This is because the stars, dust, etc in the Milky Way ensure that we can only see up and down with respect to the galaxy's plane(not sure if that's the right term). Well actually I learnt this last week. I had gone to one of nasa's visitor's centres and they had this visual of the universe that one could zoom in and out. I had no idea about this fact at all and I have been looking at excuses to tell more and more folks about this. Just imagine, there might be intelligent life in a galaxy adjacent to us, but we wouldn't be able to observe it(assuming we had some way to observe stuff in real time, ie way faster than light). I just joined reddit today and saw this subreddit. And I immediately thought of this.
Edited this post for autocorrect induced errors.
On a totally unrelated note, TIL how to post on reddit. I am not exactly net illiterate, but it took me a few minutes to figure out how to post this. Not intuitive at all methinks, but then again, it's probably like this on purpose.
EDIT: This is the only reference I could find. I learnt this piece of info in real life and not the internet(that seems to be quite a rare occasion now) hence the lack of a link in the post.
