Mankind has been expanding through the galaxy for millennia. FTL exists but it is only moderately fast so only a small portion of the galaxy is reachable form any position. Every time man has found another civilization, it turns out to be the remains of an earlier expansion. A starship crew that correctly believes itself to be on the very leading edge of expansion, finds another spacecraft of a different culture. It turns out tat the new culture is the leading edge of mankind expanding the other way around the core of the galaxy.
Don't remember details like name or date I read it but it was definitely a short story.
Don't remember details like name or date I read it but it was definitely a short story.