Conrad,
Like a "once upon a time" narrative, clearly explaining the story of our development without the need for fancy formulas. It's a story that tells itself with a natural force of symmetry and structure, almost like it was constructed by an unseen master builder with natural fine-tuning. The fundamental thing is that it was an accident -- or was it?
Enjoyed your narrative. It rates well. I never considered this story myself. Hope you can check out my story.
Jim Hoover
Dear Conrad,
Good to hear from you - I have happy memories of the 2012 essay contest, and the discussions we had, particularly with four of us - You, me, Edwin and Daryl Janzen. It felt good as I had been working alone for too long. There were also occasional posts from Ben Dribus and George Ellis.
Thanks for your comments on my essay, much appreciated. I've just read yours, and will read it again - it's very far-reaching, and is thought provoking - it makes one stand back further than usual.
Correct me if I'm wrong - you're talking about emergence, and mechanisms for the emergence of, among other things, time. But you're not talking about time emerging from the standard four-dimensional block of block time, which means your view is not the view that I've been arguing can't be true.
My argument against emergent time, if it's seen as coming out of the standard interpretation of SR, is that the laws of physics were frozen into the time sequence of the block at a deeper level than anything like a 'flow of time' that somehow emerged later. So if we think an apparent (or real) flow of time, like the one we seem to observe, emerged, we're then left with a coincidence to explain - why was what emerged so appropriate?
If it emerged at a shallower level, it would have been largely unconnected with the laws which it then neatly allowed to function. And yet the laws look like they were waiting for it to arrive. No-one has refuted this argument so far, though some have said they like it. One physicist said the coincidence might be explained by anthropic reasoning - that's not my view. My view is NOT that is shows time to be fundamental, but just that time looks unavoidably more fundamental than some of the laws.
Returning to your essay, you seem to be doing something a bit like Lee Smolin's attempt to find a way for the universe to have created itself in a series of stages, with his 'cosmological natural selection'. Am I right? It seems that way. There also seems to be an analogy between a living system and the universe - perhaps it's only an analogy, or are you saying that it's more than that?
The emphasis on measurability and the self-defining aspects of a system, obviously seems to come at least partly from QM. If it comes only from QM, my view is that we shouldn't infer too much from a mystery that is still unsolved, and unexplained. But perhaps you take more of a range of sources than just QM, and perhaps the analogy that relates us to the wider universe is a part of that.
Incidentally, I don't agree that we have enough to explain the foundations of physics within our current theories - the mystery about energy that I've outlined in the last few paras of my essay shows, for me anyway, that there are still major unknowns to be discovered.
Anyway, wishing you the best of luck... good to read your essay, I'll read it again.
Cheers, Jonathan
Jonathan,
Your comments are much appreciated! For now, just a brief response to a couple of points:
You're right that my emphasis on measurement comes from quantum theory. Since I've developed that connection in previous FQXi essays, this time I focused instead on fine-tuning and the argument from the context-dependency of information. But once I finally pull all this together, the title might well be Why Quantum Mechanics Makes Sense - arguing that any universe in which any kind of information is definable has to have a foundation much like QM, particularly as regards the role of measurement.
I think the reason measurement still seems like an inexplicable mystery is that its functional role hasn't been appreciated. We still tend to assume things "just exist" in themselves, without needing any context to define what they are. "Observing" then seems merely incidental to physics, and the object-observer relation gets discussed with no consideration for the informational environment that makes it work.
Lee Smolin's book on The Life of the Cosmos made a case that we need something like a theory of evolution to answer the big ""Why?" questions in physics, and I certainly agree. But his theory of self-replicating universes seems far-fetched to me, partly because it requires so many assumptions about black holes and inheritance of variation that have no solid basis in established theory. More importantly, I think there's an important evolutionary aspect to physics that's grounded not in replicating information, but in measuring and communicating it. I discussed this in my last essay on the Accidental Origins of Meaning, talking about the ways natural selection works in physics, biology and human communication. I also wrote about QM in an earlier essay on The Evolution of Determinate Information. What I've tried to outline here is something more primitive, the emergence of basic features of our universe that precede the beginnings of quantitative measurement.
Looking forward to further discussion in both our threads - and thanks again!
Conrad
Hi Conrad,
I'm wondering what you think time emerges from, I have trouble seeing time emerging from anything static. But if it emerges from something that moves, then time exists already, so one still needs to explain it. That why I don't think emergence works in the context of time, certainly not for the apparent flow of time, and to me not for its direction either (which I'd say is a far smaller mystery). I think when we eventually understand time, we'll also understand its consistent direction. And probably not before.
I agree it's surprising that the universe is measurable, definable, and (as others have also said) comprehensible, but I don't find a need to see it as having made itself so - I'd say the more surprising thing is that we can find out about it, and work things out about it - from our end. That's a more conventional view than the idea that it comes from both ends. I guess to me the universe is mostly hardware, though QM does suggest what used to be called the software/hardware entanglement.
Anyway, best wishes, Jonathan
Hi again... good question! No, I don't see time as emerging from anything static... or moving. I imagine the beginning as a plenum of happening, but with no given order or connection between events... hence no definable space or time. The events that make up our observable universe are a very tiny subset of these events, that happen to be able to define their order and connection, by conforming to the laws of physics.
So don't I think of the emergence of time as something that happened once and for all, way back when. I agree it doesn't make much sense to say, there used to be a time when there was no time, and then time began to exist. Rather, the emergence of time keeps on happening in every local present moment. The laws of physics guarantee that in every situation, there's some way of defining what happens next.
At the level of classical physics, this works so well that we can imagine the laws as divinely ordained from the beginning; we can imagine that things automatically "obey" these laws with mathematical precision - though in fact, it would take a vast computing power to calculate the real-time motion of just a handful of particles. At the quantum level, it becomes clear that something different is going on - contexts are being set up that randomly choose a particular outcome, passing that information on to other contexts where other choices can get made. In the deep quantum vacuum anything is possible - but the only possibilities that can participate in our observable world are those that help keep the process going... "time" being one basic aspect of this process.
Don't know if that will make sense to you, but that's my thought. And that's why I think of defining and measuring as fundamental - because I don't see anything as "hardware" that just sits there and keeps on being itself "over time". Incidentally, I noticed in your last comment to Marc Séguin about the map and the territory - "that something, somehow, was doubling as its own description." That might apply here: the universe is what it is, insofar as it's able to describe itself. Information about things doesn't just "exist" in the things themselves; it also gets communicated out through contexts of interaction that make it physically observable to other things, and therefore meaningfully definable. Otherwise its "existence" would be an empty concept.
Thanks for giving me another shot at this...
Conrad
Hi,
well I'm beginning to understand more about what you mean. Events can happen, but if they're not connected up in a definable way, then space and time don't exist. To me though, space and time exist without anyone there to define them (and without anyone struggling to define them, as we have on this planet).
And I think if an event can happen, then you already have time at work. It seems you think that only if events happen in an order does time exist. So to understand any view of time, perhaps one needs to know the minimum needed to make time exist.
But what we have in the universe now, with the order of events, and how they relate across distances, is either Minkowski spacetime, or something that closely mimics it. I'd say the latter, but either way, we have a complex structure surrounding time now, or seeming to. I guess to you that's a small area of definable structure, in a sea of chaos. It sounds like an anthropic type view, but I think it's not, rather as Lee Smolin tried to avoid anthropic arguments.
Anyway, to me the universe is a lot of physical systems, some of which we understand, and some of which we don't yet understand. I think we can get a glimpse of what's likely with the ones we don't understand, by looking at the ones we do. And they all turn out to play by a set of physical rules, and these rules turn out to have straightforward reasons behind them, which make sense.
Now it's true that QM seems very weird, but so have lots of things in the past, and the ones we managed to explain all had explanations that were more physically understandable than they perhaps seemed at first. That doesn't mean that everything else has to be that way as well, but to me it makes it more likely... hope that makes sense.
Yes, the map and the territory was an old idea I had in the late '80s and early '90s, and I do think that something is doubling as reality and information in QM, so perhaps that suggests something weirder than what I've said... but perhaps still something clearly understandable. Anyway, cheers,
Jonathan
Dear Conrad
If you are looking for another essay to read and rate in the final days of the contest, will you consider mine please? I read all essays from those who comment on my page, and if I cant rate an essay highly, then I don't rate them at all. Infact I haven't issued a rating lower that ten. So you have nothing to lose by having me read your essay, and everything to gain.
Beyond my essay's introduction, I place a microscope on the subjects of universal complexity and natural forces. I do so within context that clock operation is driven by Quantum Mechanical forces (atomic and photonic), while clocks also serve measure of General Relativity's effects (spacetime, time dilation). In this respect clocks can be said to possess a split personality, giving them the distinction that they are simultaneously a study in QM, while GR is a study of clocks. The situation stands whereby we have two fundamental theories of the world, but just one world. And we have a singular device which serves study of both those fundamental theories. Two fundamental theories, but one device? Please join me and my essay in questioning this circumstance?
My essay goes on to identify natural forces in their universal roles, how they motivate the building of and maintaining complex universal structures and processes. When we look at how star fusion processes sit within a "narrow range of sensitivity" that stars are neither led to explode nor collapse under gravity. We think how lucky we are that the universe is just so. We can also count our lucky stars that the fusion process that marks the birth of a star, also leads to an eruption of photons from its surface. And again, how lucky we are! for if they didn't then gas accumulation wouldn't be halted and the star would again be led to collapse.
Could a natural organisation principle have been responsible for fine tuning universal systems? Faced with how lucky we appear to have been, shouldn't we consider this possibility?
For our luck surely didnt run out there, for these photons stream down on earth, liquifying oceans which drive geochemical processes that we "life" are reliant upon. The Earth is made up of elements that possess the chemical potentials that life is entirely dependent upon. Those chemical potentials are not expressed in the absence of water solvency. So again, how amazingly fortunate we are that these chemical potentials exist in the first instance, and additionally within an environment of abundant water solvency such as Earth, able to express these potentials.
My essay is attempt of something audacious. It questions the fundamental nature of the interaction between space and matter Guv = Tuv, and hypothesizes the equality between space curvature and atomic forces is due to common process. Space gives up a potential in exchange for atomic forces in a conversion process, which drives atomic activity. And furthermore, that Baryons only exist because this energy potential of space exists and is available for exploitation. Baryon characteristics and behaviours, complexity of structure and process might then be explained in terms of being evolved and optimised for this purpose and existence. Removing need for so many layers of extraordinary luck to eventuate our own existence. It attempts an interpretation of the above mentioned stellar processes within these terms, but also extends much further. It shines a light on molecular structure that binds matter together, as potentially being an evolved agency that enhances rigidity and therefor persistence of universal system. We then turn a questioning mind towards Earths unlikely geochemical processes, (for which we living things owe so much) and look at its central theme and propensity for molecular rock forming processes. The existence of chemical potentials and their diverse range of molecular bond formation activities? The abundance of water solvent on Earth, for which many geochemical rock forming processes could not be expressed without? The question of a watery Earth? is then implicated as being part of an evolved system that arose for purpose and reason, alongside the same reason and purpose that molecular bonds and chemistry processes arose.
By identifying atomic forces as having their origin in space, we have identified how they perpetually act, and deliver work products. Forces drive clocks and clock activity is shown by GR to dilate. My essay details the principle of force dilation and applies it to a universal mystery. My essay raises the possibility, that nature in possession of a natural energy potential, will spontaneously generate a circumstance of Darwinian emergence. It did so on Earth, and perhaps it did so within a wider scope. We learnt how biology generates intricate structure and complexity, and now we learn how it might explain for intricate structure and complexity within universal physical systems.
To steal a phrase from my essay "A world product of evolved optimization".
Best of luck for the conclusion of the contest
Kind regards
Steven Andresen
Darwinian Universal Fundamental Origin
There's this basic notion that things either "exist" or "don't really exist" in some absolute sense, so that space and time can "exist" whether or not there's anything happening in them. Alternatively, there's the idea that space and time "exist" only as the structure of relationships between things and events. I go further, suggesting that space and time exist insofar as the structure of relationships makes them physically measurable. And this depends on a lot of other things being measurable too.
But I don't think we humans add anything necessary to this picture. When we observe things, we're just using the contexts physics already provides.
I imagine that QM will cease to seem weird when we've thought through the problem of what it takes to support a universe where everything is measurable in the context of other measurable quantities. QM is, after all, essentially a method for predicting measurement results. It gets weird when we try to interpret it as describing things that "exist" apart from any context that can measure them.
Thanks again,
Conrad
That makes better sense of what you've said before - it reminds me of RQM, and also of your essay in 2012, which we had an email exchange about after the contest. Yes, I do think that kind of approach works well. I'm not sure how things should be defined, but it fits with a number of things we know about already, such as aspects of SR. Anyway, wishing you all the best.
Jonathan
Conrad, I have now read your essay after replying to your comment in mine. I am glad to see that some of my reply fits with some of your ideas.
I like your physics archaeology and the sense that all levels are part of the picture. The sections about networks and loops also rang true to me, but the ideas are still a little too vague to really get a handle on. I hope you will be able to take them further.
Dear Inés,
Thanks so much... it feels splendid to have partners in this quest. Your note makes clearer to me what you mean by "searching in the opposite direction." And your thoughts about what it takes to make a conscious observer are very interesting - I particularly like that "the illusion of free will is required for the notion of I to emerge." It's not just Input/output, in other words, this business of sensation and control, there needs to be a sense of agency, maybe even of overcoming frustration, consciously choosing, etc. But it seems to me a very positive outlook that sees the value in some of our illusions.
"Consciousness" has of course a very broad range of meaning... especially, I would think, for someone professionally occupied with the neural networks both of humans and invertebrates. My sense is that the most important thing needed for the "I" to emerge is a certain kind of back-and-forth connection with "You". For us, this is the kind of connection in which language naturally grows; we learn to see the world as we learn to listen to others and talk with them about what's going on. But I think there are deep analogies between what we do and what happens in physics, between atoms. My thought has been, if we try to identify all the most basic requirements for what we humans do, and also for what atoms do, this gives us two very different and complementary perspectives on what it means and what it takes to exist.
Just by the way, the more I think about atoms, the more amazed I am at how unappreciated they are. We used to think of them just as irreducible bits of various types of matter... but then, as soon as we found out that was wrong, we got involved in going deeper. And the subatomic world was so completely intriguing and unexpected... that atoms themselves fell into the background. It's somehow been nearly overlooked, that all this complication is needed to make atoms work the way they do, in so many ways. If there's no "I" there, exactly, there's certainly a remarkable back-and-forth connection with the world, with other atoms.
When you get a chance, I would really like to hear your thoughts on "system and context". I happened to run across your 2013 paper on Noise Correlations in Neural Decoding - way over my head, of course, but just the abstract is so interesting! If there's any possibility at all of "decoding" the crosstalk of neurons, it seems very important to be able to ignore the broader context of correlations. So I can at least begin to see how this issue appears in your work.
Thanks again - Conrad
Dear Conrad Dale Johnson, your essay is a scientific picture of the world, in which is the main question - What does it take to be physically fundamental? I'll try to answer it as it looks New Cartesian Physics, which is based on the principle of identity of space and matter of Descartes. For a long time believed that the Foundation for fundamental theories is matter, an attribute which had mass. Once there was a formula of mass - energy equivalence, and mass lost the status of a value characterizing the amount of matter, about it rarely began to remember and physics has lost the Foundation. Any theory of everything is created in such circumstances would not be fundamental. The principle of identity of space and matter of Descartes, according to which physical space is matter and matter is space that moves, gives us the Foundation for fundamental theories.
When Copernicus asserted that the Earth revolves around the Sun, he had to add that along with the Earth revolves around the Sun, all the solar space. Space is what created the universe. Time is a synonym for universal movement of the physical space. Thus, space is the Foundation for fundamental theories. Space contains information about the development of the Universe. Space is the body of God.
The principle of identity of physical space and matter allows us to extend physics to living matter. For this we need to pay attention to the fact that matter within the body is the same as outside the body. Our brain creates an image of the outside world not within themselves and in the space around them. This way the outside world has an active nature, as it controls the body.
New Cartesian Physics needs your support to develop further. Visit my page and give your assessment there.
I hope on highly appreciate her ideas.
FQXi Fundamental in New Cartesian Physics by Dizhechko Boris Semyonovich
I wish you success! Sincerely, Boris Dizhechko
Conrad--
Interesting and enjoyable essay. I don't have the time and energy to record all of my thoughts on it, so I'll just ask one question that I think is interesting. Do you regard the narrative you offered here as being compatible with the more conventional narrative of spontaneous symmetry breaking at later times and lower energy regimes in the evolution of the universe, or would you regard it as a competing and incompatible alternative to that narrative? Your thoughts on this will be illuminating.
I hope you have time and inclination to take a look at my essay too. It is quite different from yours but I suspect you will enjoy it and find it stimulating. Thanks.
--Greg
Dear Conrad,
Your essay contains many different threads of thoughts but the single one I appreciated most is that you are trying to delve more deeply than many people in fundamental physics today. You are not satisfied by simply elucidating the mathematical patterns of nature, but try to understand what they signify in a physical sense as well as how it all fits together in a "big picture", and in this regard, I think our philosophies are quite similar. Furthermore, you write "My working assumption is that we already know, to a great extent at least, whatthe base-level structures of our universe are." with which I agree as well, though probably I understand this in a different way than you do. For instance, I have some working hypotheses on concretely what the U(1) and SU(2) symmetries represent (but, unfortunately, not yet SU(3)), however those are not yet ready for primetime.
Having expressed my agreement with your overarching effort, I also have some criticisms on the details:
1. It appears that you attempt to begin with some pre-metric and pre-nomological notion that "everything happened" and then try to whittle things down to the things that we observe to happen in our universe. But all the alternate and mutually incompatible happenings occur in different "versions" of our universe. That is why for the canonical formulation of quantum mechanics, it is R^3n dimensional configuration space for n particles that is the natural home for the wave function. While the natural home for the path integral is spacetime, I believe that the alternate paths are also properly parallel descriptions that conceptually (but not in a real physical sense) should be assigned different versions of the universe. I did not get a sense from your essay that this issue was adequately addressed.
2. It was unclear to me whether you make a distinction between actualities and things which exist only as unactualized potentialities or not. Such a distinction is currently not made in physics, but in my mind it is essential in order to understand quantum theory. If you meant for the "everything happens" picture in the beginning to be of the latter kind, then you did not respect that it must also assume that there is "something" already waiting to be actualized (into something else, namely what we end up describing), otherwise you are, in effect, stipulating that things come from nothing. If you meant for that picture to be of a former kind (i.e. "everything happens" refers to things that actually exist) then, it seems to me, you have already committed yourself to some kind of Everettianism. Is that what you intended?
3. I felt the transition between some of the phases of the universe was a little too fast. I understand that the limitations of the contest format did not allow you to describe everything in as much detail as you would have liked, but at times it really felt like more could have been said, even if it was just that a particular issue needed to be worked out in more detail. It may also be that the precision offered by mathematics might help to understand the transitions better.
4. It seems that your approach is to attempt to nail down the topology of spacetime first before getting to its geometry. There is, unfortunately, a major hurdle for that approach: Under the current paradigm, the topology of Minkowski spacetime and that of Euclidean four-space are taken to be the same! That means that under our current understanding, you cannot distinguish at a topological level between these two. Hence, it seems to me that an attempt to select for spacetime by purely topological means, such as a topological formulation of electrodynamics ("Luckily we don't need to figure this out, since it's fairly clear how our universe does it - through the laws of electromagnetism.") is doomed unless you bring in something extratopological or come up with a novel topological distinction. Personally, I believe such a distinction exists, but I am just pointing out that under the current paradigm no such distinction is recognized.
I have the impression that we share a belief that spacetime is in some concrete sense describable as emergent, and that the symmetries of the QFTs are a critical part of that description, so in that sense we strive toward a common point of understanding.
Armin - I'm very pleased that you read the essay and left me such thoughtful comments!
1-2. I can understand your confusion with this - I did not make clear in the essay what I had in mind with "anything was possible... no rules or constraints... so everything happened." I certainly agree that the distinction between actualities and possibilities is key to understanding QM, since all the theory describes are superpositions of possibilities, and all we ever observe are the actual outcomes of measurements. Your phrase "things which exist only as unactualized potentialities" sounds a bit like Heisenberg's Aristotelian "potentialities" - a somewhat different version is in Ruth Kastner's "Possibilist Transactional Interpretation" of QM. I think you explained your version in your essay on the Default Specification Principle?
In any case, I don't think of possibility in terms of things that might be actual or not. Rather, I see the wave function as describing the set of possible interactions set up by a certain context of previous interactions. It's convenient for us to describe this in terms of things and their properties - the electron is spin-up or spin-down - but ultimately the observable world is made of interactions that make a difference to other kinds of interactions. You may not agree, but this is in line, for example, with Kevin Knuth's "influence theory" or Sorkin's "causal set" theory - an ontology of event-connections rather than things. What makes something "actual" then is just the existence of a context that can select out one set of events from the background of possibilities.
In any specific measurement context, different possible interactions can be distinguished as "alternate and mutually incompatible." We can then imagine alternative universes branching off, depending on which result is actually observed. I also mentioned the "superposition of all possible histories." But these ideas only make sense if there are contexts in which alternative possibilities can be distinguished - and to begin with, I suggest, there were no such contexts. I'm not sure if that helps clarify matters, but you're certainly right that this was not adequately addressed in the essay.
3. You're certainly right about this too. I was able to give a somewhat adequate description of the first two stages, and ideally I would have understood pre-metric electromagnetism well enough to draw a much clearer picture than I did. But I had no hope of anything like a comprehensive description of the latter stages. They would need to be broken down much further - as I tried at least to suggest in the last stage, by showing how each of the prior stages was "reinterpreted" within the quantitative framework of the spacetime continuum. This really should not be taken as an attempt at a Theory of Everything - which of course would need to make contact mathematically with established theories. That's far beyond me; my goal was only to demonstrate that such a thing is conceivable - that there could be a way to explain all these theories functionally, without trying to reduce them to a single pattern.
4. I'm interested that you say these two topologies are taken to be the same, because it's certainly my impression that few physicists pay any attention to the difference. Certainly the usual informal ways of talking about spacetime (e.g. "block universe", "spacelike hypersurfaces", "foliations") suggest they're the same. But I think the difference is recognized by people who work on spacetime topology in GR, such as Zeeman and Hawking. In my first FQXi essay I included a section specifically focusing on the significance of the difference in sign between space- and time-intervals, so that they cancel each other - giving "null-intervals" in spacetime. This really needs an extended essay all by itself, though, since the R^4 topology seems so obvious, and the topology of the "light-cone web" is very hard to visualize (even though it's what we actually see, from inside). So while it's surely an uphill climb, under the current paradigm, I don't think it's impossible to take topology as prior to geometry.
Thanks very much for your interest, and I hope to follow your progress toward that point of common understanding. Let me know when your work on symmetries goes public!
Conrad
Greg - I did read your essay and am much in sympathy with your point of view... I'll leave you some comments when I get a chance. I'm glad you enjoyed mine, and your question is a very good one.
I'm not exactly sure how to explain the compatibility of these two stories, but I wouldn't offer mine if I thought it flew in the face of the evidence... and there is quite a bit of evidence for many aspects of the "conventional narrative," though maybe not for the symmetry-breaking part. But most physicists find the apparent convergence of coupling constants at higher energies to be very suggestive, at the least.
The conventional view assumes that all the laws of physics were well-established (almost) from the beginning. In my view, this history makes sense retrospectively - even though before the emergence of atomic structure, the quantitative features of the quarks and leptons and their various modes of interaction would not have been definable. My "alternative" story doesn't take place along a well-defined historical time-line, because it has to do with the emergence of time and space. But my thought is, once our current universe was able to define itself, it could also define its history back (almost) to the beginning. If and when I manage to rewrite this more carefully, I'll try to show that this makes sense... as it is, a lot of this is just "conceptual intuition." Which should certainly not compete with empirically grounded theory!
Thanks - Conrad
Dear Conrad,
Thank you for your reply, I understand your perspective a bit better now. I just want to comment on the last point: Yes, Zeeman, Hawking, Malament and a few others have come up with topologies specific to spacetime, but overall, it is my impression, to the extent that anybody thinks about this matter, people consider these as little more than toy models which, to put it bluntly, have failed to live up to the promise of leading to any new extratopological insights. I had a brief discussion on this with Robert Geroch a couple years ago, and he conveyed to me that for a while in the 70s this was a hot topic, then people proved everything they could about it, and then they moved on. Nowadays, people think of the topology of spacetime more in terms of the Alexandrov topology.
Having said all this, recall that part 2, when it is finished, will present an attempt to integrate the concept of existence into physics. This will, I believe, open a whole range of new questions one could ask, and one of these pertains to topological implications. Specifically, I have a suspicion that one may be able to use it to define a novel homeomorphism that distinguishes spacetime from Euclidean four-space (arising from the fact that in the latter there is no such thing as a partition of existence in n-dimensional space by absolute dimensionality; that seems to be a feature of spacetime) and which induces the difference in metric signature between the spaces. Unfortunately, it will be a while before I can take up this thread because I am already behind on working out so many others. The main point is that while I agree with you that there is a topological distinction, this is by no means universally accepted.
"Its three basic forces are "unified" mathematically". Weak and electromagnetism aren't unified in the Standard Model because each interaction is described by a different boson.
"Now the fact that things are observable is so obvious that it's always been taken for granted". It depends on what one means by observable. If we restrict the term of human observers, then observations did start with human race. The absence of human observers is a remark made on criticism of certain interpretations of QM that give a special role to humans. If we take a more general concept of observation that doesn't require humans, then it existed since Big Bang.
"Nothing remotely like this multi-leveled functionality occurs at the subatomic level". Indeed, more is complex.
"Physicists normally treat information as an abstract quantity - a number of bits or qubits. But any information that can actually be defined or used in any way is always information of a specific kind, related to other kinds". What is more, information requires a physical substratum to be relevant to our world.
"For example, in the path-integral formulation of quantum mechanics, when a particle goes from A to B it takes all conceivable paths - including those that violate our current laws of physics". The particle doesn't takes all the patch, because the action is only considering amplitudes. The particle only takes a single path, the real path. The formulation needs to take all the possible paths (real and virtuals), because it describes only the statistical motion of the quantum ensemble.
The problem of infinites is not resolved by renormalization. Renormalization simply moves the problem to another part.
Electrodynamics is time-reversible only as approximation. When we consider dissipation we have to extend the classic formulation.
Spacetime is an approximated construct. It arises from particle theory when approximating interactions locally: A(x(tau),y(tau)) ---> A(x;tau) ---> A(x,t). During the approximation procedure a Lorentzian metric emerges naturally.
"The electromagnetic field acquires several new functions, providing the medium for essentially all long-distance communication as well as structuring atomic electron-shells, forming molecules and driving all the various modes of chemical interaction". Field-theory only describes partially electromagnetic interactions. For a full description of molecular structure, we need to go beyond field theory. Several direct particle-particle action theories have been proposed and are in active development.
