The fine tuning is in the quantum equilibrium assumption. But maybe Valentini's version is able to overcome it the fine tuning, at the cost and benefit of predicting violations of present quantum theory without fine tuning. There's a discussion by Wood and Spekkens on p21 of https://arxiv.org/abs/1208.4119.Demystifier said:
See atyy's post (although I don't agree that Valentini's version fixes this).Demystifier said:
He shows that his superdeterministic model requires only 1/15 bit of shared information to reproduce QM, while a non-local model requires 1 bit.Demystifier said:
The new states and concept arr evolved IN HUMANS as it increases our fitness and responsiveness and learning. Even a human has to act under information processing constraints. The model of simulating hamilton dynamics from initial values as we know is not viable due to deterministic chaos. This is a key insight i think to understand how relations evolve and persist. Non commutative logic to me is a form fo datacompression that nature likely evolved because its the only way to achieve stability. This in itself has imo nothing todo with humans. The IGUS or agents are themsleves just subsytems of matter.Nullstein said:
OK, so why do you not agree that Valentini's version fixes this?Nullstein said:
RUTA said:
Yes, here is the explanatory sequence:physika said:A explanation for the "Tsirelson Bound" ??
"An explanation is a set of statements, a set of facts, which states the causes, context, and consequences of those facts. It may establish rules or laws"
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Hi ! I hope these questions haven't been asked a lot. I checked another thread, but couldn't find exactly this. what you said here was basically what I interpreted yours and many other replies in it: that particle A and B have non-local transfer. What about, say, a computer program of a universe like ours: it would seem like there's no local transfer in it, but there is (electrons from the program). Would such hidden variables be necessarily detectable in experiments in our universe (Bell, von Neumann Existence Theorem) if these hidden local variables existed like a program (or superdeterminism) as well? If so, does superdeterminism presuppose no contact info-transfer?DrChinese said:
As I showed in this Insight, the indeterminism we have in QM is unavoidable according to the relativity principle. And, yes, that means conservation of spin angular momentum is not exact when Alice and Bob are making different measurements. Conservation holds only on average (Bob saying Alice must average her results and Alice saying the same about Bob) when they make different measurements.kclubb said:
This is not correct; field theories that do not contain any particles still have causality.kclubb said:
No, it doesn't. Events that are not pre-determined can still happen in a way that obeys conservation laws.kclubb said:
I don't think this claim can be asserted as fact at our current level of knowledge. When we make measurements on quantum systems, we bring into play huge sinks of energy and momentum (measuring devices and environments). But we don't measure the change in energy and momentum of the sinks. We only look at the measured systems. But if a measurement takes place, the measured systems are not closed systems and we should not in general expect them to obey conservation laws in isolation; they can exchange energy and momentum with measuring devices and environments. To know that conservation laws were violated we would have to include the changes in energy and momentum of the measuring devices and environments. But we don't. So I don't see that we have any basis to assert what you assert in the above quote. All we can say is that we have no way of testing conservation laws for such cases at our current level of technology.RUTA said:
kclubb said:
Wikipedia claims that John Bell made this statement in the 1980s (I have not tracked down this)RUTA said:
Interesting. What would be an example? My understanding is that all forces have corresponding particles - the Standard Model.PeterDonis said:
We have to usually apply multiple laws simultaneously in classical Physics to arrive at a unique trajectory (energy + momentum etc). Are you speaking of not being able to measure two properties at the same time exactly, satisfying one law but not knowing the exact value for another property? In this case we just cannot measure EXACTLY the values of both momentum and energy, say, at the same time and therefore cannot say one way or the other in order to to apply the laws at the same time. But just because we cannot measure the two properties at the same time does not mean that the event happened in a non-deterministic way.PeterDonis said:
So we do need to find a valid theory that works. Sean Carrol advocates for the “many worlds” interpretation. Speculating that every time a “measurement” is made a new Universe comes into existence. Is this one of the “acceptable” and not “outrageous” assumptions that work for you? Because there is a real need to deal with non-locality. I am not studied on all the “outrageous” assumptions you speak of, but a new Universe being created every time there is a measurement seems outrageous to me, compared to a an deterministic Universe we have give up free will for. How would we ever test many worlds? I am not refuting you statements, but there are Physicists who believe SD is viable, including Bell himself. I hope to find the time to read through the original works that Bell started with, when I retire and I have the time perhaps. But I have to believe that, since there are legitimate scientists who believe SD is a possible reality, that it is a least POSSIBLE a theory can be developed. It just seems odd that most of the arguments I have read by Physicists against SD are emotional opinionated arguments dealing with free will, and “many worlds” is considered over SD as a better alternative, but Bell recognizing SD as a possible loophole to his theorem. Did he just not think it through before he made that statement? Is there something in the points that you make above the John Bell was not aware of? Specifically something that has been discovered after Bell that invalidates his claim?DrChinese said:
The Standard Model is a quantum field theory. Certain quantum field states are described as "particles", but there are many quantum field states that cannot be described that way. The fundamental entities are fields.kclubb said:
No, you need to show that a conservation law must be violated if the universe is not fully 100% deterministic because you are the one who is making that claim. I am simply pointing out that you have not shown that. You have simply assumed it, and you can't just assume it. You have to show it.kclubb said:
This is not what the MWI says. The "universe" in the MWI is the universal wave function, and there is always just one universal wave function. The wave function doesn't "split" when a measurement is made; that would violate unitary evolution, and the MWI says that the wave function always evolves in time by unitary evolution.kclubb said:
You are aware that the MWI is 100% deterministic, correct?kclubb said:
At the last resort, “questions of faith” are irrelevant for doing physics. All one needs to carry out physics are observations that can be used to construct and test models – on the basis of the observed phenomena.kclubb said:
My claim is a mathematical fact that follows from the Bell state formalism alone. It has nothing to do with experimental uncertainty.PeterDonis said:
As I said, this can't be correct because during the measurement process angular momentum is exchanged between the measured particles, which the formalism you refer to describes, and the measuring devices and environment, which the formalism does not describe. So the formalism is incomplete and cannot support any claims about conservation laws.RUTA said:
My point has nothing to do with experimental uncertainty. It has to do with the fact that during measurement, the measured particles are open systems, not closed systems.RUTA said:
Look at a Bell spin triplet state in the symmetry plane. When Alice and Bob both measure in the same direction, they both get the same outcome, +1 or -1. That is due to conservation of spin angular momentum. Now suppose Bob measures at an angle ##\theta## with respect to Alice and they do many trials of the experiment. When Alice partitions the data according to her +1 or -1 results, she expects Bob to measure ##+\cos{\theta}## or ##-\cos{\theta}##, respectively, because she knows he would have also measured +1 or -1 if he had measured in her direction. Therefore, she knows his true, underlying value of spin angular momentum is +1 or -1 along her measurement direction, so he should be measuring the projection of that true, underlying value along his measurement direction at ##\theta## to conserve spin angular momentum. Of course, Bob can partition the data according to his ##\pm 1## equivalence relation and say it is Alice who should be measuring ##\pm \cos{\theta}## in order to conserve spin angular momentum. It is impossible to conserve spin angular momentum exactly according to either Alice or Bob because they both always measure ##\pm 1## (in accord with the relativity principle), never a fraction. However, their results do average ##\pm \cos{\theta}## under these data partitions. It has nothing to do with momentum transfer with the measurement device. All of this follows strictly from the Bell spin state formalism.PeterDonis said:
Sorry, these statements are simply false as a matter of what actually happens in an experiment. Measurement involves interaction between the measured system and the measuring device. That interaction can exchange conserved quantities. So it is simply physically invalid to only look at the measured systems when evaluating conservation laws.RUTA said:
The Bell spin states obtain due to conservation of spin angular momentum without regard to any loss to the environment. Therefore, the theoretical results I shared are independent of experimental uncertainties, which is what you're trying to invoke.PeterDonis said:
How do you know? You're not measuring the exchange of angular momentum with the environment. That doesn't mean you can assume it doesn't happen. It means you don't know.RUTA said:
I don't know where you're getting this from. There can't be any experimental uncertainty in something that's not being measured. The fact that measurement involves interaction between the measured system and the measuring device is basic QM. But it does not imply that all aspects of that interaction are captured in the measurement result. In fact they practically never are.RUTA said:
I don't know, how often we have discussed these wrong statements in the forum. Should this really be part of the Insights?PeterDonis said:
I don't know. The point I have made is not one I have seen addressed in the literature. But that doesn't make it wrong.vanhees71 said:
If a particle's spin is "measured" along a certain axis, it will "exhibit" spin that corresponds to a vector parallel to the axis of measurement. The question is: Does a quantum spin "exhibition" actually impart quantum spin to the surroundings?PeterDonis said:
"Impart quantum spin" is too narrow; it should be "exchange angular momentum". Quantum spin can be inter-converted with other forms of angular momentum.Lord Jestocost said: