In terms of entropy, there is a single universe with an uncertain configuration. In terms of information, there is a multiverse of alternate universes, each of which is perfectly certain. The uncertainty of entropy and the multiplicity of information coincide momentarily in each measurable interaction in the universe. The key to understanding the informational multiverse is that it doesn’t look anything like physical reality. It is a two dimensional topology with infinite flexibility, so that the infinite configurations it can take on don’t affect its intrinsic properties.
When you make a measurement, the multiverse of information that was possible before collapses around that measurement, and opens up again into the multiverse of possibilities that arise out of the measurement. The physical entropy of the observed matter is singular and uncertain before, during and after the measurement. The measurements only collapses the multiverse of information somewhere in the vicinity of physical entropy. This is the foundation of quantum entanglement: because both quantum states are possible for each entangled particle, they both exist in the information, but if one particle is measured, the multiverses that are incompatible with that measurement cease to exist, leaving only the compatible quantum state in the other particle.
This is why Schroedinger’s cat is real. In the information plane, there is a universe in which the cat is alive and a universe in which the cat is dead, and each universe is equally real and absolutely certain. In entropy, the cat’s aliveness is uncertain, and indeed, for most of the cat’s molecules, the cat’s aliveness is irrelevant as they will act as living tissue regardless of whether the cat as a whole is officially alive or dead. This is the fundamental distinction between information in space and entropy in matter. Abstract determinism is information while real uncertainty is entropy.
Another way of looking at the distinction is that information is real but immaterial and two dimensional, and it only exists in transmission. Reality is made up of an infinite number of 2d information topologies and a single universe of infinitesimally variable 4d configurations of matter. Neither could exist without the other. Without information, matter would have no energy to share or space to exist in, and without matter, information would disappear into the void.
It may be worth thinking of the information space as an imaginary analog of entropic space, but I think the two spaces are equally real. One is abstract but definite while the other is physical but indefinite. This view helps to resolve the mathematical utility of the abstract plane in calculations that accurately represent physical phenomena. It is, in essence, a restatement of the Copenhagen interpretation that also includes the many worlds interpretation of quantum phenomena, and that is the point. Trained physicists can hold opposing views on the “many worlds” interpretation and the “wave collapse” interpretation of quantum phenomena because they are both true. They are mutually exclusive because information and physical phenomena are irreconcilable. But, in the words of Bohr, they are complementary. Neither can describe the other, but neither could exist without the other.
The renormalisation of quantum electrodynamics is a natural consequence of massive particles having a real configuration at all times. In information space, an electron’s path can be broken down into an infinite number of reconfigurations (with photon emissions and absorptions) between the start and end points. However, the physical electron cannot actually take up more than its allotted space in time. Its entropy, or configuration, is limited to its mass and momentum, and observations can place a clear limit on the actual number of configurations an electron can take between point a and point b. This renormalisation is very similar to the solution to Zeno’s paradox, that an arrow’s flight may be broken down into ever decreasing times and distances until the arrow must fly through an infinite set of spaces before beginning to move, and thus cannot move at all. The truth is that the position and momentum of the arrow cannot be determined with sufficient accuracy to divide its path into infinitesimal subpaths. The arrow flies because its position and momentum are uncertain to you; its path is independent of information. The calculus allows us to create an information model for the smooth motion of the arrow, but the arrows actual motion is not smooth, as has been determined by QED, but probabilistic. In QED, the arrow is a probability density of mass and momentum that will almost certainly fly like an arrow. Renormalisation of the equations is necessary because the information does not determine the entropy of the particle: entropy and information are complementary.
The important thing to understand is that renormalisation is not a harmonic or mathematical process, but purely experimental. As with all entropic processes, it is consistent but not periodic, harmonic, or determinable through any means other than experience. Feynman didn’t like it. In fact, nobody in physics likes it, but there it is. Entropy makes the harmonics of QED consistent with the reality of particle configurations.
In order to maintain a relationship with reality, the mind has to perform continuous renormalisation of the information it receives and processes, because the information cannot match the entropy of real matter in space.
Quantum gravity, if real, really should have worked by now. 40 years is too long for a mathematical puzzle with plenty of experimental material.
It is also important to remember that the multiverse only exists in information space insofar as it is compatible with interactions in entropic space-time, and is only useful as an allowance for imagination. Otherwise, like string theory in general, it is not even wrong:
“Many ideas that are “not even wrong”, in the sense of having no way to test them, can still be fruitful, for instance by opening up avenues of investigation that will lead to something conventionally testable. Most good ideas start off “not even wrong”, with their implications too poorly understood to know where they will lead. The problem with such things as string-theory multiverse theories is that “the multiverse did it” is not just untestable, but an excuse for failure. Instead of opening up scientific progress in a new direction, such theories are designed to shut down scientific progress by justifying a failed research program.”