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# Science and Philosophy

## The Reason for A New Biograpahy of Bohm

The following is a quote from the new biography that we have begun reading and can recommend:

As there already is a biography of Bohm, written by F. David Peat, the first question to be raised is what is the point of writing a second biography? A trivial answer would be that many great physicists have more than one biography written on them and Bohm was a great scientist. A more substantive answer requires considering the strong and weak aspects of this biography. While well written, and extensively based on letters and interviews in addition to personal acquaintance with Bohm, this biography is more a biography of Bohm’s life than of Bohm’s ideas. To be more precise, in key points in the development of Bohm’s quest to understand quantum theory and its philosophical implications, Peat’s book is too shallow and sometimes mistaken. Let me illustrate this with a conspicuous case. Bell’s theorem and its impact on physics received a mere 2-page text in the full book. Peat did not acknowledge the distinction among the two papers by Bell, which were published in the inverse order of their production, one dealing with von Neumann’s proof and Bohm’s causal interpretation, and the second suggesting what we call now Bell’s theorem. Therefore the conundrum involved in that proof and Bohm’s and Bell’s works is simply ignored. In addition, the book did not discuss how Bohm reacted to Bell’s theorem at all. Bohm evolved from an initial misunderstanding of Bell’s theorem to a full comprehension

of its implication. Furthermore, Bohm grasped these implications at a moment when there were still conflicting experimental results, those from Clauser and Freedman at Berkeley, confirming quantum mechanics and those from Holt and Pipkin at Harvard, confirming local theories. Only after Clauser’s replication of Holt’s experiment and mainly after Fry and Thompson experiment in 1976, did the balance incline towards quantum mechanics and its non-locality. Instead of analyzing this rich moment, Peat simply and briefly stated the following: “Soon after Bell’s theorem was published, a number of experimental tests, each one more refined and each one designed to overcome possible objections, confirmed the essential nonlocality of the quantum world”. Thus, Peat’s book ignored both the scientific content and the human drama of the ten years between the appearance of Bell’s theorem and the full vindication of quantum mechanics nonlocality, which later was dubbed entanglement. In fact, characters such as John Clauser, Abner Shimony, Ed Fry, Alain Aspect, and Bernard d’Espagnat are meaningfully absent in this biography. Thus a new biography of Bohm is in order, one integrating the history of his ideas and the history of his life, all articulated in their relevant contexts.

Similar comments on the strengths and weakness of Peat’s book were made by the contemporary reviewers of the book. Thus, the physicist Sheldon Goldstein praised how Peat presented the manner in which Bohm’s ideas were treated by fellow physicists but remarked that “Peat’s treatment of the relevant physics is not always entirely accurate,” and then illustrated his point. The historian Alexei Kojevnikov, after positively commenting on how Peat inserted Bohm in the contexts of the times, concluded stating “As for Bohm’s science, that awaits another, more thorough analysis”. Finally, the philosopher James Cushing went along the same lines, stating, “Peat does not always represent well Bohm’s scientific work itself (such as his 1952 papers on quantum theory) or its subsequent impact,” and “in summary, this book does make a prima facie case for Bohm as a ‘fascinating and important scientist’ and is certainly well worth reading. But it probably has not ‘given David Bohm his due.’” During the research for this book, I also realized that Peat’s biography underestimated certain aspects of Bohm’s personal life, for instance, the role of the high school in his coming of age and the roots of his early social consciousness.

## David Bohm on Science

From all that has been said about the role of insight in science, it should now be clear that although Roger Bacon’s suggestion of experience and experiment as a means of criticizing ideas that appear to be reasonable was an important contribution to making modern science possible, it was not enough to prevent the blocks inherent in the active functioning of common knowledge from imprisoning us in fixed beliefs and false presuppositions. These are generally unyielding, even in the face of a great deal of experimental evidence that should reasonably lead them to be questioned. What is needed further is the energy of insight, which dissolves such blocks. This has to be emphasized very strongly, as there is now little realization of the ultimate inability of the scientific approach to avoid the tendency to self-deception inherent in the active functioning of knowledge, if this is not penetrated by insight. – David Bohm

## Complexity and the Implicate Order Bohm-Prigogine Centenary Conference: 24th June 2017

Please visit the Scientific and Medical Network website for more information about this upcoming conference.

## Important Recent Developments

Physics World, New Scientist, and others have reported on the recent experiment titled Experimental nonlocal and surreal Bohmian trajectories.

“It is a new way of looking at quantum non-locality, which vindicates the Bohm position.” – Basil Hiley

You can view the New Scientist article here.

## Thad Roberts on Bohm’s Work in Physics

The theoretical physicist Thad Roberts wrote an interesting reply to the question on *Quora* of Why don’t more physicists subscribe to pilot wave theory?

Physicists today remain largely unaware of the fact that quantum mechanics is perfectly choreographed by the mathematics of the de Broglie-Bohm theory, otherwise known as Bohmian mechanics. Despite the fact that Bohm’s formalism is entirely deterministic, and less vague than the standard interpretation of quantum mechanics, so far it has only been widely recognized and embraced among philosophers of physics.There are several historical events, or “unfortunate accidents,” that have led to the present ignorance of the superior mathematical clarity Bohm’s formalism offers. Understanding this historical posture goes a long way towards explaining why the orthodox or “standard” interpretation of quantum mechanics is still held by the majority of physicists today—something that I would argue is one of the greatest intellectual tragedies of our time.

In his reply his also links to a lecture by Mike Towler on the pilot wave theory that our readers may also find interesting.

## Wave/Particle Duality: Interesting Visualization with Parallels to Bohm’s Work

Your question is excellent. We call a walker the ensemble of the droplet and its associated wave. Since the work you refer to we have shown that the wave field contains a memory of the past trajectory that is at the origin of the quantum like effects we observe. You will find attached a recent work dealing with this effect. In the double slit experiment, while the droplet passes through one slit the associated wave passes through both so that one coud say that the walker passes through both. Our system is similar to a pilot wave system and this is what we are working on recently. These models are usually called de Broglie – Bohm models, a term that is very misleading because the two approaches are different from one another. Bohm gets a dynamical equation from Shrödinger equation so that it concerns the dynamics of a maximum of probability. What de Broglie had in mind was a the dynamics of an individual particle associated with a wave. Our system appears to be closer to de Broglie. — Yves Couder

View the paper that the following video is referring to: Single-Particle Diffraction and Interference at a Macroscopic Scale