I have seen a depiction of the Sun traveling in it's orbit in the Milky Way. In this depiction, the Sun was bobbing up and down. 1. From what does the Sun get its movement orders from? (The black hole at the center of our galaxy?) 2. How come it bobs up and down, but none of the other stars do? Or is this just because showing the movement of all the other stars would be a nightmare? 3. If the Sun gets it's movement orders from something bigger than it, why doesn't Earth get its orders from that same object? Thanks in advance!