convincing the other side, or getting convinced, or building a better model based on the two original positions is not an option.
Because they both predict exactly the same set of experimental results? And neither feels like a strict subset of the other? Or is there something more?
What is the problem with seeing MWI as a strict subset of Copenhagen? I am not an expert, but it seems to me that MWI explains the results of quantum experiments, and Copenhagen does the same with additional experimentally untestable hypothesis that our amplitude blob is different from the others, because the others magically disappear at some unspecified moment. (You know, just like the Earth is different, because it is down, while the other planets are up there. Imagining people walking upside down makes my head spin.)
Now, if only I could figure out why I am still commenting about it...
Cognitive dissonance. One part of your brain tells you to follow Occam’s razor, other part tells you to follow the opinions of respected majority. No offense meant; following the educated majority is very strong Bayesian evidence.
MWI explains the results of quantum experiments, and Copenhagen does the same with additional experimentally untestable hypothesis that our amplitude blob is different from the others, because the others magically disappear at some unspecified moment.
That’s a common misunderstanding of the situation… The math is exactly the same in both cases, all that’s different is the handwaving around it. There are no additional meaningful assumptions in the orthodox interpretation compared to the MWI. Both have the “and then a miracle occurs” step (one calls it “collapse”, the other “world split”).
Cognitive dissonance. One part of your brain tells you to follow Occam’s razor
I don’t think this is it, given my understanding of the Occam’s razor. Could be some other type of cognitive dissonance, though.
Your conception of the MWI seems to be the DeWitt-Graham version, which is pretty outdated. According to this version, there is a global duplication of the entire universe every time there is a measurement of a quantum event with two possible outcomes. I agree that this interpretation is no less handwavey than Copenhagen.
But most contemporary proponents of the MWI (including Eliezer) don’t believe there is any mysterious world-splitting process that is extraneous to the dynamics. The theory should really be called Everettianism (or maybe, as Everett originally labeled it, the relative state formulation) rather than many-worlds. The idea is just that nothing more than the Schrodinger dynamics is required in order to account for our experience of a macroscopically classical world with determinate measurement outcomes. The appearance of collapse (or world-splitting) is fully accounted for by decoherence. This version of the MWI does not involve the periodic disruption of the dynamics postulated by Copenhagen. Nor is it empirically equivalent to Copenhagen.
So I urge you to reconsider your dislike of the MWI! Join us on the dark side...
Isn’t world split explainable an approximation of unitary math that happens when your state gets properly entangled with the state of the observed system? And in Copenhagen interpretation collapse is a new operation.
That’s what they want you to think. If you dig deeper, you will find an equivalent of the Born rule in any interpretation. This rule is usually more complicated than the Born rule, and is never used for any kind of calculations.
The Born rule does not enter into the Everettian interpretation as the consequence of an additional dynamical process. Precisely how it enters is a matter of some controversy. I think the most promising program is the Savage-style decision theoretic approach adopted by the Oxford Everettians, which I discussed here. Whatever you think about the success of this approach, it is an attempt at a rigorous foundation for the Born rule that is missing from most other interpretations. I would also argue that it is a much simpler and more philosophically sound approach than postulating arbitrary discontinuities in physical law.
I would also argue that it is a much simpler and more philosophically sound approach
Feel-good words. You still end up doing the exact same calculations using the Born rule. To me this means that the philosophical fluff around it is not worth the air used to breathe them out.
If your only interest in quantum mechanics is doing calculations, then I guess all this interpretive stuff is fluff. If you look at the history of physics, though, interpretive questions have often driven theoretical advancement. Consider, for example, the role Einstein’s Machianism played. Or—a more pertinent example—the role Everettianism played in the development of quantum computation. In neither case did the substance of the subsequent developments hinge on particular answers to the interpretive question, but philosophical speculation was the spur that led Einstein and Deutsch to their novel ideas.
I think many physicists are wise to ignore issues of interpretation. If you’re doing experimental work in quantum mechanics, it doesn’t matter. But it seems odd to suggest that scientists should just give up on the task of figuring out the actual structure of the world.
Oh, the interpretive questions are the fun stuff, for sure. Everett’s work was seminal. And yes, Mach was an inspiration for Einstein, though the eventual relativity theory was quite far from that. What I am unhappy with is the claims that one interpretation has more “truth” to it than another. More inspiration, maybe, but that’s it.
It still helps to decide whether collapse occurs in some complicated cases (like a measurement device in double-slit experiment that is secure from possibility of a human retrieving the measurement results).
Because they both predict exactly the same set of experimental results? And neither feels like a strict subset of the other? Or is there something more?
What is the problem with seeing MWI as a strict subset of Copenhagen? I am not an expert, but it seems to me that MWI explains the results of quantum experiments, and Copenhagen does the same with additional experimentally untestable hypothesis that our amplitude blob is different from the others, because the others magically disappear at some unspecified moment. (You know, just like the Earth is different, because it is down, while the other planets are up there. Imagining people walking upside down makes my head spin.)
Cognitive dissonance. One part of your brain tells you to follow Occam’s razor, other part tells you to follow the opinions of respected majority. No offense meant; following the educated majority is very strong Bayesian evidence.
That’s a common misunderstanding of the situation… The math is exactly the same in both cases, all that’s different is the handwaving around it. There are no additional meaningful assumptions in the orthodox interpretation compared to the MWI. Both have the “and then a miracle occurs” step (one calls it “collapse”, the other “world split”).
I don’t think this is it, given my understanding of the Occam’s razor. Could be some other type of cognitive dissonance, though.
Your conception of the MWI seems to be the DeWitt-Graham version, which is pretty outdated. According to this version, there is a global duplication of the entire universe every time there is a measurement of a quantum event with two possible outcomes. I agree that this interpretation is no less handwavey than Copenhagen.
But most contemporary proponents of the MWI (including Eliezer) don’t believe there is any mysterious world-splitting process that is extraneous to the dynamics. The theory should really be called Everettianism (or maybe, as Everett originally labeled it, the relative state formulation) rather than many-worlds. The idea is just that nothing more than the Schrodinger dynamics is required in order to account for our experience of a macroscopically classical world with determinate measurement outcomes. The appearance of collapse (or world-splitting) is fully accounted for by decoherence. This version of the MWI does not involve the periodic disruption of the dynamics postulated by Copenhagen. Nor is it empirically equivalent to Copenhagen.
So I urge you to reconsider your dislike of the MWI! Join us on the dark side...
...and the light side, and the grey side.
Seem my other reply.
Isn’t world split explainable an approximation of unitary math that happens when your state gets properly entangled with the state of the observed system? And in Copenhagen interpretation collapse is a new operation.
That’s what they want you to think. If you dig deeper, you will find an equivalent of the Born rule in any interpretation. This rule is usually more complicated than the Born rule, and is never used for any kind of calculations.
The Born rule does not enter into the Everettian interpretation as the consequence of an additional dynamical process. Precisely how it enters is a matter of some controversy. I think the most promising program is the Savage-style decision theoretic approach adopted by the Oxford Everettians, which I discussed here. Whatever you think about the success of this approach, it is an attempt at a rigorous foundation for the Born rule that is missing from most other interpretations. I would also argue that it is a much simpler and more philosophically sound approach than postulating arbitrary discontinuities in physical law.
Feel-good words. You still end up doing the exact same calculations using the Born rule. To me this means that the philosophical fluff around it is not worth the air used to breathe them out.
If your only interest in quantum mechanics is doing calculations, then I guess all this interpretive stuff is fluff. If you look at the history of physics, though, interpretive questions have often driven theoretical advancement. Consider, for example, the role Einstein’s Machianism played. Or—a more pertinent example—the role Everettianism played in the development of quantum computation. In neither case did the substance of the subsequent developments hinge on particular answers to the interpretive question, but philosophical speculation was the spur that led Einstein and Deutsch to their novel ideas.
I think many physicists are wise to ignore issues of interpretation. If you’re doing experimental work in quantum mechanics, it doesn’t matter. But it seems odd to suggest that scientists should just give up on the task of figuring out the actual structure of the world.
Oh, the interpretive questions are the fun stuff, for sure. Everett’s work was seminal. And yes, Mach was an inspiration for Einstein, though the eventual relativity theory was quite far from that. What I am unhappy with is the claims that one interpretation has more “truth” to it than another. More inspiration, maybe, but that’s it.
It still helps to decide whether collapse occurs in some complicated cases (like a measurement device in double-slit experiment that is secure from possibility of a human retrieving the measurement results).