TFNR - Conjugate or complementary quantum quantities / variables
Two variables are said to be complementary if knowledge of one does not imply any knowledge of the other, like position and momentum. This means that some pairs of complementary properties cannot all be observed or measured simultaneously with infinite precision. This concept is closely related to the Uncertainty Principle.
In my opinion, the element of Reality that determines this "complementarity of uncertainty", so to speak, is Time. Except for errors, all pairs of complementary variables are characterized by the presence of Time in one of the variables. Example, position (Space) and momentum (Mass times linear velocity, in turn Space divided by Time, in fact).
The Process of Formation of Reality is incessant, it cannot be stopped (fortunately). Time continues to flow (in a variable, relative, not absolute way, as seen) as new Elementary Events are always produced by the inner interaction of the two aspects of the Source of Reality, the Fundamental Force that exercises its Action on the Elementary Field.
It is therefore not possible to acquire true "states", true instantaneous values of the variables that describe the physical dynamics. If we want to measure with infinite precision the position and velocity of an object in space-time, some factors prevent us from doing so. With resonance at the Planck scale and at even smaller spatial and temporal dimensions, Space distances fluctuate over Time (behavior described by the Uncertainty Principle).
It is precisely the frequency, the rapidity of these spatial fluctuations that determines the flow of Time at a local level (and therefore also the speed of propagation of Causality, Action and Information in the Field). The position of an object, however small, or even more so if it is small, is never fixed (and then, fixed with respect to what? In the Elementary Field there are no fixed reference points, therefore...
And then, let's imagine wanting to measure the position and speed of a car speeding in front of us. Assuming we find a "fixed" reference point outside the car, to measure the position with infinite precision we would have to stop the car in a literal sense or photograph it to an infinitely short time. The same thing for an electron.
Even more so for an even smaller object. This is the point. To measure the position with infinite precision we must observe it for an infinitesimal time. To measure speed, we must measure two positions separated by a time, the larger it is, the more precision it provides us. But the position will have changed in the meantime. Goodbye to the precision in the measurement of position.
The two measurements cannot be conducted simultaneously with infinite precision, due to the indeterminate nature of Reality and the incompatibility of two measurements, one of which is spatial and the other temporal (or where a temporal element exists): position (space), velocity (space divided by "time"). similar reasoning for other pairs of conjugate/complementary quantities/variables.
Links to the tables of contents of TFNR Paper