E.T. is out there

Wildcat File Photo Arizona Daily Wildcat Jon Ward

And you thought scientists were smart.

They, of all people, should know that Earth cannot possibly be the only life-supporting planet in the cosmos, because they have a more acute appreciation of the sheer unimaginable immensity of the universe, in which we are no more than a little speck of nothing.

And not even a terribly special speck of nothing.

Our little blue living world is certainly rare in this neighborhood, but this neighborhood is nothing in the big picture. There are at least 100 billion suns in this one tiny little galaxy alone, and some estimates have the Milky Way containing as many as 250 billion suns. That number really defies comprehension. We can write it, but try imagining that many suns out there, each possibly with their own system of planets. That's a lot of planets, too.

If there's one thing we've learned from science, it's that there's nothing really special about us. There's absolutely no reason to believe Earth is the only planet of its kind among those billions and billions of solar systems in this one galaxy, much less the rest of the universe. The evolution of life is not miraculous, but the natural result of certain circumstances which can occur anywhere, and happened to occur here. So here we are.

Life is certainly rare, but given the countless billions of possible homes for life, it must nonetheless be there in huge numbers. Intelligent life is even more rare, given the fact that intelligence is only a survival adaptation and not an end or goal of evolution. Technology won't occur on most planets that do support life. But again, since there are so many billions of possibilities out there, intelligent life is bound to pop up on many planets, just as it did on this one.

Or in an entirely different manner. The possibilities are endless. Life need not even be carbon-based like us, for instance. It could be silicon-based. It may not require a planet anything like Earth, and it may not even require a planet at all. We don't know nearly enough to begin placing limits on life.

We know enough however, to make rough estimates on the quantity of life out there that arose under conditions similar to our own. These estimates consider such things as the numbers and ages of stars, the abundance of planetary systems, the likelihood of life within them, and the probability and lifetime of technical civilizations. Even plugging in very modest values yields huge numbers of alien civilizations out there: around a million in our galaxy alone.

So where are they? Why haven't they shown up or called? Well, look at us. Where are we? The quantity of stars and the vastness of space not only facilitate a galaxy teeming with life, they necessitate that life being separated and spread out over huge distances.

If our galaxy has a million technical civilizations, the average distance between them will be about 300 light-years. So it would take light, the fastest thing in the universe 300 years to reach one.

We haven't even had radio technology and the ability to send messages for half that long. It would take 600 years for a response.

Distance is why we likely haven't been heard, or heard anyone else. But, we haven't been listening either, not closely, and not for long.

And the galaxy is pretty big, about 600,000 trillion miles across, so there's a lot to listen to.

If we manage to avoid killing ourselves off for a little longer, and if we keep our ears open, and keep sending out our little signals, there's a decent chance we could make contact. And that would be the most important breakthrough in our history. It's definitely an effort worth making.

The cost is low, and the potential gain is immeasurable. But we have to break free from the mind-forged manacles of our own narrow conceit and realize our place in the universe. It's big. We're small. But that big is made up of many smalls.

Wouldn't it be nice to meet some of them?

Jon Ward is an astronomy and creative writing junior. His column, Who's the Bull Goose Looney? appears every Thursday and he can be reached via e-mail at Jon.Ward@wildcat.arizona.edu.