As I understand it, the standard model of particle physics recognizes three types of interaction: electromagnetic, strong and weak nuclear force. These are covered by quantum mechanics. Gravity is different, however, and is characterized by Einstein’s theory of General Relativity. Physicists have been trying to unify quantum mechanics and General Relativity into a single framework, a so-called Theory of Everything. Starting in the 1990s much of this work has involved postulating that the universe exists in eleven dimensions. Whatever one may think of that mathematics – I have no thoughts about it beyond, “interesting” – such attempts had, by the time Horgan wrote The End of Science, failed to yield much less pass empirical tests. That is the situation today, 25 years and one Large Hadron Collider later.
If you believe, as many of us do, that what makes science so very effective is that it systematically puts theory empirical test, then these decades of failure are, or should be seen as, an embarrassment. What’s going on? What’s going on is that the theoretical physics community is cranking our ever more theory – no doubt “interesting” in some sense – and is asking for another $20 billion that – promises, promises! – will produce the empirical results that the $10 billion LHC didn’t. If they get the money much of it will surely come at the expense of, not only other physics, but other science as well.
Horgan isn’t buying it, nor are others. The most vocal of these critics is Sabine Hossenfelder, a theoretical physicist who published Lost in Math: How Beauty Leads Physics Astray (2018). I’ve not read the book, but I attended a talk she gave a Stevens Institute in the Fall of 2018 – Horgan, who teachers there, invited her to give the lecture . On one of her slides she asserted, “The current organization of academic research strongly encourages work on topics that are popular and productive,” popular and productive within that particular physics community, but not necessarily everywhere. That assertion is followed by, “Rigorous methodology is neither popular nor productive,” where rigor implies empirical tests.
That is, she points to problems in the social organization of physics research. The foundations of physics, alas, isn’t the only field with such problems. I rather suspect it is behind the replication crisis in psychology, which Horgan discusses in his new preface.
Horgan identified a real problem with the foundations of physics in 2015, and it seems to have gotten worse since then. What should be done? Well, for one thing, don’t spend the $20 billion on a new machine . But what about all those theorists, what should they be doing? They could just drop it and enter investment banking as so-called “quants,” or perhaps help biologists, neuroscientists, or, who knows? in building “Big Data” models.
More seriously, where would that leave physics?
What kind of problem do we face? Is it epistemological or ontological? In The End of Science Horgan suggests we’re up against inherent cognitive limitations inherent in our biology, citing an analogy suggested by Noam Chomksy: Think about a rat running a maze; its brain limits it in such a way that it cannot solve mazes. If we are so limited, then we’re certainly up against an epistemological problem.
We’ll never know the ontological state of the universe. Perhaps the four forces are in fact united in the heart of things, if you will. And perhaps they are not. Our cognitive limitations will keep us from knowing.
I think that analogy is flawed. Aristotle, for example, certainly had cognitive limitations that Copernicus, Galileo, and Newton didn’t have. And they faced limitations that Einstein, and Plank didn’t have. Those limitations were cultural and culture changes, even advances, over the long term. Do we have any reason, in principle, to believe that a future generation of physicists won’t transcend the limitations of the current crop of theoreticians? Perhaps one or three of them even exist in some intellectual hinterland where they make a living by flipping burgers or spinning pizzas in some fast food joint while doing physics on the side.
I’m not claiming that such a future physics will happen, much less that its origins are sprouting even now in the boondocks. I am claiming that it would be foolish to rule such a possibility out of court and I am pointing to the long course of intellectual history as evidence that modes of thought do change.
I don’t believe that such cultural advance is easy, it is not. Nor do I believe it is inevitable. But I don’t believe we can rule it out. Not only that, I think it would be prudent for us to believe that it is possible. It is to that end that I spent years working with the late David Hays on an account of the long-term evolution of human cognitive culture . I'll return to that in a later post in this series.
One final remark: If indeed the problem faced by the foundations of physics is ontological and not epistemological, that is, if these physics have struck the “bottom” of the universe, that would be, it seems to me, a finding of the first order. It would be one of those “cataclysmic” insights Horgan talks about. What will it require for us to discover that?
Would such a “discovery” be in the realm of science or metaphysics?
 I’ve blogged about it here: Lost in Math: Sabine Hossenfelder at Stevens Institute, New Savanna, October 4, 2018, https://new-savanna.blogspot.com/2018/10/lost-in-math-sabine-hossenfelder-at.html.
 See Hossenfelder, Particle physicists want money for bigger collider, Backreaction, Jan. 16. 2019, http://backreaction.blogspot.com/2019/01/particle-physicists-want-money-for.html.
 The following blog post is a guide to that work, Mind-Culture Coevolution: Major Transitions in the Development of Human Culture and Society, New Savanna, July 4, 2020, https://new-savanna.blogspot.com/2014/08/mind-culture-coevolution-major.html. The foundation argument is in William Benzon and David Hays, The Evolution of Cognition, Journal of Social and Biological Structures. 13(4): 297-320, 1990, https://www.academia.edu/243486/The_Evolution_of_Cognition.
Note: I am collecting the posts in this series under the label, EndofScience.