Words, definitions, and Many "Worlds" ; (was Born's rule from almost nothing)

[John Clark]

On Fri, Jan 29, 2021 at 7:42 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> There is no requirement for an infinite number of degrees of freedom.

In physics there will never be a theory that requires infinite degrees of freedom, at least not until somebody performs an experiment with infinite accuracy, and I'm not holding my breath for that.  

> Escape of just one IR photon to outer space is sufficient to destroy reversibility.

Sometimes, usually in fact, but not always. Not if 2 quite different events can produce the same identical photon that escapes into infinite space, and not if the photon is not even allowed to escape but Is absorbed by a photographic plate or a brick wall. A good example of this sort of thing would be the quantum eraser experiment, or the delayed choice experiment.  Or just study how a Mach–Zehnder interferometer works. These experiments are possible but they're not easy because the experimenter must make sure that there's a difference between the two worlds but the difference must be very small so a practical way can be found to make the two worlds identical again so they can be nudged back together again into one world.

> The definition of 'world' in the context of QM is made exact precisely because of this irreversibility.

Only in pure mathematics are definitions precise, in science and and everything else they're just an approximation, a label for an idea learned through examples, a collection of words that are defined by other words. And Hugh Everett invented the theory but he didn't invent the phrase "Many Worlds", that was done by others and only gives a very approximate idea of what the theory is about.  According to Everett the debate on if matter is made of particles or waves is over, it's made of waves. And in that theory the approximate definition of the world "world" is a collection of different waves that include at least one conscious being that is approximately the same in all of them.

> Worlds are well-defined 

Words are defined by other words and those words are in turn defined by yet more words. Even the word "defined" is defined by words. But whatever physical reality turns out to be at its most fundamental level I think we can be pretty sure it's not made of words.

John K Clark   See my new list at  Extropolis

[Alan Grayson]

More Trump physics? What's a measurement? I have no clue. AG

[Alan Grayson]

When a particle hits the screen in a double slit experiment, is that a measurement? AG

[John Clark]

On Sun, Jan 31, 2021 at 12:48 AM Alan Grayson <agrays...@gmail.com> wrote:

> More Trump physics? 

More profound revelations from self proclaimed Carl Sagan co-author Alan Grayson?

> What's a measurement? 

Why on earth are you asking me of all people that question?!! In many worlds it doesn't matter one iota what the hell a measurement is! That's only important in Copenhagen and in most other quantum interpretations, in many worlds it's completely irrelevant.  So you tell me, what is a measurement?

> I have no clue. 

Yes, I've noticed.  

[Alan Grayson]

On Sunday, January 31, 2021 at 4:36:50 AM UTC-7 johnk...@gmail.com wrote:

On Sun, Jan 31, 2021 at 12:48 AM Alan Grayson <agrays...@gmail.com> wrote:

> More Trump physics? 

More profound revelations from self proclaimed Carl Sagan co-author Alan Grayson?

> What's a measurement? 

Why on earth are you asking me of all people that question?!! In many worlds it doesn't matter one iota what the hell a measurement is! That's only important in Copenhagen and in most other quantum interpretations, in many worlds it's completely irrelevant.  So you tell me, what is a measurement?

 I did, several times. Either it went over your head, or you prefer to keep it mysterious and ambiguous when it's certainly not. Same with "observer". AG

[John Clark]

On Sun, Jan 31, 2021 at 6:44 AM Alan Grayson <agrays...@gmail.com> wrote:

 > So you tell me, what is a measurement?

 > I did, several times.  [,,,] Same with "observer"

Show me. Talk is cheap, stop telling me that you did and show me that you did!  

[Alan Grayson]

For the double slit, say, a measurement occurs when a particle hits the screen (time and location). The observer is anyone, or anything, that records the measurement. AG

[John Clark]

On Sun, Jan 31, 2021 at 7:07 AM Alan Grayson <agrays...@gmail.com> wrote:

> For the double slit, say, a measurement occurs when a particle hits the screen (time and location).

That's exactly what many worlds says, a measurement, if for some reason you'd like to use that word, is a change made in the universe and it doesn't matter if that changes made in a conscious being or not. In one universe the photon hits the screen at point X, and in another universe the photon hits the screen at point Y, and in yet another universe the photon doesn't hit the screen at all because it doesn't pass through either slit. If there happens to be an observer watching all this he splits too, and they all have different memories about what happened.  And it doesn't matter if nobody is watching, the universe splits anyway. In many worlds if you like you could replace the word "measurement" with the word "change" and you don't need to use the word "observer" at all, so you don't need to ponder the question of if a cockroach can observe things and make the universe split. But what I don't understand is if you already knew what a "measurement" is why did you ask me where the measurement is?  And I don't care what an "observer" is because it has nothing to do with many worlds.    

[Alan Grayson]

One of the features of Trumpism and Trump physics is Alzheimer's onset. You made the claim, many times, that "measurement" is an ambiguous concept, as well as "observer". AG

[John Clark]

On Sun, Jan 31, 2021 at 8:28 AM Alan Grayson <agrays...@gmail.com> wrote:

> One of the features of Trumpism and Trump physics is Alzheimer's onset.

So says 90+ year old Alan Grayson, if one believes his claim to have co-authored a scientific paper with Carl Sagan. 

[Alan Grayson]

On Sunday, January 31, 2021 at 6:43:14 AM UTC-7 johnk...@gmail.com wrote:

On Sun, Jan 31, 2021 at 8:28 AM Alan Grayson <agrays...@gmail.com> wrote:

> One of the features of Trumpism and Trump physics is Alzheimer's onset.

So says 90+ year old Alan Grayson, if one believes his claim to have co-authored a scientific paper with Carl Sagan. 

More evidence of Alzheimer's?  I told you I use a pseudonym here, but you forgot. As for "measurements" and "observers", you were very firm that the concepts are ill-defined in standard QM (and, as I have shown, you are/were clearly mistaken), but you have forgotten that as well. AG

[John Clark]

On Sun, Jan 31, 2021 at 7:01 PM Alan Grayson <agrays...@gmail.com> wrote:

>>> One of the features of Trumpism and Trump physics is Alzheimer's onset.

>>So says 90+ year old Alan Grayson, if one believes his claim to have co-authored a scientific paper with Carl Sagan. 

> More evidence of Alzheimer's?  I told you I use a pseudonym here, but you forgot.

Speaking of Alzheimer's and loss of memory,  ou told me you couldn't remember what the name of the paper that you wrote with Carl Sagan was, or where to find it; you couldn't even remember what the damn thing was about. And pseudonym or not if you really did co-authored such a paper with Carl Sagan in the early 1960s as you claim then you've got to be in your 90s by now. But I don't really think you ever wrote a scientific paper in your life because after observing your posts for the last several years I don't believe Carl Sagan would've touched you with a 10 foot pole.

[Alan Grayson]

Just like a Trumper, now you're lying and exaggerating. I know you're NOT a Trumper, but you seem to have caught the disease in a different context. Those papers were written in 1966 and 1967, so at first I couldn't recall the exact titles, but I did in fact recall the subject matter.  And I am not in my 90's, not that age matters. As for perspicacity in physics, IMO anyone who endorses the MWI with such fervor despite its in-your-face foolishness, is in no position to evaluate anyone else. According to your delusion, your decision to respond on this thread causes another world to come into existence. Where's the beef, I mean the energy? AG

[Alan Grayson]

On the energy issue, what really bothers me about your stance on this issue, is NOT that you can't offer a possible model or explanation for where the energy comes from to create those other worlds, but that you don't even recognize that such an issue exists. Others in this MWI cult behave similarly. AG 

[Bruno Marchal]

On 30 Jan 2021, at 12:26, John Clark <johnk...@gmail.com> wrote:

On Fri, Jan 29, 2021 at 7:42 PM Bruce Kellett <bhkel...@gmail.com> wrote:

> There is no requirement for an infinite number of degrees of freedom.

In physics there will never be a theory that requires infinite degrees of freedom, at least not until somebody performs an experiment with infinite accuracy, and I'm not holding my breath for that.  

> Escape of just one IR photon to outer space is sufficient to destroy reversibility.

Sometimes, usually in fact, but not always. Not if 2 quite different events can produce the same identical photon that escapes into infinite space, and not if the photon is not even allowed to escape but Is absorbed by a photographic plate or a brick wall. A good example of this sort of thing would be the quantum eraser experiment, or the delayed choice experiment.  Or just study how a Mach–Zehnder interferometer works. These experiments are possible but they're not easy because the experimenter must make sure that there's a difference between the two worlds but the difference must be very small so a practical way can be found to make the two worlds identical again so they can be nudged back together again into one world.

> The definition of 'world' in the context of QM is made exact precisely because of this irreversibility.

Only in pure mathematics are definitions precise,

Relatively to some axiomatic, but once a theory is rich enough to get elementary arithmetic (and/or the Turing universal machine) it will have an infinity of non isomorphic models, and this will shows that some definition are only precise enough for their use, but irremediably vague on their semantics…

… unless we use second-order logic, but then the price is that the proof are not checkable, we most compactness (we can have all finite subset of a theory being consistent, yet the whole set of theorems get inconsistent (no model at all).

Mathematics is less different than physics in this respect. After Gödel we know that all the infinities are unable to secure the finite realm. In fact “finite” itself is a term that we cannot “really” defined, and provably so if we add Mechanism, or just the Church-Turing hypothesis in the picture.

in science and and everything else they're just an approximation, a label for an idea learned through examples, a collection of words that are defined by other words. And Hugh Everett invented the theory but he didn't invent the phrase "Many Worlds”,

Actually he did, according to his daughter and son (according to a Russian who wrote a biography of Everett). It seems that he labels his theory “many-worlds” at the start, but was asked by the publisher of its first paper to replace it with “relative state”.

I find this a bit sad, as “relative state” admit a mathematical definition, where “worlds” is just a metaphysical idea use in this context to avoid metaphysical question.

that was done by others and only gives a very approximate idea of what the theory is about.  According to Everett the debate on if matter is made of particles or waves is over, it's made of waves. And in that theory the approximate definition of the world "world" is a collection of different waves that include at least one conscious being that is approximately the same in all of them.

> Worlds are well-defined 

Words are defined by other words and those words are in turn defined by yet more words. Even the word "defined" is defined by words. But whatever physical reality turns out to be at its most fundamental level I think we can be pretty sure it's not made of words.

That is why in mathematics and in (serious) metaphysics, we use the axiomatic method, where all words are either constant or variable, and have no other definition that the principle on which we agree. Here, mathematical logician are far more in advance that most scientist, who believe words have precise meaning, where the best we can hope for is “valid use”. But this requires a bit of mathematical logic, which is not well taught, when taught at all.

Bruno

John K Clark   See my new list at  Extropolis

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[Bruno Marchal]

On 31 Jan 2021, at 06:48, Alan Grayson <agrays...@gmail.com> wrote:

When a particle hits the screen in a double slit experiment, is that a measurement? AG

You can say that it is a measurement from the screen point of view. But as screen have no re-accessible memory, it is better to define the measurement relatively to some machine with Memory, like Everett. 

Bruno

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[Bruce Kellett]

On Tue, Feb 2, 2021 at 10:09 PM Bruno Marchal <mar...@ulb.ac.be> wrote:

On 31 Jan 2021, at 06:48, Alan Grayson <agrays...@gmail.com> wrote:

When a particle hits the screen in a double slit experiment, is that a measurement? AG

You can say that it is a measurement from the screen point of view. But as screen have no re-accessible memory, it is better to define the measurement relatively to some machine with Memory, like Everett. 

Of course the screen has a memory -- it creates a permanent record of where the particle hit, and that can be accessed as many times as required.

Bruce

[Bruno Marchal]

The screen has a memory, and it is indeed accessible, but it is not re-accessible by the screen itself, as it ha no self-referential ability.

All the problems you see come from your confusion between a first person and a third person description, as you illustrated here. It is obvious that with the MWI there is no indeterminacy and probability at all, but for the superposed individual, you get the usual first person indeterminacy which enforces the use of some probability or credibility measure on the set of personal future.

Bruno 

Bruce

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