Older “testimonials”

Excerpts from emails

From N David Mermin

From: “N. David Mermin” <…>
To: Ulrich Mohrhoff <…>
Date: Sun, 28 Feb 1999 22:31:10 -7700 (EST)

All I can say so far is that it is clear that in Section I you understand the IIQM [Mermin’s “Ithaca Interpretation of Quantum Mechanics”] better than any reader I have had so far and have elegantly identified its weaknesses. I have to read more to decide whether I think the PIQM [my own “Pondicherry Interpretation of Quantum Mechanics”] does better. You write so gracefully that that I’m not without hope. I catch myself admiring isolated sentences.

From: “N. David Mermin” <…>
To: Ulrich Mohrhoff <…>
Date: Mon, 1 Mar 1999 12:29:55 -0500 (EST)

Having just told you that it would take me a while, I found I couldn’t put the paper down, so I’ve been through it once, and here are some reactions.

It is charming. Often I think that is all one can ask from an interpretation of quantum mechanics. (Most of the specimens in the cabinet [of interpretations] are not.)

From: “N. David Mermin” <…>
To: Ulrich Mohrhoff <…>
Date: Fri, 5 Mar 1999 10:28:53 -0500 (EST)

…it gave me much pleasure to be so intelligently (and respectfully — didn’t read you as confrontational) criticized.

From: “N. David Mermin” <…>
To: Ulrich Mohrhoff <…>
Date: Tue, 27 Apr 1999 23:28:25 -0400 (EDT)

I took a quick run through “Quantum Mechanics and Elements of Reality” this evening and found it quite intriguing. It fills out the PIQM nicely. I have to think more about them both (for an extended period) but wanted to say right away what a lovely essay it is. Thanks!

Date: Tue, 22 May 2001 11:21:08 -0400

Thanks for calling my attention to your attack on Stapp, which I shall read with pleasure. Do you realize that you have probably brought down upon yourself a deluge of email from Stapp from which you may never emerge? Even mild disagreement can produced hundreds of kilobytes. I shudder to think of the response “18 Errors” will elicit.

From: “N. David Mermin” <…>
To: Ulrich Mohrhoff <…>
Date: Sat, 11 Aug 2001 09:36:44 -0400

[I had written to Mermin that Found. Phys. has accepted my “18 errors” paper, that they intended to publish it along with a reply by Stapp, and that Stapp wanted no direct dialogue with me: “Thus no kilobytes.”]

On balance you should consider yourself blessed.

From: “N. David Mermin” <…>
Date: Mon, 25 Jun 2001 10:40:13 -0400

I spent a couple of hours with Ole Ulfbeck in Copenhagen before flying home…. He had clearly not run across your papers before. I told him you were a person whose views he should take seriously.

An indirect endorsement by Mermin

From: William Conrad <…>
To: Ulrich Mohrhoff <…>
Date: Fri, 22 Jun 2001 13:32:36 -0400 (EDT)

Would you mind if I sent your article to, say, David Mermin and to Abhay V. Ashtekar, for an opinion?

[William Conrad, an editor of American Vedantist, intended to publish an article by me.]

From: < conradw@…>
To: Ulrich Mohrhoff <…>
Date: Mon, 9 Jul 2001 18:06:17 -0400 (EDT)

I got a lovely reply from David Mermin. He says your physics is sound and that he has been following your work for the last 4–5 years with great admiration. A better review than that one could not hope for.

From Johann Summhammer

From: Johann Summhammer <…>
To: Ulrich Mohrhoff <…>
Date: Wed, 4 Jul 2001 10:57:08 +0200

Two weeks ago I met Mermin at a conference in Vaxjo, Sweden, and we had a few words about your thinking. He likes your ideas, he told me, but we didn’t get any deeper. Except, when I remarked that quantum theory is a philosopher’s dream come true, he retorted, no, a nightmare come true. Your vedantist paper suggests that you would tend to share the former rather than the latter opinion.

From: Johann Summhammer <…>
Date: Thu, 10 Aug 2000 17:27:23 +0200

Ich habe mit Genuss ihre arbeit „the one, the many …“ (quant-ph/0005110) gelesen. Als experimenteller Quantenphysiker kann ich Ihnen im grossen und ganzen nur zustimmen. Mir gefällt ganz allgemein Ihr Abschütteln naiver Wirklichkeitsbilder. Denn die Notwendigkeit dazu drängt sich jedem auf, der solche Experimente durch eigenes Tun „erlebt“ hat, und sich daher Schritt für Schritt der Konstruiertheit unserer Vorstellungen aus Beobachtungsdaten bewusst ist.

From: Johann Summhammer <…>
To: Ulrich Mohrhoff <…>
Date: Mon, 5 Mar 2001 12:45:04 +0100

…es ist nun schon über ein halbes Jahr her, dass Sie mir Ihr paper in Am.J.Phys. 68 geschickt haben…. Ich stimme eigentlich mit allem überein, das in diesem paper steht. Es sagt schlicht und einfach Wahrheiten, die auf diese Art noch von niemandem gesagt wurden. Vermutlich deshalb, weil der Erfolg der Engineering-physicists dazu geführt hat, wichtige Fragen mit einem Lächeln “this is just philosophy” einfach tabu zu stellen. Was wiederum dazu geführt hat, dass ein unbewusster naiver Realismus zum guten Ton geworden ist.

From other physicists and philosophers of science

From: Asher Peres <…>
Date: Thu, 8 Apr 1999 16:01:47 +0300 (IDT)

Dear Dr. Mohrhoff,

Just a few words to tell you that I enjoyed reading your paper on PIQM.

From: Dennis Dieks <…>
Date: Tue, 13 Aug 2002 17:55:45 +0200

Dear Dr. Mohrhoff,

I was asked to write a brief review, for the Mathematical Reviews, of your article “The world according to QM” (Found. Phys.). I was not familiar with this article, or other work of yours, before. I was much impressed by many of the arguments you put forward in the Found. Phys. article. In particular, I think your exposure of the all too often found question “how do probabilities turn into facts” as a pseudo-problem is extremely lucid. I agree with many other points as well, e.g. about the flow of time and the notion of a block universe. Of course, I also concur in the view that the introduction of consciousness in the way Stapp does it is a wholly gratuitous manoeuvre. Finally, I have great sympathy for the idea that spatiotemporal features should be regarded as properties of physical systems, rather than assuming a spacetime continuuum beforehand…. I have expressed similar viewpoints in writing myself, but I think not as eloquently as you have now.

[Dieks is Professor of the Foundations and Philosophy of the Natural Sciences at Utrecht University and one of the two editors of Studies in History and Philosophy of Modern Physics.]

Excerpts from books or papers by physicists

Louis Marchildon, Remarks on Mohrhoff’s Interpretation of Quantum Mechanics, Foundations of Physics 34, 59–73 (2004):

In the interpretation he has put forth, Mohrhoff has shown us a thought provoking and original view of the way that, according to quantum mechanics, the world can be.

Bernard d’Espagnat, On Physics and Philosophy (Princeton University Press, 2006, p. 239fn):

For completeness’ sake let me however mention here a stimulating suggestion from U. Mohrhoff (2000, section IV; 2001). This author aimed at preserving the notion that the physical space is strongly objective while ascribing to it some at least of the features of phenomenal space. In view of experiments of the Young-slit type he granted that all of the latter cannot be kept. And the one he chose to give up was the idea that the various regions of space should exist by themselves independently of the objects that may or may not be in them. In other words, it was the idea that physical space is intrinsically partitioned into infinitesimal regions (and can therefore be represented by a transfinite set of real number triplets). According to him the place where an object is is comparable to the color of the object, in that the latter cannot conceivably be separated from the very existence of the said object. As an alternative to my views Mohrhoff’s suggestion is certainly worth studying.

[Bernard d’Espagnat has won the 2009 Templeton Prize, valued at approximately $1.42 million, the world’s largest annual award given to an individual.]

Newton C. A. da Costa and Adonai S. Sant’Anna, The mathematical role of time and space-time in classical physics, Found. Phys. Lett. 14, 553–563 (2001):

…there is an insightful paper by U. Mohrhoff [18] that presents a novel interpretation of quantum mechanics, where objective probabilities are assigned to counterfactuals and are calculated on the basis of all relevant facts, including those that are still in the future…. To understand how EPR [Einstein-Podolsky-Rosen Gedanken experiment] correlations are possible, one needs to understand that, in and of itself, physical space is undifferentiated. At a fundamental level, “here” and “there” are the same place. If EPR correlations require a medium, this identity is the medium. Mohrhoff’s ideas about space-time may inspire us for a new perspective about spacetime, quite different from discretization.

Statements by non-physicists

Stephin Merritt in a 2006 interview with Pitchfork:

Well, there are certainly original things to say…. I just read online a few weeks ago the Pondicherry Interpretation…. It’s the physics … attitude of Ulrich Mohrhoff, who happens to teach in Pondicherry, India. The Pondicherry Interpretation is startlingly original to me. So I said to myself, “my God, there’s a new way of thinking about the world!”

[Merritt is an American singer-songwriter. Pitchfork Media is an Internet publication devoted to music criticism, commentary, and artist interviews.]

From: dabney venable <…>
To: ulrich mohrhoff <…>
Date: Sun, 18 Nov 2001 21:07:39 -0500

I am not a “quantum mechanic”. I’m not even a physicist. I’m a retired child protective service worker from New Jersey. I have had a non-mathematical interest in qm for over thirty years and have read myriad (non-mathematical) treatments of the subject. When I read Mermin’s work on objective probability I knew somewhere deep down that he was right although I also thought it was crazy. I have thoroughly enjoyed your papers. I’ve printed them up and I sit in the local diner drink black Greek coffee and read them. You have helped me realize that the reason I thought it was crazy was the amount of garbage about this subject that I’ve internalized and the amount of unlearning I face. Unlearning is a difficult and tedious process for this 60 year old. But the insights gained have and continue to make it quite worthwhile. Thank you, sir