I suspect the nature of quantum mechanics limits the possibilities to the countable regime. Max Tegmark discusses this topic here, in the section “How many parallel universes are there?”.
You know, perhaps I should apologize for my question, just a little bit; or for the intent behind it. One of my objections to MWI is that it’s ill-defined to a degree that laypeople would not guess, from the way that its advocates talk. I noticed on Rolf’s thread that you are a physicist, and I thought, OK, I’ll see how much this guy has really thought about it… Then it dawned on it me that you were just explicating rather than advocating MWI—that is, explaining a few details of an idea that you know something about because of your profession, but not necessarily an idea that you would champion as The Answer.
Nowadays I try to limit my arguing about MWI to discussions with physicists who really believe it. They need to be physicists so that it can be a technical discussion, and they need to be believers so that I can demand answers to specific questions. Most physicists have rigorous justifications for their physical opinions only for those parts of physics that they need professionally, and that usually doesn’t extend to “quantum foundations”.
Most physicists are intrigued or even enthusiastic about that topic, and they’ll certainly have opinions and thoughts about it, but when pressed they’ll admit to agnosticism, shrug their shoulders, take resort in diffident positivism, etc. When it comes to MWI, you can’t have a critical discussion if for the other person it’s just a fuzzy opinion, rather than an idea as clear as relativity or a specific equation of motion.
I could undoubtedly have a serious debate with someone like Tegmark, because he’s very serious about the multiverse concept, and he’s written technical works of quantum cosmology which provide a framework for questions like, countable or uncountable, what’s the ontological meaning of the measure, how do you avoid a preferred frame, and so on. But the framework is subtly or even radically different for each serious MWI advocate, which is why it’s just about impossible to set down a general-purpose critique of MWI.
Then it dawned on it me that you were just explicating rather than advocating MWI—that is, explaining a few details of an idea that you know something about because of your profession, but not necessarily an idea that you would champion as The Answer.
Yes, this is what I was doing.
My personal view is that the many worlds interpretation is probably closer to being correct than other popular (e.g. collapse-based) interpretations. What I mean by this is that it wouldn’t surprise me if the “correct” interpretation has not been fully realized by anyone yet, but once it is developed, we will be able to look back and say that many worlds was not as far off.
I lean toward the wave function having real physical significance rather than being just a mathematical tool; people said the same thing about quarks, once upon a time. (Many people still think quarks are just a mathematical tool, despite the 17-year-old discovery of the top quark which is too heavy to hadronize before it decays.)
As Rolf mentioned in his thread, high energy experiment doesn’t really deal directly with interpreting quantum mechanics and wave functions. While I’m probably better versed in QM than many physicists whose focus is on classical scales, I would not claim to have a conception of many worlds which is as clear as relativity.
Do you have any opinion on whether continuum-many things are possible, or whether there’s just a finite or countable number of possibilities?
I suspect the nature of quantum mechanics limits the possibilities to the countable regime. Max Tegmark discusses this topic here, in the section “How many parallel universes are there?”.
You know, perhaps I should apologize for my question, just a little bit; or for the intent behind it. One of my objections to MWI is that it’s ill-defined to a degree that laypeople would not guess, from the way that its advocates talk. I noticed on Rolf’s thread that you are a physicist, and I thought, OK, I’ll see how much this guy has really thought about it… Then it dawned on it me that you were just explicating rather than advocating MWI—that is, explaining a few details of an idea that you know something about because of your profession, but not necessarily an idea that you would champion as The Answer.
Nowadays I try to limit my arguing about MWI to discussions with physicists who really believe it. They need to be physicists so that it can be a technical discussion, and they need to be believers so that I can demand answers to specific questions. Most physicists have rigorous justifications for their physical opinions only for those parts of physics that they need professionally, and that usually doesn’t extend to “quantum foundations”.
Most physicists are intrigued or even enthusiastic about that topic, and they’ll certainly have opinions and thoughts about it, but when pressed they’ll admit to agnosticism, shrug their shoulders, take resort in diffident positivism, etc. When it comes to MWI, you can’t have a critical discussion if for the other person it’s just a fuzzy opinion, rather than an idea as clear as relativity or a specific equation of motion.
I could undoubtedly have a serious debate with someone like Tegmark, because he’s very serious about the multiverse concept, and he’s written technical works of quantum cosmology which provide a framework for questions like, countable or uncountable, what’s the ontological meaning of the measure, how do you avoid a preferred frame, and so on. But the framework is subtly or even radically different for each serious MWI advocate, which is why it’s just about impossible to set down a general-purpose critique of MWI.
Yes, this is what I was doing.
My personal view is that the many worlds interpretation is probably closer to being correct than other popular (e.g. collapse-based) interpretations. What I mean by this is that it wouldn’t surprise me if the “correct” interpretation has not been fully realized by anyone yet, but once it is developed, we will be able to look back and say that many worlds was not as far off.
I lean toward the wave function having real physical significance rather than being just a mathematical tool; people said the same thing about quarks, once upon a time. (Many people still think quarks are just a mathematical tool, despite the 17-year-old discovery of the top quark which is too heavy to hadronize before it decays.)
As Rolf mentioned in his thread, high energy experiment doesn’t really deal directly with interpreting quantum mechanics and wave functions. While I’m probably better versed in QM than many physicists whose focus is on classical scales, I would not claim to have a conception of many worlds which is as clear as relativity.