According to:

http://www.hedweb.com/everett/everett.htm#believes

...most "leading cosmologists and other quantum field theorists" thought that the "Many-Worlds Interpretation was correct 10 years ago.

Supporters tend to cite not Solomonoff induction, but simply Occam's razor.

Solomonoff induction is simply an attempt to formalise Occam's razor around an impractical theoretical model of serial computation.

Collapse theories can do something many worlds can't do: they can make the predictions! As can Bohmian theories.

Many worlds, like at least one other prominent interpretation (temporal zigzag), is all promise and no performance. Maybe Robin Hanson's idea will make it work? Well, maybe Mark Hadley's idea will make the zigzag work. Hadley's picture is relativistic, too.

Many worlds deserves its place in the gallery of possible explanations of quantum theory, but that is all.

Re: "Collapse theories can do something many worlds can't do: they can make the predictions".

Uh, the MWI is a "shut-up-and-calculate" interpretation. It mostly makes the same predictions as the other QP interpretations - except when it comes to interference patterns involving interfering observers and the like.

Whichever helps me win in the situation I am currently in. Since I don't currently need to create more advanced physics formulas, and they have the same dollar value otherwise it doesn't make much difference.

If I believe in collapse rather than decoherence is Inspector Darwin going to come and declare me bankrupt?

In fact worrying about the difference is a negative point for me anyway, I should be doing other things and devoting time, memory and processing power to this, reduces the amount I have to apply to my problems.

Tim, I thought there was only one "shut up and calculate" interpretation, and that's the one where you shut up and calculate - rather than talking about many worlds. Perhaps you mean it's a "talk rather than calculate" interpretation?

Suppose I announce the Turtles-All-The-Way-Down "interpretation" of quantum mechanics, is it fair to say that the TATWDI "makes the same predictions" if I can't actually show how to get a number or two out of this postulated tower of turtles, but just say it's a way of thinking about QM? If MWI makes predictions, show me how it does it.

But when I say "macroscopic decoherence is simpler than collapse" it is actually strict simplicity; you could write the two hypotheses out as computer programs and count the lines of code.

Eliezer,

I think you are too harsh with the Science-goggles.

I was taught that, when first proposed, the Copernican theory did not explain the then available data any better than the Ptolemaic system.

It's main attraction (to Science-goggles-wearing types, though not to Bible-goggles-wearing ones) was simplicity: it just had to be true!

I don't know if Copernicus ever invoked Ockham's name in defense of its theory, but the latter triumphed much before Rev. Bayes's (or Solomonoff's) birth.

So maybe "simplicity" - like many other concepts - has always been one element of the Science-goggles, even before a formal mathematical definition of it was available.

Um... there really aren't any extremely strong arguments for majoritarianism. That position confuses conclusions with evidence.

Just as there really aren't any good reasons to abandon the scientific methodology just because you've declared 'Bayesianism' to diverge from it. Given that the scientific methodology has been extremely successful and is extraordinarily widely adopted among people who count, if we accept your contention that Bayesian thinking diverges from its requirements, shouldn't that cause us to be suspicious of Bayesianism?

Eli: Nice post. I think your dichotomy between "rejecting scientific method" or "embracing insanity" is a bit excessive. I can see how some people feel that having all these multiple worlds around doesn't seem like the "simplest" explanation. They accept Bayesian reasoning and Occam's razor, but the notion of simplicity that they use is intuitive. Thus, I would view the essence of this post to be: if one views complexity in terms of minimum effective description length then WMI is a better explanation than Copenhagen.

I would also note that asking physicists to be strict Solomonoff/Bayesian/Occamists is asking for rather a lot considering that something like half the statisticians in the world are not Bayesian, and of those who are relatively few know of Solomonoff induction.

Finally, while this went part of the way to answering my question, the connection to AGI safety isn't yet obvious to me.

Tim: "impractical theoretical model of serial computation". Just because a theory isn't practical doesn't make it wrong. For example, should we define randomness in a way that is easy to test for? No, if we did it would break the very concept of what randomness means. Also, what does "serial" have to do with it? There is no concept of time in Kolmogorov complexity and a serial machine can emulate a parallel one, thus this distinction isn't relevant.

I love this. Science is a bias :-)

Eliezer_Yudkowsky: You discuss whether training in the art of Bayes would produce scientists who don't make these errors. What do you make of (as per Robin_Hanson's account) how in the movie Expelled, Richard_Dawkins places a >1% probability on earth life having been designed? Is this an instance of a major not "getting" Bayesian inference, since he doesn't also advocate diverting research funds to that idea?

(Incidentally, when I corrected, here, Richard_Dawkins's definition of a "good theory" on edge.org, his entry there was shortly thereafter changed. If you passed on my correction to him, I would be interested in knowing why you didn't tell him it was me.)

This may be nitpicking and I agree with your overarching point, but I think you're drawing a false dichotomy between Science and Bayes. Science is the process of constructing theories to explain data. The theory must optimize a tradeoff between two terms:

1) ability to explain data 2) compactness of the theory

If one is willing to ignore or gloss over the second requirement, the process becomes nonsense. One can easily construct a theory of astrology which explains the motion of the planets, the weather, the fates of lovers, and violence in the Middle East. It just won't be a compact theory. So Science and Bayes are one and the same.

Eli - As you said in an earlier post, it is not the testability part of MWI that poses a problem for most people with a scientific viewpoint, it is the fact that MWI came after Collapse. So the core part of the scientific method - testability/falsifiability - gives no more weight to Collapse than to MWI.

As to the "Bayesian vs. Science" question (which is really a "Metaphysics vs. Science" question), I'll go with Science every time. The scientific method has trounced logical argument time and time again.

Even if there turns out to be case... (read more)

I also think you are taking the MWI vs. Copenhagen too literally. The reason why they are called interpretations is that they don't literally say anything about the actual underlying wave function. Perhaps, as Goofus in your earlier posts, some physicists have gotten confused and started to think of the interpretations as reality. But the idea that the wave function "collapses" only makes sense as a metaphor to help us understand its behavior. That is all that a theory that makes no predictions can be -- a metaphor.

MWI and Copenhagen are differen... (read more)

If there is a "very convincing philosophical argument" that we should go with the majority, and yet we see the majority holding countless silly beliefs that even a little bit of primary evidence and some cursory examination show as being invalid, what does that tell us?

It tells us that the very convincing argument has at least one fatal error. It tells us that our ability to be convinced is falliable. And it tells us that our argumental-validity-checking has some bugs.

This dilemma feels forced. I see where you're coming from, and I do feel that a waveform disappearing spontaneously is a massive, unwarranted detail, but I don't see how this sets up a contradiction.

The further a scientific prediction feels from our intuitive human experience, the harder it is to internalise. Physicists wanted an explanation for why we only see one world. They postulated that the waveform collapses into the world we see. And fair enough, it's not difficult, on the face of it, to feel that that must be true, even if it isn't. But how is tha... (read more)

Surely "science" as a method is indifferent to interpretations with no observable differences.

Your point seems to be that "science" as a social phenomenon resists new untestable interpretations. Scientists will wander all over the place in unmappable territory (despite your assertion that "science" rejects MWI, it doesn't look like that to me).

If Bayesianism trumps science only in circumstances where there are no possible testable consequences, that's a pretty weak reason to care, and a very long tortured argument to achieve so little.

I wanted to present you with a nice, sharp dilemma between rejecting the scientific method, or embracing insanity. Why?

Rational agents should WIN. Not lose scientifically, or socially acceptably, WIN. :-)

I hope you talk about normative implications eventually, address bambi's point, so we know just why this mistake matters. (Well, actually, implications of multiverse theories generally, so MWI doesn't practically matter if we live in a multiverse for some other reason.)

The scientific method has trounced logical argument time and time again.

Humans need... (read more)

I'm trying to comprehend how this is a dilemma... Science supposedly teaches that for any two theories that explain the same data, the simplest one is correct. Bayes can't talk about explaining data without invoking the science that collected the data... Can he?

It would seem that the theory of science includes Bayesian theory.

On the other hand, the practice of science requires either exhibiting evidence for theories or testing falsifiable theories. Many Worlds can trivially be falsified by actually finding a collapse, while its main distinguishing feature ... (read more)

I don't believe you.

I don't believe most scientists would make such huge mistakes. I don't believe you have shown all the evidence. This is the only explaination of QM I've been able to understand - I would have a hard time checking. Either you are lying for some higher purpose or you're honestly mistaken, since you're not a physicist.

Now, if you have really presented all the relevant evidence, and you have not explained QM in a way which makes some interpretation sound more reasonable than it is (what is an amplitude exactly?), then the idea of a single world is preposterous, and I really need to work out the implications.

Re: "Tim, I thought there was only one "shut up and calculate" interpretation, and that's the one where you shut up and calculate - rather than talking about many worlds. Perhaps you mean it's a "talk rather than calculate" interpretation?".

No, I mean those interpretations are functionally equivalent - in that they make the same predictions. That is not true of CI, or other collapse theories - e.g. see: http://www.hedweb.com/everett/everett.htm#detect

"Um... there really aren't any extremely strong arguments for majoritarianism. That position confuses conclusions with evidence."

What's more, it implies that human beliefs are normally distributed. I posit they are not, with extra weight being given to concepts that are exciting/emotional or arousing. We have a built in bias in the direction of things that are evolutionarily important (ie - babies, scarey stuff).

"I'm trying to comprehend how this is a dilemma... Science supposedly teaches that for any two theories that explain the same dat... (read more)

They only depend to within a constant factor. That's not the problem; the REAL problem is that K-complexity is uncomputable, meaning that you cannot in any way prove that the program you're proposing is, or is NOT, the shortest possible program to express the law.

Then you certainly understood me. This is another comment that makes me want to cheer, because it means you really got it.

That doesn't logically follow. Neither acceptance nor rejection implies correct comprehension of your claims.

"The most important implication is that the scientific method can break down."

I don't understand how this is a consequence of MW. We've always known that the scientific community can and does break down. The scientific method breaks down even theoretically (if you use K-complexity to assess it). And I'm not even sure that the MWI situation is a breakdown... It seems there are more than two interpretations (it's not just collapse versus many-worlds).

"There are some minor ethical implications of many-worlds itself (e.g., average utilitarianism... (read more)

Does every event with two possible/plausible outcomes result in two distinct worlds? I don't think that's the case -- it seems that multiple plausible outcomes also result from an ambiguous problem description (even if the situation is actually completely deterministic).

If the exact physical state is underdetermined by the problem description, then there will be separate branches of the wavefunction for each possible state, although they might have diverged arbitrarily long ago. So, yes.

"I disagree; I think the underspecification is a more serious issue than the uncomputability. There are constant factors that outweigh, by a massive margin, all evidence ever collected by our species."

Agreed. The constant factors really are a problem. If one has taken a few information theory courses, it's easy to disregard it as one usually uses Kolmogorov on e.g. symbol sequences in the infinite limit. When comparing two theories though, they have finite size and thus constants does matter. It is probably possible to find two Turing machines su... (read more)

I am interested in the answer to John Maxwell's question as well.

In that vein, let me re-ask a question I had in a previous post but was not answered:

How does MWI not violate no-faster-than-light-travel itself?

That is, if a decoherence happens with a particle/amplitude, requiring at that point a split universe in order to process everything so both possibilities actually happen, how do all particles across the entire universe know that at that point they must duplicate/superposition/whatever, in order to maintain the entegrity of two worlds where both posibilities happen?

Eliezer,

Manon de Gaillande: I don't believe most scientists would make such huge mistakes.

This is the main doubt I was expressing in my comment you quoted. I withdraw it.

Physicists are susceptable to irrational thinking too, but I went and stuck a "High Arcane Knowledge" label on QM. So while I didn't mind understanding things many doctors don't about mammographies, or things many biologists don't about evolution, thinking I knew anything fundamental about QM many physicists hadn't figured out set off a big "Who do you think you are?"... (read more)

William_Tanksley et al: Correct me if I'm wrong, but I had immediately assumed that the framing "science or Bayes" means "the scientific world as it exists today, or Bayes", not "ideal scientific research vs. Bayes". Eliezer_Yudkowsky presumably equates ideal scientific research with following Bayes.

Even if we think of MWI as 'everything duplicating', Wiseman, it doesn't have to happen faster than information about the event's outcome travels, which is at the speed of light.

So if an electron on Earth causes a branching to take place, Alpha Centauri B wouldn't have to split for about four years - because that's how long it would take the information about the electron's behavior to reach the star.

Re: "a serial machine can emulate a parallel one, thus this distinction isn't relevant."

Kolmogorov complexity/Solomonoff induction are language-specific. Not all languages are equivalent, and descriptions in different languages may be totally different lengths. It is true that any universal machine can simulate any other - but it takes a description of that simulator to do so, and that takes up space, which is a big deal, if the simulation is not tiny.

Re: They only depend to within a constant factor. That's not the problem [...]

That /is/ a probl... (read more)

"That's Occam's razor, not Science. The scientific method >is taken to suggest< that an untestable theory is of no use."

Watch that passive voice -- unless you're going to actually claim that the scientific method suggests that, I don't care what someone somewhere took it to suggest.

The scientific method doesn't suggest anything. It's a method, not a philosophy. As a method, it gives you steps to follow. A hypothesis is untestable; a theory's been tested. A model integrates theories. MW is a model.

"What's more, Occam's razor isn't some ... (read more)

Sebastian_Hagen: Specifying a language with all the data already specified as one of the symbols doesn't help, because with the MML standard, you'd have to include that, AND the data you're explaining, which makes it longer than any theory that can find regularity.

William_Tanksley: The fact that K-complexity isn't computable doesn't matter for determining which scientific theory is superior; you only need to know the maximum K-complexity across all known algorithms. Then, if our theories are equally good at predicting, but your max. K-complexity is longer... (read more)

Well, the ideal simplicity prior you should use for Solomonoff computation, is the simplicity prior our own universe was drawn from.

Since we have no idea, at this present time, why the universe is simple to begin with, we have no idea what Solomonoff prior we should be using. We are left with reflective renormalization - learning about things like, "The human prior says that mental properties seem as simply as physical ones, and that math is complicated; but actually it seems better to use a prior that's simpler than the human-brain-as-interpreter, s... (read more)

"If the exact physical state is underdetermined by the problem description, then there will be separate branches of the wavefunction for each possible state, although they might have diverged arbitrarily long ago. So, yes."

Are you seriously proposing that my use of ambiguous language splits the universe? This is unbelievable. I understand how incoherency would split the universe, but how can ambiguous language do that? How about false information -- if my bank tells me that my paycheck came in, is there an alternate world where my paycheck in fac... (read more)

Specifying a language with all the data already specified as one of the symbols doesn't help, because with the MML standard, you'd have to include that, AND the data you're explaining, which makes it longer than any theory that can find regularity.

But you still need to pick a language to express (language+data) in. Infinite regress.

Are you seriously proposing that my use of ambiguous language splits the universe? This is unbelievable. I understand how incoherency would split the universe, but how can ambiguous language do that?

It doesn't split the universe; your language doesn't have any effect on the world; as I said, it means that you have to consider a larger set of microstates, which means a larger set of outcomes. The better specified the initial conditions are, the better you can predict.

How about false information -- if my bank tells me that my paycheck came in, is there an

Let me pull the money quote from the article:

"The tradition handed down through the generations says that a new physics theory comes up with new experimental predictions that distinguish it from the old theory."

This is superficially correct, but I think it's irrelevant. Quantum theory is already a theory with well-established laws. None of the contending interpretations of those laws -- many-worlds, collapse, hidden-variables, and so on -- are theories, and none of them propose new laws (suggesting that there might be a law we don't know doesn't ... (read more)

"Of course I had more than just one reason for spending all that time posting about quantum physics. I like having lots of hidden motives, it's the closest I can ethically get to being a supervillain."

Your work on FAI is still pretty supervillain-esque to most SL0 and SL1 people. You are, essentially, talking about a human-engineered end to all of civilization.

"I wanted to present you with a nice, sharp dilemma between rejecting the scientific method, or embracing insanity. Why? I'll give you a hint: It's not just because I'm evil. If yo... (read more)

I can think of a few reasons why you would do this, although I'm not sure which one you had in mind.

Primarily, it's to evaluate the extent to which we commenters accept what you say on face value, particularly when we're not well informed to begin with. I don't mean picking at the specifics of examples, but whether we're evaluating what you're saying for internal consistency between posts.

For instance, the 'many worlds' argument you've presented DOES seem more plausible that collapse, but it certainly still seems mysterious. Having universes sprouting in a... (read more)

Various people:

The reference machine is chosen to be simple, usually by limiting its state x symbol complexity. That's not perfect and various people have tried to come up with something better but as yet none of these efforts have succeeded. In terms of prediction it's not a problem as Solomonoff's predictor converges so amazingly fast - faster than 1/n where n is the number of bits of input data (this isn't quite true and Li and Vitanyi don't quite get it right either, see Hutter: On universal prediction and Bayesian confirmation. Theoretical Computer ... (read more)

You are, essentially, talking about a human-engineered end to all of civilization.

Change, not end. (The general point still stands.)

Nick, thank you for the post. It almost answered my question -- I just need to make sure I'm not totally misreading it.

"But, yes, every outcome is real in some world."

When you say "outcome" do you mean "every outcome of quantum processes", or do you mean "every event"? Do you mean "every possible result of physical processes" or do you mean "every configuration regardless of physical antecedents"?

As a specific example, is there a world where one human was born of a virgin, performed miraculous hea... (read more)

When you say "outcome" do you mean "every outcome of quantum processes", or do you mean "every event"? Do you mean "every possible result of physical processes" or do you mean "every configuration regardless of physical antecedents"?

The latter, since there are no Garden of Eden patterns in physics. (I'm not sure how the Big Bang fits in.)

As a specific example, is there a world where one human was born of a virgin, performed miraculous healings, prophesied his own death and resurrection, rose from the dea

"The latter, since there are no Garden of Eden patterns in physics."

Thank you for your excellent job of communicating (and the GoE link decreased possible ambiguities, too).

How do we know that there are no Garden of Eden patterns? That is a very interesting claim. In attempting to reverse-engineer it, I remembered that according to quantum theory, each wavefunction is nowhere zero. Thus, any collection of particles could tunnel into place over any distance in any organization you could possibly specify. Is that the key to the proof?

At any rate, I... (read more)

Among all these comments, I see no appreciation of the fact that the version of many worlds we have just been given CANNOT MAKE PREDICTIONS, whereas "collapse theories" DO.

Yes, Schrödinger evolution plus collapse is more complicated than just Schrödinger evolution. But the former makes the predictions, and the latter does not. We have been given the optimistic assertion that maybe the predictions are already somewhere inside the theory without collapse, but this remains to be shown. That's what the meaning of this whole "quest for the Bor... (read more)

Give me a single example of a successful use of Bayesianism that is not predicated on its being an explanation of the success of the scientific method and maybe then I'll consider choosing Bayes over science.

"Among all these comments, I see no appreciation of the fact that the version of many worlds we have just been given CANNOT MAKE PREDICTIONS, whereas "collapse theories" DO."

So far as I know, MWI and collapse both make the exact same predictions, although Eliezer has demonstrated that MWI is much cleaner in theoretical terms. If there's any feasible experiment which can distinguish between the two, I'm sure quantum physicists would already have tried it.

William, I've replied off-site.

As has been pointed out before, a feature of MWI that produces the Born probabilities is a priori no less likely than a collapse postulate that produces the Born probabilities. I think.

Tom, Nick, MWI does not make predictions! Well, there is a version of MWI that does, but it is not the one being advocated here.

What makes predictions is a calculational procedure, like sum-over-histories. That procedure has an interpretation in a collapse theory: the theory explains why the procedure works. The version of MWI that Eliezer has expounded cannot do that. He has said so himself, repeatedly - that the recuperation of the Born probabilities is a hope, not an existing achievement.

Is that clear? I feel like I had better say it again. The bare m... (read more)

Ah, but Mitchell, the collapse interpretation doesn't explain why the Born probabilities are what they are.

So the version of many-worlds that I believe in, as a predictive theory, is:

(1) The wavefunction is real and evolves unitarily.
+
(2) For some unknown reason, experimental statistics match the Born probabilities.

In combination, these statements constitute a predictive theory.

As for the objection that (2) hasn't been explained, collapse "explains" it by tacking on, "And the reason for (2) is that parts of the wavefunction spontaneously ... (read more)

Tim: "Solomonoff induction is simply an attempt to formalise Occam's razor around
an impractical theoretical model of serial computation."

This is distinct from a Universal Turing Machine how?

Something just clicked for me. I mean, regarding the subject of the original post. There is a true dilemma, and in that dilemma, the choices of a pure Bayesian will look crazy to a Scientist, and vice versa.

The hard difference between Science and Bayes is that Bayes does not require a model; Science does. Bayes simply predicts probabilities; Science attempts to establish a model that explains the probabilities.

Thus, a Bayesian won't care about the quality of the model he's given, EXCEPT that it must not be complex (a nonexistent model will work just fine).... (read more)

Two other examples of physicists messing up by not employing Occam's razor are provided by Fredkin: CPT symmetry should be just T symmetry - and mass, length and time should be bits, length and time - where "bits" have the units of angular momentum.

Re:"So far as I know, MWI and collapse both make the exact same predictions" - nope:

``Many worlds is often referred to as a theory, rather than just an interpretation, by those who propose that many worlds can make testable predictions (such as David Deutsch) or is falsifiable (such as Everett) [...]''

http://en.wikipedia.org/wiki/Many-worlds_interpretation

The issue is laid out in the FAQ:

Q36 What unique predictions does many-worlds make?
http://www.hedweb.com/manworld.htm#unique

Q37 Could we detect other Everett-worlds?
http://www.hedweb.com/manw... (read more)

Tim: Could you elaborate on that? How is it that CPT ought just be T?

And how should mass be in units of angular momentum?

Thanks.

Re: Fredkin, for the units issue, see:

"Chapter 20: Units B, L, T, P, D, R, A & I"

http://web.archive.org/web/20060925023734/http://digitalphilosophy.org/digital_philosophy/20_units.htm

For temporal reversibility, see:

"Chapter 30: DM and CPT"

http://web.archive.org/web/20040410145311/www.digitalphilosophy.org/digital_philosophy/30_dm_cpt.htm

I also have a page on the subject:

http://finitenature.com/cpt/

There's also a synopsis of Fredkin's ideas (incl. these two) in:

"Five big questions with pretty simple answers"

http://www.resea... (read more)

People who want to get fundamental physics out of cellular automata could be a lot more imaginative than they are. What about small-world networks? Maybe you could get quantum nonlocality. What about networks which are only statistically regular? Maybe you could get rotational symmetry in the continuum limit. And how about trying to do without a universal time coordinate? What about creation and destruction of cells, not just alteration of cell states? Euclidean, gridlike CAs like Fredkin's should only be a training ground for the intuition, not the templa... (read more)

IMHO, Fredkin picked cellular automata for good reason. Regularity helps explain how light travels in straight lines across long distances. There /are/ asynchronous CAs, but asynchrony is mostly an unneeded complication in this context - synchronous CAs are hard enough to work with, thank you. CAs can be universal, so they can do anything any other discrete model can. CAs are low-level modelling tools, that are not easy to build things with - but it seems extremely likely that low-level modelling tools will ultimately be needed to explain physics.

Eliezer: "A little arrow"? Actual little arrows are pieces of wood shot with a bow. Ok, amplitudes are a property of a configuration you can map in a two-dimensional space (with no preferred basis), but what property? I'll accept "Your poor little brain can't grok it, you puny human." and "Dunno - maybe I can tell you later, like we didn't know what temperature was before Carnot.", but a real answer would be better.

Suppose we lived in a universe before any quantum decoherance tests were done. And now suppose I (as a scientist with a favourite pet personal theory) put forward the theory that multiple parallel universes exist, and start fleshing it out. One of the predictions this theory would make would be in the way entangled photons probabilities change-at-a-distance. Would not performing the test just described and coming up with a set of probabilities that matched the theories predictions be a valid scientific prediction?

If all that can be observed in a syste... (read more)

This post is beating a strawman. Beating a strawman is bad.

It isn't really that hard to wriggle this question. Why do I have to choose Science or Bayes, can't I just choose not to have an opinion until I am more capable of making a decision? It would seem suicidal from the perspective of bias to choose a side, especially when the stakes are currently so low. Question wriggled. I don't have to choose between Science and Bayes, I can use them both when they are useful, and simply not hold an opinion in the area where they are in some form of conflict.

chuckles... I wrote a whole bunch about string theory, but I've decided to simply mention it. I have a TON of mathematical notation to learn before I can subject that glittery...whatever...to analysis.

As for many worlds... I like the way many of the ""paradoxes" of quantum mechanics don't even LOOK like paradoxes in many worlds. starting with-you don't need to specify a special exemption to the no-ftl rule. "information" for "collapse" happens because the little pieces of the waves almost-touch and slip past each other when you perform the comparison operation...at least, that's how I visualize it.

I just wanted to contribute by saying that in one of his lectures (I cannot remember the exact name), Feynman said that it is important for a physicist to know many interpretations that give the same predictions but are different computationally. The simplest example that comes to my mind is Newtonian and Lagrangian mechanics. I do not know which one is simpler in the technical sense of the word, but I am sure that every physicist is expected to know and understand both of them.