Oooh. I get it now. It's a wormhole. A naturally occurring tranversible wormhole. That's why no pesky temporal causality paradox. Can't change the past. Right. But you can travel back in time to create a new future. But Daniel needs to brush up on his antecedal causal relation and probability theory. Blowing up the hatch in 1977 doesn't mean that Oceanic 815 will land safely in Hawaii.
Which is to say, there's no way to know what traveling to the past will do to the future, so don't bother. Jeez. What a dumbass.
I need sleep.