Uncertainty about Uncertainty Redux

[DrChinese]

That does not make sense at all. What is the Uncertainty Principle fundamental to? Reality? Or our understanding of reality?

It is a fundamental consequence of Quantum Theory. According to tenets of the scientific method, we should consider the HUP as supported due to experimental considerations. You could call it "true" or "accurate" or a "description of reality" as well. Those are simply terms.

The distinction between "reality" and "our understanding of reality" is more philosophical than scientific. In my opinion, theories are distinct from reality. They may be considered useful descriptions. Past that, you end up mostly in a semantics discussion - and those bore me to tears.

 

[dx]

That does not make sense at all. What is the Uncertainty Principle fundamental to? Reality? Or our understanding of reality?

All theorems/results/principles of theoretical physics are about our description of reality. Realizing the logical presuppositions for the use of the concepts of momentum and position in our description of reality is what the uncertainty relation is about.

 

[Upisoft]

You are correct but when you look at the double slit experiment and notice wave-particle duality, how can it not trigger the idea that there must be an underlying different behavior that governs a world that is beyond our ability to measure it classically.

And how do you suggest we will start to collect non classical measurements? Using psychics? If so, I want the job...

Instead of saying that an observer pollutes the experiment, you can integrate that into this worldview. No one said that our human brain is enough to know the universe, but we can imagine what it's like really, by inferring from the experiment.

OK. I'm listening. Tell me more about the experiment.

I understand that this is not something you can "know", but using ideas that are "beyond" what we can really know usually helps in advancing physics forward.

That's true. But it will not help unless we have created equipment able to use "beyond" forces so we can interact this possible reality.

 

[etamorphmagus]

All theorems/results/principles of theoretical physics are about our description of reality. Realizing the logical presuppositions for the use of the concepts of momentum and position in our description of reality is what the uncertainty relation is about.

Do you think it makes sense to think of the HUP as a representation of deeper quantum-mechanical-behavior in the form of classical position and momentum, which is equivalent of classical particles and waves? I am not talking about the different philosophical interpretations.

Or is it a philosophical argument on its own - that HUP is the fundamental statement and the world is "run" by waves a particles, or the quantum-mechanical-behavior — a.k.a something more fundamental than particles and waves is the fundamental concept?
I don't think it is, because I don't dictate the nature of the "hidden behavior" just saying that it is there.

 

[DrChinese]

I don't think it is, because I don't dictate the nature of the "hidden behavior" just saying that it is there.

Well, now you are running afoul of Bell. Or at least coming very close.

 

[etamorphmagus]

@Upisoft:

You are of course correct, but say we find an effect QM right now can't predict, but string theory in ONE of it's forms (which I know nothing about) can. I think in that case adopting a worldview of strings makes sense, as if it is more fundamental.

But that is not the case, and right now we see that QM is correct and even if not completely right, some of its aspects will always remain, like HUP.

You could always find a better-prettier-more elegant theory and adopt its worldview, but of course not really, QM is kind of elegant, compared to crazy flying triangles worldview, or whatever.

Well, now you are running afoul of Bell. Or at least coming very close.

I don't mean hidden variables! I mean unintuitive-unapproachable-behavior.

 

[arkajad]

Realizing the logical presuppositions for the use of the concepts of momentum and position in our description of reality is what the uncertainty relation is about.

I wouldn't go that far. Different physicists may have different presuppositions depending on their vied whether QM is an ultimate description or only an approximate one, good, perhaps, for all practical purposes today, but not necessarily tomorrow.