I have some questions for people who think they believe in quantum worlds that split and join, and/or in “timeless physics”.
Consider the sentence that you just read. The implication of such beliefs is that the person who started reading the sentence is not the same person who finished reading the sentence. According to the splitting quantum worlds idea, the person at the start would have split into many different people, who split into even more different people… by the time the sentence was finished. According to the timeless perspective, the person-moment who “began reading the sentence” and the person-moment who “finished reading the sentence” are fundamentally different entities, coexisting eternally in a universe where nothing actually changes.
Don’t confuse this with the commonplace observation that every experience changes you a little bit. According to that “theory”, first you exist, then you still exist but you’re a little bit different, then you’re still existing but you’re even more different, and so on for the rest of your life. The metaphysics there is of one person changing over time.
The metaphysics in these avantgarde theories is of one person who becomes many, who become many^2, who become very many… or of disconnected person-moments, none of which actually changes, but all of which “feel like” they are changing. The important aspect, for my argument, is the denial of continuity: the person at the end of the sentence is literally not the person at the beginning of the sentence; not the same person changed, but a different being. That is a remarkable thing to believe—and “remarkable” is an understatement. (It resembles some well-known delusions.)
Or perhaps that is not what believers think? I don’t know. Eliezer claims to believe in timelessness. He posts comments here, and presumably they take time to type out and submit; how does he reconcile this with his belief? As he goes through the motions, does he tell himself something like, “this ‘change’ is an illusion, this ‘change’ is an illusion, all that really exists is a set of unchanging Eliezers, frozen in different postures, which conceptually could be assembled into a causal sequence”?
As for many worlds that branch in time, it’s a little harder to make the argument that the concept is radically at odds with experience; someone can say, yes, I agree that subjective time is like a line, but a branching world is like a tree, and my line is like one branch of the tree. In other words, it seems that someone who believes in splitting quantum worlds does not have to deny any of their experience, they just have to claim that stuff happened that they didn’t feel and don’t remember, namely the branching off of their other selves. Is this how many-worlds believers reconcile their beliefs with their experience? If so, then there are further stages to the critique, but before I go there, I want a better idea of what people are actually thinking.
Obviously I’m a skeptic about these positions, to put it mildly. So what I want to know is why people believe them, and how they reconcile their metaphysical position with the facts of their moment-to-moment experience. Is this even seen as a problem? Was there a time in your life when you struggled to make sense of the disparity? Did you take such a belief for granted, and then only later realize that it might be in contradiction with basic appearances? I am interested in hearing arguments and explanations, but also in anecdotes recounting episodes of philosophical worry and resolution—thoughts you had and how you reacted to them.
According to the timeless perspective, the person-moment who “began reading the sentence” and the person-moment who “finished reading the sentence” are fundamentally different entities, coexisting eternally in a universe where nothing actually changes.
The only problem here seems to be the incorrect application of English words and intuitions to more complicated physical propositions.
The main problem is that in a timeless universe, there is no time, therefore there is no change, therefore no thing can become another thing, therefore the person at the beginning of the sentence can’t become the person at the end of the sentence.
Maybe you have a timeless definition of person as a set of person-moments, and this allows you to nominally regard the person who started reading the sentence and the person who finished reading the sentence as parts of the same overall person.
Nonetheless, the denial that time exists implies a denial that change exists, and this introduces a disjunction between successive person-moments that is metaphysically incredibly radical because it is so utterly in opposition to experience. It denies that one moment becomes the next moment; instead they’re just neighbors in Platonia, or something.
ETA: I’ve thought of another aspect of the strange implications of eliminating change from your model of reality. Not only is it an illusion to think that the present moment was previously a different one, it’s also a mistake to think that the present moment ever ends. The next moment never arrives because that would require change.
And another way to express my point about the person at the start of the sentence being different from the person at the end of the sentence, is that, if change is not real, then each moment is a separate center of subjectivity, rather than stages in the evolution of a single center of subjectivity. By a center of subjectivity I mean something that is a locus and an agent of subjective activity, especially reflective or higher-order thought in which mental states themselves become objects of awareness. Most of us may lack the combination of “luminosity” and articulateness required to talk about these matters with great precision, but hopefully you will agree that thought sometimes has the characteristic of consciously compounding on itself: one thought becomes part of the next thought which becomes part of the thought after that.
I would also claim that part of this experience involves perceiving the preceding thought as something that you thought. Really, all I’m calling attention to here is one form of experience of time’s passage, that is internal rather than external. Its significance in the present discussion is that, if there is no such thing as change, then again we have to treat significant components of the experience as illusory. If you are a static, timelessly-existing person-moment, thinking a higher-order thought which seems to have been created by reflective use of a thought you had just a moment ago—then you’re deluded, because there was no “just a moment ago”.
The only reason I’m not just flatly declaring that time obviously passes and that timeless ontologies are therefore obviously false, is the phenomenon of illusory continuity of consciousness after anesthesia. Roko reminded me of this once, and I think I may have experienced it myself, many years ago—the feeling that no time has lapsed, when in fact you just had an operation but you were unconscious.
The implications of timelessness for consciousness take this to the ultimate extreme: every moment of your life in which you feel as if the present moment evolved out of an immediately previous moment, has to involve the same illusion. As I have endeavored to point out, it’s also a mistake to think that the present moment ever ends (we can’t call this an illusion because you don’t perceive the future coming, you only perceive the past going, and an illusion is a mistaken perception; so I’ll call this a mistake instead), and aspects of reflective phenomenology have to be wrong too.
So even if I cannot truly disprove timelessness, I can at least point out that it is a skeptical hypothesis at least as extreme as “we’re living in a simulation”. That’s skepticism in the philosophical sense—doubt as to whether there is an external world, or other people are conscious, or the world existed five minutes ago. Frankly, I think timelessness is more extreme than simulationism, because it asks me to deny something even more fundamental than belief in the external world, namely, belief that change is real and that the present that I experience flowed out of the past that I remember.
I have the strong impression that one reason people adopt timelessness (when they do) is that they only have timeless models. Modern physics spatializes time, and it seems it’s always a small step from adopting a conceptual tool to believing that reality fits the shape of the tool perfectly, e.g. from “reality can be described by numbers” to “reality is numbers”. Ever since relativity, time has become just another spatial coordinate, and experienced time is explained as something to do with the thermodynamic arrow of time, applied to memory formation and retrieval. Well, thermodynamics can create a particular timelike ordering of events in your space-time manifold, but I don’t think it explains the experience of time, and it doesn’t provide an ontology which “re-temporalizes” time, it doesn’t give a genuinely time-like character back to time.
So hey wedrifid, I think your demure one-sentence response has given me a lot of what I wanted. I do maintain that utterly basic features of experience all but refute timelessness, and I suspect that believers in timelessness hang onto it only because they don’t see a way to think rigorously about time in its phenomenological aspect, whereas they do have rigorous formalisms that don’t contain time, except as a coordinate. So time, in the original and intimately known sense of the word, is sacrificed for the sake of belief in the ontological completeness of the available, timeless formalisms. (Incidentally, my own strong preference would be to find a quantitatively successful formalism for physics whose notion of time can be reinfused with the metaphysics implied by the experience of time, that is, time as change, and not just as another direction in space.)
If I have a paper containing an arrow, it makes sense to say that here the arrow “begins” and here the arrow “ends”, even if the paper is not changing in time, and our intuitions of “beginning” and “ending” are usually time-related.
Similarly, in a timeless universe there is a “before” and “after”, as if you imagine moments in space-time connected by tiny arrows. The universe is not moving, but a moment A is before a moment B because they are connected by such arrow, which means there is a mathematical relation between them.
A person P2 at the end of reading a sentence is thus mathematically connected to a person P1 at the beginning of reading a sentence. This connection (together with million details about human physiology) means that the mind of P2 is similar to the mind of P1, with some sentence-related changes. Being connected by a time arrow is “becoming”, and it implies similarity.
Time exists inside of the universe. It does not exist for a hypothetical observer outside of the universe. We are people living inside of the universe, what’s why it is so opposed to our experience. (However we have experience with books and movies, and the idea that the book itself does not change when we read it, is not opposed to our experience.)
It denies that one moment becomes the next moment; instead they’re just neighbors in Platonia, or something.
To be “just neighbors” they have to follow some mathematical laws (known inside of the universe as the laws of physics). They are not just two different things randomly put together. Those mathematical laws are what creates the time.
If I make a model of you using some lines on paper, I don’t get to say that fundamentally you are just lines on paper, but that “inside the model” you’re a real person. For the same reason, just because you can make a diagram of time that is not “made of time”, doesn’t mean you can say that the universe itself is timeless.
In an early paper, Max Tegmark struggles to define his concept of possible worlds. He starts out by defining “formal systems” (page 5). There’s lots of talk about letters, strings, rules. So wait, is he going to say that reality is made of letters? Well, no, he manages on the next page to get as far as talking about equivalence classes of formal systems, and then saying “When we speak of a mathematical structure, we will mean such an equivalence class, i.e., that structure which is independent of our way of describing it.” This is still rather confused—he equates a mathematical structure with the set of all formal systems which describe the mathematical structure. So possible worlds still seem to be based in manipulations of letters, but now the possible world is something that mysteriously and platonically inhabits a manipulation of letters (and other letter-manipulations in the same class).
The point is that for certain topics, the conceptual and notational system for reasoning about X tends to be substituted for X itself. Possible worlds are identified with formal systems that represent them, and time is identified with a sequence of imaginary arrows. I think the reason for the substitution is obvious: the properties of the representation are less elusive and easier to talk about, than the properties of the reality that they represent. It’s easier to talk about rules for rewriting a string of symbols, or about chains of little arrows, than it is to talk about possibility and change.
Time exists inside of the universe. It does not exist for a hypothetical observer outside of the universe.
Now I’m wondering: does the ‘outside the universe view’ come into contradiction with the whole thou art physics thing? How could our brains run an algorithm for a super-physical perspective?
I have almost no idea what to do with this observation, but I think there’s a point of disanalogy between geometric and temporal continua, even if we take geometric continua to be ‘directional’.
Take a geometrical line from A to B. Here, we have a pair of limits and the extension between them. Now take a temporal continuum. But let’s understand the temporal continuum as the time of some particular change. So a block of wood bleaches in the sun, going from dark to pale. The temporal continuum we’re concerned with is the time that this change takes (say, one week).
So suppose this temporal continuum also has two limits, C (at the beginning) and D (at the end of the change), and an extension between them. Geometrical continua needn’t actually have minima and maxima, the ‘line on a paper’ is a case where they do. If this is so, then geometrical and temporal continua are in this sense analogous. But there’s a problem with the idea that temporal continua have a minimum. Suppose C is an indivisible moment. Has any change been accomplished at C? If yes, then given that no change can be accomplished in a moment (since there is no temporal difference), there must be previous moment at which some change had been accomplished, and therefore C is not early enough to be the first moment of the change.
If no change has been accomplished at C, then C is too early to be the first moment: it is not properly called part of the time of the change. So no matter what, the moment C cannot be the first moment of change.
Nothing prevents us from having a last moment, but temporal continua (so long as they are considered the time of some particular change) cannot have a first moment. Temporal continua can have greatest lower bounds, but no actual minimum.
I am interested in hearing arguments and explanations, but also in anecdotes recounting episodes of philosophical worry and resolution—thoughts you had and how you reacted to them.
Well, I certainly possess the intuitive model of personal identity that you refer to here, which includes the idea that I am a unique entity which we can call a “person”, distinct from all other entities at any given moment, and that I have an existence that extends throughout a region of time in a very specific way.
And I agree that this intuitive model is in tension with the timeless model you refer to here, which includes the idea that I am a set of unique entities which we can call “person-moments”, which are not only distinct from all other entities at any given moment but also distinct from all other entities at all other moments.
That said, by the time I was introduced to the timeless model, I had long since reconciled myself to the fact that what I mean by “I” is an extremely variable and often inconsistent thing.
This caused me some philosophical worry in my late teens, but eventually I got clear in my head that “I” is a symbol I manipulate, and that most of my intuitions about identity are based on manipulations of that symbol, and if there is any underlying unique distinct referent for that symbol (whether a person that changes, or a set of person-moments that are connected in some way, or an immortal soul that exists outside of time and space, or something else) it’s nevertheless a mistake to attribute to that referent properties that are properly ascribed to the symbol.
So, no, it doesn’t much bother me that there are two models which imply different (even mutually exclusive) things about what “I” refers to. “I” refers to many different (even mutually exclusive) things. I’m cool with that.
I have the tree of subjective experience trails branching out in the direction of time’s arrow as a working hypothesis for thinking about personal identity. I’m using it as a way to seemingly consistently model various uploading and teleporting thought experiments that otherwise seem to lead to incongruities when you start getting into things like Moravec Transfer. I feel like I really should get deeper into analyzing the part where the tree hypothesis assumes no fundamental connections wrt. subjective self from present states toward future states, and the interpretation that assumes a continuity of self consistent with everyday intuitions seems to assume one. (That would be a thing that gets cut if someone breaks your original body apart and replaces it with a perfect replica in the span of a nanosecond, but stays intact during normal waking hours. Jury’s out on what happens when you fall asleep or flatline during a therapeutic coma.)
Don’t know enough physics to have an opinion on MWI versus collapse. Don’t know even more physics to have an opinion on timelessness. The motivating problems for me are more of the Reasons and Persons sort of stuff.
My answer to why I’m nevertheless experiencing the things happening right now is the somewhat unsatisfactory “because someone has to”. It feels like a continuous stream of experience because that someone is always operating on memory-carrying brain state that encodes the previous experiences.
I have some questions for people who think they believe in quantum worlds that split and join, and/or in “timeless physics”.
Consider the sentence that you just read. The implication of such beliefs is that the person who started reading the sentence is not the same person who finished reading the sentence. According to the splitting quantum worlds idea, the person at the start would have split into many different people, who split into even more different people… by the time the sentence was finished. According to the timeless perspective, the person-moment who “began reading the sentence” and the person-moment who “finished reading the sentence” are fundamentally different entities, coexisting eternally in a universe where nothing actually changes.
Don’t confuse this with the commonplace observation that every experience changes you a little bit. According to that “theory”, first you exist, then you still exist but you’re a little bit different, then you’re still existing but you’re even more different, and so on for the rest of your life. The metaphysics there is of one person changing over time.
The metaphysics in these avantgarde theories is of one person who becomes many, who become many^2, who become very many… or of disconnected person-moments, none of which actually changes, but all of which “feel like” they are changing. The important aspect, for my argument, is the denial of continuity: the person at the end of the sentence is literally not the person at the beginning of the sentence; not the same person changed, but a different being. That is a remarkable thing to believe—and “remarkable” is an understatement. (It resembles some well-known delusions.)
Or perhaps that is not what believers think? I don’t know. Eliezer claims to believe in timelessness. He posts comments here, and presumably they take time to type out and submit; how does he reconcile this with his belief? As he goes through the motions, does he tell himself something like, “this ‘change’ is an illusion, this ‘change’ is an illusion, all that really exists is a set of unchanging Eliezers, frozen in different postures, which conceptually could be assembled into a causal sequence”?
As for many worlds that branch in time, it’s a little harder to make the argument that the concept is radically at odds with experience; someone can say, yes, I agree that subjective time is like a line, but a branching world is like a tree, and my line is like one branch of the tree. In other words, it seems that someone who believes in splitting quantum worlds does not have to deny any of their experience, they just have to claim that stuff happened that they didn’t feel and don’t remember, namely the branching off of their other selves. Is this how many-worlds believers reconcile their beliefs with their experience? If so, then there are further stages to the critique, but before I go there, I want a better idea of what people are actually thinking.
Obviously I’m a skeptic about these positions, to put it mildly. So what I want to know is why people believe them, and how they reconcile their metaphysical position with the facts of their moment-to-moment experience. Is this even seen as a problem? Was there a time in your life when you struggled to make sense of the disparity? Did you take such a belief for granted, and then only later realize that it might be in contradiction with basic appearances? I am interested in hearing arguments and explanations, but also in anecdotes recounting episodes of philosophical worry and resolution—thoughts you had and how you reacted to them.
The only problem here seems to be the incorrect application of English words and intuitions to more complicated physical propositions.
The main problem is that in a timeless universe, there is no time, therefore there is no change, therefore no thing can become another thing, therefore the person at the beginning of the sentence can’t become the person at the end of the sentence.
Maybe you have a timeless definition of person as a set of person-moments, and this allows you to nominally regard the person who started reading the sentence and the person who finished reading the sentence as parts of the same overall person.
Nonetheless, the denial that time exists implies a denial that change exists, and this introduces a disjunction between successive person-moments that is metaphysically incredibly radical because it is so utterly in opposition to experience. It denies that one moment becomes the next moment; instead they’re just neighbors in Platonia, or something.
ETA: I’ve thought of another aspect of the strange implications of eliminating change from your model of reality. Not only is it an illusion to think that the present moment was previously a different one, it’s also a mistake to think that the present moment ever ends. The next moment never arrives because that would require change.
And another way to express my point about the person at the start of the sentence being different from the person at the end of the sentence, is that, if change is not real, then each moment is a separate center of subjectivity, rather than stages in the evolution of a single center of subjectivity. By a center of subjectivity I mean something that is a locus and an agent of subjective activity, especially reflective or higher-order thought in which mental states themselves become objects of awareness. Most of us may lack the combination of “luminosity” and articulateness required to talk about these matters with great precision, but hopefully you will agree that thought sometimes has the characteristic of consciously compounding on itself: one thought becomes part of the next thought which becomes part of the thought after that.
I would also claim that part of this experience involves perceiving the preceding thought as something that you thought. Really, all I’m calling attention to here is one form of experience of time’s passage, that is internal rather than external. Its significance in the present discussion is that, if there is no such thing as change, then again we have to treat significant components of the experience as illusory. If you are a static, timelessly-existing person-moment, thinking a higher-order thought which seems to have been created by reflective use of a thought you had just a moment ago—then you’re deluded, because there was no “just a moment ago”.
The only reason I’m not just flatly declaring that time obviously passes and that timeless ontologies are therefore obviously false, is the phenomenon of illusory continuity of consciousness after anesthesia. Roko reminded me of this once, and I think I may have experienced it myself, many years ago—the feeling that no time has lapsed, when in fact you just had an operation but you were unconscious.
The implications of timelessness for consciousness take this to the ultimate extreme: every moment of your life in which you feel as if the present moment evolved out of an immediately previous moment, has to involve the same illusion. As I have endeavored to point out, it’s also a mistake to think that the present moment ever ends (we can’t call this an illusion because you don’t perceive the future coming, you only perceive the past going, and an illusion is a mistaken perception; so I’ll call this a mistake instead), and aspects of reflective phenomenology have to be wrong too.
So even if I cannot truly disprove timelessness, I can at least point out that it is a skeptical hypothesis at least as extreme as “we’re living in a simulation”. That’s skepticism in the philosophical sense—doubt as to whether there is an external world, or other people are conscious, or the world existed five minutes ago. Frankly, I think timelessness is more extreme than simulationism, because it asks me to deny something even more fundamental than belief in the external world, namely, belief that change is real and that the present that I experience flowed out of the past that I remember.
I have the strong impression that one reason people adopt timelessness (when they do) is that they only have timeless models. Modern physics spatializes time, and it seems it’s always a small step from adopting a conceptual tool to believing that reality fits the shape of the tool perfectly, e.g. from “reality can be described by numbers” to “reality is numbers”. Ever since relativity, time has become just another spatial coordinate, and experienced time is explained as something to do with the thermodynamic arrow of time, applied to memory formation and retrieval. Well, thermodynamics can create a particular timelike ordering of events in your space-time manifold, but I don’t think it explains the experience of time, and it doesn’t provide an ontology which “re-temporalizes” time, it doesn’t give a genuinely time-like character back to time.
So hey wedrifid, I think your demure one-sentence response has given me a lot of what I wanted. I do maintain that utterly basic features of experience all but refute timelessness, and I suspect that believers in timelessness hang onto it only because they don’t see a way to think rigorously about time in its phenomenological aspect, whereas they do have rigorous formalisms that don’t contain time, except as a coordinate. So time, in the original and intimately known sense of the word, is sacrificed for the sake of belief in the ontological completeness of the available, timeless formalisms. (Incidentally, my own strong preference would be to find a quantitatively successful formalism for physics whose notion of time can be reinfused with the metaphysics implied by the experience of time, that is, time as change, and not just as another direction in space.)
If I have a paper containing an arrow, it makes sense to say that here the arrow “begins” and here the arrow “ends”, even if the paper is not changing in time, and our intuitions of “beginning” and “ending” are usually time-related.
Similarly, in a timeless universe there is a “before” and “after”, as if you imagine moments in space-time connected by tiny arrows. The universe is not moving, but a moment A is before a moment B because they are connected by such arrow, which means there is a mathematical relation between them.
A person P2 at the end of reading a sentence is thus mathematically connected to a person P1 at the beginning of reading a sentence. This connection (together with million details about human physiology) means that the mind of P2 is similar to the mind of P1, with some sentence-related changes. Being connected by a time arrow is “becoming”, and it implies similarity.
Time exists inside of the universe. It does not exist for a hypothetical observer outside of the universe. We are people living inside of the universe, what’s why it is so opposed to our experience. (However we have experience with books and movies, and the idea that the book itself does not change when we read it, is not opposed to our experience.)
To be “just neighbors” they have to follow some mathematical laws (known inside of the universe as the laws of physics). They are not just two different things randomly put together. Those mathematical laws are what creates the time.
If I make a model of you using some lines on paper, I don’t get to say that fundamentally you are just lines on paper, but that “inside the model” you’re a real person. For the same reason, just because you can make a diagram of time that is not “made of time”, doesn’t mean you can say that the universe itself is timeless.
In an early paper, Max Tegmark struggles to define his concept of possible worlds. He starts out by defining “formal systems” (page 5). There’s lots of talk about letters, strings, rules. So wait, is he going to say that reality is made of letters? Well, no, he manages on the next page to get as far as talking about equivalence classes of formal systems, and then saying “When we speak of a mathematical structure, we will mean such an equivalence class, i.e., that structure which is independent of our way of describing it.” This is still rather confused—he equates a mathematical structure with the set of all formal systems which describe the mathematical structure. So possible worlds still seem to be based in manipulations of letters, but now the possible world is something that mysteriously and platonically inhabits a manipulation of letters (and other letter-manipulations in the same class).
The point is that for certain topics, the conceptual and notational system for reasoning about X tends to be substituted for X itself. Possible worlds are identified with formal systems that represent them, and time is identified with a sequence of imaginary arrows. I think the reason for the substitution is obvious: the properties of the representation are less elusive and easier to talk about, than the properties of the reality that they represent. It’s easier to talk about rules for rewriting a string of symbols, or about chains of little arrows, than it is to talk about possibility and change.
Now I’m wondering: does the ‘outside the universe view’ come into contradiction with the whole thou art physics thing? How could our brains run an algorithm for a super-physical perspective?
I have almost no idea what to do with this observation, but I think there’s a point of disanalogy between geometric and temporal continua, even if we take geometric continua to be ‘directional’.
Take a geometrical line from A to B. Here, we have a pair of limits and the extension between them. Now take a temporal continuum. But let’s understand the temporal continuum as the time of some particular change. So a block of wood bleaches in the sun, going from dark to pale. The temporal continuum we’re concerned with is the time that this change takes (say, one week).
So suppose this temporal continuum also has two limits, C (at the beginning) and D (at the end of the change), and an extension between them. Geometrical continua needn’t actually have minima and maxima, the ‘line on a paper’ is a case where they do. If this is so, then geometrical and temporal continua are in this sense analogous. But there’s a problem with the idea that temporal continua have a minimum. Suppose C is an indivisible moment. Has any change been accomplished at C? If yes, then given that no change can be accomplished in a moment (since there is no temporal difference), there must be previous moment at which some change had been accomplished, and therefore C is not early enough to be the first moment of the change.
If no change has been accomplished at C, then C is too early to be the first moment: it is not properly called part of the time of the change. So no matter what, the moment C cannot be the first moment of change.
Nothing prevents us from having a last moment, but temporal continua (so long as they are considered the time of some particular change) cannot have a first moment. Temporal continua can have greatest lower bounds, but no actual minimum.
Well, I certainly possess the intuitive model of personal identity that you refer to here, which includes the idea that I am a unique entity which we can call a “person”, distinct from all other entities at any given moment, and that I have an existence that extends throughout a region of time in a very specific way.
And I agree that this intuitive model is in tension with the timeless model you refer to here, which includes the idea that I am a set of unique entities which we can call “person-moments”, which are not only distinct from all other entities at any given moment but also distinct from all other entities at all other moments.
That said, by the time I was introduced to the timeless model, I had long since reconciled myself to the fact that what I mean by “I” is an extremely variable and often inconsistent thing.
This caused me some philosophical worry in my late teens, but eventually I got clear in my head that “I” is a symbol I manipulate, and that most of my intuitions about identity are based on manipulations of that symbol, and if there is any underlying unique distinct referent for that symbol (whether a person that changes, or a set of person-moments that are connected in some way, or an immortal soul that exists outside of time and space, or something else) it’s nevertheless a mistake to attribute to that referent properties that are properly ascribed to the symbol.
So, no, it doesn’t much bother me that there are two models which imply different (even mutually exclusive) things about what “I” refers to. “I” refers to many different (even mutually exclusive) things. I’m cool with that.
I have the tree of subjective experience trails branching out in the direction of time’s arrow as a working hypothesis for thinking about personal identity. I’m using it as a way to seemingly consistently model various uploading and teleporting thought experiments that otherwise seem to lead to incongruities when you start getting into things like Moravec Transfer. I feel like I really should get deeper into analyzing the part where the tree hypothesis assumes no fundamental connections wrt. subjective self from present states toward future states, and the interpretation that assumes a continuity of self consistent with everyday intuitions seems to assume one. (That would be a thing that gets cut if someone breaks your original body apart and replaces it with a perfect replica in the span of a nanosecond, but stays intact during normal waking hours. Jury’s out on what happens when you fall asleep or flatline during a therapeutic coma.)
Don’t know enough physics to have an opinion on MWI versus collapse. Don’t know even more physics to have an opinion on timelessness. The motivating problems for me are more of the Reasons and Persons sort of stuff.
My answer to why I’m nevertheless experiencing the things happening right now is the somewhat unsatisfactory “because someone has to”. It feels like a continuous stream of experience because that someone is always operating on memory-carrying brain state that encodes the previous experiences.