[PC_LOAD_LETTER]

The issue is that there's some force or factor at play that we don't understand - which means that it can't be modeled. If the behavior was emergent from the physics that we do understand, researchers would likely have recreated that behavior by now.

[petschge]

It's a bit harder than that. We don't understand the effect, so we don't have a good _high level_ model of it. That does not mean we can not model it using more fundamental physics. But of course that leads to much more expensive simulations. And you have to work much harder to understand the output.