Thursday, August 22, 2019

Quantum physics is not in crisis

The latest Lumo rant starts:
Critics of quantum mechanics are wrong about everything that is related to foundations of physics and quite often, they please their readers with the following:

Physics has been in a crisis since 1927. ...
You may see that they 1) resemble fanatical religious believers or their postmodern, climate alarmist imitators or the typical propaganda tricksters in totalitarian regimes. They tell you that there is a crisis so you should throw away the last pieces of your brain and behave as a madman – that will surely help. ...

In reality, the years 1925-1927 brought vastly more true, vastly more solid, vastly more elegant, and vastly more accurate foundations to physics, foundations that are perfectly consistent and that produce valid predictions whose relative accuracy may be \(10^{-15}\) (magnetic moment of the electron).

On the new postulates of quantum mechanics, people have built atomic and molecular physics, quantum chemistry, modern optics, lasers, condensed matter physics, superconductors, semiconductors, graphene and lots of new materials, transistors, diodes of many kind, LED and OLED and QLED panels, giant magnetoresistance, ...
He is attacking Sean M. Carroll's book, and other similar modern gripes about quantum mechanics.

I mostly agree with him. Quantum mechanics is the most successful theory we have, and we have professors saying it is in crisis, or it doesn't make sense, or the foundations are wrong, or some such nonsense.

If quantum mechanics does not obey your idea of what a theory should be, then it is time to re-examine your prejudices about what a theory should be. Quantum mechanics has succeeded beyond all expectations in every possible way.

Dr. Bee says:
Now, it seems that black holes can entirely vanish [over trillions of years] by emitting this radiation. Problem is, the radiation itself is entirely random and does not carry any information. So when a black hole is entirely gone and all you have left is the radiation, you do not know what formed the black hole. Such a process is fundamentally irreversible and therefore incompatible with quantum theory. It just does not fit together.
I am baffled how obviously intelligent physicists can say this nonsense. Everything in quantum mechanics is irreversible. I don't even know any reversible quantum experiments.

Quantum computers are supposed to do reversible operations on qubits, but they have never gotten it to work for more than a few microseconds, as far as I know. And Bee is worried that a trillion-year black hole decay might be irreversible? This is craziness.

Thierry Batard argues in a new paper:
In glaring contrast to its indisputable century-old experimental success, the ultimate objects and meaning of quantum physics remain a matter of vigorous debate among physicists and philosophers of science. ...

In the eyes of the Fields medalist RenĂ© Thom (2016), this makes quantum physics “… far and away the intellectual scandal…” of the twentieth century. ...

quantum physics has “… been accused of being unreasonable and unacceptable, even inconsistent, by world-class physicists (for example, Newman…)” (Rovelli 1996)
How can something work flawlessly and be so unacceptable?

This is a bit like someone going around telling everyone that cell phones cannot possibly work. What are you going to believe -- your own eyes or some philosophical professor?


  1. I think quantum theory is a perfectly good scientific theory, but it is so counterintuitive that it must be wrong.

    And I think when they find out that quantum computers cannot be scaled up, they will realize that this is because quantum theory is wrong.

  2. Dear Roger,

    >> ``I mostly agree with him.''

    Please explain the ``mostly.'' Yes, it's necessary, now.

    >>``... or the foundations are wrong, or some such nonsense.''

    Explain yourself.



  3. I agree with the part I quoted, and with his defense of textbook quantum mechanics. I disagree with his endorsement of strings.

  4. Roger, Math isn't mechanics, not even close. Quantum mechanics is as profound an understanding of reality as behaviorism is of the human psyche, meaning, not at all. When you gloss over and discard actual mechanics in the name of probability, it means you don't know how the damn thing works, you just know what it most likely will do as you track the outcomes and your algorithm becomes your 'reality'. This is very much like Gregor Mendel's fruit fly experiments which do not explain at all why fruit flies are different colors generally, just that they are in predictable ratios. If science hadn't kept prodding at the issue, we would still be just treating genetics as 'ratios of outcomes' and never have dug deeper into the foundations of life and discovered the underlying DNA and how genetics roughly functions.

    But don't take my word for it.

    Hence most physicists are very satisfied with the situation. They say: "Quantum electrodynamics is a good theory, and we do not have to worry about it any more." I must say that I am very dissatisfied with the situation, because this so-called "good theory" does involve neglecting infinities which appear in its equations, neglecting them in an arbitrary way. This is just not sensible mathematics. Sensible mathematics involves neglecting a quantity when it turns out to be small—not neglecting it just because it is infinitely great and you do not want it!

    P. A. M. Dirac, Directions in Physics (1978), 2. Quantum Electrodynamics

    So it appears that the only things that depend on the small distances between coupling points are the values for n and j-theoretical numbers that are not directly obseroable any- way; everything else, which can be observed, seems not to be affected. The shell game that we play to find n and j is technically called "renormalization." But no matter how clever the word, it is what I would call a dippy process! Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics is mathematically self-consistent. It's surprising that the theory still hasn't been proved self-consistent one way or the other by now; I suspect that renormalization is not mathematically legitimate. What is certain is that we do not have a good mathematical way to describe the theory of quantum electrodynamics: such a bunch of words to describe the connection between n and j and m and e is not good mathematics.

    Richard Feynman, QED: The Strange Theory of Light and Matter (1985), Chap. 4. Loose Ends

    Oh dear. Well, I guess when you conflate actual 'mechanics' with sleight of mathematical hand, who the hell needs good theory.