes a statement about a methodology not about values of dynamical variables.
That's of course a hard to answer question. We can always only get information about nature by observing her. It may well be that we cannot observe some aspects of nature. Also any theory is always "complete" as long as no observations indicate that something is missing. For me to say "a theory is complete" always includes an "as far as we know now", and in this sense many previous theories turned out to be incomplete in the one or the other way.By incomplete, I mean an effective theory which describes only what we, the human beings with limited abilities, can observe in practice with current technology.
What do you mean by "it has nothing to say about the underlying dynamics"? To the contrary QT has everything to say about dynamics. Given the initial state and the Hamiltonian of the system you can calculate the state at any later time. That's dynamics, isn't it? It's not a theorem but makes up part of the fundamental postulates of the theory.Told you so. I knew you would bring that up.
QM is a theory that predicts the probabilities of outcomes. It has nothing to say about the underlying dynamics. Theorems that claim otherwise are mathematically true but prove nothing except that such statements have no physical import.
So when you say that physics doesn't care about philosophical problems one might have with physics, you really mean that the best theories we currently have are just instrumental tools that work in practice, and from the point of view of their work in practice the philosophical questions are simply irrelevant. Asking philosophical questions about quantum mechanics is no more meaningful than asking philosophical questions about a hammer.For me to say "a theory is complete" always includes an "as far as we know now"
I think you are referring to the 'dynamics' of the probabilities ##\psi(t) = e^{i\hat{H}t}\psi##. I mean something else.What do you mean by "it has nothing to say about the underlying dynamics"? To the contrary QT has everything to say about dynamics. Given the initial state and the Hamiltonian of the system you can calculate the state at any later time. That's dynamics, isn't it? It's not a theorem but makes up part of the fundamental postulates of the theory.
OK, I'll read up on the KS theorem when I get the chance. But it sounds as if it assumes that ##\psi## must be real.Where did I accept it as a premise?
That was the classic Kochen Specker theorem. The modern one in the ontological models framework can be proven directly as a contradiction between pre-existing values and observations, just as Bell's theorem does not rely on the mathematical structure of QM.
It doesn't. I don't know why you think it sounds like it does because it literally does not assume it.OK, I'll read up on the KS theorem when I get the chance. But it sounds as if it assumes that ##\psi## must be real.
Are we observing from "nature " something other than a function of space and time F(r,t) or a function of sound and time F(s, t)?We can always only get information about nature by observing her. It may well be that we cannot observe some aspects of nature.