Carl Sagan Quotes

If a superior alien civilization sent us a message saying, 'We'll arrive in a few decades', would we just reply, 'OK, call us when you get here - we'll leave the lights on'? Probably not - but this is more or less what is happening with AI.

Sending greeting cards to aliens is hardly a new idea. In 2005, Craigslist solicited messages for broadcast to space by a transmitter in Florida, and in 2008, NASA beamed a Beatles song to the North Star (Polaris), on the assumption that any putative Polarians would appreciate the Fab Four's 1960s-genre compositions.

If there's anyone in space, what they'll learn about the human race will be listening to us talking on the car phone.

Perhaps the safest thing to do at the outset, if technology permits, is to send music. This language may be the best we have for explaining what we are like to others in space, with least ambiguity. I would vote for Bach, all of Bach, streamed out into space, over and over again. We would be bragging of course, but it is surely excusable to put the best possible face on at the beginning of such an acquaintance. We can tell the harder truths later.

FM signals and those of broadcast television...travel out to space at the speed of light. Any eavesdropping alien civilization will know all about our TV programs (probably a bad thing), will hear all our FM music (probably a good thing), and know nothing of the politics of AM talk-show hosts (probably a safe thing).

I can conceive of no nightmare so terrifying as establishing communication with a so-called superior (or, if you wish, advanced) technology in outer space.

Well, I hate to admit it, but it is possible that there is (one) such a thing as telepathy and (two) that the CETI project's idea that we might communicate with extraterrestrial beings via telepathy is possibly a reasonable idea--if telepathy exists and if ETIs exist. Otherwise we are trying to communicate with someone who doesn't exist with a system which doesn't work.

We feel certain that the extraterrestrial message is a mathematical code of some kind. Probably a number code. Mathematics is the one language we might conceivably have in common with other forms of intelligent life in the universe. As I understand it, there is no reality more independent of our perception and more true to itself than mathematical reality.

If we ever establish contact with intelligent aliens living on a planet around a distant star ... They would be made of similar atoms to us. They could trace their origins back to the big bang 13.7 billion years ago, and they would share with us the universe's future. However, the surest common culture would be mathematics.

The survival of the United States of America as we know it is at risk. And even more — if more should be required — the future of human civilization is at stake.

The energy requirements for interstellar travel are so great that it is inconceivable to me that any creatures piloting their ships across the vast depths of space would do so only in order to play games with us over a period of decades. If they want to make contact, they would make contact; if not, they would save their energy and go elsewhere.

If we can change our priorities, achieve balance and understanding in our roles as human beings in a complex world, the coming era can well be that of a richer civilization, not its end.

The moon invented natural rhythm. Civilization uninvented it.

Civilization did not come with fire. It came with the discovery of how to use fire to heat water.

While civilization is more than a high material living standard, it is nevertheless based on material abundance. It does not thrive on abject poverty or in an atmosphere of resignation and hopelessness. Therefore the end objectives of solar system exploration are social objectives in the sense that they relate to, or are dictated by, present and future human needs.

The problem here is that a civilization that is 1,000 light years away doesn't know we exist. They don't know that we have radio telescopes here on Earth because they see Earth as it was 1,000 years ago. Nothing can travel faster than light, so however good their instruments they can't see in affect the future. So there is no particular reason they should be sending us messages at this time.

The universe must be full of voices, calling from star to star in a myriad tongues. One day we shall join that cosmic conversation.

I think [contacting an alien civilization] would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on this planet is not very happy, and they were the same species. I think we should keep our heads low.

We will never be an advanced civilization as long as rain showers can delay the launching of a space rocket.

Extraterrestrial intelligence could have sent DNA-seed packets out through space to plant life on hospitable planets such as earth.

And no answer when we sent our message. Something like, "Hello, welcome to Earth. Hope you enjoy your stay. Please don't kill us.

The search for extra-terrestrial life is a failure until that moment when it suddenly becomes a success.

Before another century is done it will be hard for people to imagine a time when humanity was confined to one world, and it will seem to them incredible that there was ever anybody who doubted the value of space and wanted to turn his or her back on the Universe.

Forty years as an astronomer have not quelled my enthusiasm for lying outside after dark, staring up at the stars. It isn't only the beauty of the night sky that thrills me. It's the sense I have that some of those points of light are the home stars of beings not so different from us, daily cares and all, who look across space with wonder, just as we do.

During the next 50 years, in countless cycles, in countless entrepreneurial companies, this let's just go and do it mentality will help us finally get off the planet and irreversibly open the space frontier. The capital and tools are finally being placed into the hands of those willing to risk, willing to fail, willing to follow the dreams.