Talk:Transactional interpretation

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Pavel V. Kurakin (Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, me).

John Cramer is very accurate and delicate in his formulations (as far as I can judge). He specially points, that TIQM is a kind of methodological or pedagogical trick to make understanding of quantum mechanics easier, and not an model of quantum phenomena.

(Last experiment by S. Afshar changes this situation, according to John Cramer. As John Cramer argues, Afshar's experiment verifies TIQM to be more consistent with quantum mechanical formalism and predictions as compared to Copenhagen interpretation.)

I am sorry, but I suppose that I am the only person on Earth to use publicly the term model as applied to quantum mechanics. I work in mathematical modelling team and this term is so natural to me. John Cramer delicately prefers to say "underling picture".

Contrary, well-mannered physicists imply that quantum mechanics is the "underlying picture" by itself. The idea to explain quantum amplitudes is sometimes assumed as a characteristic feature of crackpots (crackpot index by John Baez).

So, what prevents TIQM to become a model of quantum-mechanical behaviour of particles? In my view, there are 2 crucial points here:

1. back-in-time is unconceivable. One can indeed crack his pot trying to understand it.

2. why one transaction? Many possible detectors send their retarded conformation waves to one single source. So how a single transaction (i.e., a full pair of waves -- offer wave and confirmation wave) happens?

The problem of "back-in-time-propagation" can be solved, I believe. Hidden time concept puts both offer wave and confirmation wave in hidden (not physical!) time, while physical time is when transaction finally ends.

I assume my model as a direct development of John Cramer's TIQM and I ask for any criticism.

—Preceding unsigned comment added by 217.70.27.189 (talk • contribs)

Minerva100 (talk) 01:32, 17 May 2012 (UTC)You might check out recent work by R. E. Kastner which addresses these issues, they are on arxiv.org Minerva100 (talk) 01:32, 17 May 2012 (UTC)

TI's standing wave is unobservable
"To an observer, this standing wave in space-time looks as if a particle has travelled through space."

This standing wave doesn't "look like" anything anybody has ever, or could ever, actually observe in any experiment. If anyone could actually observe "particles travelling through space" quantum theory wouldn't be necessary in the first place.

Furthermore, this unobservable standing wave, unlike the wave function of the Copenhagen interpretation (which is also unobservable), can't be used to predict anything as the data necessary to compute the wave is not available until the measurements it might have predicted have already been obtained.

That said TI remains very interesting.

It reminds me of the guy in the film The Matrix, who having escaped the simulated reality, regrets the choice, and desires a return. To such an end he does a deal with the artificial intelligensia who control the boundaries of this reality.

The standing wave of TI can be imagined as that "reality" bounded by the matrix - a neoclassical universe in which "particles travel through space".

But can an observer in such a reality observe what we are able to, in fact, observe - namely interference patterns!

Perhaps we are, indeed, inside the TI matrix. But since we are modelling the TI matrix from within the TI matrix the interference patterns we might have hoped to see (in the TI) get cancelled out. That would explain the "paths through space" effect that we see in the model. We would have to invert the model (eg. into the Copenhagen one) in order to see the interference patterns (in our TI model) that we otherwise, in fact, observe from within the TI matrix.

Perhaps we would.

Carl Looper 16 January 2006

Standing waves in Heim's multidimensional space
Consider a universe where waves of distortion in multiple dimensions propagate forwards and backwards in time, interacting to create a complex interference pattern. From this complex pattern emerge the observable phenomena we see, such as particles (the standing waves of the TI) and forces (momentum exchange).

In this hypothesis, knowing the underlying wave motion does not help us derive the physical laws obeyed by the emergent phenomena. It's like trying to derive analytically a formula describing the motion of objects in the n-body problem. It can't be done, even though Newtons laws are pretty simple. You have to simulate the system in a computer and see what happens.

It would be interesting to compute the propagation of advance and retarded waves in a 6 dimensional universe, and see if the familiar effects of gravity and electromagnetism emerge. Maybe other, previously unknown phenomena would emerge, giving the experimenters something new to look for.

Why 6 dimensions? An obscure mathematical theory developed by Burkhard Heim links gravity and electromagnetism by adding additional dimensions to spacetime. This is also described in Michio Kaku's "Hyperspace". With 6 dimensions you get gravity and electromagnetism. With 8 dimensions you (apparently) get the remaining forces, plus some new ones. The new forces seem to produce effects like the accelerating expansion of the universe currently attributed to dark energy.

Quantoid 06:32, 21 January 2006 (UTC)

Retrocausality
Both Cramer's standing wave and the probability wave of conventional quantum theory can only function as a model of what might be imagined as taking place behind experimental data. But unlike the probability wave, Cramer's standing wave has no use value other than to satisfy a philosophical preference for classical models. The retrospectively constructed standing wave - whether retrocausally constructed by Nature herself and/or by our theorisation, can't be used to predict future data. It can only be used to put a classical spin on how we imagine the past. This is okay. If it doesn't change the facts and establishes a possible domain of compatibility with, for example, relativity theory, we should not be concerned by its otherwise redundant decoration of the facts.

The trap is that we run the risk of confusing this redundant model with "reality". Indeed I suspect Cramer himself has fallen into just such a trap. An article in New Scientist (30 Sept 2006, page 36, "What's done is done") suggests that Cramer (and others) are on the verge of sending messages back in time - not just in theory but in fact.

In any case such an experiment is very important because although it won't succeed in sending messages back in time (am I the only one who understands why?) it will succeed in showing how retrocausality is both a redundant model and a trap. It could also establish why the sought after compatibility between relativity and quantum theory can be seen as redundant - but that's another story.

From a philosophical point of view Cramer has already succeeded in sending a message back in time. The message, in this case, is his concept of a particle's history as a retrocausally well defined path in space over time (the standing wave). But nobody in the past can ever receive this message.

Or to put it another way, if we imagine ourselves in the past, Cramer's message (the particle possessing a neo-classical path) has yet to be retrocausally constructed - if only for us.

We must use the probability wave of conventional quantum theory to represent the particle's otherwise pre-causal status. We can allow that this is an approximation and that the present "really" holds a Crameresque well defined path for us to retrospectively appreciate at a later time but until such time we have no other choice.

In other words it is only when the future finally arrives (and the particle is detected), that Cramer's model becomes appreciable. But it's too late. We will have already predicted, using conventional quantum theory, the probable location for the particle's detection (it's future), and we will have already represented it's history (by the probability function), and we will have already satisfied predispositions for classical models by disposing of the probability function (wave function collapse) at the moment we have a detection. What's left?

All that's left for Cramer's model to do is reinscribe an unreachable past as classically conceivable.

And risk deluding oneself that this is not just theoretically or experimentally demonstrable but experimentally exploitable - that we can send messages back in time - or otherwise convince science journalists we can.

Carl Looper carllooper@hotmail.com 1 October 2006

Back to the past
Cramer's original formulation was well conceived and rigorous. He expressly emphasised that his interpretation (TI) was experimentally indistinguishable from that underlying the well worn Copenhagen Interpretation (CI). At the level of fact (the data) no distinction was possible. The distinction was at the level of theory - about how we think or otherwise "philosophise" the data and the maths.

All this meant was that TI and CI were experimentally compatible. The experimental success of one would always be the experimental success of the other. TI would work wherever CI worked because the underlying maths was the same.

But then an an otherwise interesting experiment by Afshar implied (for Cramer) that an experimental distinction could be demonstrated between TI and CI. In other words Cramer reinterpreted his own interpretation as not just distinguishable in terms of thought but experimentally distinguishable in terms of fact.

The origin of this "error" (for want of a more diplomatic term) is philosophical. On one side of the philosophical divide, we find theories (models, interpretations) are treated as if they were candidate descriptions for what is "really" happening out there in the world, so to speak. It's as if all that's required for a theory to succeed/fail is to be experimentally tested and found either correct, incorrect or the "jury out" on such. But some theories, such as Cramer's original one, fall under a fourth category - untestable. Until recently Cramer's theory was just such a theory.

On the other side of the philosophical divide are theories (such as quantum theory and CI) that are purely utilitarian. They make no implicit or explicit claim about being right or wrong. Their success is measured in terms of the correlation found between the data predicted by the theory and that which is experimentally derived. But as Dirac once said, it could still be just a coincidence. There is a radical disclaimer underlying quantum theory. The model is purely fictitious. Any resemblance to Nature either living or dead is purely coincidental. This robs the classical opponent of any ammunition in the critique of quantum theory.

It also puts the classical opposition in the unfortunate position of reinforcing their assumption that theories should not be just utilitarian but about what is "really" there. That is why Cramer was excited when Afshar's experiment implied possible testability.

Up until then Cramer's model was in the same camp as the Copenhagen Interpretation - purely utilitarian. But it's use value was a little different. It's utility was not measured in terms of experimental data - that stayed the same as CI (due to the common mathematical basis). Rather, it's utility was in the the philosophical bridge it provided between the data and predispositions for classical (rational) models. In this respect Cramer's original philosophical formulation is great.

But the ground has shifted.

Cramer has retrospectively (retrocausally?) recouched TI in classical terms - as correct, incorrect or the "jury out".

This is very brave. It is also very unfortunate. Cramer has rewritten the past. TI is now - was always - not a utilitarian theory. It is now (was always) about what was/is "really there". And we're going to test it. And if we're right then it's not only possible to build a time machine but we're going to build one.

If we're right.

The lure of classical philosophy is tantalising. The hold it has on us is the result of thousands of years as Heisenberg puts it. But Bohr and Heisenberg were are able to replace this grip with a virtual handshake - a loosely defined "wave function collapse". If Cramer elaborated this into a standing wave model it was no more or no less virtual.

But now it has become more than a virtual handshake. It has become a firm grip. And Cramer has been yanked over the line into the classical or neoclassical camp.

Lets do the same.

Let's suppose that a time machine or retrocausal messaging system is not just a utilitarian construct but experimentally possible - that we can - in factum - send messages into the past. Or to put it another way - receive messages from the future. I for one would love to see such happening - not out of any philosophical predisposition for such but because I'm a fan of classical science fiction.

OK. Could we use retrocausally constructed messages from the future to selectively interrupt the channel (slit) through which the standing wave function has not been realised? In other words, if the standing wave is retrospectively computed post factum (in the future) to describe a photon "path" through slit A (in the present) could we then use such computation (from the future) to "interrupt" slit B?

Is slit B supposed to be (in the present) retrocausally empty?

That's the question. If our future informed intervention of slit B, despite being informed by the future (that the standing wave is in slit A), fails to have nil effect on that future then what does it mean to compute this standing wave in the first place (in the future) - even if we don't send it back in time?

What sort of past are we computing?

Carl Looper —Preceding unsigned comment added by 203.217.70.185 (talk • contribs) (Oct. 2006)


 * Is it not possible that such thoughts suffer from an assumption about time? Time is relative to the observer, but time may also be relative to the transaction, or rather I should say that each transaction could conceivably occur within its own isolated time 'frame' that has no direct link to what we experience.  What I am trying to say rather badly is that if the whole thing happens as a single transaction, we can't actually break the transaction apart to exploit the mechanism.  Information is transmitted using the mechanism, and to observe the workings of the mechanism is thus impossible.  If we were able to break the mechanism, we could potentially create errors in the state of the universe.  We could play with the universe like god.  It makes me think of the idea of the universe being like a big computer simulation.  If it were there would be rules governing the simulation that would be unobservable to beings simulated within it.  There would be some kind of database with transactional processes operating upon it.  Corruption of the database would be a bad thing.  But we could only observe the effects of such corruptions and potentially may would never be able to understand their consequences or deliberately exploit them.  Anyone building a time machine would be able to violate the transactional rules and would throw the universe into an invalid state (hence the well covered paradoxes of science fiction).  So, alas, time machines are not likely to be possible to build.  However, Afshar's experiment does show clearly that some kind of mechanism is operating in some extra dimensional manner.  Actually we have known this for a long time, and for a long time have just swept this inconvenience under the carpet. Irontightarguments (talk) 11:56, 17 May 2008 (UTC)

"Problem with the transactional model"; this is not a problem, and should be removed, see below.
Minerva100 (talk) 01:30, 17 May 2012 (UTC)Danko's analysis is completely wrong because he omits the fact that the wavefunctions are plane waves (or superpositions thereof) and these wavefunctions do not cancel each other out when added to their complex conjugates; in fact they give the usual real wave forms cos and sine. Minerva100 (talk) 01:30, 17 May 2012 (UTC)

Except for the problems outlined by P. Kurakin above, there is a direct way for one to show absurd conclusion within the formulation of TI itself. This comes from the asymmetry that Cramer implies for the real part of the quantum amplitudes vs. the imaginary parts. In the model the quantum transaction is formed by forming an interference between advanced wave $$\psi=Re[\psi] + Im[\psi]$$ and its complex conjugate $$\psi^{*}==Re[\psi] - Im[\psi]$$, so that in Cramer's words what remains is $$\psi + \psi^{*} = 2 Re[\psi]$$. As you can see directly the imaginary parts cancel out, and real parts constructively interfere to reinforce each other!!! However let us look at the classical beam splitter experiment. In this case the photon is split into a superposition of two branches, one real and one with imaginary amplitude. After the beam splitter the photon wavefunction is $$\psi=\psi_{A}+\psi_{B}=\imath \frac{1}{\sqrt{2}}+\frac{1}{\sqrt{2}}$$. It is known from QM that the photon can end at detector A with 50% probability, and similarly end at detector B with 50% probability. Yet the quantum transaction if formed with detector A gives a standing wave of advanced and retarded waves that is ZERO! Cramer says that before emission and post-absorption there are no advanced or retarded effects because the quantum transaction produces ZERO standing waves. HOWEVER, in this beam splitter experiment there is also ZERO standing wave with the absorber which in this case is the detector A. This is absurd, and at present I see no way out. Unfortunately Cramer is busy with promoting his work in the yellow press and does not reply to e-mails with queries addressing the TI. Danko Georgiev MD (talk) 11:39, 25 March 2009 (UTC)


 * Danko, Wikipedia is not the right place to perform original research, and is not really a very good place to discuss it either. You should find some mailing lists where you can discuss your ideas; you might try publishing your ideas in various forums.  Wikipedia is meant to review established concepts and ideas.  linas (talk) 16:40, 25 March 2009 (UTC)


 * Danko's wavefunctions don't make sense, there isn't a zero standing wave in the beam splitter case if you do the math right. Kuratowski&#39;s Ghost (talk) 00:09, 9 April 2009 (UTC)


 * This is not Danko's wavefunction, it is Cramer's quantum transaction that does not make sense. It is impossible to have transaction that produces imaginary wave, and as I say the wavefunction is $$\psi_{A}$$ only the transaction is zero, i.e. $$\psi_{A} + \psi_{A}^* = 0$$. Thus Cramer's TI is fundamentally flawed. Danko Georgiev MD (talk) 08:24, 4 June 2009 (UTC)


 * I'd like to read more of what Danko has to say on this subject. --Carllooper (talk) 07:31, 6 April 2009 (UTC)


 * You guys should find a good place to discuss it then. Talk pages are to discuss the article content, and how to improve it, not as general forums on the topic.  If Danko has published his ideas, or has sources from others who have published similar, we can consider using them to influence the article.  Otherwise, let's keep off-topic talk to a minimum. Dicklyon (talk) 15:12, 6 April 2009 (UTC)


 * Yes, talk pages are to discuss the article content, and how to improve it. Danko's contribution can be considered as the beginning of a discussion towards such an end. If what Danko is trying to say is correct then it's quiet possible there is something similar already published. By discussing the criticism one can open up avenues for tracking down such published criticism. If it doesn't already exist, or can't be found, then the discussion will be just a discussion - of what might have been but wasn't. --Carllooper (talk) 04:43, 7 April 2009 (UTC)


 * Cramer's model specifys particles in terms of where they are detected so quite obviously such specified particles can't be detected anywhere other than where they are specified as being detected. Or to put it another, any particle detected elsewhere can't be the one specified. So Cramer's conceptual framework generates a ray between emitter and detector, a ray along which the specified particle can not ever be detected! So what meaning does this ray posses? To what does it refer? --Carllooper (talk) 04:43, 7 April 2009 (UTC)


 * I didn't see anything about a ray; just waves. Dicklyon (talk) 05:05, 7 April 2009 (UTC)


 * By "ray" is meant that line along which the standing wave is realised, beyond which it's amplitude is zero. The point was not so much a distinction between waves and rays, but rather a distinction between lines and rays. Lines are (as I tend to use the word) always infinite in length whereas rays can be finite. Semantics really. The value in question is the amplitude of the wave function(s) across time, and where the values are zero or otherwise. Cramers standing waves are zero everywhere other than over a finite interval of time, ie. between emission and detection. They could be zero within this interval as well! --Carllooper (talk) 05:49, 7 April 2009 (UTC)


 * So, you made up a ray, and asked us "So what meaning does this ray posses? To what does it refer?" This is the kind of rumination that talk pages are not intended for. Dicklyon (talk) 14:31, 7 April 2009 (UTC)


 * I didn't make up a "ray". The word, as I used it, (and have subsequently clarified, which you choose to ignore) refers to Cramer's standing wave (ie. that finite interval between emitter and detector). The question I posed is (when clarified) "to what does Cramer's standing wave refer?". Hope that clears up any confusion. Might I also say that you have so far said nothing at all in relation to either the content of the article or how to improve it. --Carllooper (talk) 22:57, 7 April 2009 (UTC)

Between emission and detection the imaginary (or otherwise real) components of Cramer's double waves cancel each other out leaving behind only the real (or otherwise imaginary) components of the waves (the sum thereof). It matters not which components are called "real" or "imaginary". Everywhere else (ie. prior to emission, and post detection) both the real AND imaginary components of each wave cancel each other out (they are out of phase by exactly half a wavelength). As in conventional QM there is a discontinuity at the point of detection - a "quantum jump" as they say. Now Cramer's particle (a dual wave) can be characterised by the expression:

p + p*

What is important is that whether "real" or "imaginary" or indeed anywhere in between, this composite signal, between emitter and detector, is unobservable. It is also unobservable after detection! However lets give Cramer some oxygen. An observation can be regarded as taking place at the moment of detection - the sudden change between the absence of a particle trace and it's presence. So a detection can be understood in terms of the difference between Cramer's emitter<->detector waves (p + p*) and his cancelled waves (p - p) ie. where the detection event occurs. In mathematical terms this would be:

d = (p + p*) - (p - p)

At first I thought I found the presence of the squared wave function in a refactored version of the above but it was the result of an error in the maths (which was a pity). The above (of course) just reduces to:

d = p + p*

Now if I follow what Danko is saying (and I probably am not). As I understand it (and posit): a Cramer particle (p+p*) is formed between the emitter and detector A, so this requires a cancelled particle be formed between the beam-splitter and detector B. Now I'm assuming that what Danko is suggesting is that if p equals pA + pB (as in a conventional formulation) AND pA equals p + p* (as in Cramer's formulation) there is the yet-to-be-interpreted result that:

p == p + p* + pB ?

But I'm not sure I'm characterising the "catastrophe" correctly. Does pA == p + p* in Cramer's formulation? Does it do so in Danko's formulation (of Cramer's formulation?)

I'm going back to re-reading Cramer:


 * The TI also clarifies, but does not solve, the problem of predictivity. As was discussed in Section 3.2, the beginning of a transaction can be viewed as the emitter sending out a retarded "offer" wave in various directions and receiving an "echo" back from the absorber in the form of an advanced confirmation wave which has an amplitude proportional to Psi* (where Psi is the complex OW evaluated at the absorber locus). In the usual circumstance there are a very large number of potential future absorbers, and if all provide such echoes, the emitter, at the instant of emission, has a large menu of possible transaction possibilities from which to choose. In a single quantum event the boundary conditions will permit only one event to occur.


 * Born's probability law is therefore a statement that the probability of occurrence of a given transaction is proportional to the magnitude of the echo corresponding to that transaction which the emitter receives. This would seem to be a very plausible assumption. The quantum event, from this point of view, is a solution to a differential equation (the appropriate wave equation) for which a definite set of boundary conditions restrict the solutions but do not uniquely specify the solution. In this situation, the probability of a given solution is proportional to the "connectedness" of the participants as indicated by the size of the echo which the absorber sends back to the emitter. The emitter is presented with echoes from potential absorbers which form a weighted list of possible transactions, from which only one may be chosen. The future absorbers can influence the past emission event only through the strength of their echo entry on this list but cannot influence which entry is actually chosen for the transaction.

The crux of the matter is that the inequality:

p != p + p*

is simply a reflection of the fact that Cramer's model (and it is a model) is different from other models. If Cramer's model begs to differ with other models we should not expect to find it the same. We should expect the inequality. We should also note that the inequality is unobservable, ie. Cramer's model is not experimentally incompatible with other models.

Cramer's model (or "interpretation" if you prefer) is like many other interpretations - in a competition where there is no possiblility of either:

a. an observable winner, or b. compatible mathematical formulation (equal winners)

The false hope is that their is a possibility of one and/or the other. As an example of option A, we can recollect Cramer's temporary insanity (and subsequent recovery) with respect to sending experimental information back in time. But who amongst has not suffered this same insanity on occasion? An example of option B is that even when brick walls (inequalitys) are obviously solid someone can still insist on running head first into such (and what's more - blaming the brick wall). And again - who amongst has not done the same thing on any number of occasions?

Hope (whether true or false) springs eternal.

--Carllooper (talk) 22:55, 8 April 2009 (UTC)

Response to criticism section not neutral
The section on response to criticisms reads to like a defense by a fan of this interpretation. Please rewrite this in a neutral way. —Preceding unsigned comment added by Zvis (talk • contribs) 12:05, 10 November 2010 (UTC)


 * It does, but maybe this isn't so bad. I'm going to put up my criticism, and see whether anybody responds. I expect that it'll be deleted, but so it goes.Peterwshor (talk) 18:53, 25 January 2011 (UTC)


 * Put a citation to a reliable source with it and it can stay. For now, an unsourced criticism is just WP:OR, so I will remove it.  Dicklyon (talk) 19:16, 25 January 2011 (UTC)
 * I reverted only the latest addition, but the whole section needs to be rewritten in terms of criticisms and responses that are to be found in reliable sources; looks like maybe only the last item comes from sources, so building the section around that item might be the way to go (unless someone finds sources on the others). Dicklyon (talk) 19:22, 25 January 2011 (UTC)


 * Let me point out that the answer to the second objection is not only completely unsourced, but also does not actually address the objection. Somebody should remove it. Peterwshor (talk) 03:19, 27 January 2011 (UTC)


 * I took it out. You can take out unsourced stuff yourself; if someone objects they'll put it back (hopefully with a source, or at least a tag calling for a source).  Dicklyon (talk) 04:05, 27 January 2011 (UTC)


 * The problem isn't whether the criticisms are sourced (or rather, that's a separate problem.) The problem is the Q&A format which is clearly not WP:NPOV. Daniel Dvorkin (talk) 04:53, 28 August 2011 (UTC)

Minerva100 (talk) 01:27, 17 May 2012 (UTC)I tried to rewrite the whole section in a neutral way and the page went back to the non-neutral version Minerva100 (talk) 01:27, 17 May 2012 (UTC)


 * According to your contribs, you never edited the article. Perhaps you forgot to hit save.  Dicklyon (talk) 19:01, 1 July 2012 (UTC)

The Q&A format might be a little unorthadox but that in itself does not render the overall discussion biased. I am tempted to add a reference to Relational Quantum Mechanics as the modern rebuttal to the TI (The non-locality issue of the CI and Bell is resolved in it) to restore neutrality. (WW 01/06/2012) — Preceding unsigned comment added by William.winkworth (talk • contribs)

Intuitively correct
This concept is an elegant solution to the problem of 'how can a photon interfere with itself ?' ... it does not require the need for any 'observer' (so no need for God to keep the Universe going for the first 14 billion years after all) nor does it imply any of the 'many worlds' nonsense (if 'new Universes' are being created at every quantum 'choice', where does the energy come from ?'). We also have a neat resolution to 'wave / particle duality' (photon's 'depart' and 'arrive' as particles but travel between departure and arrival as +t/-t probability waves) .. and finally we stop arbitrarily discarding all the -t solutions to the maths involving Sqrt(t) ..

Is it testable ? I would suggest 'yes' and it has already been tested .. 1) By all the 'delayed choice' double slit experiments (how can delaying the choice of observation method effect the arrival of the photon AFTER it has 'passed' the double slits ? answer = the forward wave may have passed the double slits but the backwards (-t) wave is emitted after the choice has been made and is thus constrained to follow the path / conditions present at the time of detection (i.e. at the collapse from a 'spread out' probability wave to particle). If, at the time of detection, no backwards path exists that supports the creation of interference, then no interference takes place .. 2) By quantum 'entanglement' experiments (where what is done to observe one of an entangled pair seems to 'instantaneously' effect the state of the other - yes, it does - the -t wave from the first detected of the pair traveling to the source of the pair then constrains the probability wave of the other half of the pair that is/was created at that (past) time).

62.3.239.168 (talk) 10:22, 19 January 2011 (UTC)


 * There was a paper published in the 1980s (I think in Foundations of Physics), which I think the article currently alludes to but does not cite explicitly, basically presenting that in terms of outcomes TI is completely equivalent to the Copenhagen Interpretation -- where one understands CI to mean that one hasn't given a complete description of the quantum system until one has specified a measuring apparatus, and therefore can't talk about what's "really" going on until that stage.


 * I like to think of TI as envisioning what would happen if one were computer-modelling the optimisation of a variational principle -- so one starts with a best guess, given initial constraints/information, and iterates that forward; until the proposed solution hits some further constraints/information (ie adding information about what the measurement apparatus is, cf in eg weather forecasting meeting a new later set of data), at which point the now-observed mismatch is iterated backwards again, updating the previous trial solution, back and forth, until with luck the whole optimisation converges.


 * I don't know whether it's what "really" happens; but TI seems to me quite a good way, in an acceptably quantum-consistent way, to picture one's way to an answer that seems reasonable in otherwise challenging setups like eg delayed choice experiments; and to build in non-local constraints by iteratively building up to them at one's own pace, slowly forcing the simulation to remain consistent with more and more information, rather than having to try to envision everything all in one go, or switching on the constraints or extra information suddenly and calling it "wavefunction collapse" (in truth a discontinuous change in the analysis, rather than a discontinuous change in reality). Jheald (talk) 19:29, 25 January 2011 (UTC)

Error in the article on the Transactional Interpretation
In the second paragraph of the article "Transactional Interpretation" it is stated---incorrectly---that the ordinary (presumably, nonrelativistic) Schroedinger equation does not admit advanced solutions. In fact, the retarded (advanced) Green's functions for the nonrelativistic free-particle Schroedinger equation can be obtained by adding a small positive (respectively, negative) imaginary part to the energy in the denominator of the Fourier integral representation of the Green's function. Gehahne (talk) 02:11, 16 March 2011 (UTC)

Minerva100 (talk) 02:54, 17 May 2012 (UTC) Yes what it should say is that the Schrodinger Eqn only has positive energy solutions. Sometimes people equate 'advanced' to 'negative energy' but strictly speaking they are not the same.Minerva100 (talk) 02:54, 17 May 2012 (UTC)

Can the page explain the differences between this interpretation and the Two State Vector Formalism?:

http://en.wikipedia.org/wiki/Two-state_vector_formalism — Preceding unsigned comment added by 50.164.80.14 (talk) 09:27, 10 December 2013 (UTC)

Usage and notability
Is this interpretation being used or advocated by anyone other than John G. Cramer and Ruth E. Kastner? If not, then its notability is questionable. --188.252.130.227 (talk) 14:16, 19 March 2014 (UTC)


 * That might be the problem. See my comments below. But I'm happy to be inclusive if it's a good article. 129.132.210.184 (talk) 09:18, 21 April 2015 (UTC)

Worst writing ever
''1. “TI is not mathematically precise.”

''Offer waves (OW) obey the Schrödinger equation and confirmation waves (CW) obey the complex conjugate Schrödinger equation. A transaction is a genuinely stochastic event, and therefore does not obey a deterministic equation. Outcomes based on actualized transactions obey the Born rule and, as noted in Cramer (1986), TI provides a derivation of the Born rule rather than assuming it as in standard quantum mechanics (QM).

This is in no way a "criticism" and a "response". Instead, it's a cross between Yahoo Answers and a politician changing the subject.

1) "It is not mathematically precise." Neither the article nor this one-line "criticism" contains enough detail to yield a risk of anything ending up being viewed mathematically precise! Nor verifiably the opposite. It is a sound bite.

2) The answer does not answer the criticism. Instead it simply states a floating fragment of information.

I have edited this criticism-response pair in a way that I hope leads to its rapid deletion. The rest of the "criticism-response" section is pretty bad too. It's simply the wrong format for Wikipedia.

The response in itself is interesting. With enough explanatory context, maybe it could be used in the article. Therefore I have preserved it below.

''Offer waves (OW) obey the Schrödinger equation and confirmation waves (CW) obey the complex conjugate Schrödinger equation. A transaction is a genuinely stochastic event, and therefore does not obey a deterministic equation. Outcomes based on actualized transactions obey the Born rule and, as noted in Cramer (1986), TI provides a derivation of the Born rule rather than assuming it as in standard quantum mechanics (QM).''

129.132.210.184 (talk) 09:16, 21 April 2015 (UTC)