Speaking of changing history, I've always found the episode about baby Clark to be interesting. (Tempus Fugitive, I believe it was called.) The reason that the Kents stopped their truck was because they saw what looked like a meteor streak across the sky. But in this episode, we find out that Clark created the meteor to catch their attention. The ship had actually landed a few hours earlier.
So if Tempus never went back in time to try to kill the baby, it seems to me that the Kents never would have found him. The ship would've landed during the day. That night the Kents would've driven down the road, but because there would've been no meteor, they wouldn’t have stopped....
Therefore, Tempus inadvertently caused the Kents to find Clark. Talk about irony! The man who hates Superman made it so Superman would exist!
