Demolishing prejudices to get to the foundations by Flavio Del Santo and Chiara Cardelli

I think FQXi.org might be trying to find out if there could be a Natural fundamental. I am surprised that so many of the contest's entrants do not appear to know what am fundamental to science, or mathematics, or quantum histrionics.

Joe Fisher, Realist

Dear Flavio Del Santo and Chiara Cardelli,

I read with great interest your extremely deep essay on the problem of fundamentality in natural scientific knowledge and your conclusions on a new methodology for finding a reliable support for knowledge, a higher form of a philosophical approach to the fundamental problems of natural science with the aim of overcoming the crisis of interpretation and representation, the crisis of methodology , the crisis of understanding. Great essay. My highest score. Yes, indeed, it's time to "demolishing prejudices to get to the foundations".

Successes in the contest!

Yours faithfully,

Vladimir

Dear Flavio and Chiara

Your essay is a very high quality work, mainly as a critique of the physical sciences for determining what is fundamental.

A very in depth discussion of the Popperian falsificationism, as applied and adapted by physicists in different frontiers of physics.

It is a very good methodological application of epistemology for "demolishing the prejudices" implicit in the construction and falsification of scientific theories in physics.

But it ends abruptly without constructing or proposing an epistemological methodology for establishing what is and what is not fundamental in science, avoiding the biases of reductionism and implicitly accepted traditional conceptions. This would have made a superb closing for this essay.

Dear Del Santo and Cardelli,

Your paper is very well written. Your focus on no-go theorems with respect to quantum mechanics is a good overview of that area. It is as you indicate the case that modern physics does lean on such ideas. In relativity there is something similar with the invariance of the interval that gives a "no-go" theorem result that information and matter must move at the speed of light or slower.

These bounds on quantum mechanics and no-go theorems such as no-signaling and no-cloning have interesting analogues with spacetime. For instance we have the no-cloning theorem that a quantum state |П€> can't be cloned in a unitary transformation |П€> в†' |П€>|П€>. This can be seen if we write this quantum state as |П€> = a|1> + b|2> so this cloning is

|П€>|П€> = a^2|1>|1> + b^2|2>|2> + ab(|1>|2> + |2>|1>),

but cloning on the basis {|1>, |2>}gives

|П€>|П€> = a^2|1>|1> + b^2|2>|2>.

This means cloning is basis dependent, which violates unitarity. This connects with spacetime physics if we assume we have a spacetime has a wormhole. A wormhole where one opening is transformed under a succession of Lorentz boosts or a send and return motion will exhibit closed timelike curves. It would then be possible to clone a quantum state. An observer with the quantum state |П€> will have a copy appear so that |П€> в†' |П€>|П€> if that observer later throws one |П€> into the wormhole.

The types of spacetime solutions that may exist could then be constrained by quantum no-go theorems and restrictions on quantum measurements. I wrote a paper last year on a correspondence between the Tsirelson bound and the invariant interval of spacetime and how spacetime is built from entanglements. In general we then have that spacetime physics and quantum mechanics are mirrors of each other. The limits in both of these areas are then specific manifestations of the same constraints. It could be that the ultimate foundations of physics is just plain vanilla quantum mechanics.

I wrote an essay that attempts to look at this correlation between quantum mechanics and general relativity. In part I attempt to look at empirical ways of supporting or falsifying this. At any rate I enjoyed your essay

Cheers LC

Chiara and Flavio

Your idea that we should look for very basic assumptions and prejudices is in good agreement to my article. I regard the confusion in physics to be started before Einstein and even before Lorentz and in reality due to Stokes.

I therefore think that it would be very interesting to here your opinions about my article. So, I hope that you will take a look at Fundamental Errors in Physics.

Regards from ______________ John-Erik Persson

Dear Del Santo and Cardelli,

I found your essay very interesting, systematic and well written, and voted it very high, congratulations. Sadly I was lost in the §3.1 due the lack of mathematical tools - my formation is in philosophy.

Anyway, you wrote that "the search for foundations is a dynamical process that aims at removing "philosophical prejudices" by means of empirical falsification.". I was wondering, could we consider also "empirical falsification" like a possible philosophical prejudice?

Thank you for your reply as well.

(Crepi! Allora oltre che connazionali siamo anche concittadini, perché sono nato e cresciuto a Firenze pure io, e attualmente ci abito :)

Hi Stefan,

What is fundamental? I see it my business to ask whether or not so called no-go theorems may be questionable. In other words, are these claimed theorems and their interpretation in physics really fundamental or are they merely the fundaments of something called by Einstein's castles in the air?

I tried to explain without any emotion why I consider causality a most indispensable basis.

I am however disappointed if experts ignore my strict distinction between established theoretical constructs and what I defined in a previous essay as conjectured reality. Wigner's delayed choice gedanken didn't persuade me that it isn't reasonable to accordingly strictly distinguish between ideal past and ideal future in reality.

An ear is definitely not aware of the chosen reference point for time.

I consider this a most fundamental in the sense of undeniable fact, and I hope, at least you will agree on that.

Eckard

Flavio and Chiara--

I found your essay very interesting and stimulating. Although your essay is more rigorous and technical than mine, we actually cover some of the same ground and arrive at some similar conclusions (e.g. about the limits of reductionism). Also, in addition to being less formal, my essay argues for some conclusions that are a bit different than those you argue for here. I hope you will have a chance to read my essay and comment on it, I'd be interested in your analysis.

Meanwhile, I have a few brief comments on your essay to offer some (hopefully) constructive criticism. Regarding what you call "fundamental constraints," my issue is that I don't believe that we can establish those reliably. Historically, what seemed like a fundamental constraints in one time period was sometimes found to not be so--how can we know what we don't know? Regarding Popper, it's true that philosophers dispute his approach and that scientists typically quote him approvingly, but I disagree with the contention that scientists behave in accordance with Popper's dictums. If you examine what scientist do instead of what they say, you find very little to support Popper. For a more sophisticated alternative view, I think Polanyi was a much better thinker. On a related note, it seems like you are not taking into account at all the Quine-Duhem thesis and underdetermination more generally. Well, I'll leave it at those comments for now. Thanks.

Dear Flavio and Chiara,

Thank you for a beautiful essay and well done criticism of some of the current prejudices in science. I agree with most of your criticism, including of conventionalism, reductionism, the pop-Popperianism which pervaded much of current research. Not that I would find the current situation wrong, I think that it was expected (1) since we departed so much of the possibility to easily falsify our ideas, much of the gestation of a theory can inevitably be based much more on deduction and mathematics and less to physics than it used to be, and (2) we need to develop and explore so many possibilities to explain the world, that it is unavoidable that a large part of them would simply fail. These problems, along with the current pressure to publish, led to a very difficult situation. So it is important to go at least once in a while back to square zero and reconsider our methodology. Maybe I look a bit like devil's advocate of conventionalism, but I am not, I just try to understand the reasons of this situation. After all, despite a spread belief that Popper invented the scientific method, I think what he actually did was to describe it by looking at the most successful theories of that time, particularly special and general relativity. Since 100 years passed since then though, we should expect an improvement of the scientific methodology, but this didn't happen. By contrary, due to the current crisis, more and more voices advocate an evasion from Popper's demarcation. And it is in fact what already happened in practice.

I like the proposed solution, which you exemplified with no-go theorems about quantum mechanics and explained very well. In the previous edition, in my essay, I used these no-go theorems as illustration of what I meant by metalaws, not in the same way as you did though.

I like how you closed, "We have shown that the search for foundations is a dynamical process that aims at removing "philosophical prejudices" by means of empirical falsification." Of course, some may want to conclude from this that, to avoid "philosophical prejudices", one should avoid philosophy, but I would say by contrary. Even though some philosophers are caught themselves in some prejudices about various ideas in physics, and a handy example is the quote you gave from Feyerabend, who seems to adhere to a widespread idea among philosophers that the debate about the foundations of quantum mechanics was about determinism, when this was in fact just incidental. If he was right, then for those who accept indeterminism there should be no foundational issue in QM, but there still are.

Very good essay, I wish you success!

Best wishes,

Cristi

Interesting essay, but I have found something to object:

" forPopper, a statement is scientific if and only if it can be formulated in a way that the set of its possible falsifiers (in the form of single existential statements) is not empty"

I disagree because this misses the important distinction between particular statements and scientific theories. Particular statements are almost always unfalsifiable, to obtain falsifiable statements one needs complete theories, and (if one takes into account Quine's arguments for his holism) even a lot of different theories. Popper has discussed this somewhere in Conjectures and Refutations.

Then, there is no "impossibility of instantaneous signaling implied by both quantum formalism and special relativity". The impossibility is purely relativistic, non-relativistic QM has no limiting velocity.

"Indeed, a theory that would violate this condition allows for instantaneous signaling and it thus would mean a failure of the scientific method as we conceive it. It would be in principle not falsifiable"

This is wrong. Only a particular observation which falsifies relativity would not falsify this theory. The theory could make a lot of other falsifiable predictions. For example, such superluminal signaling would define a preferred frame. A natural falsifiable prediction would be that this is the CMBR frame.