You will rapidly expose my amateur knowledge of these matters! I am interpreting the HUP just as a limit example of the observer effect, meaning that while causality must operate, the act of looking for it obliterates the trace. I will leave it to the physicists to discuss hidden variables as that is beyond my competence. Is it correct that this apparent limit to our perception creates a blockage regarding the integration of the four forces into a grand unified theory?

Someone else might be able to answer this question better than I.

Lee Smolin wrote a paper where he states

source: http://philsci-archive.pitt.edu/arch.../me-hidden.pdf

Which seems to imply to me that even a unification theory like M theory still has apparent limits to our perception.

How can we legitimately project the verb "to know" on the universe? And how can we claim that it "knows because it is inside it"? This makes no sense to me and seems a continuation of the human tendency to assume the universe behaves in humanistic or biological terms.

Is the universe self-aware? because it seems to me that is the only way we could accept that it "knows" anything.

Just to be somewhat controversial:

I really think Einstein's comments about his refusal to believe God plays dice was perhaps his worst moment. Its a completely unscientific statement. However it shows that even the greatest scientists are prone to the sort of bias or pre-conceived ideas suffered by humans. If we deconstruct what Einstein is saying it makes some ridiculous assumptions:

Who or what does he mean by God? Its not enough to say he just meant the universe - which is what his apologists usually claim. He is implying that something or a God designed the universe with a purpose in mind. And that something had a choice. Its inescapable no matter how you interpret his statement that he must have believed there was some methodology or consistent idea of how the universe should be at the point of creation.

I find the fact that people still use his statement as some sort of argument for Determinsim rather silly when had that statement emanated from anyone else it would have been flatly rejected as dubious speculation.

Now Im not trying to goad Einstein fanatics but just pointing out that his insistence on Determinsim was deeply flawed from any logical perspective. That doesnt take away from his brilliant work on GR one iota.

That depends entirely on the definition of particle-- some definitions imply those things, some do not, and both types of definitions are used in various physical theories. But what really matters is not the definition of particle, it is the source of that definition: us. Reality does not define our terms, we do that. Yes, we try to use definitions that work in reality, but that is all that can be said about our definitions.

Again, this statement is irrefutable, because no one can speak meaningfully about information that we have no access to, except to say that information we have no access to would not fit various forms of definitions of the word information (and might fit other definitions). Which definition of informaiton are you using, and why did you select that definition? While you're at it, provide your definition of "true", and why you chose that one too. Those are the relevant questions. If you take the scientific meanings of those words, then they do not support the argument you are making.
There are few definitions of "position" that are not "abstract concepts", and none of those non-abstract definitions (say, empirical ones) are what you mean by the term. So what do you mean by a position that is a "property of the thing itself"? How is this property established, and what are you imagining that it means physically? Are you not simply idealizing some simplified notion that is actually quite a vague concept?

It seems to me that the sole way that you are deciding what particles "make up" the object are that they must be "in the object". Your words are just two ways of saying the same thing, but it begs the question, because somehow we have found a way to identify what particles "make up" an object without specifying any exact positions for them.
That is not an example of logic, because it is simply an assertion. Logic requires that you state your assumptions and demonstrate how a logical process connects them to your conclusions. I would in particular point to your use of the word "can" in that statement-- what is your definition of that word that actually makes sense in that statement?

The usefulness of astronomy is in how it gives us a sense of understanding the nature of the universe, that is its utility. But conveying that sense to us is hardly the same thing as actually establishing the nature of the universe, as the history of science has quite clearly demonstrated over and over.
The concept of application is not what I intended in my use of the term usefulness. If we primarily want to make models that we can successfully imagine convey the nature of things to us, and which pass various empirical tests, then that is the usefulness of those models, as usefulness is defined in science.
The latter sentence I agree with, but not the former. It is not logic to claim something must be true even though one cannot present any argument that it is true, other than the claim itself. Is that what logic has become now?

That statement is only logical solid if one includes determinism as a law of physics. But then of course we fall again into tautology: the argument is nothing other than: if particles are deterministic, then they are deterministic.
But of course the key word in that sentence is "postulate". So the question should be asked, at what point does something that is postulated in the human mind become a logical imperative for reality to obey? At no point, that is simply not the connection between logic and reality, according to that same logic.

The primary goal of QM is to be a predictive mathematical model, to be able to predict how things work, not to find out the nature of reality.

Is there a difference?

IMO, yes there is. If they should happen to be identical, it would only be conicidental.

I actually think it was not such a bad or unscientific position for him to take, but it is certainly a remark that is easily misinterpreted. It is not Einstein's apologists that provide the intended meaning of that statement; Einstein himself was quite clear about what he meant. Einstein's only concept of "God" came in a form very similar to simply saying that God is in the laws of physics. Now, it is true that Einstein had certain preconceived notions about how those laws ought to be, and those notions both helped him come up with relativity and were galvanized by the success of relativity. They also hindered his appreciation of quantum mechanics. But it's not bad science to ask what a certain philosophical perspective on reality can give you-- his desire to find theories with certain attributes was helpful to him when such theories were effective. When they were not, it was not helpful. But that's all part of good science-- no one individual is needed to do everything, so each one can choose their own approach-- as long as reality, not rhetoric or philosophy, is the ultimate arbiter.
Actually, that isn't really what he was implying, he was implying that in his mind a scientific theory should have certain attributes, aspects that he associated with his concept of how reality worked. Yes that is a biased approach, and is not guaranteed to work, but it is more a description of something that he was looking for and would not be satisfied without, moreso than a claim about how reality had to be. It was a statement of a personal aesthetic, a search for something that when he found it, served him well, and when he did not, left him empty and unsatisfied. A double-edged sword, if you will. The rest of us are not incumbent to accept that interpretation of what physical theories should be, if we find others that serve our purposes better.

I think a fair way to classify it is a statement of a particular possibility. In philosophy, it is important to get all the ideas out on the table, and if they come from renowned thinkers, more's the better. But nothing is true by authority in either philosophy or physics-- they are just possibilities to ponder. You are right that no one should ever say "it must be true because Einstein said it". It is significant that Einstein himself said in his letter to Born "I, at any rate, am convinced that He does not throw dice." He is speaking for himself, about what he believes is the way reality works, but it is nothing but an opinion for consideration-- like all philosophy.

I can agree that Einstein had no strong argument in favor of determinism. But I also don't see the statement about God not rolling dice as being directly related to the concept of determinism. It seems to me that Einstein is basically asking, if reality needs a dice to figure out what to do, then where are the dice? In other words, a physical theory should provide all the instructions that reality has at its disposal, so if reality at some point says "now roll a die to figure out what happens", then those dice should be part of the what the theory is describing, but where are the dice in the theory? How do they get rolled, how does their output get factored into the reality? A theory that needs dice is incomplete if it can't describe the mechanism whereby the outcome of the dice get determined. But determinism is something much more, it is the claim that all the instructions for all future events is contained in the present.

To see this difference, consider a movie. When we go to a movie, we know perfectly well that the end of the movie is already determined-- it's already on the film. Yet we would never claim that all the events of the movie are somehow contained in a set of instructions that exist in the present frame that we are looking at. So what do we mean when we say the ending is predetermined? That is not the sense that the term "deterministic" gets used in science, where most people mean not that the future must come out a certain way (a scientifically untestable claim), but rather, that the outcomes are (at least in principle) predictable based on information that is encoded in the present.

Let's push the movie analogy a little farther. Let's say a famed director is known for always rolling dice to determine the outcomes of his/her movies. Does that make the experience of going to a movie by that director any different than a movie by a more conventional director, especially those not particularly known for "happy endings"? Is a movie by the dice-rolling director any less determined, when we go see it, then any other movie? The issue of predetermination, and the issue of some inherent role for randomness, are just not the same thing at all.

I agree with you here-- science is about testability, and testability is about predictions. This does not mean that science is only about making predictions, because we do hope that some insight into the "nature of reality", as Robert Tulip puts it, will come from it-- we should not ignore the important philosophical component to the exercise, there's a reason science was born of philosophy. But the proper flow of knowledge is from what passes the tests implied by its predictions, into what can be called insight into reality-- never the other way around.

Now, it's true that Einstein explored the problem in the reverse direction-- he conceptualized about the nature of reality, and used that to design a predictive theory, but he knew about some of the kinds of predictions his theory would need to produce (a constant speed of light being the most important). Quantum mechanics also had some elements like that, it was a mixture between a mathematical formalism that made some kind of sense, and a set of preknown observations that would need to come out a certain way, even if counterintuitive. Both theories were quite counterintuitive, and neither was designed in the absence of surprising observational results. It was always those results that gave the theories their teeth-- they are why we accepted the theories. No scientific theories are based in logic, they are all based in predictive success.

Ken,

"Actually, that isn't really what he was implying, he was implying that in his mind a scientific theory should have certain attributes, aspects that he associated with his concept of how reality worked. Yes that is a biased approach, and is not guaranteed to work, but it is more a description of something that he was looking for and would not be satisfied without, moreso than a claim about how reality had to be. It was a statement of a personal aesthetic, a search for something that when he found it, served him well, and when he did not, left him empty and unsatisfied. A double-edged sword, if you will. The rest of us are not incumbent to accept that interpretation of what physical theories should be, if we find others that serve our purposes better."

To be able to examine all perspectives from a neutral standpoint as you do is a great quality.You'd make an excellent science teacher as you are very level headed and honest about the interpretational side of physics.

"I think a fair way to classify it is a statement of a particular possibility. In philosophy, it is important to get all the ideas out on the table, and if they come from renowned thinkers, more's the better. But nothing is true by authority in either philosophy or physics-- they are just possibilities to ponder. You are right that no one should ever say "it must be true because Einstein said it". It is significant that Einstein himself said in his letter to Born "I, at any rate, am convinced that He does not throw dice." He is speaking for himself, about what he believes is the way reality works, but it is nothing but an opinion for consideration-- like all philosophy."

Yes i think this is probably the most painful aspect; that he was so brilliant. Its hard to feel comfortable disagreeing with a known genius, whom one respects tremendously.

" ....The issue of predetermination, and the issue of some inherent role for randomness, are just not the same thing at all."

Yes Predetermination frightens me because it means an ultimately closed finite system, and i would feel conned by nature. To me it seems like Determinism is the slippery slope to full blown Predetermination.

It would be preferrable (to me) to know that creativity is spontaeous and not some pre-programmed code executed at the beginning of the universe. I realise that preference is based on my experience of reality with daily life and seeing all the variety of what appear to be creative forces in the universe.

Personally I think that there is a logical inconsistency built right into the concept of predetermination-- which comes from the prefix "pre". The future could be determined, just like the past is, without being "pre" determined-- it might be determined in a way that is outside time. That's like the way the outcome of a historical nonfiction book is-- you are reading about people exercising free will, and you know exactly what they will do and what will come of it. When they were making those decisions, was it somehow determined that you would later be reading about them? Perhaps, but it was not predictable. Could anything ever have happened any different than it did? I can't see what it means to say that it could, but nothing is "pre" determined, we just don't know it was determined until it happens, unless it is perfectly predictable.
Spontaneity is another interesting concept-- if we see a movie in which the actor does something spontaneous in that moment, was that not a spontaneous act? Why is it less spontaneous to know that the action was captured on a film that has been in a box for a month and could not suddenly be different when you watch it?

Ken,

"The future could be determined, just like the past is, without being "pre" determined-- it might be determined in a way that is outside time"

Yes i see what you mean. Do you think that "spooky action at a distance" could be evidence of a sort of time-less fundamental level of which we are usually completely unaware?

Quantum entanglement is a very subtle issue indeed, but personally I think that particular conundrum is unnecessarily hung on the word "action". Quantum mechanics is about the proper way to process the information that is accessible in a quantum system, so it can be thought of as being about what we can know, moreso than what the system is "actually" doing. We are so separated from the systems in question that we can only talk about our experience in relation to those systems, and that's why the "reality" has to be translated into information that we can process. Hence quantum entanglement is about how the information is extracted from a system-- and when we compare observations on a system made in two very separated places, we find information that shows correlations over that distance.

We also find that the information could not be "stored" only locally, such that the two different places correspond to two different sets of information. There is no need to connect them with an "action" that happens when we do the measurement-- the action that connected them happened when they were not widely separated, but we are not extracting that information until later. The moral is, reality does not need to store its information locally, even though we do our measurements locally. The reason that quantum mechanics gets this right is that quantum mechanics uses a nonlocal form of information storage: the "wave function". It is just a very good example of a situation where classical thinking, which stores all its information as local attributes of a system, simply doesn't work. Einstein thought the classical thinking had to be right and the quantum mechanics had to be wrong, but the opposite is how we now think of it.

So does this imply a kind of time-lessness? I think it does, yes-- both a timeless and a spaceless quality to the information that applies to an entangled system. Perhaps the best way to say that is that time and space do not underlie all information, instead they are examples of the kinds of information we can access with our measurements. An even deeper issue is, when we do extract that information, are we reading reality, or constructing reality, in our own image in some sense?

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Logic is the grammar of truth.

Meaning and absolute certainty are incompatible, and profound meaning and absolute certainty are profoundly incompatible.

The only thing intelligence is capable of is recognizing itself.

Einstein once said, "For we convinced physicists, the distinction between past, present and future is only an illusion, however persistent". The only thing that is real is the whole of spacetime.

He argued that all events "are". They eternally occupy their distinct point in spacetime. There is no flow of time.

One can picture spacetime as a loaf of bread, the slices represent different spacetime snapshots (in this analogy, clearly only two physical dimensions.)

Our conscious experience seems to sweep through the slices.

Yes, this is the big unknown, whether our conscious experience is somehow responding to a flow of time, or constructing it. I do rather feel it is the latter. That sense gives a very different flavor to questions like "what happens to your consciousness after you die", which make the question seem not so much unknown as downright internally inconsistent. But that leaves the realm of what science can actually say, now and perhaps ever.

Rather poignantly, he wrote that in a letter to the family of his old friend Michele Besso, expressing his feelings about Besso's death. The quotation above is preceded by "Now he has departed this strange world a little ahead of me. That signifies nothing."

And the "seeming" can come from the fact that each space-time instance of our consciousness codes up its "present" interactions and its "past" interactions, but not its "future" interactions. Any moment of my conscious experience contains a sense of an expanding past, as I remember the past, and remember remembering the past.

Grant Hutchison

Another possibility---supported by Von Neummann's Chain---is that consciousness does indeed exist independently; it would be part of the system, but also outside it. Not saying that is the case, just saying it could be.

Yes, once you've taken the (big!) decision to resuscitate Cartesian dualism in order to tidy up the measurement problem, I suspect the substance of consciousness (whatever it may be) would also require exotic properties with respect to time and non-locality.

Grant Hutchison

I think the basic question is, is consciousness like the person writing the book, or like the person reading it? Can one book not have many readers, and can a reader not read many books? A book has a different identity than its reader-- are we not confusing one kind of identify for the other?

Almost a koan. I distinctly heard the sound of one hand clapping as I read it.

Grant Hutchison

Personally, I think that physics is the investigation of how the books get written, but consciousness is not in there anywhere, except that consciousness does not read what is not written. Of course, that is not a scientific theory of consciousness, but it is a picture that I doubt any scientific result could ever refute. Supplant, possibly-- we shall see (or somebody will, perhaps).

In case Ken G's comments did not clarify this point:

The evidence clearly shows that the HUP is NOT somehow a result of lack of knowledge, or that we somehow disturb particles by observation. It is fundamental.

For example, you can test the spin of a photon in a particular direction repeatedly, and will always get the same answer. Obviously the spin observation itself does not alter the photon just because it is being observed, because the answer remains the same. But try observing that same photon at other angles, and uncertainty and chance will be introduced - just in the amount (and no more) as the HUP would predict!

Also: Einstein imagined in his EPR paper that the HUP could be beaten by entangled particles and performing measurements once they were separated by a suitable distance. But we know now that the HUP still applies in this situation, and you cannot use entanglement as a way to exceed the limits of the HUP.

How the HUP operates is itself a mystery, and one which continues to lead to tantalizing possibilities such as Many Worlds and Bohmian Mechanics. There are very few professional scientists who hold the opinion that there exist local hidden variables (as you seem to imply). This possibility was ruled out with the advent of Bell's Theorem.

As far as anyone knows, the HUP has nothing to do with issues involving unification of gravity with the other 3 forces (strong-electro-weak).

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The map is not the territory.-Korzybski

I think there is a connection there, actually. The HUP means that space cannot be infinitely continuous, as it is treated in GR, because to give meaning to such spatial precision would require so much energy that spacetime would curl up on itself at scales smaller than the Planck length. So the HUP seems to imply that GR will need some kind of coarse-graining to unify it with quantum mechanics. That would seem to involve quantizing the gravitational field, which many think will be done with a spin 2 particle called the graviton. Why that has eluded a consistent theory so far, I don't know-- maybe it isn't possible after all.

Please excuse my limited understanding of the physics of this topic, but I have always found the HUP an intriguing puzzle regarding how to reconcile (a) the observation that position and movement cannot both be known precisely; with (b) the requirement that the universe is self-consistent. The deductive principle that physics operates by consistent laws seems contradicted by the observation that uncertainty is built into subatomic physics.

Newton’s Third Law of Motion, generalizing equal and opposite reactions, implies that for every cause there is a measurable effect. Does this break down at the quantum level? The idea that quanta are both particles and waves seems to contradict the logical law of identity, that a thing is what it is and not something else. These deductive principles are the logical foundation against which inductive measurement assesses its findings, giving the options of saying the deductive principles are wrong or that the findings are incomplete.

In looking at this material Kant’s critique of Hume is still relevant. Hume famously argued the skeptical modern empirical case that no necessary connection could be perceived between a cause and an effect. Kant, in his Critique of Pure Reason, said Hume’s skepticism did not enable us to recognise the existence of the universe, in which time, space and causality are necessary truths not given from empirical observation alone. As Einstein implied in his comments on Schrodinger’s cat, the rejection of determinism implied by the findings of quantum mechanics seems to deny this basic Kantian principle of necessary deductive truths by suggesting that causality does not operate at the subatomic level. It should be noted that this principle of causality does not diminish human freedom, because the ultimate cause can only be available to a hypothetical omniscience towards which human knowledge can only ever make a minimal approach.

The thing is, the uncertainty is uncertain in a consistent way, you can repeat the experiment as many times as you want and you'll always get the same result, that measuring one of the properties means that the other becomes unknown.

Being consistent doesn't mean the same as making sense

The particle/wave duality doesn't really break the idea of identity, since those are merely different ways of behaving rather than different identities.
It's basically saying that if you're measuring the wave-like behavior of en electron, you'll see it behave like a wave and if you're measuring it's particle-like behavior you'll see it behave like a particle. That it's capable of both types of behavior doesn't retract from it being the same.

This is not a failure of deductive reasoning as such, it's a failure of your ability to conceive of something that can have both types of behavior, because you're basing your thinking on concepts learned from the macroscopic world where the two types of behavior can't be observed in the same things.

I think Einstein's comment on Schrödinger's cat missed the point he tried to make with the thought experiment.

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‘To those who regard “crime fiction” as some sacred icon which must follow a rigid formula, I will always be the man who writes 18-syllable haiku.’Trying to make sense of computers, The Error Log.

Actually symmetry and conservation seem to be very fundamental principles that reappear over and over. So again, as far as anyone knows, I don't think such "breakdown" would be an accepted idea. Not to say there isn't speculation, but not too much to support it at this point.

My points being: the HUP appears NOT to be something that applies only to our experimental precision; it seems fundamental. Conservation laws appear to be fundamental, and many successful predictions have been based on these considerations alone. So there is substantial experimental support for these ideas.

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The map is not the territory.-Korzybski

The indetermancy of the micro (quantum) world and the determancy of the macro world are supposed to meet in this experiment, with that of the micro world imposing itself on the macro world (the cat).

The Copenhagen interpretation states that the act of measuring something causes the Schrödinger wave function to collapse. In reality, the act of measurement takes place by the Geiger counter.

By the time we come to the cat, the measurement has already been made - measurements have been made - by the atoms of the Geiger counter, the vial-breaking apparatus, the vial, the poison gas, and the cat itself. So the cat is not in quantum limbo.

Kant never knew relativity. It would be interesting to see him revisit these remarks after learning relativity. Personally, I think a "necessary truth" is a truth that is necessary to help us gain a limited understanding of that which is not necessarily understandable, so the words "necessary" and "truth" are contradictory but manage to work together anyway.

Yes, the cat paradox relies on the bizarre assumption that the "quantumness" of the atom can rub off on the cat, placing the cat in a quantum state, rather than the perfectly natural assumption that the "classicalness" of the cat (and the rest of the apparatus) can rub off on the atom, placing the atom in a classical state.