First of all, I know objects are not meant to model the real world, although they have been marketed as such and perhaps that was an intention at some point.
Here I say 'modeling the real world' in a general sense. That includes simulations, modeling of abstract (non-real) concepts and modeling of business support applications, although I'm not sure it is appropriate to develop all of them in a single general-purpose OO language.
Under the assumption that modeling the real world in software development is a desirable and advantageous trait (not considering inappropriate models), I'm inspecting the foundations of object-oriented programming and the Simula languages.
However I'm asking this question in the hope that someone can provide a quick spoiler.
I am under the impression that objects (i.e. endurants) may not be enough to model the real world since a) their classes are static across time, e.g. a Person is always a Person, not a Child who becomes an Adult and thus his/her responsibilities and actions change b) processes (i.e. perdurants) are not first-class citizens as objects are, and c) time also is not a first-class citizen.
Aren't requirements such as these necessary for a language to properly model the real world? Why haven't they been included in the concept?