You wouldn't recognize a question-begging infinite regress if it bit you on the tuchus, woild you? (Rhetoruc question, Mr. D-K.) — 180 Proof

I even answered it for you 180booze! Hidden variables to stop the regress and send it backwards.

Where's Occam the Barber when you need him?

Hidden variables — EugeneW

Gremlins & poltergeists! :monkey: :lol:

Space! What else? Could harbor Gremlins...

:sparkle:

Where's Occam the Barber when you need him? — 180 Proof

Haha! He couldn't find his shaving gel. Space is hard to shave....

It's the question if this is the case. — EugeneW

That's not the case with mathematics. The axioms are not produced with the intent of representing 'what is the case'. And the ones which get accepted are the ones which prove to be useful. So they are produced by imagination, and accepted by pragmaticism, and there is no question of if what they say is the case.

There are some versions where conciousness does cause wave function collapse, or there is Quantum Bayesianism, which shifts the ground to conciousness, but in general you are correct.

However, the relevance of conciousness is not the part that makes objective measurements impossible. If you attempt to set up clever experiments to measure the same thing from different places, and the measurement of the same physical entity changes by observation point in ways not related to the effects of your measurements on the entity (Bell inequalities and variants are normally used to test this sort of thing), you can show mathematically that:

1. No hidden variables can account for the correlations of entangled entities unless those hidden variables are non-local (e.g., Bohm, Pilot Wave Theories, etc., but these theories imply hyper determinism and no free choice in what is measured to begin with). Only recently have experiments shown that non-locality cannot be simply faster than light, its speed must be infinite, something that shows up in the formalism; or

2. The theory can be local if you follow Everett and don't assume wave function collapse (or decoherence in normal terms). This actually is the straight forward interpretation of Schrodinger's Equation. The wave function should persist. The introduction of collapse was always ad-hoc, essentially a philosophical addition that was a common sense take on what "must happen," to have observations "make sense." It's an addition highly influenced by Mach and the birth of logical positivism around the time, and so is also a theory where subjectivity is absolutely essential. That is, in Bohr's interpretations, it is meaningless to even talk of things not observed by an observer.

But if you assume this may be dogma, and that there is no arbitrary split between macro and micro scales, then observers, be they photoreceptors or conciousness, should just get entangled with what they observer. So all events happen. The main argument against this line isn't based on the formalism, but that "we don't split, we don't observe two outcomes."

That is exactly what the equation and formalism predicts though. Many Worlds variants are seen as the "cooky ones," but actually are removing ad hoc additions based on classical bias, retain locality, and remain realist.

Arguments against Many Worlds from common sense were countered by Everett by comparisons to the claim that "the Earth was once thought to be the center of the universe because we didn't "feel" it move," but this was dogma. And indeed, for a long time, Ptolemaic astronomy continued to predict many events better than Copernican astronomy, but sticking with the former and attempting to prove it eventually proved it to be the better theory, so lack of observation to fully support these variants today doesn't necissarily mean they are wrong. Indeed, the same sorts of issues show up in all interpretations, but with more ad hoc explanation to fit human preconceptions of what "must be the case "

However, in more recent experiments, it begins to appear that different observers will see an "objectively" different in ways that ditching locality and free choice won't explain. Ironically, Everett's universal wave function still gets around this issue, maintaining realism and locality, but at the cost of things that don't happen, happening in other worlds.

Aside from this issue, modal interpretations introduce things that "may happen," as physical entities. However, I don't know if these dynamical entities are likely to hit your bar for being causal, although obviously they can be modeled.

The whole concept of causality, as commonly conceived, also needs a twist when there is non-local, infinite speed causality that does not, to my knowledge, suppose a gauge field or any "entanglement boson."

Information centric theories deal with this causal issue neatly and we get decoherence instead of the ad hoc collapse, but at the cost of making reality essentially informational. While this has the benefit of possibly explaining conciousness and subjectivity emerging, it comes at the cost of objective frames being nonsense, information is always relational between systems.

No hidden variables can account for the correlations of entangled entities unless those hidden variables are non-local (e.g., Bohm, Pilot Wave Theories, etc., but these theories imply hyper determinism and no free choice in what is measured to begin with). Only recently have experiments shown that non-locality cannot be simply faster than light, its speed must be infinite, something that shows up in the formalism — Count Timothy von Icarus

Which means non-local hidden variables are possible. Why should infinite lightspeed be a problem? As long as no information is propagated this should be no problem. I think hidden variables is the only viable theory in which you can embed QM. No measurement problem, no many worlds, only advantages. Why is hyperdeterminism a problem? The will needs determination to be free. We are not determined by deterministic processes. We are the process.

That's not the case with mathematics. The axioms are not produced with the intent of representing 'what is the case'. And the ones which get accepted are the ones which prove to be useful. So they are produced by imagination, and accepted by pragmaticism, and there is no question of if what they say is the case. — Metaphysician Undercover

So you can build up a, say, 1d continuum with aleph1 0d points?

but these theories imply hyper determinism and no free choice in what is measured — Count Timothy von Icarus

That's the question. What if it's determined to measure different aspects of a piece of reality, like looking at a hologram from various angles (Bohm)?

I appreciate the survey. I'm familiar with most and prefer the MWI most of all.

See, I always thought the Many Worlds Interpretation sounded bonkers, but have come around on it. I didn't understand the formalism of the Schrodinger equation, (I still don't lol), but I recently read a book on quantum foundations, which led me to a bunch of journal articles and eventuality to actually opening this textbook I bought a long time ago, and feel like I sort of get it now. This is turn made me appreciate it a lot more.

There doesn't seem to be as much in the way of good reasons, aside from intuition, to be assuming wave function collapse. When we open Schrodinger's box, we should be getting entangled with the simultaneously dead and alive cat. In this view, decoherence would represent extremely high levels of correlation that make apparent quantum behavior at larger scales essentially nearly infinitely unlikely.

The problems I still see are:

1. If we're part of a universal wave function, why do we still observe quantum entanglement? This is probably a lack of understanding on my part but it seems like a regress of wave functions within wave functions.

2. This interpretation seems to create all sorts of problems for objectivity too. Other "worlds" are real, physical entities, but we can observe then or measure them, and they don't have causal relationships "for us." They can only be modeled. I know there are some proposed ways to test MWI but I don't fully understand them. It seems like much of reality would then be inaccessible however.

MWI is as bonkers as the guy who invented it. Can't wrap my head around the fact that people have faith in such a weird fantasy. And it doesn't even resolve what its made for. Maintaining unitary evolution. The branching points introduce the same weirdness as the so-called problem it tries to get rid of. The only viable interpretation is the objective collapse interpretation, equivalent to hidden variables.

When we open Schrodinger's box, we should be getting entangled with the simultaneously dead and alive cat — Count Timothy von Icarus

Why should the cat be entangled with the poison device in the first place? If the device is a vial with poison connected to a Geiger counter, the cat will simply die when the poison is released by a count and stay alive if not. Regardless if we look or make a measurement. It's the standard interpretation (fundamental probability without an underlying mechanism as in the throwing of a die) that causes this mayhem.

MWI is as bonkers as the guy who invented it. — EugeneW

It's far less "bonkers" than ideas like "god" or "life after life" or "substance dualism" and those who believe in such woo-of-the-gaps nonsense.

Well, gods or a life after this life (or before this life) is something which I can imagine at least, and if considered closer the only logical conclusion, if all gaps are closed. If a woo of the gaps is to be considered, I'd go for the MWI...
:cool:

Because that's how Schrodinger's Equation works. You don't get multiple waves interacting, you get a single wave function describing the system.

Objective collapse theories have certainly been useful in clarifying many things about QM, but there are a number of things that do not particularly recommend them.

They don't work with relativity, they don't conserve energy, and they don't do one of the jobs their creators had in mind for them, describing "what is really happening," when we get information about quantum states.

Another difficulty is determining when spontaneous collapse should be occuring. Macroscopic drumheads have been entangled, a molocule of over 2,000 atoms has been entangled, a cloud of 15 trillion atoms has been entangled. This seems like it could be a death blow to GRW (TEQ in Europe is testing similar things so more information should be coming). The question becomes, "where is the demarcation where objective collapse should be occuring?" Current objective answers don't seem to be holding up. As technology improves, it seems more and more like the size at which we can detect quantum activity will keep increasing.How is the amplification mechanism supposed to account for these macroscopic quantum states though?


Second, I'm not totally sure how it is supposed to deal with decoherence. If the wave function is a measure of a particle's mass, smeared out across infinite space, how does this mass become more local on a gradient? This seems to assume the mass is relocating faster than light, or non-locally, but perhaps I misunderstand it. This shift also means energy is increasing, which is why it violates conservation.

More problematic, experiments on consecutive quantum measurements of a system don't give us a view of collapse as representative of a Markov chain. That is, information about prior states isn't vanishing as in conventional collapse. So, for objective collapse versions following to old model, this seems to be another blow (more so for Copenhagen).

Diosi-Penrose objective collapse was recently falsified by experiment, so at least that form of a gravity dependent mechanism seems out.

Non-local hidden variable theories offer the same outcomes as standard interpretations. Interactions between particles offer the key to collapse and entanglement. The cat in the cage is entangled wìth the device of doom not with a state being alive and one being dead. The cat enters the cage alive, and the device is in a superposition. If there is any kind of interaction in the device, internal or with an external source, there is a collapse which might kill the cat or not. In hidden variable theory, the cat, or the past of the Earth, simply are not in superposition states until measured.

I think you are mixing up your concepts here. Things that are observed are not in superposition, they have distinct values. Superposition is pre- observation, including in Objective Collapse. Only in MWI do observed particles remain in superposition.

Second, Objective Collapse does predict different outcomes from QM. That is what makes it exciting, different forms should be testable in the fairly near future. GRW has already been tested, it just happened to be falsified by the results. You may be thinking of Pilot Wave theory, which does not differ in its predictions.

Objective collapse also has nothing to do with concious observers.

The problem of concious observers seems unfalsifiable and unprovable. To know the results of any experiment requires someone to see the read outs of the test. However, this problem isn't unique to QM, it's true of all empircism.

On a related note, there is an argument to be made here that physicalism is tying itself into knots throwing ad hoc explanations of the apparent absence of an objective reality independent of observation (i.e. one observers observation's change what another will observe) at the wall hoping something sticks. However, if idealist ontologies have a leg up in this arena, they still seem to have a problem with explaining why the extrinsic mental representations of concious organisms take the forms they do, so they have their own major problems even if they can deal with QM and the Hard Problem more clearly.

Since recent experiments have left even less doubt of this "quantum weirdness," it seems now that the world is non-local and not objective. This isn't a problem for scientific inquiry, but it does show the relevance of Humple's Dilemma.

Things that are observed are not in superposition, they have distinct values. Superposition is pre- observation — Count Timothy von Icarus

Before the observation they are in superposition. Then the observation project the state on one of the eigenstates. The measurement of position collapse the wavefunction to a limited domain in space. In the hidden variable picture this collapse is a true, non-mathematical non-local happening. There are experiments planned to discern between the classical standard approach and this hidden variable theory. They give tiny empirical differences but modern equipment can't measure these differences yet and it's very expensive.

The cat in the cage is never in a superposition with the poison device. This happens only in the standard interpretation.

I appreciate the survey. — 180 Proof

:smile:

That's not the case with mathematics. The axioms are not produced with the intent of representing 'what is the case' — Metaphysician Undercover

:up: What ought to be the case! Math is an invention! Felicific calculus! Kind courtesy of Jeremy Bentham (presently mummified in University College London). All that's needed now is the Egyptian Book of the Dead. Note: Read backwards/forwards, I fail to recall. Ask an expert (on Quora).