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rejectednocomments t1_jc1urdp wrote

Reply to comment by Elijah_Turner in Why There Is No Absolute Ground For Truth: A Review of Criticisms Against Strong Foundationalism by throwaway853994

I don’t want to scrap QM. Those examples don’t look like violations of PNC to me, and I think the author is just misunderstanding the examples or PNC.

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Elijah_Turner t1_jc1vti6 wrote

Ok this is the section right after the description of the double slit experiment, maybe you can point me to where there’s a misunderstanding:

“Now if we look at the logic behind this sequence of events that have been empirically observed we can see a clear contradiction with classical logical laws. A product of quantum mechanics is an understanding of wave-particle duality in which all quantum entities behave in two contradictory manners, as particle and as wave, and as a result of how they are observed as behaving the same matter can be given two separate identities. Two logical impossibilities have occurred; quantum entity x behaves as wave x and particle x when the two are contradictory and this quantum entity x is always identical to both wave x and particle x at the same time. Furthermore, given that we can not state determinately whether at any given moment a proposition about the nature of a quantum entity behaving as a particle or a wave is true or false, the answer being completely subject to incalculable probability, the final law of the excluded middle is also not being followed here. Thus, scientifically observed, empirical and existent phenomena in the form of quantum mechanics displays to us that three classical laws of logic are non-universal.”

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rejectednocomments t1_jc1w5ve wrote

I read that. Where is the violation of PNC? Asserting that there’s a contradiction doesn’t mean there is one.

Take wave-particle duality as an example. There are experiments where light behaves as a wave, and some where it behaves like a particle. But none where it behaves as both! How to understand this is a good question, but it’s a big leap to just assume a violation of PNC.

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Elijah_Turner t1_jc1xfbj wrote

“a particle is going through both slits, none of the slits and only one slit all at once.”

Is this incorrect then?

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rejectednocomments t1_jc1xn0s wrote

That’s wrong.

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Elijah_Turner t1_jc1xtzd wrote

Is it the author who’s wrong about the theory, or is the theory wrong?

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rejectednocomments t1_jc1yh45 wrote

The author.

Okay, when you have one slit open and fire a photon or an electron or whatever, you get a dot on the screen on the other side. When you have the other slit open, you get a dot in a different location. If you have both slits open, you don’t get either dot, but instead a band suggesting a wave.

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Elijah_Turner t1_jc1zokz wrote

Ok I’m trying to read up on it, and other articles explaining the double slit experiment kinda say the same thing. The photon simultaneously takes every possible trajectory. Again, I’m reading things in layman’s terms.

Can you please give me something more substantial than just negation here? Because I still don’t see how the author is wrong…

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rejectednocomments t1_jc200c7 wrote

Who says it also goes through none of the slits and only one slit all at once?

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Elijah_Turner t1_jc21kzx wrote

Superposition implies that the electron both exists and doesn’t exist at any point at the same time. Like, that’s the proof of that statement right there. As observed by the double slit experiment…

Unless you’re gonna substantiate your side a bit more, I’m not that into the endless negation. Explain to me why QM is fundamentally misunderstood in this article as it relates to the PNC.

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imdfantom t1_jc228wm wrote

Different person

I was going to answer elsewhere but I will respond here quickly for now.

>Superposition implies that the electron both exists and doesn’t exist at any point at the same time

Ah, not exactly.

The electron isn't in both "A" and "not A" states, it is in one state which is a superposition of "A and not A".

I understand the distinction seems meaningless, but it makes all the difference

Also, the discussion points seem to be veering to interpretation of QM which is a can of worms we shouldn't really open.

QM is a very useful tool, but we have to be very clear when we are discussing QM results versus QM interpretation. The former is agreed upon by all people who study QM, the latter is still up in the air .

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AspiringWorldbuilder t1_jc4w18u wrote

I am by no means an expert on quantum physics so please correct me if I am wrong, but my understanding of the double slit experiment is that the particle acts as a wave when unobserved and as a particle when observed. Such a conclusion is unintuitive (as mentioned earlier) because it implies that our observations can affect reality and that particles can act as both particles and waves under different circumstances. It seems a leap, however, to go from this point to arguing that it does both simultaneously (which would imply a contradiction). As far as I can tell, the only statement we can make is that it's nature is undetermined as it approaches the slit because it has the potential to be both a particle and a wave, but both are not actualized simultaneously.

Regardless, I would agree with the original argument that if something appears to violate the PNC, we should disbelieve it rather than disbelieving the PNC. The reason for this is that without the PNC everything becomes trivial. A tree is both a tree and not a tree. Everything is everything and nothing at once. Logic becomes impossible. As Aristotle would put it, we would become vegetables rather than human beings. If something appears to violate the PNC, then we should examine it closely and seek out any potential errors. Given that we are here dealing with empirical experiments that are at the forefront of science (and thereby not very well understood), I don't think we have any justification for believing the PNC is violated even if I have massively misrepresented the experiment and the article is right on that point.

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