I have argued elsewhere that the peak moment for physics was actually the mid-'70s. Here we had the taming of the particle zoo into one of the most impressive achievements of human intelligence, the Standard Model. The action in science after the 1970s shifted to biology, which, for many years, had been stuck to principles borrowed from physics, the chief of which is the search for simplicity at the heart of the profusio (the constant buzz) of breathing, heart-beating, biting things. Biology is now in the process of abandoning this search for the simple in the middle and embracing the irreducible complexity of living organisms. The future for this field is opening. But the one for physics is becoming more and more constrained.
Sure, physics is still making some discoveries and performing important experiments, such as the recent teleporting of "an electron to a low-orbiting satellite 300 miles away." But this still does not eliminate the fact of the general trend downward from the peak in the mid-1970s. Teleporting a particle to space may look impressive, but quantum entanglement is old hat. It is still, as weird as it all sounds, in the realm of the knowable. But something like dark matter, which is believed to account for over 80 percent of all matter in the universe (25 percent of "total energy density"), may not be. It is possible that this stuff is not at all stuff as we can even understand it. But physicists insist that it is. DM can be explained with the reality represented by the splendid Standard Model. What can we do but believe them? There is one theoretical physicist, however—Sabine Hossenfelder—who thinks this is all hogwash.
The problem, writes Hossenfelder on her blog Backreaction, is this:
By and large, experimentalists like to think that looking for [dark matter] particles is business as usual, similar to how we looked for neutrinos half a century ago, or how we looked for the heavier quarks in the 1990s.
But this isn’t so... We had theoretically sound reasons to think that neutrinos and heavy quarks exist, but there are no similarly sound reasons to think that these new dark matter particles should exist.
One another post, she writes:
In the past decades, the searches for the most popular dark matter particles have failed. Neither WIMPs nor axions have shown up in any detector, of which there have been dozens. Physicists have finally understood this is not a promising method. Unfortunately, they have not come up with anything better.
What all of this has done, according to Hossenfelder, is produce lots of papers and little to no results. She writes:
Theorists invent new particles (papers will be written). Experimentalists use those invented particles as motivation to propose experiments (more papers will be written). With a little luck they get funding and do the experiment (even more papers). Eventually, experiments conclude they didn’t find anything (papers, papers, papers!).
Understandably, there has been a strong reaction to her criticism of the current state of theoritical physics, large sections of which, she believes, have descended to the condition of a religion. But the real problem with her position is that she assumes that all of this thinking, modeling, and writing of papers is useless unless it's apparently productive. She has a utilitarian view of the sciences, and she constantly worries about how money is "poured" into research that's in a state of pure speculation/philosophy/religion ("Some want to look for domain walls, or weird types of nuclear matter, or whole 'hidden sectors,' and again we have no reason to think these exist"). Here I sharply disagree with her. These papers and theories are not a waste of time and money because in science (as in philosophy and poetry), errors are of as great importance as correct calculations and observations.
This point is made brilliantly in a paper by philosopher Steven Shaviro, "Whitehead on Causality and Perception." For one, according to Shaviro's reading of philosopher and mathematician Alfred North Whitehead, what matters more than truth is that a paper or hypothesis is interesting. But also, trying to find something that's not there does not mean that all is lost. It may appear so from one position in time and space, but for another point in space and time, it can be revolutionary. Nothing in culture is really useless. Philosophy is the department of lost and found.
A scientific observation, a common-sense hypothesis, or even a rigorous philosophical formulation may have relevant and important consequences despite the fact that it is erroneous. For this reason, the [20th century British philosopher Alfred North Whitehead] is less concerned with eliminating error than with experimenting with it, and seeing what might arise from it. Error is not an evil to be exterminated, but a frequently useful ‘lure for feeling.' It is a productive detour in the pathways of mental life: ‘We must not, however, judge too severely of error. In the initial stages of mental progress, error in symbolic reference is the discipline which promotes imaginative freedom
And now for the substance of this post, bearing in mind that searching for something (in this case particles) that may not exist is not a bad thing: Is the state of particle physics—much of which Hossenfelder sees not as a science but a branch of philosophy—pointing in some sense to the possibility of a cosmic Kantianism? What I mean by this: Immanuel Kant , an 18th century German philosopher, theorized that humans could only know reality by the way the human mind is structured. We do not experience the whole world, but the world our in-built concepts or constructs could make sense of. This was his big contribution to philosophy. It was vividly challenged in the last decade by a number of philosophers described as speculative realists. The Kantian model made the world outside of human knowability non-existent. But there is, we must believe, a world before, and there will be world after, the existence of humans. This was the speculative realist's prime position.
But I want to introduce the possibility of a cosmic Kantianism. It's found in a short book by the Italian theoretical physicist Carlo Rovelli, The Order of Time. He presents the idea that the universe that humans and living beings experience is not the entire universe but one of its many parts (or subsets). More radical yet, we animals can only see a subset of the universe that is, exactly, seeable. There are subsets that are unmemorable; and they unfold in a way that's unthinkable. As I said in another post, the knower and the known are one and the same in this subset that call the whole universe. This, in my thinking, is a cosmic Kantianism. Rovelli has taken the famous bachelor of Konigsberg out of the head and to the stars.