Dear Julian,
An intriguing enjoyable and intriguing essay from an author I really respect. However I am not completely convinced that a holistic approach is always indispensable. Could one not argue, that if the result of the reductionist approach is a concept, idea or formula that is physically *very close* to nature then the whole would emerge from it on its own without further ado? As a minimalist example cellular automata interact according to a local rule and from it the whole emerges in due time.
Even so, perhaps I have implemented a species of Mach's principle in my Beautiful Universe Theory (BU) on which I based my fqxi essay Fix Physics! . My reductionist idea is that the Universe is made up of a lattice of just one type of building block. These blocks or nodes are discrete bundles of angular momentum rotating around their axes in units of (h) and the axes have various angular orientations in each timeless universal State. . Thus L =/= 0 in this scheme. Attached is figure 11 from my BU theory showing how a twist in the angular orientation of two nodes to lock into matter is caused by (or causes) the entire linkage of nodes throughout the universe to mimic the twist, and explaining why E=mc^2
I did not know about Mach's idea that time is emergent from motion. Interesting. I feel that the reductionist source idea in GR (space-time warping = gravity) is physically misleading. GR's Achilles heel is that it includes SR. Why should an observer-related physics enter in realms out there where it is only nature interacting with itself in the same inertial frame - for example light curving around the sun? Without SR, GR becomes very simple - gravity can be reduced to an optical density field, as Eddington proposed, and I have explained in BU.
Shape Dynamics (SD) sounds like a new concept that, at first sight, I wish I do not need to think about! - if there is a simple, local,causal explanation for gravity=acceleration=curvature I would be satisfied with that. In BU it is the curvature of the classical gravitational potential streamlines (or the orthogonal wavefronts) that defines this equivalence. You wrap SD in a probabilistic interpretation.
Quantum probability as a physically realistic phenomena is another of my bête noires . In BU I have shown how probability emerges naturally in the lattice interactions, and how the false point-photon idea made it seem that probability is an abstract interpretation of a dualistic particle-wave nature resistant to physical realism. Have you read the amazing experimental work of Eric Reiter reported in his current fqxi essay in which he proves that gamma rays are not point photons? In such a Nature where probability is the result of systematic, linear local interactions, entanglement can be understood simply and directly without resorting to further ingenious but perhaps complicating holistic ideas as SD.
Hope I have made some sense! I welcome your learned response to my rather qualitative and incomplete ideas.
With best wishes,
VladimirAttachment #1: 2_BUFIG11.jpg