We're about to begin a journey that will take us from the infinitesimal to the infinite , from the dawn of time to the distant future. We will explore galaxies and suns and worlds, surf the gravity waves of space-time, encounter beings that live in fire and ice, explore the planets of stars that never die, discover atoms as massive as suns, and universes smaller than atoms.

Cosmos is also a story about us. It's the saga of how wandering bands of hunters and gatherers found their way to the stars, one adventure with many heroes.

This adventure is made possible by generations of searchers strictly adhering to a simple set of rules, test ideas by experiment and observation, build on those ideas that pass the test, reject the ones that fail, follow the evidence wherever it leads and question everything. Accept these terms, and the cosmos is yours.

In the dimension of time, the past lies beneath us. If you want to see the future, look up.

三刷「Comsmos：A Spacetime Odyssey」，记一些句子

Science works on the frontier between knowledge and ignorance. We're not afraid to admit what we don't know. There's no shame in that. The only shame is to pretend that we have all the answers.

Democritus of Abdera was a true scientist, a man with a passionate desire to know the cosmos and to have fun. This is the man who once said, "a life without parties would be like an endless road without an end."
- "You mean, that's it? That's all there is? Just a bunch of atoms in a void?"
- "Yep. Well, think about it. The world has to be made of countless indivisible particles in a void. Otherwise, nothing could move or grow, be divided or changed without atoms and empty space for them to move in. So don't be sad, my friends. Just think of the infinite possibilities that arise from different arrangements of those atoms. Hails to the atoms, in this cup and in this wine... And to the laughter they make possible."

↓ Carl Sagan, "Pale Blue Dot"

That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distingui****le inhabitants of some other corner. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity – in all this vastness – there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image. To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we've ever known.

↑ Carl Sagan, "Pale Blue Dot"

How did we, tiny creatures living on that speck of dust, ever manage to figure out how to send spacecraft out among the stars of the Milky Way?