Quotes by Carl Sagan

“The major religions on the Earth contradict each other left and right. You can't all be correct. And what if all of you are wrong? It's a possibility, you know. You must care about the truth, right...”

“We will know which stars to visit. Our descendants will then skim the light years, the children of Thales and Aristarchus, Leonardo and Einstein.”

“Meanwhile the Cosmos is rich beyond measure: the total number of stars in the universe is greater than all the grains of sand on all the beaches of the planet Earth.”

“The dangers that we face are part of the process, now well underway, of the unification of the planet--in language, culture, science, and commerce. They are both driven by the identical technologic...”

“Everything not forbidden by the laws of nature, he assured her - quoting a colleague down the hall - is mandatory.”

“Even if the aliens are short, dour, and sexually obsessed—if they’re here, I want to know about them.”

“The total amount of energy from outside the solar system ever received by all the radio telescopes on the planet Earth is less than the energy of a single snowflake striking the ground.”

“Our television signals leave this planet and go out into space...the signals spread out from the earth in spherical waves, a little like ripples in a pond. They travel at the speed of light, 186,00...”

“Black holes collect problems faster than they collect matter.”

“But if they called everything divine which they do not understand, why, there would be no end of divine beings.”

“We sometimes hear of things that can travel faster than light. Something called 'the speed of thought' is occasionally proffered. This is an exceptionally silly notion especially since the speed of...”

“Advertising teaches people not to trust their judgment. Advertising teaches people to be stupid.”

“Imagination will often carry us to worlds that never were. But without it we go nowhere.”