i want to make getWorld a static variable but i dont know how. is it even possible?
Why would you want to do that? If for an actor to access a field or method in your world class, you can just typecast what world is returned from using getWorld. Like so:
MyWorld myWorld = (MyWorld)getWorld();
If the actor can be in more than one type of world, you can check its type before typecasting it: