“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.”

“There is much that science doesn't understand, many mysteries still to be resolved. In a Universe tens of billions of light-years across and some ten or fifteen billion years old, this may be the case forever. We are constantly stumbling on new surprises”

“Long ago, when an early galaxy began to pour light out into the surrounding darkness, no witness could have known that billions of years later some remote clumps of rock and metal, ice and organic molecules would fall together to make place called Earth; or that life would arise and thinking beings evolve who would one day capture a little of that galactic light, and try to puzzle out what had sent it on its way. And after the earth dies, some 5 billion years from now, after it's burned to a crisp, or even swallowed by the Sun, there will be other worlds and stars and galaxies coming into being -- and they will know nothing of a place once called Earth.”

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

“Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.”

“The immense distances to the stars and the galaxies mean that we see everything in space in the past, some as they were before the Earth came to be. Telescopes are time machines.”

“At the very moment that humans discovered the scale of the universe and found that their most unconstrained fancies were in fact dwarfed by the true dimensions of even the Milky Way Galaxy, they took steps that ensured that their descendants would be unable to see the stars at all. For a million years humans had grown up with a personal daily knowledge of the vault of heaven. In the last few thousand years they began building and emigrating to the cities. In the last few decades, a major fraction of the human population has abandoned a rustic way of life. As technology developed and the cities were polluted, the nights became starless. New generations grew to maturity wholly ignorant of the sky that had transfixed their ancestors and that had stimulated the modern age of science and technology. Without even noticing, just as astronomy entered a golden age most people cut themselves off from the sky, a cosmic isolationism that ended only with the dawn of space exploration.”