Science is based on the ability to observe and repeat  observations and come to some conclusion about weather something is true or not. A lot of things are thought to be true but are not known for certain.
Can we know when the Universe began? Probably not! The things we observe in the universe today may have happened millions, or billions of years ago. Can we duplicate the conditions that happened at the beginning, NO. Can we ever know the conditions that were in effect when the Earth and life on it were created? NO! Why? Because no one was there when this took place (except God). The conditions then may have been completely different than what scientist speculate. Maybe some other events have happened since the beginning that we have no way of knowing. We don't even know if the Universe we see billions of light years away even still exists, maybe it is no longer even there.

I'm not a scientist but I do know that science does not have all the answers that we are told it does.
This is what I mean:

I like science and discovery, I love seeing the stars in the Universe and hearing about the planets, I'm really interested in what happened thousands of years ago. But I also know that much of what we see on T.V. and in magazines and movies isn't scienc but fiction. Things that aren't proven are being taught as science fact, I think that is weird science.