Dear Professor D'Ariano,
I am happy that so excellent essay as yours is top rated among some others that are also close to my ideas. I dare to express your "It is not easy to abandon the idea of a universe made of matter and embrace the vision of a reality made of pure information" in a paraphrase: It is not easy to abandon the idea of a universe made of matter and embrace the vision of a reality made of a pure (conformally flat, isotropic, elastic, homeomorphic and self-organized) spacetime.
I would like to fill your beautiful ontology with details that are able to reconcile, in a sense, Einstein with Bell. The details are powerful because they generate clear predictions. I will also add a real experiment to get ability to falsify that details.
"failures in explaining relevant phenomena-e.g. gravity or dark matter and other astrophysical observations-phenomena that even a reasonable revision of the particle notion seems unable to explain. An ontology that works perfectly well in accounting for a large class of phenomena may later prove having not the same power in explaining other phenomena, e.g. those occurring at scales that are much larger or much smaller than those where the ontology is successful"
That revision of the particle notion is a kind of geometrization of matter. I have tried to apply the geometrization concept not only to the "matter" but also to all "force fields" i.e. electromagnetic, strong and weak nuclear. The gravity would then be emergent as a superposition. The job is not easy so I have proposed an experiment to be sure this is not a huge waste of time. As you know Einstein GR failed outside the Solar System distance scale ( so some physicists try to save GR by means of dark things) and Wheeler-deWitt geometrodynamics has the well-known flaws: the problem of time, the problem of Hilbert space and others. QM's Standard Model in turn does not offer any metric. The other theories using canonical approaches (connection dynamics, loop dynamics etc.) or covariant approaches (perturbation theory, path integrals etc.) and string theories also have not acceptable flaws or generate no predictions.
I also do not use any lattice as it seems to be too limiting. Instead I use deformations of spacetime (wavepackets). Any spacetime deformation is unlimited (to some extent, it deforms the entire spacetime in Gaussian distribution mode, due to its elastic and homeomorphism properties). Than Quantum nonlocality becomes GR type locality by the emergence out of Gaussian distribution.
I am looking for that one, universal, distance scale invariant metric (eventually reducing to Einstein GR metric within Solar System distance scale) and having ability to generate predictions. The first prediction of that geometrization concept is the spin experiment outcome. Depending on the outcome we shall look for a proper metric or give up.
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"we should trust observations, even against our intuition, and ground our knowledge on the logic of the experiment, focusing theoretical predictions on what we actually observe."
Einstein has asked: could we not reject the concept of matter and build a pure field physics? Paraphrasing him let us assume that what impresses our senses as matter is really a strong deformation of spacetime.
Let us start out with our simple thought experiment: we emit a wave to observe that small region in spacetime (the size of an elementary particle radius). That region is deformed to the grade that the wave actually detected (observed) comes back to us along a geodesic ("straight line" in differential geometry). In fact we observe only a strongly deformed spacetime region and redirecting our wave but apparently... we perceive a particle. "We perceive" means that our measuring instruments and our language out of the force of habit say so. The fact that deformation of spacetime exist is generally recognized as a part of general relativity theory (e.g. gravitational lensing). In contrast to GR's distance scale the metric under consideration refers to the quantum scale [3].
Before we proceed (in future, depending on the outcome of our real experiment) to calculate the proper scale invariant metric we need to take some assumptions regarding the spacetime properties to decide what could possibly emerge out of our reasoning:
a) the spacetime is continuous, i.e. not perforated, not torn and has a homeomorphism property
b) the spacetime has elastic properties (possible to calculate)
c) the elastic properties of spacetime are isotropic
d) any spacetime deformation is unlimited (to some extent, it deforms the entire spacetime in Gaussian distribution mode, due to its elastic and homeomorphism properties). Quantum nonlocality becomes GR type locality by the emergence out of Gaussian distribution
e) the spacetime is a dissipative coupled system that exhibits self-organized criticality. That assumption is necessary to use the general law of survival of the stable for the evolution of spacetime deformations)[3]
The spacetime here is not the infamous ether which was rightly rejected because it was to be a frame of reference and a background for all events. The spacetime is not the background, but the material (fabric) of matter and energy itself and then it is quite natural that energy and matter can be transmitted as waves/wavepackets.
The real experiment
A source emits a right-handed photon, the photon impinges almost perpendicularly a mirror being reflected to a detector set up to measure the spin of particle. The photon shall be a low-energy photon to avoid a photoelectric effect, Compton scattering or pair production.
According to Standard Model of QM the reflected photon's spin is the opposite to that of the photon emitted at the source.
According to our thought experiment carried out above the "reflected" photon's spin is the same as that of the photon emitted.
According to Standard Model the photon does not go "around" along a geodesic but it is simply reflected and as a cause of that reflection the spin is changed.
We try to prove that the photon is not a point particle (like in Standard Model) that is reflected from another point particle (one of the many creating our mirror) but instead it travels around a "particle" being a part of the mirror and comes back along a geodesic. The way it goes is a geodesic because the mirror's "particle" is the spacetime deformation only. If our photon goes along the geodesic (straight line) it does not change its spin.
So it is a realization of the thought experiment.
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My next proposal is to exchange the emergence of spacetime from Qubits into the emergence of Qubits from the conformally flat, isotropic, homeomorphic, self-organized and elastic spacetime.
My answer to "What is then the teleported human?": He/she is a wavepacket.
My proposal for your holism is to narrow it down to emergentism that is the direct consequence of any evolutionary approach.
Finally my comment for the Quantum Cellular Automata issue. To me the universe is a dissipative coupled system that exhibits self-organized criticality. The structured criticality is a property of complex systems where small events may trigger larger events. This is a kind of chaos where the general behavior of the system can be modeled on one scale while smaller- and larger-scale behaviors remain unpredictable. The simple example of that phenomenon is a pile of sand. When QM and GR are computable and deterministic, the universe evolution (naturally evolving self-organized critical system) is non-computable and non-deterministic.
I am sorry for that long comment.
Anyway your essay deserves the highest rating.
I do believe you will win the contest!