Leonardo said:

For "atheist explanation", you mean "unbiased by religion and only based on fact", right?

Here is an example of how atheists are all individuals. An atheistic point of view might or might not be a scientific point of view. I bristle at atheistic arguments that claim to be based on "facts"... scientific arguments rarely assert facts, they assert observation and reasoning. It is religion that usually claims to have facts. A proper scientific point of view understands the limitations of our observational powers, and offers only the strongest analysis currently available - the one that is considered most likely. Most science is eventually superceded by increasingly better analysis over time, and therefore is loathe to casually claim either its observations or its claims as fact. It is religion, by contrast, that is based on the concept of "facts".

As such, a huge percentage of both theists and atheists fail to understand what a scientific proof is (and isn't).

My own personal atheistic explanations of things would be based on scientific method, and would always be open to ANY possibility, including that of divine intervention by a monotheastic holy trinity (although the latter I currently consider to be vanishingly unlikely).