Is it a causality issue, or that you don't personally know the mechanism that drives the expansion?
The physical universe defines things and mechanisms.
Before the universe existed, therefore, there is nothing to discuss, including causality and the reality that no one personally knows or can know what created something that doesn't exist.
But the universe doesn't have any requirement--mathematical or philosophical--that anything come "before" it, just as there's no requirement for anything to be south of the South Pole. Causality presupposes time, and time presupposes the universe. The universe doesn't require a cause.
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson