Questions re Cramer's Transactional Interpretation?

[rkastner]

The only severe problem here is some posters' failure to read the relevant literature. There is no problem re absorbers. You can have one absorber or a collection of absorbers which is what someone listed earlier in the mistaken belief that this was a problem for TI; when, if they had bothered to read Cramer's paper, would have easily seen that TI is quite happy to deal with one or more absorbers (in fact a large collection of absorbers, as in a continuous shell of material, is a typical example considered in the literature on TI).

It is really sad when people get all negative and dismissive and haven't even done their basic homework. You only embarrass yourself. If you are going to try to critique an interpretation, do some basic required reading with an open mind and good faith.

In view of the ongoing irresponsible posts, I will not longer check or respond to this thread.

Thanks again to those of you with the decency to do some basic reading and ask well-informed questions.

RK

 

[Dmitry67]

This is classic.
Instead of answering basic questions (even Yes/No), saying "do your homework"
Then saying somethign like "you are all idiots"
and quickly leave the thread, before anyone replies.
It is very common on ordinary forums, but it is a pity I see the same on the scietific one :(

 

[Dmitry67]

P.S.
I checked again the original text by John Cramer because I read it about 10y ago
I did not find anything where he tries to define an absorber. He uses words "transaction is formed", "absorbed" etc without even making an attempt to define it.

I assume, as it was written in 1986, the sharp border line between 'microscopic' and 'macroscopic' was so obvious to him, that he even did not bother to talk about that problem, because macroscopically it is quite obvious what is the 'measurement device' or an 'absorber' - it does not work in 2010 anymore.

 

[Dmitry67]

And BTW yet another problem in TI.

light waves are just 1 example of boson interactions by photons. Whats about exchange of W, Z bosons? Gluons exchange? Do they form transactions?

If no, then what's so special about photons?
If yes, then how the stuff about 'retarded waves' work for non-abelian charges?

 

[Frame Dragger]

This is classic.
Instead of answering basic questions (even Yes/No), saying "do your homework"
Then saying somethign like "you are all idiots"
and quickly leave the thread, before anyone replies.
It is very common on ordinary forums, but it is a pity I see the same on the scietific one :(

@Dmitry67: Agreed. Nothing like starting a thread on a topic about which you supposedly have expertise and want to start an open discussion. That occurs... the OP bails. I suppose that's one way of resolving cognitive dissonance. Since she's clearly left the buildng, could you perhaps point me in the direction of some good new thinking on absorbers/emitters?

@rkastner: If you think this felt "unfair" or "harsh", good luck in the field; it's going to be a terribly long ride for you. If you can't answer what you see as the least of your critics, it's time to open a deli.

Now, we get to see if dear Ruth has the self control to let this go, or if that was a rhetorical flourish. It's kind of a losing proposition either way at this point.

 

[Dmitry67]

Since she's clearly left the buildng, could you perhaps point me in the direction of some good new thinking on absorbers/emitters?

Well, as I said, it is clear from the old view, where macroscopic world is something absolutely different from the microscopic one. The same way of thinking, which is used in CI. So there is nothing new.

TI in fact makes the understanding easier, so between CI and TI I would prefer TI.

Advantages of TI over CI:
* in TI microscopic entities can have objective properties, and it is still compatible with Bell. For example, entangled particles 'know' in advance how they will be measured by Bob and Alice in the future;
* in TI the 'collapse' is objective. It is a physical process (called a transaction). In CI it can't be made objective, because we would face FTL issues as it is instantaneous (spooky action at distance), so wavefunction is called 'just a knowledge about the reality'. In TI collapse (transaction) does not have a specific time, as it is explicitly a-casual, hence there is no problem at all with making both wavefunction and it's collapse objective.

Disadvantages of TI:
* What's special about light? Whats about other bosons? (see my previous post)
* Main As any collapse Int, TI provides no solution to measurement problem. 'absorbing' and 'absorbers' are as magic in TI, as 'measurements' and 'measurement devices' in CI.

 

[Frame Dragger]

Well, as I said, it is clear from the old view, where macroscopic world is something absolutely different from the microscopic one. The same way of thinking, which is used in CI. So there is nothing new.

TI in fact makes the understanding easier, so between CI and TI I would prefer TI.

Advantages of TI over CI:
* in TI microscopic entities can have objective properties, and it is still compatible with Bell. For example, entangled particles 'know' in advance how they will be measured by Bob and Alice in the future;
* in TI the 'collapse' is objective. It is a physical process (called a transaction). In CI it can't be made objective, because we would face FTL issues as it is instantaneous (spooky action at distance), so wavefunction is called 'just a knowledge about the reality'. In TI collapse (transaction) does not have a specific time, as it is explicitly a-casual, hence there is no problem at all with making both wavefunction and it's collapse objective.

Disadvantages of TI:
* What's special about light? Whats about other bosons? (see my previous post)
* Main As any collapse Int, TI provides no solution to measurement problem. 'absorbing' and 'absorbers' are as magic in TI, as 'measurements' and 'measurement devices' in CI.

Ok, I'm clear on this now, I appreciate the comparison to the CI, it helped a great deal. I really do with that rkastner would return and truly engage in this conversation she started. I appreciate the complementary nature of the TI theory with some of the 'problems' with retarded waves in mainstream EM theory. I don't think it's any more valid than most Int, but then, it has the benefit of working very well with some of the most non-classical bits of QM such as a DCQE.

I'm curious about photons as you said... I can't find anything on the other bosons, or even work on conjectures. This seems to have come a bit from the existing "problem" with Maxwell's equations, but by embracing the notion of a retarded and advancing wave. I like that basis in well accepted work in an interpretation, but as a salesperson of the brand, rkastner just hasn't sold me. If you present an interpretation that doesn't solve an essential question, but rather reframes it in another way... AND ignores other force carriers... I have to wonder.

 

[Vanadium 50]

In view of the continuing unfriendly tone and lack of preparation of some posters (by no means all!), I will no longer be regularly checking this board as of 2/24/10.

In view of the ongoing irresponsible posts, I will not longer check or respond to this thread.

The "dramatic exit' works best when it is not repeated.

I understand your frustration, but you also need to understand that most people who use QM daily don't care about interpretations. Many of the people who care the most are amateurs who have been introduced to QM via popularizations - nothing wrong with that, but these folks are simply not prepared enough to follow the primary sources.

I've had several discussions with John about the Transactional Interpretation, including one delightful dinner on the eve of a meeting we were both going to, and I can tell you that John's own view about whether this is a theory or not - i.e. makes different predictions from standard QM or not - is neither clear nor constant. Until this is settled, I expect it to get relatively little attention from the people who actively use QM.

 

[Dmitry67]

Vanadium 50, during your discussions did you have a chance to touch the following subjects (see my posts above):
1. special role of photons, or do other interactions (weak, color) create transactions.
2. what is an absorber

 

[Frame Dragger]

In view of the continuing unfriendly tone and lack of preparation of some posters (by no means all!), I will no longer be regularly checking this board as of 2/24/10.

It is one thing to be dismissive or disrespectful; such is wrong and shouldn't be tolerated. There is no requirement that debate be FRIENDLY however. If you can only discuss your views in "friendly" company, I question the rigor of your thinking and the questions you're being asked. I also would just like to express a measure of disgust that one of the few women in this field to show up RUNS AWAY. I was raised by a single mother who is unappreciative of such 'glass ceiling' lowering behaviour.

Do yourself a favour, swallow the pride and embarassment that we all know is behind this dramatic flourish, and discuss this like a grown women.

 

[Fredrik]

FrameDragger, if you're trying to convince her to come back, you're doing it really badly.

Rkastner, I don't think there was any unfriendly stuff in this thread until after you started saying that there was. When you started this thread, you said that the article you're working on will "address questions, confusions, or concerns about TI". We certainly don't need to study the original article to have questions or concerns (or confusions, ) about the TI, so I don't see how the type of responses you got could surprise you or offend you.

 

[conway]

But the processes of absorption and emition cannot be described by the Schrodinger equation (or a couple of Schrodinger equations). Right?
So either
1) TI replaces Schrodinger equation(s) by a different (set of) equation(s), or
2) TI does not provide a mathematical description of absorption and emition

Now please tell me which is correct: 1) or 2)?

I know there is a problem with describing absorption, but is there really a problem explaining the emission process via the Schroedinger equation?

 

[Demystifier]

I know there is a problem with describing absorption, but is there really a problem explaining the emission process via the Schroedinger equation?

If we talk about the emission of electron (described by Schrodinger equation), then yes. In Schrodinger theory, electron lives forever, it is neither created nor destroyed.

If your will say now that creation and destruction are described by QFT, I have a ready objection too.

 

[Demystifier]

FrameDragger, if you're trying to convince her to come back, you're doing it really badly.

Rkastner, I don't think there was any unfriendly stuff in this thread until after you started saying that there was. When you started this thread, you said that the article you're working on will "address questions, confusions, or concerns about TI". We certainly don't need to study the original article to have questions or concerns (or confusions, ) about the TI, so I don't see how the type of responses you got could surprise you or offend you.

Obviously, rkastner writes an article for people who already read other relevant literature on TI. There is nothing wrong with it, after all ANY article assumes that readers already know something, and there are allways interested readers who do not satisfy that assumption. You cannot write an article for everybody.

Of course, we all here would like to see a pedagogic modernly written paper for those who know nothing about TI, but that's not what rkastner is attempting to write.

 

[Dmitry67]

Obviously, rkastner writes an article for people who already read other relevant literature on TI. There is nothing wrong with it, after all ANY article assumes that readers already know something, and there are allways interested readers who do not satisfy that assumption.

Well, TI is not commonly accepted. For such questionable things one can't assume that people know it, or support it. You always need to 'sell' that thing by answering ANY questions, even the "not friendly" ones, which she failed to do.

 

[Dmitry67]

If your will say now that creation and destruction are described by QFT, I have a ready objection too.

I am intrigued :)

 

[Frame Dragger]

FrameDragger, if you're trying to convince her to come back, you're doing it really badly.

Rkastner, I don't think there was any unfriendly stuff in this thread until after you started saying that there was. When you started this thread, you said that the article you're working on will "address questions, confusions, or concerns about TI". We certainly don't need to study the original article to have questions or concerns (or confusions, ) about the TI, so I don't see how the type of responses you got could surprise you or offend you.

I was attempting something closer to the opposite. I have no patience for drama queens in scientific fields. If that's who you are, fine, go act or sing or join a theatre troupe, but please stay out of intellectual endevours.

Anyway, I'm far more interested to hear Demyst's ready objection at this point. This is an area where I'm truly uninformed, and a debate between Dmitry67 and Demystifier is bound to be more informative and entertaining than someone who starts a thread and then runs away in a huff.

Oh... and I AM the son of a single mother, and I really DON'T appreciate women pulling this kind of thing; some men expect women to cut and run (especially in science) when challenged, and it makes me ill to see someone do just that.

@Demystifier: That is a very kind way of telling someone that if they want to simply espouse a theory, then try a non-educational site. I believe there is a booming industry in TFRBs.

 

[conway]

If we talk about the emission of electron (described by Schrodinger equation), then yes. In Schrodinger theory, electron lives forever, it is neither created nor destroyed.

I don't see the problem with emission. Are you talking about the photo-electric effect? There are populated states in the metal, and there are unpopulated free states outside the metal. The incident radiation introduces a coupling term between the bound states and the free states. The electron wave which was occupying one of the bound states mixes into the free state until there is nothing left of it in the metal. Isn't that all exactly described by the Schroedinger equation?

 

[DrChinese]

In view of the ongoing irresponsible posts, I will not longer check or respond to this thread.

Thanks again to those of you with the decency to do some basic reading and ask well-informed questions.

RK

I hope you reconsider. This board consists of a variety of readers. Some are physics professionals, and many of those do original research. There are also novices, students and amateurs - all with varying degrees of polish and expertise.

While you may have come here with a specific purpose and expectation, I suggest you would gain from a fluid interaction with other readers. Cramer's work has been discussed here a number of times previously, and there are a lot of points which have been soundly debated. I think if you will forgive the rough edges to some of the conversions, you will discover that the meat of the argument is taken quite seriously by many.

For example: The TI - as I understand it - involves certain elements of time symmetry in that there are advanced and retarded interactions. There are other time symmetric interpretations as well, such as relational blockworld (RBW). So, how does TI compare to RBW? Are they somewhat similar or radically different?

 

[cesiumfrog]

Ruth, would you clarify, do you agree or disagree that TI allows Schroedinger's cat to have actually been in a superposition of "having forgotten dreaming about mice" and "having forgotten dreaming about fish"?

Look at decoherence. [..] In TI, the same mathematics obtains--an extremely small prob. of a superposed cat--and you have an account of determinate outcome[..]

That's an evasive yes, right, qualitatively?

I've had several discussions with John about the Transactional Interpretation, including one delightful dinner on the eve of a meeting we were both going to, and I can tell you that John's own view about whether this is a theory or not - i.e. makes different predictions from standard QM or not - is neither clear nor constant.

If TI features superpositions of buckyballs and cats, why does Cramer say it avoids the problem of determining when the collapse occurs? Say Wigner's friend performs an experiment on the cat: if this friend's lab is arbitrarily well isolated we can describe his period of solitude (from Wigner outside) as a transaction, so the lab will actually have contained (in parallel) the infinite number of friends who all contribute non-zero amplitude to the two definitive states of Wigner's friend before and after his period of solitude (but who differ subtly, such as in the exact moments they closed or opened the cat's box). But according to each one of those parallel-friends, at the moments when the cat's box was open (and not the moments in between) the cat was similarly in a definitive state. But Wigner himself knows this isn't entirely true (and that his friend is mistaken about whether the transaction was complete) since there exists a moment when only some of the parallel components of his friend had opened their respective cat's box. Even though Wigner and his friend are both applying TI, it gives them mutually incompatible answers about the reality of the cat.

We could go further, explicitly treating each atom in the lab (nay, universe) individually according to TI, and then we'd need the very framework that is being developed for MWI, just to understand how each of the parallel "Wigner's friend"s ever perceived himself to be experiencing a consistent history.. It seems to me that TI is trumped by dBB if it does not allow superpositions of buckyballs, by CI if it does but not of cats, and by MWI otherwise.

 

[Demystifier]

I don't see the problem with emission. Are you talking about the photo-electric effect? There are populated states in the metal, and there are unpopulated free states outside the metal. The incident radiation introduces a coupling term between the bound states and the free states. The electron wave which was occupying one of the bound states mixes into the free state until there is nothing left of it in the metal. Isn't that all exactly described by the Schroedinger equation?

That's all correct, but that's not what I'm talking about. What you are talking above has nothing to do with emission in the sense of TI, which is related to genuine creation of the electron wave function which did not exist before.

 

[Demystifier]

I am intrigued :)

Without a collapse, a state in QFT is typically a superposition of states with DIFFERENT numbers of particles. On the other hand, in experiments you observe a definite number of particles. In standard QFT, you describe it by the collapse. In a transactional interpretation of QFT (I don't know if it really exists), you need a generalization of absorption/emition that replaces THAT sort of collapse.

 

[Dmitry67]

Ah, yes, I see.
In any case, I think TI is incompatible with QFT for the reasons I explained above:
a) QFT uses emission/absorbtion almost everywhere and it does not cause any collapse;
b) QFT does not make principal difference between exchange of photons, W,Z, g or any other partcles

 

[Frame Dragger]

Ah, yes, I see.
In any case, I think TI is incompatible with QFT for the reasons I explained above:
a) QFT uses emission/absorbtion almost everywhere and it does not cause any collapse;
b) QFT does not make principal difference between exchange of photons, W,Z, g or any other partcles

Given that the OP tucked-tail and ran, I'm guessing that we'll have to wait until another TI "expert" shows up.

"b" for me is the damning one btw... "a" is a problem with other problems attatched in other interpretations.

 

[Count Iblis]

I hope you reconsider. This board consists of a variety of readers. Some are physics professionals, and many of those do original research. There are also novices, students and amateurs - all with varying degrees of polish and expertise.

While you may have come here with a specific purpose and expectation, I suggest you would gain from a fluid interaction with other readers. Cramer's work has been discussed here a number of times previously, and there are a lot of points which have been soundly debated. I think if you will forgive the rough edges to some of the conversions, you will discover that the meat of the argument is taken quite seriously by many.

For example: The TI - as I understand it - involves certain elements of time symmetry in that there are advanced and retarded interactions. There are other time symmetric interpretations as well, such as relational blockworld (RBW). So, how does TI compare to RBW? Are they somewhat similar or radically different?

How will Rkastner respond to this friendly offer wave?

 

[Dmitry67]

How will Rkastner respond to this friendly offer wave?

I collapsed of laughter when I read your post!

 

[Frame Dragger]

I collapsed of laughter when I read your post!

The retarded wave had already informed her that it was coming!

 

[rkastner]

Hi, folks. My email is easily locatable by anyone who wanted to seriously discuss TI with me, and given time constraints, I have responded to everyone who contacted me with well-informed questions or concerns about TI. Those of you who continue to have questions are welcome to do so. I think you'll find that nobody (of either gender) will want to spend a lot of time responding to frankly ill-informed and insincere comments; but not everyone will be willing to tell you that's why they're not replying. I respected this Forum enough to be straightforward about these circumstances.

All best, RK

 

[rkastner]

Dmitry, anything that is described by a current in QFT, which can couple to other fields, can be an absorber. A confirmation wave is generated when an annihilation operator acts with certainty (i.e., destroys the incoming quantum state); this is the case in, e.g., relativistic scattering for the free 'outgoing particle'. I stopped replying to the TI thread when people (including yourself) indicated they weren't interested in reading the basic material (eg Cramer's 1986) about TI. How can you expect to participate in a well-informated manner if you haven't read the basic material first?

Thanks for your interest,

RK

 

[rkastner]

Follow-up to question by Dmitry on what constitutes an absorber in TI: the demand for an algorithm for 'yes' or 'no' [as to whether something acts as an absorber] presumes a lot both methodologically and ontologically which is not necessarily appropriate for the quantum realm. Consider a relativistic scattering process, in which coupling at vertices have an amplitude less than unity (eg the fine structure constant). Under PTI (my possibilist version of TI) this is the amplitude for a confirmation wave (CW) to be generated. This applies to any coupling between microscopic currents. Macroscopic absorbers contain millions of such currents, so the probability that such an object will generate a confirmation is close to unity. That is what a macroscopic absorber is: a collection of enormous numbers of microscopic currents capable of coupling to fields and of therefore generating a CW somewhere in the macroscopic object (and we generally cannot know which microscopic current was the source of the CW).

RK