Even the PTI? With the given description, that’s really really weird.
Weird, but true! See the discussion of PTI in the paper I link to in this comment. As far as I can tell, PTI is just a relabeling of the original TI. Where TI would have said only one branch is real and the other branches do not exist, PTI says only one branch is actual and the others are real but not actual. Our universe consists only of that which is actual, so the other branches are not part of our universe. They exist in other possible universes, which (and this is the innovation, I take it) happen to be real. I don’t see how merely renaming the selection procedure from “collapse” to “actualization” helps, but I will admit to not having read that much about the PTI.
I’m reminded of David Lewis’s response to Armstrong’s theory of laws of nature. According to Armstrong, two properties are associated in a law-like manner if and only if there is a specific second-order relation that holds between them. Armstrong labels this relation the “necessitation relation” and claims to have thereby accounted for the ineluctable character of the laws. Lewis responds: “I say that [Armstrong’s ‘necessitation relation’] deserves the name of ‘necessitation’ only if, somehow, it really can enter into the requisite necessary connections. It can’t enter into them just by bearing a name, any more than one can have mighty biceps just by being called ‘Armstrong.’”
I think you’ll agree that the observed frequencies confirm the conjunction of Schrodinger’s Equation with the Born Rule.
This is actually a tricky claim to adjudicate from the perspective of MWI. It’s certainly true that the relative frequencies of experimental results in our world support the Born rule. But why should the reference class be restricted to our world? For someone who has seriously absorbed MWI, this is akin to declaring that you only care about the frequencies of experimental results in North America. If you include all experimental results in your reference class, including those from other worlds, it is no longer the case that they confirm the Born rule unless you already assign weights to worlds based on the Born rule. But of course, assigning weights to worlds in this way would be question-begging if you were trying to provide evidence for the Born rule itself.
To put it another way, as a proponent of the MWI you believe that there are real scientists out there, in other branches of the wave function, who perform their experiments with just as much care and diligence as you do and who end up with wholly different observed frequencies within their world. What makes you think you have the right frequencies and they don’t?
But of course, assigning weights to worlds in this way would be question-begging if you were trying to provide evidence for the Born rule itself.
You have completely missed my point. It’s the difference between, on the one hand: proving that there is life on Earth, and on the other proving that if there is life in the universe, it must be on Earth.
Where TI would have said only one branch is real and the other branches do not exist, PTI says only one branch is actual and the others are real but not actual.
actual = the branch we’re observing.
real = part of the wavefunction of the universe.
I maintain my position that it’s the same thing as MWI.
To put it another way, as a proponent of the MWI you believe that there are real scientists out there, in other branches of the wave function, who perform their experiments with just as much care and diligence as you do and who end up with wholly different observed frequencies within their world. What makes you think you have the right frequencies and they don’t?
Please clarify the question. Do you identify these scientists using the Born Rule to interpret the wavefunction so as to provide the basis for their consciousness, and making them just really unlucky in the outcomes? Because in that case, for every one of them, there are sixty gazillion jillion squillion ridiculillion others that get the same frequencies we get. This is very unlucky for them. Prospectively, we could expect their frequencies to fall in line immediately (and of course we can also expect that a vanishingly small measure of them will continue to fail to do so).
OR, are you finding these scientists out there in the wavefunction without using the Born Rule to interpret the wavefunction when identifying their consciousness, but using some other rule instead? If so, then the Born Rule isn’t right for them.
Weird, but true! See the discussion of PTI in the paper I link to in this comment. As far as I can tell, PTI is just a relabeling of the original TI. Where TI would have said only one branch is real and the other branches do not exist, PTI says only one branch is actual and the others are real but not actual. Our universe consists only of that which is actual, so the other branches are not part of our universe. They exist in other possible universes, which (and this is the innovation, I take it) happen to be real. I don’t see how merely renaming the selection procedure from “collapse” to “actualization” helps, but I will admit to not having read that much about the PTI.
I’m reminded of David Lewis’s response to Armstrong’s theory of laws of nature. According to Armstrong, two properties are associated in a law-like manner if and only if there is a specific second-order relation that holds between them. Armstrong labels this relation the “necessitation relation” and claims to have thereby accounted for the ineluctable character of the laws. Lewis responds: “I say that [Armstrong’s ‘necessitation relation’] deserves the name of ‘necessitation’ only if, somehow, it really can enter into the requisite necessary connections. It can’t enter into them just by bearing a name, any more than one can have mighty biceps just by being called ‘Armstrong.’”
This is actually a tricky claim to adjudicate from the perspective of MWI. It’s certainly true that the relative frequencies of experimental results in our world support the Born rule. But why should the reference class be restricted to our world? For someone who has seriously absorbed MWI, this is akin to declaring that you only care about the frequencies of experimental results in North America. If you include all experimental results in your reference class, including those from other worlds, it is no longer the case that they confirm the Born rule unless you already assign weights to worlds based on the Born rule. But of course, assigning weights to worlds in this way would be question-begging if you were trying to provide evidence for the Born rule itself.
To put it another way, as a proponent of the MWI you believe that there are real scientists out there, in other branches of the wave function, who perform their experiments with just as much care and diligence as you do and who end up with wholly different observed frequencies within their world. What makes you think you have the right frequencies and they don’t?
You have completely missed my point. It’s the difference between, on the one hand: proving that there is life on Earth, and on the other proving that if there is life in the universe, it must be on Earth.
actual = the branch we’re observing.
real = part of the wavefunction of the universe.
I maintain my position that it’s the same thing as MWI.
Please clarify the question. Do you identify these scientists using the Born Rule to interpret the wavefunction so as to provide the basis for their consciousness, and making them just really unlucky in the outcomes? Because in that case, for every one of them, there are sixty gazillion jillion squillion ridiculillion others that get the same frequencies we get. This is very unlucky for them. Prospectively, we could expect their frequencies to fall in line immediately (and of course we can also expect that a vanishingly small measure of them will continue to fail to do so).
OR, are you finding these scientists out there in the wavefunction without using the Born Rule to interpret the wavefunction when identifying their consciousness, but using some other rule instead? If so, then the Born Rule isn’t right for them.