B Is it time to rebuild quantum theory?

[slow]

Hi. Maybe you can help me clarify the ideas a little. I've put in google the following.

rebuilding.quantum

It seems that there are scientists interested in founding quantum theory on bases that harmonize with simple criteria.

After more than 100 years of elaborating and debugging quantum theory, is an attempt to remake quantum theory on new bases acceptable?

 

[DennisN]

After more than 100 years of elaborating and debugging quantum theory, is an attempt to remake quantum theory on new bases acceptable?

Hi slow!
Remake? Quantum theory is not a movie . Debugging? Quantum theory is not a software.
I'm not perfectly sure what you are asking about, but there are (1) something called interpretations and also (2) something called string theory (not yet verified by experiments).

 

[Stephen Tashi]

Hi. Maybe you can help me clarify the ideas a little. I've put in google the following.
rebuilding.quantum

apparently refers to an article in Wired https://www.wired.com/story/physicists-want-to-rebuild-quantum-theory-from-scratch/

 

[A. Neumaier]

apparently refers to an article in Wired https://www.wired.com/story/physicists-want-to-rebuild-quantum-theory-from-scratch/

Yes. It is hype, based on very little evidence. Quantum mechanics is a huge edifice and cannot be rebuilt by simply tinkering with some ideas on the foundational level and linking it to famous unsolved problems by mentioning quantum gravity.

It is like saying ''let us rebuild Europe from scratch'', based on a vision that just spans a dozen of papers.

 

[Fra]

apparently refers to an article in Wired https://www.wired.com/story/physicists-want-to-rebuild-quantum-theory-from-scratch/

Those kind of popular articles unavoidably describes things in imperfect and dramatic ways.

No sane physicist would suggest we throw away gained knowledge of subatomic physics more than we need to discard classical mechanics. This is not what "rework from scratch" should mean.

It rather means a reanalysis of the constructing principles of the THEORY in order to extend it. This has zero implication for the massive body of knowledge of high energy physics we have so far and that are nicely encoded in the curreny theory. Which will make no less accurate predictions just because a better theory eventually is found.

All this is not only "acceptable" it as one of the primary tasks of a theoretical physicist.

But different ideas compete and only the future will tell which previously holy cows that become "relaxed". Sometimes you can build onto things. Sometimes you need to take a step back.Nothing wrong with that.

/Fredrik

 

[atyy]

After more than 100 years of elaborating and debugging quantum theory, is an attempt to remake quantum theory on new bases acceptable?

apparently refers to an article in Wired https://www.wired.com/story/physicists-want-to-rebuild-quantum-theory-from-scratch/

That's a good article. There are already technically successful efforts to "rebuild" (large parts of) quantum theory, eg.
Hardy, Quantum Theory From Five Reasonable Axioms
Chiribella et al, Informational derivation of Quantum Theory

They basically take as axioms "nice" features of quantum theory that are usually derived. From these new axioms, the standard axioms are derived. It is similar to recovering Euclidean geometry from metric geometry.

Whether this approach will point the way to new physics remains to be seen.

 

[PeroK]

apparently refers to an article in Wired https://www.wired.com/story/physicists-want-to-rebuild-quantum-theory-from-scratch/

Which is, IMO, a particularly wretched example of science by soundbite!

 

[A. Neumaier]

There are already technically successful efforts to "rebuild" (large parts of) quantum theory, eg.
Hardy, Quantum Theory From Five Reasonable Axioms
Chiribella et al, Informational derivation of Quantum Theory

So successful that they not even reconstructed the canonical commutation rule on which all the successes of the first 20 years of quantum mechanics are based. They want to rebuild a skyscraper and succeed in building a tiny Lego toy house using well-known prefabricated bricks.

Let them first recover the spectrum of hydrogen including the multiplicities before praising their plans!

 

[slow]

Hello DennisN, Stephen Tashi, A. Neumaier, Fra, atyy, PeroK. Thank you very much. Your messages have been instructive and clear. It is true, one must have a broad look, open to attempts to progress, without getting distracted to the first bus that appears.

A phrase of Fra has left me thinking.

But different ideas compete and only the future will tell which previously holy cows that become "relaxed". Sometimes you can build onto things. Sometimes you need to take a step back.Nothing wrong with that.

That of sometimes needing to go back one step has invited me to reflect and ask something else. We can call steps to the stages of expansion of a theory. Or we can call steps to paradigm changes in the historical development of physics. With the enlargement stages we would go back to Schrödinger at the most. But with the paradigms we would go back to the context prior to Planck. If the latter happens, what is there prior to Planck that is sufficiently coherent, consistent and confirmed, as to build on that and connect it with the quantum postulates, or directly deduce from that the quantum postulates?

 

[Fra]

(I am assuming here prior to Planck, refers to historical development of physics(Max Planck), rather than historical development of the universe at Planck times;)

But with the paradigms we would go back to the context prior to Planck. If the latter happens,

Rewinding the historical inferences might not be what i had in mind, we would still be going forwards anyhow. I think we, thanks to a more experimentally developed theory probably can ask much better questions than was possible for Max Planck. Then i particularly think about the information theoretic, and algorithmic ideas. These things would be quite far sighted to expect from Max Plancks, not to mention that we can do "experiments" on these things today with fast computers, that was not possible before the transistor and modern electronics was developed. Interestingly much thanks to quantum mechanics. Even computer science an insight to things about computational complexity and limits, brings new deep perspectives to deductive systems. And these are exactly the things we face in the foundations of QM, and unification of forces from a theoretical perspective.

what is there prior to Planck that is sufficiently coherent, consistent and confirmed, as to build on that and connect it with the quantum postulates, or directly deduce from that the quantum postulates?

One possibility is that there simlpy exists no such sufficiently confirmed premise to from which you can DEDUCE QM. I think that whole quest is slightly mistuned, and this is why i personally focus on the inference logic. How about if physicists learn from biology. What is the sufficiently consistent solid basis for life? Yet life evolves? One key is that we are not looking at a deductive system here. This is a hard thing to accept as physics by tradition is extremely reductionistic. Ie. you always explain things IN TERMS of something more fundamental. But what if you reach a point where you can not resolve things further? Then what happens to this logic?

/Fredrik

 

[slow]

Hi Fra, your note # 10 is very interesting. You have left me thinking about reaching a level that does not support something underlying.