Chris Talbot

When I described the two slit experiment I discussed elsewhere we also all knew it was all a big simplification that physicists make because the math is what matters; in trying to get to the level of understanding I’m attempting, you have to know it is an approximation. In reality the electron goes everywhere. In one of Feynman's pop science books there's a good explanation of this. It's called the path integral approach. So the electron (remembering it's actually a quantum wave), essentially goes through all parts of the barrier, through the slit, through the other slit etc etc. All these paths give a little different phase when the particle hits a particular location you consider on the screen/detector. All these phases (equivalent to the phase of a classical wave) superpose - some add, some cancel, some partially add and cancel, etc. This leads to the probability amplitude at that location having a particular value and we detect the electron according to that. This makes it seem as though the electron passes through a particular slit, or not, or both. But the important thing to note is that the elections really goes everywhere, when we talk about it going through the slit, it's an abstraction/simplification.

Please don't misunderstand. I believe our understanding of the laws of physics can have a profound impact on the quality of our experience. However it requires a leap of faith to presume what we experience is in fact our reality, and cosmological issues focus or reality and not necessarily how we experience life. When people start talking about the big bang theory, they are fallaciously assuming that there is a concrete universe out there, when QM is showing us that the so called concrete universe is made of abstract components. A field is abstract and a photon is, at best, a real disturbance in a abstract noun. Now if a photon was a disturbance in an ether, then the photon might be objective, but since it is a disturbance in a field it will always be subjective. that is why I believe idealism is the only rational way to view reality. The world of appearances is a lot light the matrix was in that outstanding movie.

Experiments with entangled pairs of particles have amply confirmed these quantum predictions, thus rendering local realistic theories untenable. Maintaining realism as a fundamental concept would therefore necessitate the introduction of 'spooky' actions that defy locality. Here we show by both theory and experiment that a broad and rather reasonable class of such non-local realistic theories is incompatible with experimentally observable quantum correlations. In the experiment, we measure previously untested correlations between two entangled photons, and show that these correlations violate an inequality proposed by Leggett for non-local realistic theories. Our result suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned.

To me the "feature" of realism that has to be abandoned is space. The space that appears to separate two entangled particles is the illusion, not how they "communicate" over distance. I believe quantum mechanics debunks realism. If you believe realism is tenable, can anyone please tell me how you see space according to your world view? Kant said space (and time) are not phenomenons but rather ideas or mental constructs.

Reading the letters with Miriam Yevik, Melba Phillips, and Hanna Loewy, in this volume and in Talbot’s “David Bohm's Critique of Modern Physics: Letters to Jeffrey Bub, 1966-1969” (LINK) along with Bohm’s "Wholeness and the Implicate Order" gave me a clearer understanding of what Bohm was all about (“panpsychism” first and foremost because it permeates all of his work). We need another Bohm in Physics nowadays to make us deviate from the usual trodden paths and I’m saying this as someone who does not “believe” in Bohm Mechanics…Maybe if someone finds a way to devise a QFT version out of it…we all know the transition from QM to QFT was not easy... Bohmian mechanics as well was just a step, exactly as QM can be seen as a step towards QFT. The difference is that QM has been accepted even with its weird lack of an interpretation and its first celebrated step towards QFT was acclaimed... even if it was based on a totally mathematically unfounded truncation of a divergent series (something that would make a student fail its maths test). However, these gave rise to new ideas and stronger mathematical formalism to support them. Bohmian mechanics simply did not enjoy such a luxury, which is necessary for a theory to mature. Coming to Bell it was stated that reality is either non-local, non-causal, or non-real. Or some combination. I prefer non-causal but whatever, Bell showed that at least one of those had to be so. Bohmian theory obeys bell's inequalities therefore cannot be a good theory of reality, even if reality is non-real. Isn't physics fun?

After “David Bohm's Critique of Modern Physics - Letters to Jeffrey Bub, 1966-1969” by Chris Talbot this is another great addition to showcase what Bohm was (still is?) all about.

NB: Too bad Peat’s wife was not able to photocopy all of the letters between Bohm and Yevik who died in 2018 (this book was published in 2017 and Talbot writes that he made several attempts at getting the rest of the letters from the wife).… (plus d'informations)

It was good to read in these letters between Bohm and Bub a sort of philosophy of science angle on modern science and philosophy theory. After reading these set of letters my advice would be to shift the emphasis from theory and the physical world to the concept of human understanding. What does it mean to understand the world around us? If we take the concept of human understanding in physics to mean what it meant for Galileo and Newton, i.e., representation in terms of a mechanical model, then physics parted company with human understanding following Newton's discovery of gravity and the very notion of action at a distance. Newton, according to Hume, showed the "imperfections of the mechanical philosophy and thereby restored Nature's secrets to that obscurity in which they ever did and ever will remain." Quite a statement from a philosopher of outstanding genius and one which, I think, should be taken very seriously. Some of the greatest physicists, including Bohm, have since echoed this insight in one way or another expressing their dissatisfaction with the nature of modern physics theories both at the micro level of QM and at the macro level of cosmology. For example, Dirac pointed out that leading physicists themselves understand that modern science no longer even tries to present models or pictures of how the world works. What they give us instead, according to Dirac, are ways of looking at the fundamental laws which make their self-consistency obvious. Dirac was no fool either. Neither was Bohm.

I'd say we're still only beginning the process of inquiry, with maybe billions of years of thinking and discovery ahead. So, being humble and recognizing our "place in time" is the correct approach. With 1 cm as 5000 years of thinking "completed", we've kilometres to go. It's also hubris to say we're the first to get this far, so we're just not typical as an intelligent technological species. Babes in the woods. Still, a complex picture has emerged, at least physically (physics), with many facts established that seem to be universal in Nature.

Every time I read something by Bohm et al regarding the foundations of QM my question is always the same: could an AI or "zombie" observer collapse a wave function? I know it's hard to test (impossible in the case of zombies) but it kind of gets at the heart of the matter, doesn't it? Since a machine apparently can (see the Quantum Zeno Experiment at the University of Texas, you would have to say yes. However since we don't know the basic meaning of "collapsing the wave function" in terms of how the model relates to reality, it doesn't get to the heart of anything. In QFT the quantum vacuum is a good model of abground and agrees with postmodern interpretations of reality as not constituted in a sustained manner, but only re-constituted as change. The neurological system being primarily an intra-action with abground, or the quantum vacuuum, looks like the most attractive approach for modeling how it produces an ontologically constituted experience of the real as already meaningful.

Incidentally Bohm's interpretation of quantum mechanics wasn't 'provocative' as I heard someone mention recently in a reply to one of my posts on a Physics book. Bohm’s take on QM was a genuine attempt at doing science that most people recognised as potentially valuable. It's just that the basis for his work, hidden variables, seems to have been disproved. Even so, some still think QM might get some future mileage from Bohm's work.

Much food for though for philosophers of science here in this Bohm's collection of letters… (plus d'informations)