The sciences do not try to explain, they hardly even try to interpret, they mainly make models.
By a model is meant a mathematical construct which, with the addition of certain verbal interpretations, describes observed phenomena.
The justification of such a mathematical construct is solely and precisely that it is expected to work – that is, correctly to describe phenomena from a reasonably wide area. Furthermore, it must satisfy certain aesthetic criteria – that is, in relation to how much it describes, it must be rather simple... If only relatively little has been explained, one will absolutely insist that it should at least be done by very simple and direct means.