I recently was invited by Curt Jaimungal, of the Theories of Everything podcast, to debate philosopher Tim Maudlin on issues of philosophy of physics. I accepted after briefly looking up Maudlin's name and seeing that he was an academic. The result of this attempted debate, however, was a complete and unqualified disaster:
As much as this unfortunate event is deserving of forgetting, I think I owe my audience some clarifications. I'll try to keep it brief, to the point, and factual.
Did I know about Tim Maudlin's work before this attempted debate? No, I didn't. I essentially knew nothing other than the fact that he teaches philosophy of science at NYU, which I considered sufficient to justify my engaging in a conversation. I do follow the field of foundations of physics as closely as I can, but I follow the physics literature, not philosophy of physics. This doesn't mean that I dismiss philosophy of physics; it means only that I don't have time to follow everything of relevance to my work, and thus have to make choices. My past with experimental physics makes me more predisposed to prioritise the physics literature directly, and that's all there is to it.
Therefore, my usage of the expression 'grotesque theoretical fantasies' in my opening statement was not directed at Maudlin at all; I had no idea what his positions were. If he presumed that I did, then he presumed too much and that's not my responsibility. What I did know was that Maudlin wasn't a creator of any of the theories or interpretations I was alluding to. The expression 'grotesque theoretical fantasies' is one I had used many times before, and it has always referred to ideas, such as Everettian Many Worlds and Bohmian Mechanics. It was never directed at individuals, alive or dead. That Maudlin seemed to be offended by my usage of this expression is something I could not have anticipated; for all I knew, he would wholeheartedly agree with it. But if he felt, instead, that the hat fit his head, that was his judgment, not mine.
Maudlin stated that "everything [I had] just said is silly." So let us look into what I said and see whether any of it could conceivably be considered silly:
I started by saying that there was no consensus in the physics community about whether the experiments in question refuted physical realism. Maudlin obviously agrees, so that couldn't have been the silly part.
I said that, in addition to Bell's inequalities, there were also Leggett's inequalities, which can discriminate between physical realism and locality. Was that the silly part? Clearly not; it's a fact. Here is the paper in question.
I then said that these inequalities had been experimentally verified. Was this silly? No, here is one paper reporting on the experimental results. And here is another.
I proceeded to say that these results refuted a broad class of non-local hidden variables theories. Was that silly? No. This is an explicit conclusion of one of the papers in question, one of whose co-authors is a 2022 Nobel Prize Laureate in physics.
I then said that Bohmian Mechanics, which Maudlin refers to as "Pilot Wave Theory," is one of the speculations that could perhaps survive the experimental results. Maudlin obviously agreed with that, so that wasn't silly either.
I followed up by stating that there were other reasons why Bohmian mechanics wasn't plausible, one of them being that it does not have a relativistic extension. Is that silly? No, it's a broadly known fact that doesn't even require a citation. So what was the 'silliness' Maudlin was alluding to?
Towards the end, I shared my view that, short of "grotesque theoretical fantasies," physical realism is untenable in the face of those experimental results. Is this silly? Perhaps in Maudlin's opinion it is, but I certainly substantiated my view explicitly and rigorously enough before stating it, so immediately characterising it as silly seems to be just that: silly and gratuitously provocative.
Finally, although acknowledging that physical realism seemed to be refuted experimentally, I still expressed my support for a realism of another kind; a realism entailing that the world is still made of real, external states, but states that aren't describable by physical quantities or properties. Clearly, Maudlin is a realist, so my expressing support for some surviving form of realism couldn't be silly from his point of view.
Given the above, the vast majority of what I said in my opening statement wasn't even polemical, let alone silly; it was factual in a manner that no informed player in the field of foundations of physics would fail to see. Maudlin's prompt and thoughtless characterisation of it as silly was purely emotional; it betrayed a surprising level of insecurity. I inadvertently poked his sensitivities and he took his frustrations out on me. Something in him clearly knows that his theoretical preferences are in serious trouble, otherwise he would have maintained a normal, calm, confident demeanour appropriate for the situation.
Now, why did I leave the debate? There are three reasons:
In an of itself, the usage of the word 'silly' is, in my view, acceptable in a debate, provided that it is substantiated by the preceding context and the corresponding tone conducive to conversation. But Maudlin's overtly aggressive, obnoxious, disrespectful tone in his loud outbursts made it clear to me that he wasn't open to any such conversation. My taking exception at his characterisation of my opening as 'silly' was as much about his tone and demeanour as it was about the word itself. He was simply out to have a schoolyard brawl with me (which I could even be in for, as long as we did it in the schoolyard, and without the pretence of intellectual aspirations). As things stood, there clearly was no point in pursing the exchange further.
Secondly, I frankly didn't feel like being insulted again, for although I take myself less seriously today than I ever did before in my life, I still have self-respect, which I think is healthy. There is no contradiction between these two things. Be that as it may, Maudlin's uncalled-for insult and overt toxicity angered me, and still anger me when I re-watch the video. I am not a saint and have never made a secret of it; much to the contrary. As someone who was educated to never tolerate bullying or insult at any age, I found myself wishing that Maudlin would speak to me in that tone in person, man to man, not from behind a camera. Clearly, such a thought was not conducive to continued conversation.
Thirdly, Maudlin's claims that the experimental results were also "predicted" by physically realist interpretations of quantum mechanics struck me, content-wise, as so outdated and biased as to make the engagement pointless. For instance, he claimed that the experimental results were also "predicted" by the Everettian Many Worlds Interpretation (MWI). Strictly speaking, this is indeed correct, in that MWI predicts that everything happens; every possible outcome is 'predicted' by MWI to actually unfold, just in some inaccessible parallel universe for which we have precisely zero direct empirical evidence. Obviously, this 'predictive power' of MWI is what makes it unfalsifiable and explanatorily useless, since a theory that predicts that everything will happen might as well predict nothing. That Maudlin should appeal to the 'predictive powers' of MWI to justify his calling me silly was rather rich.
Maudlin then appealed to Bohmian mechanics as an interpretation consistent with the experimental results. Bohmian mechanics is very niche in physics today for a number of excellent theoretical reasons, and even the experiments that once were construed to give it some basis have turned out to be wrong and do exactly the opposite. Its own creator, Louis de Broglie, abandoned the theory already a century ago. Yet I don't have to refute Bohmian mechanics, as the burden of argument here is not on me; it is on its proponents. It is they who need to show how it could be reconciled not only with the experimental results, but with Relativity. They also have to show how Bohmian mechanics could replace Quantum Field Theory, whose basic tenet—namely, that particles are field excitations—contradicts Bohmian mechanics (according to the latter, particles are little marbles riding a pilot wave). Before Bohmian mechanics can be used to base any philosophical argument, it first needs to be proper physics. Of all possible interpretations of quantum mechanics, that Maudlin chose to use "pilot wave theory" to substantiate his charge of my being "silly" was remarkably ironic; the man seems to completely lack self-awareness.
Finally, Maudlin's repeated rhetorical questioning of how any physical experiment could possibly refute physical realism, as if such a thing were obviously impossible a priori, betrays such a lack of awareness of the issues in contention, and of developments in foundations of physics, that further discussion was pointless.
You see, I am known to like and engage in confrontational critiques and robust exchanges, as accepted and even encouraged in academia. I am also known to have used words such as 'silly,' 'naive,' and even 'crazy' when referring to certain ideas. But I challenge you to find a face-to-face debate or conversation wherein I gratuitously insulted my interlocutor in tone, demeanour or language, or treated them with any level of disrespect. Therefore, my usage of the words above should be evaluated in their proper context, and not be misconstrued as permission for others to take on a nasty or disrespectful tone with me in any conversation; I shall tolerate no such thing.
I was sincerely willing to engage in a robust exchange with Maudlin, provided that the opportunity for such an exchange were there. Maudlin's unbecoming, unacademic and rude behaviour made it clear that such was not the case. He came across to me as a nasty and crass street brawler, not a thinker. I have thus no plans to engage with him ever again, for I have no respect for the attitude he displayed and what it betrays about his character. Nor do I find his ungrounded, tendentious, hand-waving and wishful technical statements worthy of in-depth discussion in debate format. I am sure he can continue to believe in his unfalsifiable, pseudo-scientific fantasies without my help.