The philosopher Kuhn distinguished normal science that grows theories, from paradigm shifts that change their foundations, where the foundations of a theory are the axioms it is built on. Changing foundations is hard, so Kuhn argued that science involves long periods of normal science interspersed with occasional revolutionary paradigm shifts (Kuhn, 1970).
For example, Euclid’s assumption that parallel lines can’t converge was accepted for two thousand years, until it was realized that on curved surfaces like the earth, parallel longitudes do converge (at the poles). Changing that axiom gave hyper-geometries that work on curved surfaces, and made Euclid’s geometry the special case of a flat surface. Einstein’s relativity was also a paradigm shift that made its predecessor, Newton’s mechanics, a special case. Science sometimes has to change its foundations to advance.
What then are good theory foundations? Chaitin argued that good axioms support more than one fact (Chaitin, 2006), based on Gödel’s proof that all theories are incomplete (Gödel, 1962). Good theories use a few axioms to predict many facts. Ignoring this criterion by adding new axioms for every new fact increases size not success, just as putting a shack on every new plot of land gives a shanty town not a city of skyscrapers. That a theory isn’t increasing knowledge is a sign that a paradigm shift is needed. It is increasingly obvious that particle physics today is in this category, as:
“One experiment after another is returning null results: No new particles, no new dimensions, no new symmetries.” (Hossenfelder, 2018).
It is also obvious that it has had to add new axioms to explain new facts for a while now, so particles and fields have increased but not their predictions. Gravitons were assumed to explain gravity, but predicted nothing new. Virtual particles with mass were assumed to explain neutron decay, but again predicted nothing. A Higgs field was assumed to explain how those particles had mass, but it also led nowhere. The field has increased in complexity but has made no breakthrough in decades, suggesting the need for a paradigm shift.
The shift proposed is to base physics on waves, as quantum theory does, not on particles, as materialism does. This change seems radical but disruptive innovations are often the price of progress (Sandström, 2010) and physics already uses wave equations, so the practice won’t change. For example, Schrödinger’s equation stays the same but it now describes what exists, not what doesn’t. In general, the equations don’t change but their meaning does. Giving quantum theory a semantic heart might not seem important but just as giving up geocentrism led to new directions in astronomy, giving up materialism suggests new directions in physics, like colliding light not matter (4.5.9). Yet this paradigm shift challenges the belief that we have all, or nearly all, the answers already.