Multiverse/fungibility

Post by hibbsa
On BoI someone recommended this book
http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199546961.0\
01.0001/acprof-9780199546961
<http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199546961.\
001.0001/acprof-9780199546961>
I looked at the chapters and didn't see anything about fungibility...and
I guess Deutsch.
I don't think MWI is correct, but....what do I do see is that his -
Deutsch's - realization about fungibility is the most important and
reasoned idea within MWI. You have to have it. You can't explain the
wave-function as it is before it is interupted without fungibility.
Not wanting to teach people to suck eggs but clearly, if you go down a
thousand metres into granite, all on your own, and set up a little
science lab and do the two-slit experiment. If you are seeing an
interuption, and if the explanation is going to be MWI-esque, then there
has to be a multiverse of other worlds, identical enough, that someone
just like you, just went 1000 metres into granite with the same just
the same kit and just the same ideas...such that he just did that same
experiment in the same instance such that you all get the wave function.

I think some of the language there is loose, but yes. That's the idea. There exist copies of you in other universes. Right now there are fungible copies of you which will become differentiated from you because of choices you make and because quantum events differentiate universes in which copies of you exist.

I'm not sure what the story about the person entering a granite hole 1000m deep is about. Is it just supposed to be strange enough that it seems improbably more than one person would do this? That's not that strange. We know what David has previously called "Harry Potter Universes" are real. These are places in the multiverse where everytime someone raises a wand, they can shout a command and lightening bolts can issue forth and strike down evil people. This happens. In some vanishingly small measure of universes. But it is wrong to think that the wand, the raising of it or the commands cause the lightning. It just so happens, in that universes, lightning bolts always follow such a sequence. But the next time someone tries this, it has exactly the same probability of occurring as it does h
ere. Namely, very, very close to zero.

I personally find none of this more amazing than contemplating what evaporation is. Yes...evaporation.

Consider first boiling water in one's kettle. It's at 100 Celsius, so why does it turn to gas? Well that's what water does at that temp at sea level. Why? Because temperature, to a first approximation is a measure of the kinetic energy of molecules. How much they are vibrating, that is. With water, they need to vibrate a lot to overcome molecular forces that keep them bound one to another. At 100 Celsius, and higher, The molecules have sufficient kinetic energy to break free of their neighbours, overcoming the molecular bonding between one molecule and the next and they become gas. Okay, well who cares?

Well what about evaporation?

Consider a luke warm glass of water - say about 30 celcius. Why does it, eventually, turn all to gas if it is not over the magic temperature of "boiling". Well the thing is that some of it - some few molecules - actually *are* over 100 Celsius even though on the other hand this statement makes no sense. After all, temperature is a measure of the average kinetic energy. To be precise, the (Boltzmann) distribution of all the molecules is centred around 30 celcius but some few are at or over 100 and some are below freezing.

In short, for pretty much any cold glass of water, some molecules are boiling. That, to me, is counterintuitive in the same way as any strageness that happens with the MW. It's simply a consequence of the explanation and consistent with how the mathematics describes what's *really* going on. I can no more reject the fact that there are some molecules of water - which are "boiling" in a glass of cool, 10 degree water, than I can reject that in a multiverse where I'm sitting here typing this reply to you...some small number of me is down a granite shaft doing an experiment.

Post by hibbsa
Yet it doesn't get mentioned by other proponents of the theory. Weird.

What's "it", exactly? People going down holes? Strange stuff? Well they might skirt the issue for bad philosophical issues. They might not talk about those Harry Potter universes. If you do *not* understand the whole explanation but you *can* understand what a Harry Potter universe is, and reject it on the basis of implausibility, then you will regard this as a successful criticism of MWI. You're wrong, but you don't know it. Because you have bad understanding and bad philosophy.

The lesson here is: don't open with Harry Potter universes, people going down holes or anything truly out there. Do what David does in FoR. Write a brilliant chapter called "Shadows" and just explain clearly how the *only* explanation we know of is the MWI to make sense of the twin slit experiment.

Apparently some other physicists are *not* taking it seriously enough. Maybe if they actually say how strange quantum theory really is, people will think *they* are strange. I get the impression this sort of thing happens a lot in physics. Some "macho" physicists want to be uber 'conservative' in saying 'we are not sure what this means' and as David shows this means they end up spouting absolute nonsense. It has always been the case. That it has been the case, on this issue, for so many decades now, is a travesty. It's as if most biologists were *still* committed to creationism while saying that evolution by natural selection as described first by Darwin, works only to make predictions (and, they admit, better than any other biological theory ever). We don't know who the creator is, they m
ight say, or how the guiding hand of that creation works (and there's no point asking these questions either) but we do know it seems "as if" mutations and natural selection is occurring. But we also know that's ridiculous...and no serious biologists would believe such a silly idea.

Brett.
[Non-text portions of this message have been removed]

urmenonhigh

2013-03-24 17:55:18 UTC

The above use of "fungible" lacks precision when attempting to discuss any individual living sentient being. The ongoing acceptance of this imprecision over the past twenty or thirty years has always resulted in a strange and useless conundrum when attempting to apply MWI to living sentient entities.
The quantum divergence would be so severe at the level of a central nervous system (CNS) that any suggestion that fungible copies of an individual's CNS exist is absurd. Any scientific discussion of MWI that implies quantum copies of sentient beings are fungible is philosophically meaningless.
Imagine a science fiction story in which a quantum copy of an individual is held accountable for the transgressions of another quantum copy because they were considered "fungible". Obviously an objective interpretation of quantum behavior at the probabilistic level is of limited scope when attempting to completely understand a universe in which living sentient beings actually exist and whose essential property is what they subjectively remember from a moment ago.

Post by Brett Hall
I'm not sure what the story about the person entering a granite hole 1000m deep is about. Is it just supposed to be strange enough that it seems improbably more than one person would do this? That's not that strange. We know what David has previously called "Harry Potter Universes" are real. These are places in the multiverse where everytime someone raises a wand, they can shout a command and lightening bolts can issue forth and strike down evil people. This happens. In some vanishingly small measure of universes. But it is wrong to think that the wand, the raising of it or the commands cause the lightning. It just so happens, in that universes, lightning bolts always follow such a sequence. But the next time someone tries this, it has exactly the same probability of occurring as it does here. Namely, very, very close to zero.
I personally find none of this more amazing than contemplating what evaporation is. Yes...evaporation.
Consider first boiling water in one's kettle. It's at 100 Celsius, so why does it turn to gas? Well that's what water does at that temp at sea level. Why? Because temperature, to a first approximation is a measure of the kinetic energy of molecules. How much they are vibrating, that is. With water, they need to vibrate a lot to overcome molecular forces that keep them bound one to another. At 100 Celsius, and higher, The molecules have sufficient kinetic energy to break free of their neighbours, overcoming the molecular bonding between one molecule and the next and they become gas. Okay, well who cares?
Well what about evaporation?
Consider a luke warm glass of water - say about 30 celcius. Why does it, eventually, turn all to gas if it is not over the magic temperature of "boiling". Well the thing is that some of it - some few molecules - actually *are* over 100 Celsius even though on the other hand this statement makes no sense. After all, temperature is a measure of the average kinetic energy. To be precise, the (Boltzmann) distribution of all the molecules is centred around 30 celcius but some few are at or over 100 and some are below freezing.
In short, for pretty much any cold glass of water, some molecules are boiling. That, to me, is counterintuitive in the same way as any strageness that happens with the MW. It's simply a consequence of the explanation and consistent with how the mathematics describes what's *really* going on. I can no more reject the fact that there are some molecules of water - which are "boiling" in a glass of cool, 10 degree water, than I can reject that in a multiverse where I'm sitting here typing this reply to you...some small number of me is down a granite shaft doing an experiment.

Post by hibbsa
Yet it doesn't get mentioned by other proponents of the theory. Weird.

What's "it", exactly? People going down holes? Strange stuff? Well they might skirt the issue for bad philosophical issues. They might not talk about those Harry Potter universes. If you do *not* understand the whole explanation but you *can* understand what a Harry Potter universe is, and reject it on the basis of implausibility, then you will regard this as a successful criticism of MWI. You're wrong, but you don't know it. Because you have bad understanding and bad philosophy.
The lesson here is: don't open with Harry Potter universes, people going down holes or anything truly out there. Do what David does in FoR. Write a brilliant chapter called "Shadows" and just explain clearly how the *only* explanation we know of is the MWI to make sense of the twin slit experiment.
Apparently some other physicists are *not* taking it seriously enough. Maybe if they actually say how strange quantum theory really is, people will think *they* are strange. I get the impression this sort of thing happens a lot in physics. Some "macho" physicists want to be uber 'conservative' in saying 'we are not sure what this means' and as David shows this means they end up spouting absolute nonsense. It has always been the case. That it has been the case, on this issue, for so many decades now, is a travesty. It's as if most biologists were *still* committed to creationism while saying that evolution by natural selection as described first by Darwin, works only to make predictions (and, they admit, better than any other biological theory ever). We don't know who the creator is, they might say, or how the guiding hand of that creation works (and there's no point asking these questions either) but we do know it seems "as if" mutations and natural selection is occurring. But we also know that's ridiculous...and no serious biologists would believe such a silly idea.
Brett.
[Non-text portions of this message have been removed]

Alan Forrester

2013-03-24 18:42:27 UTC

Two objects that are fungible are "identical in literally every way except that there are two of them." (BoI, p. 265) Suppose there are two distinct versions of Jim, one of which has done something bad like murder Pete. The version of Jim that murdered Pete is not the same as the version of Jim that did not murder Pete, so they are not fungible.

However, there are multiple fungible instances of each version of Jim that is not fungible with other versions of Jim. Only instances of a system that are fungible with one another can undergo quantum interference. Many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another: this is required for the existence of stable atoms.

Alan

urmenonhigh

2013-03-25 00:52:25 UTC

Two objects that are fungible are "identical in literally every way except that there are two of them." (BoI, p. 265) Suppose there are two distinct versions of Jim, one of which has done something bad like murder Pete. The version of Jim that murdered Pete is not the same as the version of Jim that did not murder Pete, so they are not fungible.
However, there are multiple fungible instances of each version of Jim that is not fungible with other versions of Jim. Only instances of a system that are fungible with one another can undergo quantum interference. Many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another: this is required for the existence of stable atoms.
Alan

While many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another, they do so within a certain instantiation of "Jim". This copy of "Jim" is the only Jim in question. Attempting to discuss some other "Jim" in terms of MWI still obscures the true nature of Jim's personhood and only leads to confusion and misunderstanding at a philosophical level.

Brett Hall

2013-03-25 01:50:56 UTC

Two objects that are fungible are "identical in literally every way except that there are two of them." (BoI, p. 265) Suppose there are two distinct versions of Jim, one of which has done something bad like murder Pete. The version of Jim that murdered Pete is not the same as the version of Jim that did not murder Pete, so they are not fungible.
However, there are multiple fungible instances of each version of Jim that is not fungible with other versions of Jim. Only instances of a system that are fungible with one another can undergo quantum interference. Many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another: this is required for the existence of stable atoms.
Alan

While many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another, they do so within a certain instantiation of "Jim".

So you admit that all of the electrons, protons and other particles that compose Jim have fungible counterparts, but that together, collectively, there is no fungible counterpart of Jim?

Does this seem to you to be a strict logical contradiction? It does to me.

Post by urmenonhigh
This copy of "Jim" is the only Jim in question.

No, it's not. Although...what's the question in question that you're worried about?

There are *copies* of Jim in question that are not Jim. Namely, copies that are *not* fungible.

Jim can have many fungible copies of himself that can differentiate later and cease to be fungible. Copies that *are* fungible, I am not sure about. Are my fungible copies me? I don't know. I don't know that anyone does.

The subjective experience of *being* Jim is not explained by this theory. But then, it's not explained by any theory. The Nature of Subjectivity - consciousness - is an open question. But prima facie, I do not see why this concept of fungibility or MWI presents any new problems for philosophical questions about personal identity.

The same old problems apply. How can an objective universe give rise to subjectivity? How are descriptions of how the world is - ever communicate what it's like to actually be that which is described? MWI and fungibility is altogether silent on this.

Every scientific theory is. So what?

Post by urmenonhigh
Attempting to discuss some other "Jim" in terms of MWI still obscures the true nature of Jim's personhood

Then tell us...what is the "true nature of Jim's personhood"?

I assert that whatever it is, we don't have a good explanation of it yet.

It has something to do with Jim's ideas. It has something to do with his ability to be a creative agent. It has something to do with his subjective experience of qualia - his consciousness. But I've not yet heard a satisfactory explanation of this that ties it all to physics. As such, some non-existent theory cannot possibly refute well-established physics.

What theory of personhood do you have that would be inconsistent with this view of the MWI?

Post by urmenonhigh
and only leads to confusion and misunderstanding at a philosophical level.

No. Objections to the MWI lead to confusion and misunderstanding "at a philosophical level". And infact, every other level too. Whatever the "true nature" of personhood turns out to be, my guess is it will be entirely consistent with the MWI. One possibility is that it refutes MWI...though I am not sure how that could be. An infinite number of things could refute MWI, but I'm not worried until one actually does. Meantime, our best theory is that physical reality is explained by MWI.

We don't have a theory of subjective personhood.

What is it about this poorly described problem (that is, what personhood actually is) that you think will be inconsistent with MWI (i.e: quantum theory)?

Brett.
[Non-text portions of this message have been removed]

Bruno Marchal

2013-03-25 15:37:08 UTC

Post by hibbsa
On BoI someone recommended this book
http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199546961.0

Post by hibbsa
01.0001/acprof-9780199546961
<http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199546961

Post by hibbsa
001.0001/acprof-9780199546961>
I looked at the chapters and didn't see anything about fungibility...and
I guess Deutsch.
I don't think MWI is correct, but....what do I do see is that his -
Deutsch's - realization about fungibility is the most important and
reasoned idea within MWI. You have to have it. You can't explain the
wave-function as it is before it is interupted without fungibility.
Not wanting to teach people to suck eggs but clearly, if you go down a
thousand metres into granite, all on your own, and set up a little
science lab and do the two-slit experiment. If you are seeing an
interuption, and if the explanation is going to be MWI- esque, then there
has to be a multiverse of other worlds, identical enough, that someone
just like you, just went 1000 metres into granite with the same just
the same kit and just the same ideas...such that he just did that same
experiment in the same instance such that you all get the wave function.

Two objects that are fungible are "identical in literally every way except that there are two of them." (BoI, p. 265) Suppose there are two distinct versions of Jim, one of which has done something bad like murder Pete. The version of Jim that murdered Pete is not the same as the version of Jim that did not murder Pete, so they are not fungible.
However, there are multiple fungible instances of each version of Jim that is not fungible with other versions of Jim. Only instances of a system that are fungible with one another can undergo quantum interference. Many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another: this is required for the existence of stable atoms.
Alan

While many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another, they do so within a certain instantiation of "Jim".

So you admit that all of the electrons, protons and other particles
that compose Jim have fungible counterparts, but that together,
collectively, there is no fungible counterpart of Jim?
Does this seem to you to be a strict logical contradiction? It does to me.

This copy of "Jim" is the only Jim in question.

That's not correct. Testable theories exist. It is just that the
solution does not fit the mood of the time, plausibly since theology
has been abandoned to political authorities, and progress are ignored.

Post by Brett Hall
But prima facie, I do not see why this concept of fungibility or MWI
presents any new problems for philosophical questions about personal
identity.
The same old problems apply. How can an objective universe give rise
to subjectivity? How are descriptions of how the world is - ever
communicate what it's like to actually be that which is described?
MWI and fungibility is altogether silent on this.
Every scientific theory is. So what?

Scientific theory are silenced on this, because it threats the current
physicalist paradigm, perhaps.

Attempting to discuss some other "Jim" in terms of MWI still obscures the true nature of Jim's personhood

Then tell us...what is the "true nature of Jim's personhood"?
I assert that whatever it is, we don't have a good explanation of it yet.
It has something to do with Jim's ideas. It has something to do with
his ability to be a creative agent. It has something to do with his
subjective experience of qualia - his consciousness. But I've not
yet heard a satisfactory explanation of this that ties it all to
physics. As such, some non-existent theory cannot possibly refute
well-established physics.
What theory of personhood do you have that would be inconsistent with this view of the MWI?

and only leads to confusion and misunderstanding at a

philosophical level.
No. Objections to the MWI lead to confusion and misunderstanding "at
a philosophical level". And infact, every other level too. Whatever
the "true nature" of personhood turns out to be, my guess is it will
be entirely consistent with the MWI. One possibility is that it
refutes MWI...though I am not sure how that could be. An infinite
number of things could refute MWI, but I'm not worried until one
actually does. Meantime, our best theory is that physical reality is
explained by MWI.
We don't have a theory of subjective personhood.

Computer science provides a theory. In fact it shows that simple (but
subtle) machines already have a theory.

Bruno

urmenonhigh

2013-03-25 23:26:28 UTC

Two objects that are fungible are "identical in literally every way except that there are two of them." (BoI, p. 265) Suppose there are two distinct versions of Jim, one of which has done something bad like murder Pete. The version of Jim that murdered Pete is not the same as the version of Jim that did not murder Pete, so they are not fungible.
However, there are multiple fungible instances of each version of Jim that is not fungible with other versions of Jim. Only instances of a system that are fungible with one another can undergo quantum interference. Many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another: this is required for the existence of stable atoms.
Alan

While many of the electrons, protons and other particles that compose a particular version of Jim are fungible and interfere with one another, they do so within a certain instantiation of "Jim".

So you admit that all of the electrons, protons and other particles that compose Jim have fungible counterparts, but that together, collectively, there is no fungible counterpart of Jim?
Does this seem to you to be a strict logical contradiction? It does to me.

Post by urmenonhigh
This copy of "Jim" is the only Jim in question.

This is my point I do not think fungible copies of Jim should be considered apart from the particular person denoted by and understood to be this "Jim" in question. Instead, the fungible copies should be understood only as quantum aspects of this "Jim". Copies of Jim that are not fungible are not aspects of this particular "Jim". Objectively they represent other persons with no more connection to "Jim" than his classmate named Jim.

Post by Brett Hall
The subjective experience of *being* Jim is not explained by this theory. But then, it's not explained by any theory. The Nature of Subjectivity - consciousness - is an open question. But prima facie, I do not see why this concept of fungibility or MWI presents any new problems for philosophical questions about personal identity.
The same old problems apply. How can an objective universe give rise to subjectivity? How are descriptions of how the world is - ever communicate what it's like to actually be that which is described? MWI and fungibility is altogether silent on this.

Agreed, MWI is altogether silent on the rise of subjectivity. I suppose that in an objective universe with no resident subjectivity within it, the MWI of QM could be a completely satisfactory theory of physical reality. However, in a universe in which physical reality apparently also includes active participants living out their finite existence in subjective terms, a MWI does not appear to be up to the task of completely explaining that physical reality.
Perhaps the rise of subjectivity within later stages of cosmological history should be correlated with the very inadequacy of MWI to completely explain the physical reality of this later stage.

Post by Brett Hall
Every scientific theory is. So what?

Post by urmenonhigh
Attempting to discuss some other "Jim" in terms of MWI still obscures the true nature of Jim's personhood

Then tell us...what is the "true nature of Jim's personhood"?
I assert that whatever it is, we don't have a good explanation of it yet.
It has something to do with Jim's ideas. It has something to do with his ability to be a creative agent. It has something to do with his subjective experience of qualia - his consciousness. But I've not yet heard a satisfactory explanation of this that ties it all to physics. As such, some non-existent theory cannot possibly refute well-established physics.
What theory of personhood do you have that would be inconsistent with this view of the MWI?

Post by urmenonhigh
and only leads to confusion and misunderstanding at a philosophical level.

No. Objections to the MWI lead to confusion and misunderstanding "at a philosophical level". And infact, every other level too. Whatever the "true nature" of personhood turns out to be, my guess is it will be entirely consistent with the MWI. One possibility is that it refutes MWI...though I am not sure how that could be. An infinite number of things could refute MWI, but I'm not worried until one actually does. Meantime, our best theory is that physical reality is explained by MWI.
We don't have a theory of subjective personhood.
What is it about this poorly described problem (that is, what personhood actually is) that you think will be inconsistent with MWI (i.e: quantum theory)?
Brett.
[Non-text portions of this message have been removed]

Alan Forrester

2013-03-25 09:15:41 UTC