宇宙时空之旅：未知世界

From Ep02 - The Fleeting Grace of The Habitable Zone

Ep02 - The Fleeting Grace of The Habitable Zone

Are we venture out into space?
Move worlds, re-engineer planets, spread to neighboring star systems?
We who cannot even put our own planetary home in order. Riven with rivalries and hatreds, despoiling our environment. Murdering one another through irritation, and inattention as well as on deadly purpose. And moreover, a species that until only recently was convinced, that the whole universe was made for its sole benefit. I do not imagine that is precisely we, with our present customs and social conventions, who will be out there. If we continue to accumulate only power and not wisdom, we will surely destroy ourselves. Our very existence in that distant time requires that we will have chained our institutions and ourselves. How could I dare to guess about humans in the far future? It is, I think only a matter of natural selection. If we become even slightly more violent, short-sighted, ignorant, and selfish than we are now, almost certainly, we will have no future. If you are young, it's just possible that we will be taking our first steps on near-earth asteroids and Mars during your lifetime. By the time we are ready to settle even the nearest other planetary systems, we will have changed. The simple passage of so many generations will have changed us. The different circumstances we will be living under will have changed us. We are an adaptable species. It will not be we who reach Alpha Centauri and the other nearby stars. It will be a species very like us, but with more of our strengths and fewer of our weaknesses. A species returned to circumstances more like those for which it was originally evolved. More confident, far-seeing, capable, and prudent. The sorts of being we would want to represent us in a universe that for all we know is filled with species much older much more powerful, and very different. The vast distances that separate the stars are providential. Beings and worlds are quarantined one from another. The quarantine is lifted only for those with sufficient self-knowledge and judgment to have safely traveled from star to star. Our remote descendants safely arrayed on many worlds through the solar system and beyond will be unified, by their common heritage, by their regard for their home planet, and by the knowledge that whatever other life may be the only humans in all the universe come from the earth. Thank you, mother!

Carl Sagan (1934–1996)
Astronomer, astrophysicist, cosmologist, author, and popularizer of science