Besides that the total content of the material universe, can not be so simply solved and quantified, the main problem in the idea of <i>creation ex nihilo</i> is just that it supposes that the world and everything in it, did have a begin in time, that the world which is in ever change, did have this first change.
This isn't equal to the statement that time had a beginning, since time is not simply equal to change. Since time can be measured by change, this means time and change must be something different.
What the whole idea of the beginning of the world therefore defaults to is the idea that some unknown cause, immaterial in nature, started the world, while this cause itself, does not need any such causation.
This position is however beyond further inquiry. About immaterial causes by definition nothing can be known. Neither can be said anything about this 'first change' that came into the world, and caused the world to develop since then.
A more profound analysis that is based on the material unity of the world which can resolve the issue, is simply stating that anything that exists, needs a material cause for its existence. Since there is nothing that can cuase itself, this idea leads then to the position that the chain of cause and effect does not have a begin. Since the world then did not begin, there is no first cause, and neither do we need to explain something out of the ordinary.
This position is valid, even despite the fact that all material things do have some sort of begin. Unlike the "begin of time" or "creation ex nihilo" argument, it is expeted in here that this relative begin was based on previous causes.
For all practical applications and purposes, the two positions don't make any difference. The empirical knowable world, can not be proved to have existed always (even though there are a number of arguments that upports that position), neither can one proof the opposite.
The position though that confines the world to be a material unity, without a begin, encourages though the search for material explenations of the origin of the known universe. So far with good results, and which raises the expectation that this issue somewhere in the future can be dealt with.
