The key is that we don't know how God created the universe. Wouldn't it be just as reasonable that since we can't fully comprhend Creation, that God would inspire the writers to give their people the stories in terms that they could understand?
I spent some time thinking about that question and it leads to some interesting assumptions and conclusions.
1. The story will be read by generations of people who have various theories about how the world was created. ie. It needs to be relevant to todays scientists as well those hundreds and thousands of years ago.
2. If he was too specific he runs the risk of giving us too much dangerous information and he runs the risk having the story be dismissed by every arrogant generation that knows better.
3. If he is too general he loses the awe inspiring effect that its had on so many generations.
It needs to stay relevant throughout the ages, it needs to be correct, it needs to be specific yet general, and it needs to set the foundation for all of the theology that follows for both Judaism and Christianity.
And oh yes, in 500 words or less.