On Jun 20, 2013, at 1:10 AM, Basil Hiley wrote:
On 19 Jun 2013, at 22:52, Ruth Kastner wrote:
OK, not sure what the 'yes' was in response to, but I should perhaps note that you probably need to choose between the Bohmian theory or the transactional picture, because they are mutually exclusive. There are no 'beables' in TI. But there is a clear solution to the measurement problem and no discontinuity between the relativistic and non-relativistic domains as there are in the Bohmian theory (which has to abandon particles as beables at the relativistic level).
This last statement is not correct. Bohmian theory can now be applied to the Dirac particle. You do not have to abandon the particle for Fermions at the relativistic level. There is a natural progression from Schrödinger → Pauli → Dirac. See Hiley and Callaghan, Clifford Algebras and the Dirac-Bohm Quantum Hamilton-Jacobi Equation. {em Foundations of Physics}, {f 42} (2012) 192-208. More details will be found in arXiv: 1011.4031 and arXiv: 1011.4033.
BJH.
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  • Jack Sarfatti On Jun 21, 2013, at 3:54 AM, Basil Hiley <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:

    Ruth,

    My work on the ideas that Bohm and I summarised in "The Undivided Universe" have moved on considerably over the last decade. But even in our book, we were suggesting that the particle could have a complex and subtle structure (UU p. 37) which could be represented as a point-like object only above the level of say 10^-8 cm. This comment, taken together with point 2 in our list of key points on p. 29 implies that we are not dealing with 'small billiard balls'. There could be an interesting and subtle structure that we have not explored-indeed we can't explore with the formalism in common use, i.e. the wave function and the Schrödinger equation. This is my reason for exploring a very different approach based on a process philosophy (See my paper arXiv: 1211.2098).

    In the case of the electron, we made a partial attempt to discuss the Dirac particle in our book (UU chapter 12). The presentation there (section12.2) only scratched the surface since we had no place for the quantum potential. However we showed in arXiv: 1011.4033 that if we explored the role of the Clifford algebra more throughly, we could provide a more detailed picture which included a quantum potential. We could then provide a relativistic version of what I call the Bohm model or, more recently, Bohmian non-commuting dynamics to distinguish it from a number of other variants of the model.

    In our approach all fermions could then be treated by one formalism which in the classical limit produced our 'rock-like' point classical particles. Bosons had to be treated differently, after all we do not have a 'rock-like' classical limit of a photon. Rather we have a coherent field. Massive bosons have to be treated in a differently way, but I won't go into that here.

    reference? I have been struggling with that in my dreams.

    We noted the difference between bosons and fermions in the UU and treated bosons as excited states of a field. In this case it was the field that became the beable and it was the field that was organised by what we called a 'super quantum potential'. In this picture the energy of say an emitted photon spread into the total field and did not exist as a localised entity. Yes, a rather different view from that usually accepted, but after all that was the way Planck himself pictured the situation. John Bell immediately asked, "What about the photon?" so we put an extra section in the UU (sec. 11.7). The photon concept arises because the level structure of the atom. It is the non-locality and non-linearity of the super quantum potential that sweeps the right amount of energy out of the field to excite the atom.

    Since the photon is no longer to be thought of as a particle, merely an excitation of the field, there is no difficulty with the coherent state. It is simply the state of the field whose energy does not consist of a definite number of a given hν. A high energy coherent field is the classical limit of the field, so there is no problem there either.

    All of this is discussed in detail in "The Undivided Universe".

    Hope this clarifies our take on these questions.

    Basil.
  • Jack Sarfatti The Brown-Wallace is an interesting paper, but I do not agree with its conclusions. Of course, this is exactly what you would expect me to say! What is needed is a careful response which I don't have time to go into here, so let me be brief. The sentence that rang alarm bells in their paper was "Our concern rather is with the fact that for Bohm it is the entered wave packet that determines the outcome; the role of the hidden variable, or apparatus corpuscle, is merely to pick or select from amongst all the other packets in the configuration space associated with the final state of the joint object-apparatus system." (See top of p. 5 of arXiv:quant-ph/0403094v1). As soon as I saw that sentence, I knew the conclusion they were going to reach. It gives the impression that it is the wave packet that is the essential real feature of the description and there need be nothing else. For us the 'wave packet' was merely short hand which was meant to signify the quantum potential that would be required to describe the subsequent behaviour of the particle. For us it was the quantum Hamilton-Jacobi equation that was THE dynamical equation. The Schrödinger equation was merely an part of an algorithm for calculating the probable outcomes of a given experimental arrangement. ( Yes it's Bohr!) But for us THERE IS an underlying dynamics which is a generalisation of the classical dynamics. Indeed my recent paper (arXiv 1211.2098) shows exactly how the classical HJ equation emerges from the richer quantum dynamics. The term 'wave packet' was merely short hand. There is no wave! This is why we introduced the notion of active information which is universally ignored.

    On Jun 20, 2013, at 5:21 AM, Ruth Kastner <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:

    Thank you Basil, but what about other particles? E.g. photons and quanta of other fields. -RK

    On Jun 20, 2013, at 9:19 AM, Ruth Kastner wrote:

    Well my main concern re photons is coherent states where there isn't a definite number of quanta. Perhaps this has
    been addressed in the Bohmian picture -- if so I'd be happy to see a reference. However I still think that TI provides
    a better account of measurement since it gives an exact physical basis for the Born Rule rather than a statistical one,
    and also the critique of Brown and Wallace that I mentioned earlier is a significant challenge for Bohmian approach. What
    B & W point out is that it is not at all clear that the presence of a particle in one 'channel' of a WF serves as an effective reason for collapse of the WF.

    RK

    From: This email address is being protected from spambots. You need JavaScript enabled to view it.
    Subject: Re: Reality of possibility
    Date: Thu, 20 Jun 2013 09:13:10 -0700
    To: rekastner

    Never a problem for boson fields just look at undivided universe book now online

    Sent from my iPhone

    Subject: Re: Reality of possibility
    From: b.hiley
    Date: Thu, 20 Jun 2013 09:10:39 +0100
    CC: This email address is being protected from spambots. You need JavaScript enabled to view it.

    On 19 Jun 2013, at 22:52, Ruth Kastner wrote:

    OK, not sure what the 'yes' was in response to, but I should perhaps note that you probably need to choose between the Bohmian theory or the transactional picture, because they are mutually exclusive. There are no 'beables' in TI. But there is a clear solution to the measurement problem and no discontinuity between the relativistic and non-relativistic domains as there are in the Bohmian theory (which has to abandon particles as beables at the relativistic level).

    Basil: This last statement is not correct. Bohmian theory can now be applied to the Dirac particle. You do not have to abandon the particle for Fermions at the relativistic level. There is a natural progression from Schrödinger → Pauli → Dirac. See Hiley and Callaghan, Clifford Algebras and the Dirac-Bohm Quantum Hamilton-Jacobi Equation. {em Foundations of Physics}, {f 42} (2012) 192-208. More details will be found in arXiv: 1011.4031 and arXiv: 1011.4033.

    BJH.

    RK

    > Subject: Reality of possibility
    > From: This email address is being protected from spambots. You need JavaScript enabled to view it.
    > Date: Wed, 19 Jun 2013 13:14:42 -0700
    >
    > To: rekastne
    >
    > Yes
    > That's what i mean when I say that Bohm's Q is physically real.
    >
    > Sent from my iPhone