Quotes from Carl Sagan

There are as many atoms in one molecule of DNA as there are stars in a typical galaxy.

The near side of a galaxy is tens of thousands of light-years closer to us than the far side; thus we see the front as it was tens of thousands of years before the back. But typical events in galactic dynamics occupy tens of millions of years, so the error in thinking of an image of a galaxy as frozen in one moment of time is small.

Life is but a momentary glimpse of the wonder of this astounding universe, and it is sad to see so many dreaming it away on spiritual fantasy.

Science cuts two ways, of course; its products can be used for both good and evil. But there's no turning back from science. The early warnings about technological dangers also come from science.

The hole in the ozone layer is a kind of skywriting. At first it seemed to spell out our continuing complacency before a witch's brew of deadly perils. But perhaps it really tells of a newfound talent to work together to protect the global environment.

And it is here that we are, in some pain and with no guarantees, working out our destiny.

We must understand the Cosmos as it is and not confuse how it is with how we wish it to be.

I think if we ever reach the point where we think we thoroughly understand who we are and where we came from, we will have failed.

Civilization is a product of the cerebral cortex.

The symbolism seemed so apt. The same technology that can propel apocalyptic weapons from continent to continent would enable the first human voyage to another planet. It was a choice of fitting mythic power: to embrace the planet named after, rather than the madness ascribed to, the god of war.

Once intelligent beings achieve technology and the capacity for self-destruction of their species, the selective advantage of intelligence becomes more uncertain.

We are fortunate: we are alive; we are powerful; the welfare of our civilization and our species is in our hands. If we do not speak for Earth, who will? If we are not committed to our own survival, who will be?