Carl Sagan on Extraterrestrials

(electronic instrumental music) (instrumental synthesizer music) - [Carl] That's inevitable that humans would project their hopes and fears upon the cosmos.

The standard Hollywood attempts are to portray the extraterrestrials as red of claw and fang.

Pointed heads and nasty dispositions.

Steven Spielberg has made an important step forward, E.T.

and Close Encounters of the Third Kind, to show the possibility of benign extraterrestrials, but even there, the extraterrestrials are only slight variants on human beings, when the evolutionary record is clear that extraterrestrials would be very different from us and also they're not awfully smart, his extraterrestrials.

- [Studs] Sweet, but not smart.

- [Carl] Sweet, but not smart.

If you look at timescales, you realize that our civilization is the most backward civilization in the galaxy that could communicate at all, because we've just invented radio telescopes, just a few decades ago.

We had not the ghost of a chance of communicating with anybody else.

So If we receive a message, it can't be from anybody less capable than we, because anybody less capable can't communicate at all.

So it has to be somebody much in advance of us and maybe as much in advance of us as we are in advance of the ants, say, or the worms.

- [Studs] You, Carl Sagan, scientist, astronomer, enlighten me.

You think that indeed there may be some sort of intelligence out there?

- [Carl] May, surely, surely may.

There is, we now realize, an enormous number of planets.

A range of planetary systems around the nearby stars.

So there's a lot of potential abodes for life.

That's one thing.

Then there's the question of organic matter.

The carbon-rich complex molecules that are essential for the kind of life we know about, are fantastically abundant.

They litter the universe.

We see them in asteroids, in comets, in the moons in the outer solar system and even in the cold dark spaces between the stars, so the stuff of life is everywhere, and then there's time.

There are billions of years for biological evolution on all those worlds, there are many worlds that are much older than ours.

So you put those together, lots of places, lots of organic matter, lots of time and it seems very hard to believe that our paltry little planet is the only one that's inhabited.

- [Studs] You know, there's a phrase you use about the earth people us, we, are so benighted.

"The Earth is the ghetto of the universe."

We're the ghetto of the universe.

- [Carl] Well in an extremely backward and obscure part of the Milky Way galaxy.

We're 30,000 light years from the center of the galaxy.

We're in the galactic boondocks.

This whole galaxy is only one of probably hundreds of billions of other galaxies, a useful calibration of our place in the universe.

- [Studs] There's also religion and science.

- [Carl] There is a tendency in both schools of thought to think that they have a corner on the truth.

I mean, a way to look at it is the following, science and religion on some level are after the same thing.

Take the question of our origins.

Both science and religion attempt to approach this question.

But the religions all contradict each other, so they can't all be right.

The Judeo-Christian Islamic religion holds that the world is about 6,000 years old, you just count up the begats in the Old Testament.

It's very clear, 6,000 years old.

The Hindus have an infinitely old universe with an infinite number of creations and destructions of the whole universe.

Now those two major religions can't both be right.

How do you tell which is right and which is wrong?

Well, the only way is to appeal to the natural world around us and the natural world around us shows that the Earth, for example, is about four point six billion years old and nothing like 6,000 years old.

So a literal reading of the Bible simply is a mistake, I mean it's just wrong, it's just wrong.

As a work of science, it is flawed, it's the science of the Babylonians in the sixth century B.C.

We've learned something since then.