Humans, in one form or another, have been on Earth for maybe 2.5 million years. The Andromeda galaxy is 2.5 million light years away.
Under dark, clear skies, you can see the Andromeda galaxy with your own two eyes. If you do, you’ll be looking at light which has been travelling through space for roughly as long as our genus has existed on this planet.
@InvaderXan What blows my mind is that the stars we see might already have exploded millions of years ago.
No doubt some have. But many, many more are still there now, and will still be there long after our own star is no more. I find that far more impressive.
I'm not sure that this is really what Sagan meant, but when we study stars that change and do things, "now" means "when the light left" - for example, my pet pulsar lit up, we don't know why, about five years ago. That is, five years plus the about four thousand it took the light to get here, but we don't know exactly how far it is and it never changes, so we ignore that and talk about what it's doing "now".
This is so beautiful and humbling to me. Space is just awe inspiring.
Sunbeam City is a Libertarian Socialist solarpunk instance. It is ran democratically by a cooperative of like-minded individuals.