“Light is the only connection we have with the Universe beyond our solar system, and the only connection our ancestors had with anything beyond Earth. Follow the light and we can journey from the confines of our planet to other worlds that orbit the Sun without ever dreaming of spacecraft. To look up is to look back in time, because the ancient beams of light are messengers from the Universe's distant past.”

“We are the cosmos made conscious and life is the means by which the universe understands itself.”

“When we gaze at a star in the Milky Way which is 50,000 light-years away from our sun, we are looking back 50,000 years in time.""The idea is much too big for my little head.""The only way we can look out into space, then, is to look back in time. We can never know what the universe is like now. We only know what it was like then. When we look up at a star that is thousands of light-years away, we are really traveling thousands of years back in the history of space.”

“It is trite to speak of a broken heart. Hearts are not broken; they continue to beat, the blood still courses, even in the bitter after-days of betrayal. but something is broken when pain beyond words is suffered; some connection that formerly existed with light and hope and bright mornings is severed, and can never be restored.”

“We explore because we are curious, not because we wish to develop grand views of reality or better widgets.”

“(On the energy radiated by the Sun)It's four hundred million million million million watts. That is a million times the power consumption of the United States every year, radiated in one second, and we worked that out by using some water, a thermometer, a tin, and an umbrella. And that's why I love physics.”

“The Cosmos extends, for all practical purposes, forever. After a brief sedentary hiatus, we are resuming our ancient nomadic way of life. Our remote descendants, safely arrayed on many worlds throughout 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 Earth. They will gaze up and strain to find the blue dot in their skies. They will love it no less for its obscurity and fragility. They will marvel at how vulnerable the repository of all our potential once was, how perilous our infancy, how humble our beginnings, how many rivers we had to cross before we found our way.”