"rules for wandering monster movement in B/X D&D—there aren't any. While player food, light and movement through the dungeon are all tracked meticulously, all of that is hand-waved for monsters.
Monsters (or townspeople) just appear when a wandering monster roll says they should, and nobody worries about their precise location before that. Their precise inventory doesn't matter either, not until they're dead and examined more closely.
Until it actually matters, most of this stuff is completely undefined, held behind a "curtain of vagueness," until it matters."
I ran across this and it got me thinking about quantum mechanics and Schrodinger's cat. The wandering monster is a better analogy/explanation than a cat in a box. This just clicked for me, I guess you could say others have already explained this with the quantum ogre to some degree, but I'm thinking more in terms or actual physics and less gaming. The common presence of wandering monsters in old school games is the clearest way of explaining quantum physics to the average person that I have seen.
If you substitute electron, or other subatomic particle, for monster and human measurement for roll, then the above paragraph is an apt explanation of how quantum mechanics (at least as I understand them).
While in standard Physics every particle and object can be all tracked meticulously, all of that can be in a state of flux for subatomic particles.
Subatomic particles just appear when a measurement made by our instruments says they should, and their precise location before that is unknown. The position and Characteristics of these particles on the smallest scale are not defined until they are examined more closely.
Until it actually matters, any information about these particles is undefined, held behind 'a curtain of vagueness,' until it matters.
Basically it is our measurement of the "quantum realm" (to use a Marvel term) which brings it into focus, before such measurement the quantum is present/existent but unknown. Like the wandering monster, it is there and has a possibility of appearing, but until a roll is made its exact features and location are unknown and could be anything within a certain range of possibility.
I find Schrodinger's cat to be flawed because the cat is either dead or alive, poisoned or healthy. your knowledge of it does not change the fact that it is dead. The cat can't be both dead and alive, it is one or the other, no matter whether we can see into the box or not. In comparison the wandering monster has both a possibility of being in the same location as the party and not being there, until the die is rolled the monster occupies both locations/possibilities and neither of them at the same time. Quantum Mechanics operate in a fashion more similar to the wandering monster, it is both here and not here a the same moment until it is measured.
So that's a little perspective on science for you.