Any question that can be asked from the framework of science is worth pursuing, if only quixotically/philosophically at the time.
The very issue of what was really going on with quantum entanglement was a huge deal with Einstein, as asserted by Bohr. Experimental evidence since has shown Bohr was right, functionally, but it only adds to the mountain of questions that have since accrued in trying to bring our fractured understanding of nature together.
Serious philosophical propositions have illuminated and shed much insight on issues borne out of scientific experimentation and observation in the past, leading to great leaps in knowledge and understanding. To sideline such thought as trivial, metaphysical shenanigans now would be a sad development.
I think this is especially so given the fact that as it turns out, the quantum universe is quite a bit stranger, regardless of interpretation, than pretty much any mainstream incarnation of human metaphysics.
It is important to note that the quantum mechanical foundations most often discussed are observationally equivalent. In particular, the basic “many worlds” interpretation and the “wave-function collapse” interpretation are identical in every testable way.
To be sure, it can be fruitful to confront theoretical interpretations, as this often leads to the development of actually different theories. This is a true scientific endeavor, and plenty of physicists work on it. But not most, in the same way that most physicists don’t work in any specific line of research (high-T[sub]c[/sub] superconductivity; atomic magnetometry; supernova dynamics; …) because there are lots of topics out there.
The trouble comes about when someone claims that an interpretation is “right” even when it is mathematically and predictively identical to another. Sometimes such claims are made during purely philosophical discourse. More often, a “rightness” claim heard from a physicist is just short-hand, with “I think interpretation is right” being shorthand for “I think interpretation is more intuitively helpful and/or more likely to lead to a furthering of our understand via generalizations of said theoretical picture and/or just plain less weird to me and I’m saying so tongue-in-cheek-ly.”
The distinction between the short-hand but scientifically useful claims and the explicitly philosophical musings is very often blurred, unintentionally or not. When folks upthread point out that all this isn’t worth thinking about, they are talking about the bold explicitly ontological claims of rightness for equivalent theories and they are not (if I dare speak for them) denying the value of pushing on various interpretations as a way to develop new underlying frameworks.
This, basically; also, 33 people isn’t really that good a sample size.
Well, I sympathize with this view to a degree, but I also see it as a bit problematic. Because ultimately, quite distinct from the question of whether what you say is right or wrong, which is ultimately for empirical investigations to decide, there’s also a question of whether what you say makes sense or not, is well justified or not; and an instrumentalist or purely operationalist viewpoint is completely blind for this question.
So in the end, pursuing such a view all the way through, you’re ultimately not better off than someone who merely guesses, even if you happen to be right, or someone who has access to a black box that, if you twiddle its knobs and dials just the right way, miraculously produces outcomes that agree with experiment for some reason. What you say in such a case may be right, but it is thus only incidentally, without any sort of foundation, and hence ultimately meaningless.
Now it may still be argued that only the ‘back end’, the (presumably empirically decidable) question of truth or falsity is subject to scientific investigation, all the rest being ‘for the philosophers to sort out’, but I think drawing such hard-and-fast border serves little purpose beyond shifting the burden of difficult questions to someone else. Ultimately, natural science gets to pick the ripe fruits of factual, empirical knowledge because we have the luxury to sit all the way out on the branches of the tree of knowledge; but disregarding the philosophy that gives meaning to this knowledge is like breaking out the saw and cutting of the branch on which we sit: it’ll matter little to the tree, but we and our precious fruit are just going to end up in the dirt, to torture the metaphor a little more.
Of course, if you’re sat at some problem doing some calculation, all of this matters preciously little, and you can happily disregard the abstract questions in favor of some nice, concrete math; but I think that using this as a starting point and raising young physicists to be capable calculators more than anything else is the wrong way to go. That’s what computers are for, after all…
[QUOTE=zoid]
Why is it an embarrassment? Even scientists can have differing opinions about matters that aren’t clearly settled.
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It’s a bit worse than that. I see it as an embarrassment because it doesn’t require a particularly high level of reason to come to the conclusion that the Copenhagen interpretation is internally inconsistent. It doesn’t require a specialist in Quantum Information, or a genius deciding to study subtle and obscure corners of quantum mechanics. No; it requires only that a student of quantum mechanics have sufficient interest in understanding the theory that he or she thinks about it for a while outside of just trying to get his or her homework problems done. To me, this is very sad.
HMHW gave a more diplomatic response. I think it is a basic fallacy to separate philosophy from science so completely. Any mathematical equivalence in physics, whether it is the difference between Newton’s Laws and the Principle of Least Action, or the difference between Feynman’s Path Integral Formulation and Schrodinger Evolution, could be casually dismissed as “philosophy”, and yet these differences have proved immeasurably important in the development of scientific theories. Many prominent physicists agree with me that understanding these sometimes-equivalent descriptions of quantum mechanics could provide a similar role in our ability to push physics forward, as, for example, the Principle of Least Action did.
I don’t understand the view that any two interpretations of quantum mechanics are functionally or observationally equivalent.
If MWI is correct, I could potentially put together a multi-round Russian Roulette gambling game, where a bunch of people had to pay me a lot of money if I lived, but they’d get all their money back if I died any time during the session. Take a revolver with six chambers, put five bullets in, have a sufficiently “random” quantum spin mechanism, and then run the game for scarily many rounds. Obviously, with a certain frame of mind, it could be functionally useful for a person to know that at least one version is going to have enough money to retire no matter how many rounds they play. Anthropic. The others would be dead, so they would have no opportunity to feel bad about what they’d lost.
This is a legitimate difference between the interpretations with real functional and observational differences, for the right sort of person. There is potential real-world significance here, and there is no necessary fault for anyone who decided the bet was worth taking (by which I mean rational fault, outside of other moral considerations). With the right set of strange preferences, it is a worthwhile game given the “guaranteed” payout. If the rules of the universe are one way, then there is a possible exploit. If the rules are another way, then that exploit does not exist. It doesn’t get any more functional than that.
Your example of Quantum Immortality does not represent a difference between interpretations that can be put to scientific test. The reason: repeatability; another scientist attempting to repeat your experiment will be dead in your timeline.
That is not to say that there are not scientific differences between some of the interpretations. For example, quantum computation is not compatible with interpretations in which quantum phenomena are macroscopic manifestations of complex classical behavior. This should be testable in a few years, hopefully.
The many-worlds Russian Roulette problem only applies if you mix together different interpretations. If, in a single-world interpretation, you would want to maximize your probability of survival, then in a many-world interpretation, you should want to maximize the proportion of worlds in which you survive. You shouldn’t comfort yourself by saying that the you in the world where you survive is the “real you”, because it’s just as valid to say that the “real you” is any one of the many where you didn’t survive, and you’ve just volunteered to commit suicide.
Well said, and I should have said something like that. Any calculation that can be done in any interpretation can be done in any other interpretation, as well, but for us humans, it can sometimes be easier to see how to set up the calculation in one interpretation or another. So, yes, in that sense, one interpretation might be preferable to another, if it helps us to more easily see how to set up a calculation. But which interpretation is easier to think in certainly depends on what problem you’re trying to solve, and can often also depend on who’s doing the thinking about it, so you still can’t really say that one interpretation is more right than another.
I think the most common view on this issue is that a proper interpretation of quantum theory is something which yields exactly the same observations; anything else, such as objective collapse theories, really is just an alternative theory and can in principle be experimentally ruled out.
As for quantum immortality, the only possible verification of that is necessarily subjective, so not traditionally thought of as scientific. Besides, there’s nothing to it even in splitting-worlds interpretations: there’s really no process such that afterwards, you end up either dead or alive; things are much messier than that. There may be no ‘cul de sacs’ such that all options lead to you ending up dead, but there are almost certainly ‘roads to nowhere’, when after a given event (such as the gun firing), you are not dead, but ultimately will die; and just as there’s no sharp point where dinosaurs became birds in evolutionary history, there is no sharp point beyond which you will be dead.
Besides, if you believe you were born, i.e. your consciousness came into existence at some point, you also believe that you can die, by the simple reversal of this process.
There’s actually an interesting quote somebody penciled in on his response to the original poll that sort of makes the same point that I was trying to make in my first post:
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]([1301.1069] A Snapshot of Foundational Attitudes Toward Quantum Mechanics)
Overall, I would always prefer such a viewpoint—ultimately wrong, but well founded and deeply analysed—over one that happened to be right, but ‘for all the wrong reasons’. I at first wanted to mention Bohr as a proponent of such a view, but I don’t think that would be really fair. The way the Copenhagen thinking (of which there really is not one single unified strand) is presented mostly today is certainly quite naive, but from what little I know of Bohr’s original position, he—and even more so Heisenberg—had a much more subtle position than what is generally ascribed to him.
Though, again, a pencil-in response about Bohr’s view apparently was that it’s
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But what they don’t seem to realize is that this progress made from the “value of pushing on various interpretations as a way to develop new underlying frameworks” is contingent upon intelligently choosing which interpretations to push on. You can try to separate things out and call the making of this choice “philosophy”, but it is and always has been one of the core unspoken tools used by physicists in advancing physical theory. Focusing on the Copenhagen interpretation, for example, is a dumb and costly (in terms of man-hours) mistake, given how easily it is ruled out philosophically (or whatever word you want to attribute to the logic that rules it out).
I agree that that choice isn’t philosophy. It only becomes philosophy when the word “right” comes into it in a literal way. That’s what I meant by “right” usually being a shorthand for what you are saying. It’s when it slips over to more than that that the philosophy begins.
It’s the phrase “ruled out” here that is troublesome. If you have two things that are observationally equivalent, you can’t rule one out just by thinking about it. You can decide, based on history and experience, that one is so obtuse that mankind’s limited resources are better applied pushing on something more sensible. But theoretical prejudice can be arbitrarily strong and actionable yet still not cross over into establishing rightness.
I suspect that you aren’t disagreeing with this point and that the thread is just deep into semantics now, but perhaps not?
So far as I can see, you are doing nothing more here than warning against too much dogmatism about matters that cannot, currently, be readily and decisively settled. That is, doubtless, good advice, but pretty trite, and really nothing to do with the distinction (if there really is a useful one to be made) between “science” and “philosophy”.
“Philosophy” in the pejorative sense you are using it bears no relation to the way actual philosophers (most of the great names of the past, and certainly actual philosophy faculty and grad students today) go about their work. As someone who has spent a lot of time with, and reading the works of, both philosophers and scientists, I would say that philosophers are no more inclined to be dogmatic than scientists, and, if anything, are usually less so. As I see it, philosophers and scientists are engaged in the same enterprise – to gain as wide and deep as possible rational understanding of the world – and are allies rather than rivals in this enterprise (even when they are not simply one person wearing two slightly different hats). The distinction between these fields has more to do with the needs of large organizations, such as universities, to organize themselves into specialist departments, rather than any true fault line in the structure of the enterprise of inquiry.
The real difference between science and philosophy (which provides a very vague and blurry distinction, rather than a sharp line of demarcation) is that scientists tend to focus on relatively well defined questions, where there is a reasonable hope that issues can be settled by some relevant and specific experiments, observations, or measurements, and philosophers tend to focus more on ill defined questions that cannot, yet, be so readily settled. Thus the philosopher’s work is more about getting questions clear (a process that can take generations, or even centuries) than about answering them. When philosophy succeeds at this (something that had happened occasionally, but rather rarely, over the course of history), and refines a question to the point at which it becomes appropriate and fruitful to apply empirical and/or precise mathematical methods to its solution, that area of philosophy, in effect, transforms itself into science, and those philosophers responsible for the success are retroactively credited with having been scientists all along.
An important point to be made here: It’s not that we can’t yet experimentally distinguish between any of the mainstream interpretations of quantum mechanics. That implies that someone, someday, might come up with an experiment that would distinguish between them. Rather, all of the mainstream interpretations of quantum mechanics have been mathematically proven to be exactly equivalent in terms of their predictions of observables. No matter how much progress we make in understanding physics, we’ll never be able to conduct an experiment to distinguish between them. At most, we could potentially disprove them, but if so, we’d disprove them all at once.
