Interesting Scientific American article (The end of QM?)

[PeroK]

Please give me an actual argument beyond telling me that I do not know anything about QM.

An argument about what?

 

[weirdoguy]

Are you claiming that those physicists did not write as I quoted them?

They did not write those thing in their textbooks nor peer-reviewed papers. Pop-sci sources are not bases for scientific discussion.

 

[wittgenstein]

Actually that was from Heisnberg's book and alo hawkings. So they lied in their books.

 

[wittgenstein]

I should have said "debate" rather then "argument". I am weird I guess. I ask questions because having my entire world view shattered is not a problem. It is actually the most exciting thing I can imagine.

 

[weirdoguy]

Actually that was from Heisnberg's book and alo hawkings.

I said textbooks, not pop-sci books.

 

[mgeorge001]

Are you claiming that those physicists did not write as I quoted them? I gave Heisnberg's quote source. I can give the primary sources for the others.

I was only commenting on the Scientific American article. I thought it was interesting. As far as the accuracy of quotes of physicists, I did not check into that. Thanks for the mention of the article. I enjoyed reading it.

 

[PeroK]

Actually that was from Heisnberg's book and alo hawkings. So they lied in their books.

It depends what you mean by a lie. Let's take a non-QM example. Here on PF, we do not use the concept of relativistic mass:

https://www.physicsforums.com/insights/what-is-relativistic-mass-and-why-it-is-not-used-much/

In academia the concept is (almost) obsolete.

Now, I challenge you to find a popular science source that does not emphasise relativistic mass as an important tenet of modern physics.

Why the discrepancy? Why does a concept that disappeared from academic textbooks over 50 years ago still persist as a pillar of modern physics in popular science? I have no idea.

Wave-particle duality is the same.

And: the universe started from a single point of infinite density. Popular version of the big bang theory. Nonsense.

I'm sure there are others. Basically, there is a set of things that popular science writers are obliged to promote. But, if you study the subject at university, you'll find the actual theory is very different.

Ultimately, QM (and Relativity) can be laid out as purely mathematical frameworks - with all the logical watertightness of any mathematics, and all the rules of logic intact.

It's only when you suggest these frameworks apply to our universe that the fun starts - and people claim that Relativity and QM are self-contradictory or defy logic. But, these people are using logic in the everyday sense.

In answer to all your questions, I would say: forget nature and our universe. Present QM as a branch of functional analysis. It's pure mathematics, all nice and logical.

 

[EPR]

So all the quotes from Nobel Prize winning physicists about how QM violates logic and how no one can conceptualize it are the result of being uneducated?

Violates what logic? It must be a preconceived something about how the world works.

I find no breach of logic in my minimalist, no-assumption, personal experience of something that appears like a universe.

 

[DrChinese]

So what is it? A particle or a wave?

As you must have read a hundred times by now, quantum objects do not have classical properties such as position and momentum. They can exhibit elements of these at times, and do not exhibit them at other times. So calling them a particle or a wave is just a convenience. Experiments can make a quantum objects appear as a particle, a wave, or any combination in between. There certainly is no excluded middle.

So you can twist definitions, meanings, etc but that does not in any way change the ability of QM to make accurate statistical predictions. And yes, QM can appear strange, bizarre, counterintuitive or whatever... or not. How it affects your sensibilities obviously has no impact on its scientific quality or value.

I think it is fun to explain some of those elements to people because it piques their interest and makes them think. I always hope it will open people's minds to the vast amount of research that has been done in the past 50+ years. Many folks are quite unaware of the incredible amount of progress that was made long ago that holds up today. The quantum discoveries of the 1920's are mostly alive and well today. These ideas are well represented in many popular books, including ones written by famous physicists. I am not aware of anyone "lying" as you say. Rather there are things at the quantum level that operate quite differently than one might initially guess. That's true in a lot of scientific areas.

 

[Nugatory]

Are you claiming that those physicists did not write as I quoted them? I gave Heisnberg's quote source. I can give the primary sources for the others.

One must be careful about the context in quoting anyone. Some of the more common pitfalls when quoting quantum physicists are:
1) Picking up a quote from the decades before the modern form of the theory was understood and formalized. Statements from that period will reflect the incomplete understanding of the era.
2) Physicists use natural language descriptions instead of math when trying to explain physics to non-mathematical audiences. Because these are natural language descriptions they are subject to the limited accuracy and precision of natural language descriptions - they can never be an adequate substitute for the real thing.

You have been fairly consistently suckered by #2

 

[vanhees71]

Are you claiming that those physicists did not write as I quoted them? I gave Heisnberg's quote source. I can give the primary sources for the others.

The problem is that popular-science writing is among the most difficult tasks for a scientist. Particularly in theoretical physics you cannot use the only adequate language to talk about it, which is math, including quite some advanced methods (calculus, linear algebra, functional analysis). Even the best popularizers cannot give a fully correct account of the subject, because they cannot use the adequate tools to express it right.

That said, there's another category of popular-science writing physicists, who like to promote some personal world view and try to apply the results of their research to realms of the human experience, where they simply don't apply. Heisenberg and (to less extent) also Bohr were among those scientists. Particularly Heisenberg had a strong philosophical opinion about the meaning of quantum mechanics, and this never does good in popular-science writing. Even his scientific papers, if not checked by his more down-to-earth collaborators (most importantly Pauli) are hard to understand and partially even wrong.

If you want to study QM by reading the original papers (not a good strategy to learn the subject for yourself properly), then rather stick to the "no-nonsense people" like Born, Jordan, Pauli, Dirac, Schrödinger, and Sommerfeld than to consult Heisenberg or Bohr.

 

[H_A_Landman]

please explain how contradicting Law of excluded middle - Wikipedia is not extraordinary.

Classical logic is not the only possible logic. It has many undesirable properties, such as being explosive (one contradiction destroys the whole system). For a general overview of other possibilities, see Graham Priest, An Introduction to Non-Classical Logic, 2nd Ed.

Consider a monotonic database of facts (i.e. you can add new facts, but never delete old ones) that starts empty. You also have a set of axioms and allowable proof methods. You are allowed to add facts if either (1) you learn them externally (from some outside source) or (2) you can prove them using the existing facts, axioms, and methods. A fact is TRUE if it is in the database. A fact is FALSE if its negation is in the database. It is quite clear that these are not the only two possibilities. A fact is NEITHER if it is neither TRUE nor FALSE; in an empty database, all facts are NEITHER. A fact can also be BOTH, i.e. contradictory. So there are 4 logic values, and the NEITHER value violates the law of the excluded middle. It is the excluded middle. Yet this is a perfectly sensible logic system.

Note that any logic system which is paraconsistent (doesn't explode on 1 contradiction) cannot be an extension of classical logic and contain it as a subset, because the subset would still explode. It instead must give up at least one part of classical logic. In the above, we have given up both Excluded Middle and Non-contradiction (including proof by contradiction).

Another example: Discursive logic models a room full of people with different beliefs. A statement is TRUE if at least one person consistently believes it. So "Trump was a good president" and "Trump was a bad president" can both be TRUE if there are different people who consistently believe one or the other. However "Trump was a good president & Trump was a bad president" cannot be consistently believed by anyone. Thus in this system we have given up conjunction: "A" being true and "B" being true does NOT imply that "A & B" is true. So you can have "A" and "~A" both be TRUE, and still not be able to construct the contradiction "A & ~A" and explode.

At any rate, the Law of the Excluded Middle is missing from many paraconsistent logics, and can not at all be assumed to be universally true or applicable. In particular, there is no reason to assume that it must apply to quantum logics, which we already know have many non-intuitive properties (like negative probabilities).