An Interview with Theoretical-Mathematical Physicist

 Since I am very-very-very busy right now, spending days and nights on the light cone (in energy-momentum-frequency space), there are no new posts for a while. But, by chance, I stumbled upon a very interesting item that the reader may enjoy in the interim: 

"An Interview with Theoretical-Mathematical Physicist, Arkadiusz Jadczyk"

I was reading it with great interest, so here it is - just follow the link.

That's me, standing on my head and proving that you can swallow upward (chocolate, of course!). 

P.S.1. 02-10-23: John G. Cramer

"Despite his description of the transactional "handshake" as atemporal, Cramer says the collapse occurs when the emitter accepts the confirmation wave from an absorber. It is the absorber that precipitates the collapse, he says,

In the transactional interpretation the collapse, i.e., the development of the transaction, is atemporal and thus avoids the contradictions and inconsistencies implicit in any time-localized SV collapse.

Furthermore, the transactional description does not need to invoke arbitrary collapse triggers, such as consciousness, etc., because it is the absorber rather than the observer which precipitates the collapse of the SV, and this can occur atemporally and nonlocally across any sort of interval between elements of the measuring apparatus.

Cramer is quite critical of the need for a "conscious observer."

This "consciousness" interpretation, while it is a reasonable working hypothesis for an observer who does not wish to find himself dissolved into the state vector of the system he is measuring, does beg a number of questions. Did the SV of the universe remain uncollapsed until the first consciousness evolved? Where is the borderline between consciousness and unconsciousness? Will "smart" measuring instruments eventually achieve the abihty to collapse SV's, and how will one know when they do? And so on.

Schrodinger (1935) suggested an alternative to the consciousness interpretation, which he called the principle of state distinction and which asserts, "states of a microscopic system which could be told apart by macroscopic observation are distinct from each other whether observed or not. " In other words, the SV collapses as soon as some macroscopic record of the result of a measurement is made, whether a conscious observer looks at that record or not. Heisenberg (1960) and others have suggested a variant of this position which asserts that as soon as the quantum measurement passes from the domain of reversible processes into the domain of thermodynamic irreversibility the SV collapses.

The latter two "collapse triggers" are more appealing to most physicists than the former because they avoid giving some special significance to consciousness and because, as pointed out by Weisskopf (1959,1980), they correspond more closely to the operating assumptions that practicing physicists use in thinking about how quantum measurements are done. However, these models also beg the question of borders: Where precisely is the border between macrophysics and microphysics and the border at which irreversibility begins?

John G. Cramer,  The Information Philosopher

P.S.2. 15:34 John. G. Cramer, "Gravity with 4-Vector Potentials - A Theory Revolution?" 

P.S.3.03-10-23 16:20 Came today. Will have to see if I can manage to happily marry the Quantum Handshake with EEQT?

P.S.4. 04-1023 15:54 Version 2 of the preprint "Physical unambiguity of the definition of the photon position operator and its special eigenstates" by Grzegorz M. Koczan appeared on arxiv. I am very pleased to see there the following in this new version:

ACKNOWLEDGMENTS

I would like to thank Arkadiusz Jadczyk – co-author of an important publication [9] – for his active help. Extensive consultations concerned both the definition of the photon position operator (the use of zero modes and definition equivalence) and the eigenstates (on a straight line and on a circle). More- over, the consultations resulted in the Lemma on the commutation of the photon position operator with the helicity operator.

P.S.5. 05-10-23 8:14 In P.S.1. 04-08-23 I have mentioned the poster that G.M. Koczan presented at the annul meeting of the Polish Physical Society. In the list of References there is this item:

[14] Koczan G. M., Jadczyk A. (2023), Uniqueness of the definition of the photon position operator and its special eigenstates, przesłane do arXiv

As I have mentioned in the previous P.S. the preprint, with a somewhat different title, had appeared, but with my name in Acknowledgement. The reason for that change of plans is that the differences in our respective views on the subject, on what is important and what less important or incomplete, were too severe. I could not add my name to a paper that I would never accept as ready for publication if I was a Referee. These differences persist and get even stronger with time. That does not prevents us from having a fruitful discussions. G.M. Koczan is a stubborn and ambitious researcher, but I am stubborn, though in a somewhat different way. So we continue our intense exchanges. Communication, even when difficult, is very important. And keeping the sense of humor all the time is an important tool in the communication. For instance concerning the withdrawing my name as a co-author of the paper, he suggested that I consult Laura about the issue! To which I replied that Laura is informed and supports my decision. It's nice and funny when otherwise very serious physicists feel free to talk this way. 

P.S.6. 05-1-23 12:49 Concerning a possible  vision of the "physics of densities":

"Paul nodded and stepped to the blackboard, writing with chalk as he talked. 'Our normal matter is only one particle state, and there are six others. I found it was confusing to think of that many different states, so I visualize them as seven parallel planes. A particle can lie only in one plane at a time and can interact with other particles in the same plane. Our universe is the middle plane, say, and there are three adjoining "up" planes and three "down" planes. Or you can think of these shadow planes as six other shadow universes, all parallel to ours and interacting with ours only through gravity."

John Cramer, "Twistor"

What kind of Cramer's advanced waves is needed? Electromagnetic? Or gravitational? Or, perhaps, gravimagnetic? The last ones seem to be the best candidate, though not without a danger lurking there. But "kairon waves" as the mean of carrying the information is another guess...

P.S.7. 16:12 I have ordered Ruth E. Kastner, "The Transactional Interpretation of Quantum Mechanics. A relativistic treatment", 2nd ed., Cambridge University Press 2022. Should come in about ten days. Table of content very promising and interesting:

1 Introduction: Quantum Peculiarities 1

1.1 Introduction 1
1.2 Quantum Peculiarities 4
1.3 Prevailing Interpretations of QM 13
1.4 Quantum Theory Presents a Genuinely New Interpretational Challenge 25

2 The Map versus the Territory 26
2.1 The Irony of Quantum Theory 27
2.2 “ Constructive ” versus “ Principle ” Theories 30
2.3 Bohr ’ s Kantian Orthodoxy 31
2.4 The Proper Way to Interpret a “ Principle ” Theory 34
2.5 Heisenberg ’ s Hint: A New Metaphysical Category 36
2.6 Ernst Mach: Visionary/Reactionary 38
2.7 Quantum Theory and the Noumenal Realm 40
2.8 Science as the Endeavor to Understand Reality 42

3 The Original TI: Fundamentals 44

3.1 Background 44
3.2 Basic Concepts of TI 50
3.3 “ Measurement ” Is Well De fi ned in TI 54
3.4 TI Sheds Light on Feynman ’ s Account of Quantum
Probabilities 57

4 The New TI: Possibilist Transactional Interpretation 65

4.1 Why PTI? 65
4.2 Basic Concepts of PTI 66
4.3 Addressing Some Concerns 73
4.4 “ Transaction ” Is Not Equivalent to “ Trajectory ” 79
4.5 Revisiting the Two-Slit Experiment 83
4.6 Null Measurements 85

5 The Relativistic Transactional Interpretation 88

5.1 TI Has Basic Compatibility with Relativity 88
5.2 The Quantum Direct-Action Theory 89
5.3 The Micro/Macro Distinction 107
5.4 Classical Limit of the Quantum Electromagnetic Field 109
5.5 Nonlocality in Quantum Mechanics: RTI versus rGRWf 113

6 Challenges, Replies, and Applications 117

6.1 Challenges to TI 117
6.2 Interaction-Free Measurements 122
6.3 Delayed Choice Experiment 129
6.4 Quantum Eraser Experiments 134
6.5 Transactions and Decoherence 140
6.6 RTI Solves the Frauchiger – Renner Paradox156
6.7 The Afshar Experiment 162

7 The Metaphysics of Possibility in RTI 167

7.1 Traditional Formulations of the Notion of Possibility 168
7.2 The PTI Formulation: Possibility as Physically Real Potentiality 168
7.3 Offer Waves, as Potentiae, Are Not Individuals 170
7.4 The Macroscopic World in PTI 172
7.5 An Example: Phenomenon versus Noumenon 179
7.6 Causality 182
7.7 Concerns about Structural Realism 185

8 RTI and Spacetime 189
8.1 Recalling Plato ’ s Distinction 189
8.2 Transactions and Spacetime Emergence 200
8.3 Transactions Break Time Symmetry and Lead to an Arrowof Time 215
8.4 Spacetime Relationalism 220
8.5 RTI versus Radical Relationalism 222
8.6 Ontological versus Epistemological Approaches, and Implications for Free Will 224

9 Epilogue

P.S.8. 16:32 And another "must read" paper:

Michal Dobrski, Maciej Przanowski, Jaromir Tosiek, Francisco J. Turrubiates, "Construction of a photon position operator with commuting components from natural axioms", Phys. Rev. A 107, 042208 – Published 11 April 2023.

P.S.9. 06-10-23 8:40 Have finished "Twistor". The second part is written just right for children age 10 or less. I liked it. Somewhat disappointing is however the part of Wikipedia's entry on   Transactional interpretation, where it says

"TI is an exact interpretation of QM and so its predictions must be the same as QM. Like the many-worlds interpretation (MWI), TI is a "pure" interpretation in that it does not add anything ad hoc but provides a physical referent for a part of the formalism that has lacked one (the advanced states implicitly appearing in the Born rule). Thus the demand often placed on TI for new predictions or testability is a mistaken one that misconstrues the project of interpretation as one of theory modification.[17]"

and also this part:

"Thus the so-called "retreat" to Hilbert space (criticized also below in the lengthy discussion of note[24]) can instead be seen as a needed expansion of the ontology, rather than a retreat to anti-realism/instrumentalism about the multi-particle states. The vague statement (under[24]) that "Offer waves are somewhat ephemeral three-dimensional space objects" indicates the lack of clear definition of the ontology when one attempts to keep everything in 3+1 spacetime."

But still I consider TI as a good try. I will impatiently wait for Kastner's book which seems to be more philosophically oriented with understanding of the need of logical and ontological consistency."

P.S.10 07-10-23 8:54 Started reading "A lady mathematician in this strange universe : memoirs"  by Yvonne Choquet-Bruhat, World Scientific 2023. There I find:

"When I was working to be admitted in the “École Normale” for girls — indeed the rue d’Ulm ENS was not, in those times, open to girls — my father liked to look at my mathematics problems, quite ready to help me if I expressed desire for it. On the other hand, if I asked a question about physics, he would often answer with a reference to one of his books. Thus, my father was not one of the physicists hostile to mathematics. Those can be forgiven because at that period, the Bourbaki school of mathematics showed deep contempt for physics. I heard Dieudonné, a great mathematician and very active member of Bourbaki, say, “If I knew that the mathematics I do are useful for physics, I would stop doing them.” However, Dieudonné was a man with powerful intelligence and great honesty."

Well, I like Dieudonne for his clear and precise writing. I was learning math from his books. But why would he say such things about physics? This I do not understand. Perhaps subconsciously he really loved physics, but expressing this love would interfere with his love to the purity of mathematics?

P.S.11. 08-10-23 9:22 While reading "A lady mathematician in this strange universe : memoirs", in the chapter "First Works, the 3+1 Formulation", I have found this:

 "I published, in 1948, three other papers in the Comptes Rendus of the Académie des Sciences — among them, two are cosigned par Lichnerowicz. In one of them, we simplify a hypothesis made in constructing the Schwarzschild metric, fundamental in Einsteinian gravitation. Lichnerowicz then proposed to me, as a subject for my thesis, the generalization of one of his theorems, itself a generalization of a fundamental theorem from Georges Darmois. The problem was to formulate the Einstein equations of General Relativity, in replacing the particular coordinates chosen by him generalizing the particular ones chosen by Darmois, by fully general ones. This formulation, called now three plus one, highlights the local splitting of the roles of space and time. I had essentially finished this work, which required little imagination, and published a summary in a paper to the Académie, when Leray suggested to me a more interesting subject. I will come back to that later."

3+1. This is what I am playing with now, though for a different reason. There are, in fact, many more common points of interest.

P.S.12. 10-10-23 7:40 There are also significant differences. Yvonne runs away from waves travelling faster than light. She is in love with Einstein's causality. In this respect I am the opposite. She became famous doing important research. I am, on the other hand, one of those fringe physicists fitting black lists. But I read that one of her friends, Yves Rocard, was also blacklisted because of his interest in dowsing.:

"His non-election in the French Académie des Sciences is an example of the narrow-mindedness of some who are afraid of an idea which disagrees with beliefs forged by their predecessors; in the case of Rocard, the detection of water by dowsers. "

Another difference: Yvonne complains that she was not allowed to teach a course on quantum mechanics, which prevented her from learning it. I was more lucky in this respect teaching several courses on quantum mechanics and learning it - unfortunately (or fortunately?) mostly from books and papers, not from real human experts. Working now on a little paper (of mainly pedagogical nature) about "quantum mechanics of photons" - attempting to finish what Varadarajan (and Daniel Kastler in his "Introduction à l'Electrodynamique quantique") left unfinished. 

P.S.13 12-10-23 11:04 Found in "Lady mathematician":

"Jordan, in 1947, wrote the obtained equations without this last hypothesis and interpreted the new coefficient as what was previously the gravitational constant, now variable. The geometric formulation of Jordan’s work and the physical interpretation of results were proposed to Yves Thiry as the subject for a thesis by Lichnerowicz, who then named the result “Jordan-Thiry theory”. The unification in a geometric formulation of gravitation, electromagnetism and the new fields (weak and strong interactions) called Yang-Mills, discovered after Einstein’s death, was done by Richard Kerner, Andrezj Trautman and myself, by considering even higher dimensional space-times. They are called “Kaluza-Klein theories” — too bad for Jordan. "

Notice the interesting morphism: Andrzej -> Andrezj. I love it! Fortunately Ryszard, after moving from Warsaw to Paris, became Richard - much easier to remember correctly.

From my private collection. Smiling physicists: Richard Kerner on the left. Jakub Rembielinski on the right.

P.S.14. 13-10-23 10:24 While reading "Lady mathematician" found this:

"In 1979, I renewed my old friendship with Irving Segal at his sixtieth birthday, celebrated in MIT (Massachussetts Institute of Technology) where he was a professor. (...) He directed with great dedication the researches of several students, mathematicians interested in physics who shared his belief in his cosmology, an unchanging universe, invariant under the Lorentz group. (...)  Irving was interested in the method used by Demetrios and myself to prove the global existence of solutions to the Yang-Mills equations on Minkowski spacetime. He hoped we could extend this result to his cosmos. We attacked this problem and a combination of methods and ideas allowed us to achieve the result. Irving entrusted the drafting of the demonstration to his student and favorite disciple, Paneitz. The latter performed his task, using the definitions and specific notations of his master, which were for me, I have to admit, foreign. The article cosigned by the three of us appeared in the journal dear to Irving, “Journal of Functional Analysis”, thirty years after our first article in collaboration written in Princeton. I, however, granted myself the satisfaction of writing a demonstration with my usual notations for a note in the “Comptes Rendus de l’Académie”. Unfortunately a tragedy occurred soon after: Paneitz, a tall, apparently robust young man, drowned while trying to cross, with Irving who was a man of about sixty and not particularly athletic, a lake close to a place where both had participated in a congress. Irving told me this later, after having consulted a psychologist, a very American reaction, to alleviate the sorrow caused to him by this death"

Segal's "cosmology" is that of the conformally compactified Minkowski space, though he did not like the "cyclic time", so he was unwinding the time loops in his model. Not so long ago I was asking my friend, mathematician in Novosibirsk, who is working in this area for many years, about references dealing with the subject mentioned in the quote above. He told me me about papers about photons on the conformally compactified Minkowski space by Segal and Paneitz, without however being precise. And here, in this quote, I am finding the needed additional useful information.

P.S.15. 15-10-23 7:22 Still fighting with guardians and dragons. Taking the limit...

m → 0+

P.S.16. 17-10-23 8:42

(...) He was often tempted to give up. Then the sluggish wave returned: "After all, no one measures the results according to the intentions; it is only you who knows what the results are in relation to the issue at hand, or rather, you know that they are essentially nothing; apart from that, however, the results are quite interesting and your work has not been in vain." 

Leon Rappaport, "Determinanta"

 

P.S.17. 17-10-23 16:18

From "Lady Mathematician":

Among theoretical physicists, one could distinguish, as Gustave Choquet did for mathematicians, strategists and tacticians. Strategists propose a new theory — general relativity, for example, or the existence of quarks — anticipating its verification by possible observations. Tacticians, on the other hand, critically analyze the theories proposed by strategists, deducing their consequences and foreseeing their possible experimental verification with instruments one has or might build. In physics, I am essentially a tactician, using the Einstein equations of General Relativity to prove the existence of the gravitational waves that were only recently observed after about fifty years of experimental efforts."

I am also a tactician (a small one). Today I finally won the little battle that I have started more than a month ago (yesterday the result was still unsure), when I wrote about Varadarajan;

"He did not go into these ideas neither here nor anywhere else that I know about. But I have to go into these ideas. It's my duty."

Now I have to write it all down, and there is a lot to write,  and make it public. It will take probably another week or two. And today finally came the awaited

Which may cause me to start another little battle. But first things first. I need to well secure my borders first, and make the foundations firm.

P.S.18. 18-10-23 9:59 Started reading "Properties of Light: A Novel of Love, Betrayal, and Quantum Physics, Houghton Mifflin (Boston, MA), 2000, by Rebecca Goldstein. 

Interview with Rebecca Goldstein

Her ex-husband, Sheldon Goldstein, is a theoretical physicist working on the foundations of quantum mechanics (in particular, in the past,  on "Bohmian mechanics", which I shortly criticized in my "Quantum Fractals").