Imagine you're on a planet in a distant part of the milky way, 2000 years from now. You don't know where you are or how much time has passed. You have access to modern astronomical data and technology and the knowledge to use it. Could you figure out where you are and how much time has passed?
I've put some thought into this and come up with a few possibilities and challenges:
- The Andromeda Galaxy might be the biggest hint that you're still in the milky way. But after 2000 years of galactic motion, at a different angle, would it still be recognizable? Could you tell the amount of time that's passed by measuring how much closer it is?
- Would there be easy ways to tell that you're in the milky way that a lay person wouldn't think of? Are there features of the galactic center that would make it recognizable or other "galactic landmarks"? Or something that would be identifiable using spectroscopy?
- I think one of the biggest hurdles would be the fact that stellar bodies would all look different from a different angle, and everything has also moved over time.
Thanks!