This is part of a series of articles on various interpretations of quantum physics. As described here, the central problem is the measurement problem, that is, the collapse of the wave function, and how consciousness appears to be involved with bringing about the results.
While the math of QM is very clear, it only answers the question of how things happen, and not why. But man’s nature is to know, and so over the years and decades, several interpretations of the quantum physics mathematics have sprung up that attempt to fill in this hole.
The Transactional Interpretation of Quantum Mechanics
In this post I discuss one such interpretation: The Transactional Interpretation (TI) of Quantum Mechanics, as first proposed by John G. Cramer in 1986.
It appeals to me, because it uses a fundamentally different notion of time.
I have already written about in physics all equations are time reversible and imply time symmetry (that is, almost all equation: except entropy and the k-meson decay). For example, the Maxwell equations of electromagnetics actually have two equations, one with waves traveling towards the future (called the retarded solution), and another moving towards the past (the advanced solution) — yet the latter is simply discarded. But if we take the equations literally, we have to leave open the possibility, just as I had always stated, that time does not only ripple forward into the future, but can also ripple into the past.
And that is a central idea in the TI: in a typical interaction between two particles, say one electron emits a photon that is absorbed by another electron, a transaction is formed between the two electrons that involves waves both going forward and backwards in time.
Think about this as being similar to how a transaction takes place when you purchase something from a vendor: the vendor offers you an object, you accept and confirm the offer (you pay the money), and the item is transferred.
Along those lines, the emitter electron first sends out “an offer wave” aimlessly into the void, going forward in time. As this so called “retarded wave” travels through 3D space and time, it is received by infinite other electrons at various times in the future. Each such potential absorber electron now can answer that offer, and send a “confirmation wave” which says in effect “Hey, emitter: I am ready to form a transaction with you.”
And here is the thing: the confirmation wave travels backwards in time!
This has several interesting consequences. For once, because this wave is in a way an “echo,” it has the same frequency and amplitude as the offer wave, and thereby will cancel out parts of the offer wave as it travels past the absorber forward time, and past the emitter backwards time. What is left, if a transaction is formed, is only a standing wave between the two electrons.
Secondly, it gives the wave function Ψ that we find all throughout the math of QM a real physical meaning in 3D. Whereas most other interpretations speculate that it is only a purely mathematical space, TI statues that Ψ is the offer wave in 3D, and its complex conjugate Ψ* the confirmation wave (TI is actually the only interpretation that gives the conjugate also a physical interpretation).
Lastly and most importantly, by traveling backwards in time the confirmation wave will take exactly the same amount of time to get back to the emitter as the original offer wave took in the other direction.
The net effect is that the emitter will receive the conformation answer from the absorber at the same moment it sent out the offer wave.
And not just one answer, but infinitely many from any and all potential absorbers that will eventually receive its offer wave sometime in the future and answer back. Not all confirmation waves will be quite similar, they will be attenuated by distance, so the ones from closer absorbers are stronger.
The emitter can now “choose” from these echo waves, and will do this choice biased by the strength of the echo. If it does choose one of the confirmation, a transaction is formed between the emitter and the absorber, and the photon (or energy) is transferred.
Cramer describes this crucial step as follows: ‘To proceed with the process, the emitter must “choose” one (or none) of these offer-confirmation echoes as the initial basis for a photon-emission handshake or “transaction,” with the choice weighted in probability by the strength of the echo. … After the choice is made, there must be repeated emitter-absorber wave exchanges that grow exponentially until the strength of the space-time standing wave that thus develops is sufficient in strength to transfer a quantum of energy ℏω and momentum ℏk from the emitter to the absorber, completing the transaction.”
[“The Quantum Handshake,” John Cramer, Chapter 5, p.63 ]
Using the Transactional Interpretation to resolve QM paradoxes
TI does resolves many of the strange paradoxes of QM very nicely.
Let’s take one well known paradox as an example, Schrödinger’s cat. In this theoretical setup, a cat is placed in a sealed container along with a small radioactive element, which, if it was to decay, will trigger a bottle of poison to be smashed that subsequently would kill the cat. The chance of this event happening during some timeframe is exactly 50%. From the outside, we do not know if the cat is dead or alive until we open the box.
QM mathematics state that there is a superpositioned state, which overlays the 50% probabilities of the event happening and not. So the cat would be in this inbetween state of dead or alive, and only when the outside observers takes the measurement, that is opens the box and checks, does this superpositioned state collapse into the real world outcome.
Now, are we really to believe that the cat is in some inbetween state of 50% dead and 50% alive? In his original 1935 paper, Schrödinger posed this theoretical experiment quite tongue in cheek. His point was to show the ridiculous consequence if we extrapolate the QM collapse to our marcoworld. In the setup of this paradox, a single quantum event is magnified so much that it affects a real-world object, the cat. Schrödinger felt strongly there is something wrong with QM as stated, and while he did accept the mathematics, he (and Einstein and others) felt deeply there is something missing.
TI now takes the role of the outside observer completely out of this.
The transaction happens only between the decaying element and the detection mechanism inside of the box. The decaying element sends out an offer wave during the whole time, but there is a 50% chance the offer wave is picked up by the detector, and only then forming a transaction. The cat is thusly either truly dead or alive. End of paradox.
Just like in the case, TI can cleanly resolve other paradoxes and explain observations like the two-slit experiment or setup for the Bell’s theorem inequality.
Critique of the Transactional Interpretation of Quantum Physics (TI): what chooses?
TI explains a lot of paradoxes very nicely; there no longer is this strange collapse, and consciousness is no longer needed to form these transaction.
Or is it?
To me, there is one critically important point in TI where the theory simply waves it hands too much: it states that an electron “chooses” among the confirmation waves (see the key quote above).
Not only does it choose, but it chooses in such a way that is stochastically in line with the predicted outcome from QM, and that is in itself a hard problem to explain (the same problem also plagues the many-world interpretation).
But let me stay with “it chooses.” Now, to me the word “choose” implies either:
- Some sort of truly random selection (within the bounds of the QM stochastic probabilities, and that seems hard).
- Or some deterministic, yet still unknown, algorithm like a random number generator, i.e. a hidden variable.
- Or some sort of consciousness that chooses.
Because it is never clearly explained how exactly this choice is made, we must at least be open, again, to the idea of some consciousness choosing. Only here it is not some consciousness of an outside observer, but it is possibly inherent to the respective particles involved in the transaction.
I have previously argued that consciousness is a universal phenomenon and everything has some consciousness. In that view, even an electron would have indeed a consciousness – not the same as ours, but some other (lower?) consciousness that makes sense at this level. TI may show us here a possible indication for this.
Along the same lines, other parts that TI appears to argue away are also still possibly. If a choice is made, then there may be hidden variables, like David Bohm's inplicate order. Likewise, as soon as we have choice, we have many alternatives to choose from, and the arguments in the “many-world-interpretation” (Everett, DeVitt, etc) may still apply that all alternatives are taken, and we just happen to be locked into one branch.
My main point of critique is that TI appears to argue away all these “nasty” elements, such as consciousness, hidden variables, and many-worlds, but in that word “it chooses” they are all still there implicitly.
To me, that is not a bad thing, but a possibly further indication that these aspects are indeed part of what is really going on.
But TI brings something new to the table, which I had suspected for a long time: time symmetry. In other posts I have argued that time forms a temporal whole structure, with past events rippling towards the future (repercussion), AND future events rippling towards the past (prepercussion), AND events from variant alternatives rippling across (cross-percussions). What I see in TI is description that forms such a wholeness of future and past.
Another interesting aspect is that an offer wave does not simply go to just one potential absorber, but spreads out unlimited in space and forward in time, forever. Likewise, the confirmation wave spreads out in space and backwards in time, forever (that is, until it hits the moment of the big bang and potentially reflects back again). Now, in the case of a one dimensional example, Cramer shows how parts of these waves may cancel out due to interference, but I don’t see how this works in 3D – they can only cancel out in the direction given by the vertices that are involved in the transaction.
They rest of these offer and confirmation waves travel through space and time forever. So at any given moment, space and time are saturated with these offer and confirmation waves – virtually all particles EVER interacting with each other.
I am not sure if this is another strike against TI, but what it does remind me of is the holographic model, where each part contains all others.
Here, we have a universe filled with potential offers and confirmations. All it takes is a choice to bring about a given transaction, out of this sea of possibilities. The future is merging with the past, multiple and all alternatives are not only possible but may in fact be taken – by the choice of the electron that has consciousness appropriate for its level.
TI to me is in fact a real possibility. However, it is only a part of the solution – a solution which at this point for me contains consciousness at each level, as well as variant (alternate realities), and the holographic model.
Namaste — I bow to you and the Divine in you.
Copyright © Hanns-Oskar Porr