I have often wondered why Vader, as powerful as he is, does not realize that Leia is his daughter in "A New Hope". I know later on,in Empire Strikes Back I believe, he realizes but why not sooner. Is it because Leia has not really discovered the force yet? Or because he simply didn't know he had kids? Or is it because the force is so strong in Leia he can't see through it. However, if that's the case why didnt he notice the force itself. What does everyone else think?