Steve,
"Do possibilites exist that are unknowable or is the universe deterministic?"
I don't know. i.e. 'unknowable' in the model as it only resolves one order of the hierarchy at a time (parameters may change at smaller scales). Godel's fuzzy logic and Chaos theory always apply. But the bits logically resolved include QM non-locality, SR, (with the LT 'limit' mechanism) and GR.
Annoyingly the 2nd half of my post is lost in cyberspace as I used a 'more than' chevron. At least that made is 'digestible'! There is ONLY 'Proper Time' (absolute rate) because SR only banned a SINGLE 'ether' frame, not many hierarchical local background rest states. The SR postulates and AE conceptions survive, the paradox ridden 'interpretation' is junked.
BEAMSPLITTER
The probability of getting precisely 50;:50 are the same as you chopping a sausage precisely in half blindfolded or not. Now look at a 2D cosine 'wave', strike a vertical line blindfold, and check the probability of hitting it precisely at the peak. It's infinitely small (remember the red dots on my 2012 essay Fig 4 rings). So rule one is there's always an energy imbalance.
Now also consider in terms (almost whichever you like but they overlap) of re-emissions at the surface (mirror or glass), Huygens construction, QED sum-over paths, and the non-linear Schrödinger equation. There is NO 'photon' as such following any 'path'. Our preconceptions are nonsense. There are spreading fluctuating energy distributions. If something physically interacts at any number of spatial positions a 'quanta' will however only manifest at ONE position, where any constructive interference is highest. (in kiddies terms, the 'path' the original positive charge took, which DID have a 50:50 random probability).
If a 2nd splitter is introduced to 'recombine' the patterns the same thing happens. BOTH patterns are requantized/re-emitted at the splitter. But NOW they BOTH have 'peaks and troughs' (2D simplification) so phase can be 'tuned' to create the positive energy peak in EITHER direction! i.e. by changing transit time/distance. (A bit more precise to think of playing with two representative twin helices, but less familiar!).
That solution is pretty well as Wheeler anticipated. As usual it's only silly starting assumptions that make nonsense of all that follows. The ontology is powerfully predictive across the board.
I think I also posted the application to cosmology, which suggests a cycle of galaxies and universes. When we look for the specific evidence we find it all lined up for us, presently 'anomalous'. There were two more new 'anomalous' findings this last week which were predictions of the model (satellite galaxy orbits, and anomalous large morphologies in the early universe)
Velocity anti-correlation of diametrically opposed galaxy satellites. and
Anomalous Galaxy Formation and Evolution(finding not interpretation!.
It seems now that even the Higg's may be better described as the 'dipole' the DFM suggests!? Twin Peak Higg's anomaly!
The cyclic evolution paper also derives galaxy bars. It's in print but preprint here (with other papers). None will of course get accepted by a 'big' journal as I'm not an academic, and they're on the 'big picture' not minutii. www.academia.edu/6655261/A_CYCLIC_MODEL_OF_GALAXY_EVOLUTION_WITH_BARS.
The model is as Freeman predicted, incomplete, imperfect and apparently confusing (as it's unfamiliar) but the basics couldn't be simpler (see my prev 3 essays, all top 10 scorers). It's open for all attach and falsification, as well as help to tidy up and help 'describe' in current doctrine terms!
Akinbo
Free protons also scatter EM energy, and provide most of the gravitational mass of pure plasma (dark matter). Parts of space with few electrons are big to compensate. There will always be a kinetic state and radius for any mass where centripetal and centrifugal forces balance. But electrons are not 'orbiting particles'. They may better be seen as an additional wider 'spin state' when 'bound' to a proton. It seems they then can't 'annihilate' with free positrons. Further evolution is then to the more complex bound molecular gases.
Best wishes
Peter