Not long ago I read a fiction piece (linked here in HN)that would imagine the world (and universe) in 10^1, 10^2, 10^3, 10^4, 10^5, 10^6... years. In this tale

Not long ago I read a fiction piece (linked here in HN)that would imagine the world (and universe) in 10^1, 10^2, 10^3, 10^4, 10^5, 10^6... years. In this tale, Earth would have several species achieving intelligence, all of them failing on interestelar colonization, and the last one, the wisest, figured out from the basic physics knowledge they develop, that this kind of travel would be impossible. This basic assumption is very strong for me. Even if one civilization can travel at light speed, the multiple civilizations on our universe right now could be at millions of years of distance one of other.