If the later world indeed has to be conceived as an emergent property based on an abstract fundamental layer of qubits, it will, according to Verlinde, have observable effects on a cosmological scale. In the case of emergence, more gravity will turn out to exist near galaxies than the (original) Einstein equation predicts (see the repetition below).
The fact that Verlinde presumes this, is quite extraordinary. It concerns a major problem in Western cosmology. In 1978, the American astronomers Vera Rubin and Kent Ford discovered that the outer areas of spiral galaxies rotate faster than was expected on the basis of the amount of gravity calculated with the einstein equation. This is called the galaxy setup problem.
So, the (original) einstein equation calculates an insufficient amount of gravity in the halos of galaxies, which it does not near the sun and other stars. The explanation requiring the fewest adjustments to the laws of nature is, therefore, an amount of invisible matter in the halos, generating the extra gravity. This mass is difficult to detect and therefore called dark matter. Once it has been detected, it can be processed by the einstein equation in order to make it accurate. After all, the einstein equation needs an amount of matter on the right side of the equal sign, e.g. the matter of a galaxy, for determining the amount of curvature of the underlying gravity spacetime (2 + 2) in a location, expressed on the left side. This curvature in the earlier world defines the path of moving objects in the vicinity of that galaxy in the later world. Finally, the amount of gravity generated by the galaxy can be deducted from the paths of objects. Finding dark matter therefore means that its estimated amount must be added to the tensor (Tμν) of galaxies.
By now, intensive research has been going on for some forty years, searching for yet unknown (elementary) particles, that could be the source of dark matter. The results are disappointing, however, and Verlinde now expects that this shortage of gravity in the halos of galaxies will be explained if gravity is regarded as an emergent phenomenon. This way, he hopes the Einstein equation is correct again. How is this accomplished?
Simply put, in the case of emergence, by assigning the shortage of gravity, and thereby the halos of all galaxies (26.8% of the universe), to the intergalactic space.
Verlinde's assumption is that the 'dark universe' (read: earlier world) consists of qubits and therefore has an identical structure everywhere. His basic assumption of gravity being an emergent phenomenon based on these qubits, therefore essentially means that no distinction should be made between the earlier world of galaxies and the earlier world of intergalactic space.
Note 49 Note that the western dichotomy of the universe is based on the abstract fundamental layer of spacetime shells, but that this principle does not apply to the abstract tissue of the qubits.
This makes the (original) Einstein equation correct again, because this 'intergalactic' gravity can only manifest itself at the edge of the galaxies which, as it were, causes the outer stars of the galaxies to be drawn into the intergalactic space. In the case of emergence, the (original) Einstein equation does not have to apply to the halos.
This is consistent with re-entering the term Λgμν (see image below), which Einstein had added to his equation for some time to prevent the universe from imploding. Nowadays Λgμν is associated with the accelerated expansion of the universe, and therefore with intergalactic space, the vacuum. This was described in section 5.4.2 and depicted in the repeated diagram below.
Since the term Λgμν is on the left side of the equal sign, it is an expression of the earlier world of the vacuum (interstellar space) or, in other words, Minkowski spacetime. The Einstein equation, according to modern insights, thus comprises all of the earlier world of the universe: both timelike gravity spacetime and spacelike Minkowski spacetime.
On the basis of emergence it is therefore self-evident that the earlier world of intergalactic space, i.e. spacelike Minkowski spacetime, is somewhat curved, and thus generates gravity in its later world, without matter playing any part. It is therefore feasible to attribute the estimated gravity deficit in the halos of galaxies to the curvature of Minkowski spacetime. Using the above diagram, the Einstein equation, in my opinion, can simply be made correct by adding the calculated amount of dark matter (26% of the universe) as "cold dark matter" (CDM) to the equation.
The point of view of (classical) Western physics is, however, complicated by its paradigm. After all, curving Minkowski spacetime is not done. In contrast to the modern insights on which the above diagram is based, Minkowski space time is still treated as being flat (not-curved) in Western physics. The dichotomy in the Einstein equation, schematically shown above, is not formally known, and is not addressed in Verlinde's theory. As far as I know, the concept of 'cold dark matter' (CDM)' is not even mentioned in Verlinden's theory. In order to prove that gravity is based on emergence and therefore must exist in the nonmaterial universe as well, Verlinde restricts himself solely to the idea that the minkowski space time generates gravity without being curved. This is, however, very hard to demonstrate. One consolation, however, is the fact that he actually only has to prove the possibility, because measuring the actual amount of it (as is the case with dark matter in galaxies) is probably impossible.
It is therefore clear that Verlinde will respect the paradigm of Western physics in his theory. As a result, his theory is a bit less transparent, and therefore I hope I can be so bold as to make a single addition to it, in order to reveal the western dichotomy of the universe (galaxies versus intergalactic space and halos).
Continue to: 6.4.1. Classifications of the universe