But science never claims to know anything. It simply claims to have a pretty good idea. Science deals in theories, not facts.
Sorry, I didn't mean to say the bible was self contradictory, I meant that the people who follow it often are. Take yourself, for example. You surely don't honestly believe that the Creation story, or the Ark story, are actually the literal truth, do you? Most rational Christians I've met treat them as myths, as possible evidence for intelligent design. But they don't really believe God created the world, and all life on it, in six days ten thousand years ago.