Here is what you said:kered rettop said:I don't think I did make a positive claim.
That's a positive claim. Either give a reference to back it up or retract it.kered rettop said:It is sufficient to identify a subsystem in which "which-branch" information is not available. This can be personified as an observer who is ignorant of the branch in which they are embedded.
Um, yes, it is. What I quoted was all of your post except the first sentence, which just said you were disagreeing with me. If you don't think that two declarative assertions by you are a positive claim, then I am very confused about what language you think you are speaking.kered rettop said:It's no good just throwing my post back at me verbatim, saying "it's in there".
Neither of those is going to happen, are they?PeterDonis said:That's a positive claim. Either give a reference to back it up or retract it.
If not, then the subject is off topic for this thread and I will delete both of our posts that refer to it.kered rettop said:Neither of those is going to happen, are they?
Would it help to recognise that there is a difference between dividing a world-state using arithmetic and dividing it by means of decoherence?PeroK said:I just don't see how one could possibly pull off this trick in general.
But in the MWI, there is no accepted derivation of the Born Rule. And if you adopt it as an extra assumption, you can't then use it to justify a concept of probability in the MWI; that would be arguing in a circle.kered rettop said:You can calculate the required probabilities using the Born Rule
No, the context was arguments based on world-counting, specifically about how to count worlds correctly. One criterion, pointed out by the previous poster, PeroK, is that world-counting must sucessfully reconcile amplitudes with probabilities. The correct probabilities are given by the Born Rule. The Born Rule is thus an objective of the argument, it has no place as an assumption of the argument. That's why I said "required probabilities".PeterDonis said:But in the MWI, there is no accepted derivation of the Born Rule. And if you adopt it as an extra assumption, you can't then use it to justify a concept of probability in the MWI; that would be arguing in a circle.
Which means the MWI. Which means you can't just take the Born Rule as given.kered rettop said:the context was arguments based on world-counting
Are you claiming that this argument is a valid derivation of the Born Rule in the MWI? On what basis? Do you have a reference?kered rettop said:The Born Rule is thus an objective of the argument
In the context of the MWI, before you can even get to this point, you have to justify how the concept of "probability" even makes sense.kered rettop said:One criterion, pointed out by the previous poster, PeroK, is that world-counting must sucessfully reconcile amplitudes with probabilities. The correct probabilities are given by the Born Rule.
If by "you", you mean the formulator of the candidate argument, then sure, of course they do.PeterDonis said:In the context of the MWI, before you can even get to this point, you have to justify how the concept of "probability" even makes sense.
Where do they do that?kered rettop said:If by "you", you mean the formulator of the candidate argument, then sure, of course they do.
Oh I see what you mean. Yes, I was assuming that the desired probabilies would be the Born Rule. I should have left it at "desired probabilites" and left it to the formulators or PeroK to decide and justify what they should be.PeterDonis said:Which means the MWI. Which means you can't just take the Born Rule as given.
Oh good grief!PeterDonis said:Where do they do that?
No.PeterDonis said:Are you claiming that this argument is a valid derivation of the Born Rule in the MWI?
Take Schrodinger's cat as an example. But, instead of the 50-50 probability of decay, make it 10%. There should only be two decohered worlds. The fundamental branching of the radioactive sample is fundamental to the experiment. And, yet, there would have to be 9 times as many decohered worlds with a live cat than a dead one. Unless that ratio is driven by an initial weighted or probabilistic branching, how can it be otherwise conjured?kered rettop said:Would it help to recognise that there is a difference between dividing a world-state using arithmetic and dividing it by means of decoherence?
It depends what you mean by simple. Introducing probability as a primitive complicates the fundamentals of the theory. It may simplify the development of the theory. Occam's Razor vs Shut Up And Calculate.PeroK said:Moreover, the probabilistic explanation is simple. The sample has a probability of ##p## to decay; the probability the cat dies is ##p##.
I don't see how what is proposed can claim the moral high ground and insinuate a shut up and calculate accusation against a probabilistic theory. You need a constructive argument to support the MWI counting process. Throwing mud in the form of cheap soundbites doesn't cut it.kered rettop said:It depends what you mean by simple. Introducing probability as a primitive complicates the fundamentals of the theory. It may simplify the development of the theory. Occam's Razor vs Shut Up And Calculate.
Sorry, I misinterpreted your post.kered rettop said:Oh good grief!
"do have to justify" not "do justify"!!!
Hardly a theory. Just the status of probability.PeroK said:I don't see how what is proposed can claim the moral high ground and insinuate a shut up and calculate accusation against a probabilistic theory.
Somebody might. I don't, since I am not advocating anything.PeroK said:You need a constructive argument to support the MWI counting process.
Oh, it's much worse than that. I have only just realized what you've been talking about. Even if I'd used a phrase which you found acceptable, my point would have been invalid. SUAC isn't so bad in the context of my misundertanding.PeroK said:Throwing mud in the form of cheap soundbites doesn't cut it.