@miria notwithstanding that physical phenomena are merely approximated in most applications, a description has many properties other than accuracy, such as simplicity, generality, expressivity, any pair of which are in conflict with the other. I it's simple and general, it's likely not expressive enough, general + expressive = too complex, expressive + simple = too specific. Balancing these (and probably many other subjective criteria) to fit a human mind best is the name of the game.