Carl Sagan Quotes

No Green Revolution, no hydroponics, no making the deserts bloom can beat an exponential population growth.

Let's go back to the solar nebula... with the temperature declining the farther we get from the Sun. ...at different distances from the Sun, different materials will condense out, because they have different vapor pressures or different melting points. ...water condenses out roughly at the vicinity of the Earth, whereas silicates condense out closer to the Sun... you have to go out to somewhere near the present distance of Saturn before methane condenses.

the English philosopher John Stuart Mill argued that silencing an opinion is “a peculiar evil.” If the opinion is right, we are robbed of the “opportunity of exchanging error for truth”; and if it’s wrong, we are deprived of a deeper understanding of the truth in “its collision with error.

Does trying to understand the universe at all betray a lack of humility ? I believe it is true that humility is the only just response in a confrontation with the universe, but not a humility that prevents us from seeking the nature of the universe we are admiring. If we seek that nature, then love can be informed by truth instead of being based on ignorance and self-deception. If a Creator God exists, would He or She or It or whatever the appropriate pronoun is, prefer a kind of sodden blockhead who worships while understanding nothing ? Or would He prefer His votaries to admire the real universe in all its intricacy ? I would suggest that science is, at least in part, informed worship. My deeply held belief is that if a god of anything like the traditional sort exists, then our curiosity and intelligence are provided by such a god. We would be unappreciative of those gifts if we suppressed our passion to explore the universe and ourselves. On the other hand, if such a traditional god does not exist, then our curiosity and our intelligence are the essential tools for managing our survival in an extremely dangerous time. In either case the enterprise of knowledge is consistent surely with science; it should be with religion, and it is essential for the welfare of the human species.

This planet is run by crazy people. Remember what they have to do to get where they are. Their perspective is so narrow, so...brief. A few years. In the best of them a few decades. They care only about the time they are in power.

in the forty-five years centered on 1910, the nature of the atom was first understood — partly by shooting pieces of atoms at atoms and watching how they bounce off.

I worry that, especially as the Millennium edges nearer, pseudoscience and superstition will seem year by year more tempting, the siren song of unreason more sonorous and attractive. Where have we heard it before? Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self-esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us - then, habits of thought familiar from ages past reach for the controls.

The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir.

We—we Americans, we Russians—have spent 43 years and vast national treasure in making ourselves exquisitely vulnerable to instant annihilation. We have done it in the name of patriotism and “national security,” so no one is supposed to question it.

We are alive and we resonate with idea of life elsewhere, but only careful accumulation and assessment of the evidence can tell us whether a given world is inhabited.

I consider it an extremely dangerous doctrine, because the more likely we are to assume that the solution comes from the outside, the less likely we are to solve our problems ourselves.

Faith is clearly not enough for many people. They crave hard evidence, scientific proof. They long for the scientific seal of approval, but are unwilling to put up with the rigorous standards of evidence that impart credibility to that seal. What a relief it would be: doubt reliably abolished! Then the irksome burden of looking after ourselves would be lifted. We're worried - and for good reason - about what it means for the human future if we have only ourselves to rely upon.

Edmund Way Teale in his 1950 book Circle of the Seasons understood the dilemma better: It is morally as bad not to care whether a thing is true or not, so long as it makes you feel good, as it is not to care how you got your money as long as you have got it.

The chief danger of adopting a credible pose of irrationality is that to succeed in the pretense you have to be very good. After a while, you get used to it. It becomes pretense no longer.

Look again at that 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 distinguishable 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.

According to the World Health Organization, smoking kills three million people every year worldwide.