On Fine-Tuning and the Functionality of Physics

[Fra]

But apart from my own peculiar notions, I get where you’re coming from. I’m glad someone takes seriously that there’s a functional dimension to physics, and that we can try to understand it in terms of the requirements of an evolutionary process. And the method of your madness seems to be similar to mine – i.e. to trust a certain basic intuition about how things work in the world, and try to find language – in your case mathematics – to make it more concrete.

Yes, I think although we may have slightly different emphasis I think there is a similarity in the our thinking. I think that's why I find your points highly readable.

If we go back and consider how mathematics was developed, it's basically first founded by notions of logic, true and false, and various ways of COUNTING. This is exactly where my notions of distinguishability (boolean) states come in. Either you can make a distinction, or you can't. Then I add a notin of counting. To basically count how many times this occurs.

Eventually this boils down to a way to "count evidence" and thus form a rational opinion.

Next, comes the issues of howto keep counting records, when resources are limited. Then distinguishable patterns in the data, can be used to instead count patterns, so that this works as a compression of data.

I think that Quantum mechanics is the result of optimal inferences made during the constraints of bounded resources. Then the non-commutative information spaces are simply more fit than the commutative cases. The competition requires quantum or non-commutative logic for survival. What I'm offering here is a way to understand also what "non-commutative logic" is and how it naturally extends the commutative logic and normal probability, into quantum logic. But this no just inventing explanations from something we want to undertstand (QM), this framwork also comes with suggestions how to extend QM to incorporate gravity.

/Fredrik

 

[ConradDJ]

I've actually given my assumptions quite some thought. They aren't ad hoc starting points. After all my vision is not just mental understanding, my vision is a mathematical model for physics that allows predictions and computation of statistics etc. I have really tried to find the simplest possible constructive starting points. I could give some further elaborations and details beyond the main ideas we've already discussed, but instead of that maybe I can first ask:

Given the basic idea here - what starting points would you chose? After all, I assume that the result we need is something that makes a difference? And without a quantitative predictions (=mathematics) what difference do we make?

Fredrik – I agree that your assumptions seem well thought-out. And I agree with you that this business of “inference” is a remarkable evolutionary mechanism. The history of science is fascinating to me, because it shows all kinds of strange pathways that led to the major discoveries.

And I agree that Popper’s attempt to identify a logical core to this process is off-base. I’m not a mathematician, so I’m not in any position to judge whether your construction is viable from that point of view... but I’m happy to trust you that this approach is a good bet.

As to my starting-point – The basic thought I’m working from is that there are separate systems connected to each other through momentary interactions, where the interactions in some way "make a difference." Like you, I want to avoid assuming any background reference-frame in which these “differences” can be defined. The basic fact that impresses me about our universe is that everything observable in physics is in fact definable in terms of other observable aspects of physics.

Of course it’s possible that the physical world is built on structures that are unobservable, such as the intrinsic geometry of spacetime, or “hidden variables” built into things as intrinsic properties. Traditionally, physics has always assumed an underlying, unobservable reality of “things-in-themselves” with intrinsically determinate characteristics. The goal of theory has always been to identify the simplest set of hypothetical unobservables that can account for all the phenomena we observe.

My basic idea is that no unobservable reality can in principle account for the fact that things are observable. In order to be observable, something has to be defined in terms of other observables, and those have to be defined in terms of still others. So even apart from QM, the fact that anything is observable, in our world, shows that physics has a remarkable kind of self-referential structure – since it clearly provides the physical means of measuring each of its observable parameters.

QM adds to this strong evidence that there is in fact no determinate information in the world that isn’t part of this self-referring measurement system – no definite “reality in itself” that underlies the web of phenomenal interaction. But even if there were such an unobservable reality that “causes” everything to appear the way it does, it still would not explain how or why all these appearances work together to provide measurement contexts for each other.

So I take this as the primary thing we need to analyze and explain. That leads me to a starting-point involving the topology of networks, per the suggestion I made in another thread.

https://www.physicsforums.com/showthread.php?t=331008"

But this is, as you say, just a “mental understanding” – and one that seems to be quite difficult to get across, at that! So my sense is that you and I share some basic assumptions, but are working on different levels in trying to clarify what those assumptions imply.

 

[Fra]

As to my starting-point
...
the suggestion I made in another thread.

https://www.physicsforums.com/showthread.php?t=331008"

But this is, as you say, just a “mental understanding” – and one that seems to be quite difficult to get across, at that! So my sense is that you and I share some basic assumptions, but are working on different levels in trying to clarify what those assumptions imply.

Conrad, I skimmed the first two of your posts in that thread, and you are right that these ideas are hard to convey. Probably partly due to somewhat difficulties of finding a unambigous language for it, and second because it suggests a new way of thinking that's simply alien to many. It may take a while to digest and see the new "logic of reasoning" in what first seems as madness in the light of the old thinking. So it's not hard to understand why it's hard to get across.

I agree that there are clear similarities in our thinking.

In particular things like this

Instead I wanted to focus on an aspect of the world’s structure that I think is underappreciated -- that is, to the extent information in the world is observable, it must be able to be defined entirely from a point of view inside the interaction-web, in terms of the “experienced” structure of interaction.

This is exactly what I mean with intrinsic(=inside perspective) inference. To me, what you say here is pretty clear.

What I suggest is that all we have are "interacting" inside views, but unlike Rovelli I do not assume that interactions are constrained to OBEY the mathematical structure of QM, with fixed hilbert spaces etc. Instead the question I then ask - that Rovelli does not (*) - is, how can this insight also lead to predictions of the interactions? Ie. can our further analysis of this "idea" put constraints on the interactions themselves? OF course I've convinced the answer is yes.

So although as you say, you seek a more philosophical stance and I try to find some kind of formalisation of this, I symphatise with a lot of what you say.

(*) In addition to this, I just have on more comment with regards to your reference to QM. It seems to me that you sometimes use QM as an argument supporting your argument? And that I THINK you enjoyed rovellis RQM? Here I just want to say that, as far as I am concerned, what I am talking about here, and what I think you are talking about as well although it's hard to convey details is definiteily MORE radical than QM indeterminism and Rovelli's RQM!

This is a very important point for me. As you know, QM is still deterministic. The evolution of the information state in QM, is deterministic. Also Rovelli's nice talk about relations and observers needing to commmunicate to compare results are broken when he still simply assumes that all communication OBEYS the mathematical rules of QM.

So Rovelli's RQM is an attempt of something say "in this direction" but not sufficiently radical as he does not want to CHANGE or GENERALIZE QM, all Rovelli does is to find a different interpretation which keeps the same mathematics.

My conclusion is that sticking to the very reasoning I think we both have praised, implies by consistency of reasoning that we are forced to conclude that the rigid structure of QM, simply CAN not be the proper framework we seek, it is rather a special case where the observer is NOT interacting with the system, and qualifies as an infinite information sink. Two conditions that are completely off-sense if we require that the pictures we seek is a proper inside-view.

/Fredrik

 

[ConradDJ]

What I suggest is that all we have are "interacting" inside views, but unlike Rovelli I do not assume that interactions are constrained to OBEY the mathematical structure of QM, with fixed hilbert spaces etc...

As you know, QM is still deterministic. The evolution of the information state in QM, is deterministic. Also Rovelli's nice talk about relations and observers needing to communicate to compare results are broken when he still simply assumes that all communication OBEYS the mathematical rules of QM.

Thank you for your kind words!

I interpret Rovelli's RQM paper a little differently, which is why I like it. But in any case, Relational QM appears to have been a curious side-step for him -- I don't see any solid connection with his work on Loop Quantum Gravity.

For me, it's not that QM gives us deterministic laws that things must obey. It's just that empirically, these are the laws we've discovered (so far) -- including the fact that measurements turn out to be random, "unlawful" events, without which nothing would be "determinate". So the "determining" process is always only partly lawful.

Then the question is -- what kind of universe would operate this way? Rovelli gives only a partial answer, but it's in the right direction... He says -- it must be a universe in which systems don't have real, intrinsic states "built in". So he gives a dynamic picture of systems communicating with other systems -- "asking questions" of each other and giving answers -- that somehow eventually constitutes a shared "objective reality".

He doesn't try to tell us how this happens. His goal is just to derive the formalism of QM from axioms representing this questioning process -- so in other words, he tries to make it plausible that the Hilbert-space structure of QM is what such a universe would look like.

As you know, others have worked at deriving the formalism from the logic of inference, also with some success. And any successful theory would have to show why QM works so well. But it’s still an open question – what’s ultimately going on here that gives rise to this kind of observed structure? So the QM structure is what we want to explain, not the ultimate (and incomprehensible!) explanation.

The way I use QM is at a more "primitive" and philosophical level, but in parallel with Rovelli's argument. I use it to suggest that a real-time process of “determining” reality is basically what the universe is doing. Like Rovelli, I believe that the basic obstacle is our traditional belief that some kind of reality just has to be given to begin with, in the nature of things. (But in his LQG work, it seems he may slip back into that belief?)

You focus systems that use data from past interaction to direct future interaction, according to rules that evolve by trial-and-error. This seems to address an aspect of this “determining process”. You’ve identified what seem to be the basic structures needed to make this work. But it’s possible that the kind of system you’re dealing with evolved from something more primitive.

As an analogy – human language is an extremely effective system of communication based on words, syntax, grammar. But it presumably evolved from a more primitive, wordless connection between people that had none of these kinds of structure. Or likewise, the biological process based on replication of RNA/DNA must have evolved from more primitive mechanisms that did not have available any way to store huge quantities of information in long-lived complex molecules.

So it's possible that my efforts to understand how communication channels work, in physics, are complementary to your evolutionary process, which seems to assume the existence of such connections between systems (or between data-sets within a system).

Given that "communication" in physics is not basically a simple and reliable data-transfer mechanism, but more like the process involved in human interaction. This is a process of mutual "guessing" about what the other person might mean, where we can gradually come to a common view of the world, but it's also a process of trying to make and maintain connection with the other person at a level more primitive than words or ideas.