I already have, several times. If the presence of the universe had a scientific explanation then that would mean the universe existed before it existed. The explanation for it (like all scientific explanations) would be in terms of matter, laws, energy, fields - yet the presence of these are what we seek to explain!
Basically science offers no prospect of explaining the origin of a material system, it can only ever describe how an already existing system changes. We must seek a non-scientific explanation or we must conclude that it has always existed and had no start, no beginning, take your pick.