While I am on board with analytic philosophy in general, I am skeptical of totalizing positivist worldmaking.

Even speculative physics of other possible physical worlds is intended to be fully mathematical as soon as the needed maths are invented. — magritte

If you are thinking of such things as multiverses in cosmology or the many-worlds interpretation in quantum mechanics, then it's the other way around: mathematics is there from the start, evocative metaphors of "worlds" are interpretations.

Is it really possible to say anything whatsoever in any language that is not predicated on at least implied metaphysics? — magritte

Identifying metaphysics with just any conceptualization is selling it a little cheap, don't you think?

There are theoretical physicists (hand waving) and mathematical physicists (mathematicians working in physics). — jgill

To be fair, I don't think that these disciplines are very distinct. I don't know any mathematical physicists well, but some theoretical physicists that I've known have gone back and forth throughout their career between working on specific problems in physics and working on less specific mathematical problems, depending on their engagement.

You are engaging in a strange exercise. You have no idea what philosophy of physics is, and you are trying to figure it out from what you think the words mean. Why? Is there some reason why you can't just use the resources at your disposal - you know, Internet, books, journals - to get some idea of what actual practitioners do?

Philosophy is not so much about the how. If it were, it would be a science. What does that leave? It leaves the what and the why. A philosopher of physics is going to be interested in what physicists are thinking and why they're thinking it, and mainly in terms of the history of the thinking that has led to the moment. Probably they will document the axioms in use by the thinkers under consideration. Then perhaps to document their presuppositions, this latter much the more difficult because presuppositions, being presupposed, are usually not apparent. — tim wood

Yes, that is part of what philosophy of physics is (or more broadly, philosophy, history and sociology of science). And it isn't much different in its scope and methods than a lot of the philosophy that you are probably more familiar with, that has more to do with history, biography and philology than with logic and metaphysics as such. This is probably not what @magritte thinks of as philosophy, but it has long been part of the academic discipline.

But that's not all there is to the philosophy of physics.

philosophy in its highest sense, which I take to mean knowledge of man, his peculiar character and the nature of his life, I would welcome it. — Todd Martin

That's more than a little arrogant, don't you think? Who are you to legislate what "philosophy in its highest sense" should be? Here's a thought: philosophy is what people do when they do "philosophy."

If physicists understood the underlying metaphysics of modern philosophy — magritte

The underlying metaphysics of modern philosophy? Really? There is such a thing?

The first is that philosophy is a logical enterprise, an application of some pure logic just as mathematics is. Like mathematics or other axiomatic systems, philosophy attempts to stay as simple as possible but not too simple and touches any other ground only as necessary to meet the demands of some arbitrary (strings, tiles, whatever) application domain. There are many possible mathematics and philosophies with the distinction being in their axiomatic choices. Thus, neither mathematics nor philosophy should be thought of or treated as monolithic.

If any of this makes any sense, then that is the rational for my answer to question 5. above. Theoretical physics is very different from observational physics. They are totally different games by philosophical standards. Knowing the formula for the flight of the bumblebee says nothing about why I was stung when I stuck my hand in there or how I should whack one. — magritte

To be honest, I don't recognize either philosophy or physics in your description.

I ask because I am pretty sure that physics and a philosophy of physics cannot be the same thing. I have a pretty good idea what philosophy is and what physics is, but no idea what is here meant by a philosophy of. And unless we find some good starting point at least, philosophy of physics seems to border on the oxymoronic. — tim wood

So ok, you are clueless. I don't blame you for that: one cannot and doesn't need to know about everything. But if you are interested enough to join the conversation, why can't you make even a tiny effort to learn?

Here, let me google that for you.

Want to see some examples? Here.

Just for the heck of it, what do you suppose a philosophy of physics is? What does it look like? How does the thinking of a physicist differ from the thinking of a philosopher of physics? Can there even be such a thing? — tim wood

Did Google ban your or something?

We see more and more that science, mainly physics, has strayed into the realm of philosophy and though experiments — CallMeDirac

There was never a firm partition between science and philosophy. As academic disciplines they only became distinct relatively recently. Natural science used to be called Natural Philosophy (hence Ph.D.), and this nomenclature was a true reflection of the state of scholarship, which knew no boundaries between what we today call "science" and "philosophy."

Nowadays scholarship, like most professional pursuits, is much more specialized. But the reason most scientists don't have to give philosophy much thought, if they don't feel so inclined, is that the theoretical groundwork has already been laid down before them, frameworks have been built, and they can now do productive work within those frameworks, only occasionally doing some maintenance and expansion that does not call for much philosophizing.

But even today's academic boundaries are porous, and at the forefront of theoretical science it is often hard to make a distinction between science and philosophy. And that is how it should be.

I don't even see any physicists with a glimmer of understanding of the philosophy of their own field. — magritte

What do you mean? No doubt, the share of all physicists who are knowledgeable about the philosophy of physics (as an academic field) is quite small. But that is to be expected, and the same can be said about every other field outside of philosophy itself. But surely you must know that there are some physicists who are, at the very least, interested in philosophy, and some are actually knowledgeable enough to participate in the academic process. If you had even a casual interest in the philosophy of science, you would have encountered such examples by now. Certainly on the other side of the fence, philosophers of physics nowadays usually have at least some physics background, all the way to postgraduate degrees.

Effectively, yes. TQM is a conspiracy of sorts. — Kenosha Kid

Well, as I said, so long as, over the lifetime of the experiment, the holes on average occupy a uniform distribution, we will obtain the characteristic banded pattern. — Kenosha Kid

So if the holes (at the screen and elsewhere downstream) don't participate in the conspiracy (indeed, such an extended conspiracy would seem problematic), and there aren't many holes available at any one time, then the emitter has to time its transactions so as to build up the right pattern over time. Indeed, you need to posit that the process of picking the site of the transaction unfolds not instantaneously, as Cramer posits, but in all 3+1 dimensions. That's the only plausible solution that I can think of.

Is it plausible? I suppose the bare-bones theory (not including a specific mechanism for the Born rule) does not rule it out, and neither does its empirical basis, which consists of just such accumulation over time of apparently probabilistic events.

Mods, this is dangerously stupid. I don't think that our board should be adding to the Covid disinformation on the 'net. (And I don't care if some shrill idiot calls us fascists, and neither should you.)

The problem that Block considers is how to define the mind in a non-circular way, which would mean avoiding mentalistic terms and concepts as part of the definition. (This is a notoriously difficult, perhaps intractable challenge.) What about behaviorism, i.e.diagnosing the presence of a mind in some entity by judging its behavior? This is what the Turing Test is supposed to accomplish. But can we describe the test without recourse to any mentalistic concepts, such as thinking? (Remember, thinking is what we want to define, so we cannot appeal to it as part of the definition, on pain of circularity.) So that's the problem that Block is grappling with here:

For example, one might specify that the judge be moderately knowledgeable about computers and good at thinking, or better, good at thinking about thinking. But including a specification of the mental qualities of the judge in the description of the test will ruin the test as a way of defining the concept of intelligence in non-mentalistic terms. — Ned Block

I'm not sure why you think so. The electron doesn't have to be transmitted at all. In fact, wherever the hole is located, we expect no electron to be transmitted most of the time. Any time the hole is at a site where the probability of finding the electron (as given by its wavefunction) is zero, then no transmission event will occur at all, for instance (i.e. you cannot slow the rate down to 0.001 Hz and get an event every 1 ms if the only available hole is sometimes inaccessible). — Kenosha Kid

In our example of a diffraction through slits the wavefunction is non-zero almost everywhere on the back screen, so that is not an issue. If an electron is ready to fire, and there is (in the edge case) just one hole that it can fill, then it will go there almost always, because where else would it go? Which means that the distribution over time will just be the distribution of holes popping up on the screen. We could put one slit, or two, or ten - doesn't matter, the distribution will be the same.

(Unless holes and/or emission events conspire to construct the distribution that we expect to see.)

Similarly if the probability of finding the electron at a given site is 0.2, you would expect an electron to transmit there when there is a hole there at most 20% of the time. — Kenosha Kid

Not if that's the only place where it can go, or one of the few places where it can go. Perhaps the emitter is picky and won't always transact with a hole just because it's available? So in your example if the only available hole is at a 20% probability spot, then 80% of the time the electron will wait out until another hole opens up (and then make another probabilistic decision). That would work, but where is the mechanism for this process?

In reality, the screen is more complex, and electrons will usually be able to squeeze in somewhere. But there should, as per Pauli, always be places it cannot squeeze, and that is neglected in ideal treatments. — Kenosha Kid

Yes, but in order to explain experiments where we see nice diffraction patterns, we must conclude that the number of holes available at any given time is not too few, or else we would be seeing something different (or we need to modify the theory).

You mean this?

Three of the fundamental equations of quantum physics are:
E=mc2,
w=P/mv,
and E=Pf,
where E=energy, m=mass, c=the velocity of light, w=wavelength, f=frequency, v=velocity, and P=Planck’s constant.

If the first two equations are solved for mass, followed by substituting and canceling such that the absolute minimum of variables remain, the simplest synthetic formulation is v=fw. This implies that all matter is in motion, and the structure of this fluxing matter takes the intrinsic form of a wave. It appears that since mass can be vacated from the hybrid expression in favor of a more essential form, namely a wave, the structurality we associate with mass, namely three dimensional particularity, is an epiphenomenon. Then we must inquire as to the sense in which this is true. — Enrique

You seem to be groping around the idea that massive objects exhibit irreducibly quantum behavior, which is expressed in the equation for the De Broglie wavelength. Since massive objects exhibit wave-like behavior, each of them has a characteristic wavelength associated with it. For example, when a basketball falls through a hoop, it undergoes diffraction, just like when light shines through a pinhole - an immeasurably tiny bit of diffraction, which nonetheless we can theoretically estimate via its de Broglie wavelength. This isn't about matter being in motion - that is a triviality. Since motion is relative, everything is or is not in motion, depending on the reference frame. Rather, this is about one specific manifestation of quantum behavior of matter, which you overthink at your peril absent the understanding of its full context.

As for the rest... I couldn't get much further than the next paragraph, which quickly devolves into a word salad. This is not a theory in any meaningful sense.

Not *only*: the wavefunction of the emitted electron still natters; my point was rather that it can't be the *only* thing that matters.

In TQM itself, the probability of a transaction causing absorption at (r, t) is the amplitude of the retarded wavefunction arriving at (r, t) times the amplitude of the advanced wave travelling backward from (r, t). So it depends on the probability amplitude of *both* waves. — Kenosha Kid

Well, the confirmation wave is just an echo of the offer wave: its amplitude is proportional to the amplitude of the offer wave at the would-be absorber. So the information carried back by confirmation waves is redundant, as far as the system as a whole is concerned - it's just a mechanism for establishing a transaction in accordance with the Born rule.

In your example of a screen that has only one absorption site at any one time, only this site can backwards-emit a hole wave. In the language of TQM, only this wave can handshake with the retarded wave, since the amplitude coming from all other sites is everywhere zero.

However, that single hole will move around the screen and, on average, should be smeared out such that the probability distribution we see forming is given only by the retarded wave. — Kenosha Kid

If the hole moves around independently of the impacting wave, while emissions are a Markov process, i.e. a transaction is established whenever a hole is available (as you explain below), with no "knowledge" of what comes before or after, then the resulting distribution of impacts will be independent of the impacting wave. It will only depend on the entropic movement of the hole - most likely just a uniform distribution.

Some dependence on the wavefunction will manifest when multiple holes are available at the same time, but unless there are a whole lot of them (rather than "not many"), the distribution will be blurred.

As someone with nominalist inclinations, I still find this charming, right down to the note of pragmatism: — Srap Tasmaner

Yes, this sounds like where I am at as far as ontology is concerned, though I could never put it as gracefully as Grice does here. I'll have to dig up this paper.

That's so ironic.... That's precisely how I feel about nominalists. — Mapping the Medium

Ooh, burn!

Just curious, what does "nominalist" even mean to you? You don't seem to use it in its usual meaning, but more like "motherfucker."

Is it just me or are Peirce fans rather a cultish bunch? I have yet to meet anyone with a moderate and critical interest in Peirce. It seems like anyone who talks about Peirce more than in passing is almost religiously devoted to him.

That this doesn't hold true is precisely my point. While an individual transmission may depend on the precise microstate of the screen, the screen explores these microstates continuously. A statistical number of transmission events will take place over a period of time, during which one will have a statistical spread across the precise microstates explored during that time, a spread which looks like the probability of finding a given electron at a given position depends principally on the wavefunction. — Kenosha Kid

Let's take an extreme example:

1. The emitter (of electrons, photons, ...) is under experimental control, so that for instance we can ensure that a particle is emitted every millisecond.

2. The availability of receptive absorbers is so constrained by present and future boundary conditions that at any point of time at most one site is available.

Right away, if at the time when we want to make emission happen there are no available absorbers, then we have a problem: some assumption has to give. But even if an absorber is available, the cumulative distribution of impacts will be defined only by the distribution of the available absorbers on the screen over time. And at the same time, in order for the Born rule to hold, that distribution has to match the impacting wavefunction - whatever it happens to be. If we can contrive to emit a particle that hits the screen at times (t₁, t₂, ...), the screen had better supply us absorbers at such locations r_i that (r₁, r₂, ...) form the distribution that we expect to see.

So how can this happen (or can it happen)?

A. (1) and (2) hold, which means that the screen and the universe in its future lightcone have to contrive to match the impacting wavefunction. While no individual absorber is constrained to be in a fixed position at a fixed time, there is a constraint over time on all such absorbers, which is a function of the impacting wavefunction, whatever it happens to be.

B. (2) doesn't quite hold: instead of just one absorber at a time, we have "not many" absorbers. This relaxes the constraint on the screen, but does not completely eliminate it. Unless there is such a constraint, the actual distribution of impacts will inevitably be distorted.

C. (1) does not quite hold: we cannot make emissions happen at will (can we?) This distributes the constraint of producing the right cumulative distribution between the emitter and the screen or shifts it entirely to the emitter, so that now it is the emitter's responsibility to be aware of the state of the screen (and the rest of the universe in the future lightcone) and fire particles under the constraint of producing the right distribution.

The cancellation depends on both waves being advanced waves, so it's not purely terminological. (Advanced waves cannot cancel retarded waves in Cramer's formulation.) — Kenosha Kid

Why not? If I understood it correctly, the reflected wave is out of phase with the advanced wave, so it must cancel it. That the time direction is reversed means that the cancellation occurs everywhere at once, so that to an observer it is as if neither wave ever existed. Only the advanced wave back towards the BB is cancelled; the retarded wave from the emitter is out of phase with the advanced wave, which means that it is in phase with the reflected wave.

Cramer’s proposal cannot work for EM waves, simply because the early universe was not transparent to EM radiation — Darko B

He addresses this concern in the paper, but this physics is way above my pay grade.

Getting back to this topic (sorry, this is tough slog for the old cat-brain):

Clearly then the true probability of transmission from cathode to any given site A-E is not identical to the absolute square of the wavefunction (denoted by the blue rays coming from the cathode), but also on whether each site has an electron in it or not. — Kenosha Kid

So the bolded part is what I am having difficulty with. We do, of course, observe that the cumulative distribution of impacts on the back screen is in line with the square of the wavefunction from the emitter. If emission occurs whenever, while the distribution of available absorbers on the screen is constrained by external factors, then we won't recover the expected distribution. (In the edge case where at most one site is available at any time, the distribution won't even have any dependence on the impacting wave!)

The only way to recover the expected distribution that depends only on the impacting wavefunction is if the timing of successive emissions is coordinated so as to compensate for the constraint from boundary conditions and produce an undistorted distribution over time. But I don't see how such compensatory mechanism is being realized.

Cramer claims to have mapped the above arrow of time to the cosmological arrow in the paper here:

Another paper by Cramer (Foundations of Physics, 1973) specifically treating the arrow of time: http://faculty.washington.edu/jcramer/TI/The_Arrow_of_EM_Time.pdf — Kenosha Kid


However the more I read it the less compelling I find it. He actually talks about advanced waves going forward in time, which is contrary to what an advanced wave is. — Kenosha Kid

Yes, he says the entire four-vector is reflected at the Big Bang boundary, i.e. time direction of the advanced wave is flipped, but still insists that the reflected wave is an advanced wave. But other than terminology, do you see any issues with his proposal?

But what did I say that was false? lay it out concisely: what is the problem? — jamalrob

You said stuff that a belligerent moron with no reading comprehension might interpret as you endorsing Putin. Shame on you, sir!

Well, have to say that some progress has happened. — ssu

Yes, you are right, if you look at the numbers, the good old times were pretty terrible compared to now. State and even some non-state actors have become more shy about committing atrocities, although often that just means that they lie about it (not caring very much about whether anyone believes their lies).

But the most immediately painful scars are from the 1990s. Nobody wants to go back to that, and that's partly why Putin has been popular. Pro- and anti-Putin often agree that he did what had to be done in his first years in power. Anti-Putin people differ now in thinking, come on, that's enough, time to go. — jamalrob

Some of that fear of the "chaotic 90s," as well as the nostalgia for the good old days of the Soviet rule has been helped along by state propaganda. So is the idea of Putin riding in to save the day in 1999. A lot of the economic recovery during 2000s can be quite simply accounted by the booming oil prices and the accompanying rise in Russia's oil and gas production.

I suppose piano teachers, especially, are always aware of the issue when engaging a young child. Because it may be the critical stage of development. But also because a keyboard is discussed as a diagram of the pitch dimension? — bongo fury

It was violin in my case.

Why intervals? Just to help find the notes? Or is it the other way round? — bongo fury

Intervals have a distinctive sound to them that has to do with the size of the interval rather than the pitch (that is with modern equal temperament). Once you learn what each interval is called (minor third, perfect fifth, etc.), you can learn to identify them by hearing, regardless of the pitch. Same with standard three-note chords. Such basic music theory and ear training are part of a classical musician's training.

I wouldn't overstate the importance of pitch recognition. I don't know if it's much more than a minor convenience for a musician or a party trick. There are any number of very fine musicians who didn't have a perfect pitch as an innate ability. Also, identifying the pitch of a note is not the only and not the most important ear skill. For example, while I can (could) easily identify individual notes or melodic lines, I am not that good at harmony - most professional musicians are probably much better at it than me. Another sort of discrimination is the purity of the tone: I may be able to identify a tone that is "close enough" to a standard pitch, but a more sensitive ear can pick up finer differences. An experienced conductor can instantly spot a slightly off-key note somewhere in a hundred-strong orchestra or choir.

The idea that nations can lose their will to fight and can be demoralized by bombing their cities was the theory of Douhet. The opposite appears to be the reality with conventional bombing. Yet politicians are sensitive to these kind of issues and many times the response if more about politics than military necessity. — ssu

Brutalizing civilian population on enemy-controlled territory still seems to be the standard tactic in modern conflicts, from soldiers and rebels slaughtering villagers in sub-Saharan Africa, to Russian special forces burning villages in Chechnya, to government forces bombing tenement buildings, markets and hospitals in Syria and Yemen. The only difference now is that perpetrators routinely deny their war crimes. The times during WWII and before were, in a way, more honest, but hardly more brutal than they are now.

In both cases, there's no purely rational decision. — Michael

Well, how would you define a rational decision? Any reasoned decision is anchored in values, and values as such are not rational (I don't think). I would say that as long as a decision is explicitly aimed at achieving that which you value, then it is a rational decision. If you like to gamble for the highest potential reward, then it is rational for you to play two different lotteries. If you are risk-averse, then it is rational to play one.

(As a useful oversight, the expected return is equal to the bet, so as an additional question, is there a reason to play at all?) — Michael

In commercial lotteries the expected return is much less than the bet, so if your utility function is just the expected return, then most lotteries are losers. And yet people buy lottery tickets. Which means that utility for those people is more than just the expected return.

So the answer to your question:

So, given that the expected return is the same, is there a reason to prefer one way over the other? — Michael

Depends.

I had* an absolute pitch as a kid, before any musical training. I don't remember how my first music teacher diagnosed it (since of course I didn't know notes and couldn't yet play any instrument at five), but there must be some standard tests. Pretty soon, once I learned to associate notes to sounds, the notes would just pop into my head when I heard them, sort of like how you recognize letters when you see them on a page.

My sister, who also started learning to play early and, unlike me, went on to train as a professional musician, did not have an absolute pitch. She practiced much more than I did, and she acquired some degree of proficiency in associating notes to sounds, but not to the degree that I had always had. When she was practicing for a college entrance exam, she even had me drill her on identifying notes, intervals and chords. She could recognize notes pretty well, but only after hearing a reference note or chord. She never acquired an absolute pitch.

* I used the past tense here, because as I was approaching middle age my hearing went "out of tune." (This is not uncommon.) This actually makes a difference to how I hear music. It's hard to describe the feeling; it is somewhat disorienting. At some point I realized that my inner pitch became very close to the so-called Baroque pitch, which is almost half a tone lower than the modern pitch. I was listening to a period instrument recording - and suddenly everything fell into place, the notes were ringing out in my head like they used to. Even knowing this, it's not easy for me to gauge the modern pitch. Somehow the shift makes me uncertain about my bearings.

A musical/literary anecdote: The Russian poet (and future Nobel laureate) Boris Pasternak was a gifted musician in his youth. He wanted to be a composer, but he agonized over his lack of a perfect pitch, which he thought was a major handicap. One day he got to meet his idol Scriabin and played some of his compositions for him. Afterwards, while they talked, the famous composer went to the piano and played back some of Pasternak's music from memory... but to the latter's astonishment he played it in the wrong key! It was then, Pasternak later recalled, that he realized that Scriabin didn't possess the vaunted perfect pitch either.

Exceptionally, that is, such a pattern as Three Blind Mice might be first appreciated as properly obtaining only in a particular key (probably starting at a particular place on a particular instrument), and any transpositions of it counted only and specifically (by both parent and infant) as such: as transpositions of the original pattern. — bongo fury

There are, I think, different types of musical memory. I may accurately recall some music shortly after hearing it, or often a day later, together with its original pitch. But in time I may retain the memory of the melody, while forgetting the original pitch. If then I recall or look up the key or the first note, then I can reconstruct what the original music must have sounded like in my head. This is not unlike hearing someone talk: you may retain the words longer than the way they sounded like when you heard them.

God is a transgendered Cat? — Book273

Huh?

The answer is obvious I think.

Heh. The normally reserved New York Times has dropped all pretense of impartiality:

Trump lies in the White House briefing room, and the networks pull the plug.

President Trump broke a two-day silence with reporters to deliver a brief statement filled with lies about the election process as workers in a handful of states continue to tabulate vote tallies in the presidential race. — NYT

I browse NYT regularly (usually just morning briefing Europe), and I've watched with mixed feelings their evolution from the first time when they dropped the L-bomb (there was an article from an editor at that time, explaining why they thought it was appropriate to say that Trump lied, as opposed to using a more neutral word) to this.

My early prediction (from before the pandemic) was that Trump would win reelection with a bigger margin (winning the popular vote as well). The sad thing is that in all likelihood, the main reason he isn't doing so well now is that the pandemic happened at the worst possible time for him. And what is hurting him is not his administration's incompetent and erratic handling of the response, but the fact that when times are hard - and they would have been hard even with the best possible response, for a number of reasons - people tend to allocate some blame to those at the top, regardless of how much or how little they are actually responsible. Any leader would have lost popularity after nine months of misery and at the height of the second (or is it third?) wave of the pandemic.

Yeah, we don't even know all that much about how animal eyes work - color resolution, etc. We have some idea, but there is considerable uncertainty there. As for vision at the level of cognition, my guess is that we know much less than that. And what we can learn would be expressed in the language of neuroscience or psychology, which isn't the same as conveying "what it feels like."

See The World Through The Eyes Of A Cat

Yes, we are well aware of that. Even ordinary photo-video media (film, digital sensors) don't have the same light sensitivities as the human eye, and that has long been known and accounted for in various ways. But while in a consumer photo camera, for example, you want maximum fidelity to human perception*, when it comes to scientific imaging we have been sensing far outside the human range, and for a long time. Radio telescopes, for example, have been around since 1930s (says Wiki). On Earth we also use a wide spectrum of EM radiation, magnetic fields, ultrasound, electron beams, gravity sensors and other creative sensing techniques.

* Fun fact: digital cameras include an infrared filter, without which they would be picking up IR light. If you have an old digital camera that you aren't afraid to break, you can try and remove it yourself - and presto, you can now take pictures in the infrared spectrum!

I am not sure. The motivation for the Wheeler-Feynman absorber theory is to have a time-symmetric formulation of classical electrodynamics, right? Both Type I and Type II absorptions are symmetric, but I don't see why you have to have both, and not just Type I. Type I is just an interpretation of classical electrodynamics, since it is formally equivalent to it. Type II constitutes a net new addition to the theory, for which we have no evidence.

Of course, if it could be tested and confirmed, that would be quite remarkable. Cramer says (referring to earlier analyses) that if both types occur, one of them is expected to dominate - presumably, Type I in our case. But that still leaves a possibility of some Type II absorptions. Do you think it's likely that they would have gone unobserved/unnoticed all this time? How difficult would this be to test?

I was just rereading part of the paper on type II emission and absorption events, which are interesting. If we take the emitter to be atom 1, the absorber to be atom 2, and the emission to be a photon, from the lab frame it appears as a photon (its own antiparticle) from the origin is absorbed by atom 1 (the emitter) and then, seemingly unrelatedly, atom 2 emits a photon of the same energy, which continues forever.

If the distance between the two atoms is L, the time between perceived absorption and emission (actually emission and absorption) will be L/c. So if type II is possible, it ought to be detectable experimentally in principle, though in practice it would be hard if the phenomenon is limited to CMB radiation (assuming that's all that could constitute a photon from the origin).

What's more interesting is the idea that causal relationships between events can be apparently unmediated in principle. — Kenosha Kid

I wonder why he thinks that Type II emission is equally possible as Type I. Type I is an interpretation of a well-studied phenomenon (emission/absorption of EM radiation), while it takes work to explain away Type II. What's the rationale in proposing it? Just a general preference for symmetry?

Well, Sam put a good deal of work into his posts, and he actually made philosophical points, not just jee-whiz, isn't it special. He was a crackpot and his arguments were crap, but that's for others to decide.

In TI the electron is still essentially its wavefunction, right until its inglorious end. So it will go through both slits, interact with itself, etc. The twist is that there are two interacting wavefunctions - retarded and advanced. You can go with Feynman path integral formulation for the wavefunctions (as I think would be @Kenosha Kid's choice), but that is detachable from TI itself.

It being a wave (waves) takes care of some well-known interpretational challenges that trade on the wave-particle ambiguity, like delayed choice and quantum eraser. That said, some challenges have also been proposed that are specific to TI, such as the quantum liar experiment.