> It's important to realize that the concept of a "galaxy" is arbitrary. Specifcally, it's not like stars suddenly stop and that's where the edge is. It's gradu

> It's important to realize that the concept of a "galaxy" is arbitrary. Specifcally, it's not like stars suddenly stop and that's where the edge is. It's gradual. Eh, the concept isn't that arbitrary, it's the borders that would be more arbitrary. It's like asking where does a river end and the ocean begin. No one would argue the Atlantic isn't an ocean and the Amazon isn't a river, but exactly where you draw that border requires some discrimination.