okay, the electromagnetic force affects antimatter and matter oppositely. (and i'm just guessing the same could be said for the electroweak and weak forces as well.) Now, does gravity affect antimatter the same way it affects matter? Or, maybe i should say, does gravity act as a repellant force between one matter particle and one anti-matter particle and as an attractant force between two matter or antimatter particles? Here's another interesting little question: does antimatter have antimass or just mass?