The Search for Extraterrestrial Intelligence is a quest to answer one of life's most intriguing questions: Are we alone in the universe?
Yes or no, either answer will have tremendous implications for mankind. Should the answer turn out to be YES, we are alone, then our race would be placed in a position of being the only creatures in existence capable of exploring such questions. We would be the supreme and only intelligence in the cosmos. A staggering thought.
If the answer turns out to be NO, we are not alone, then who else is out there? What are they like? What knowledge do they have? How do they act towards other races? What are their philosophies, sciences, and arts? The questions are endless, as are the possibilities.
We have the technology to communicate over vast distances - millions of lights years. We are capable of sending and receiving radio signals across the vast expanses of space. Actually we have been sending them for over half a century. All radio, television, and radar signals from Earth leak out into space and spread across the galaxy.
Perhaps some other advanced civilization has detected our signals and is now sending their own in an attempt at communication. The only way we'll know is to look and to listen.
That is exactly the premise behind SETI (The Search for Extraterrestrial Intelligence). The idea is to listen, using radio telescopes, for radio emissions from other worlds.
Not as far away as the nearest star, but in just about as remote a place you can send a signal to, is a payphone smack dab in the middle of the Mojave Desert.
Searching any state map, you'll find a small dot with the word "telephone" beside it, a lonely little communication device 15 miles from the main interstate in the middle of nowhere.
With the glass shot out and the phone book missing, this working phone booth was put in after W. W. II for the use of a nearby mine that ceased operations in the '60s.
Why the local phone company keeps it operational is anybody's guess. A nearby rancher told us that in the '70s they replaced the old rotary style phone with push buttons because the sheep were having trouble dialing.
Oh, if you're interested, the number is +001 760 733 9969. Let it ring a long, long time if you want a response.
Radio waves were chosen because they are capable of traveling the vast distances between stars and can be generated with reasonable amounts of power. We have been sending radio waves out into space for more than sixty years. All of our radio, TV, satellite, and radar signals are currently spreading out throughout the galaxy.
Perhaps they've already been detected by someone.
At the same time as Cocconi and Morrison's paper was published a young astronomer named Frank Drake was putting together plans for the first search.
The search, named Project Ozma, was conducted in 1960. Over a two week period the stars Tau Ceti and Epsilon Eridani were scanned for alien signals. No signals were found but the search had begun.
In the 30 years since the initial Ozma search many others have been carried out with more sensitive equipment, over much longer time frames, observing thousands of other stars.
So far no alien signals have been detected but we've really only begun to scratch the surface. There are an estimated 100 billion stars in the Milky Way galaxy alone.
To complicate matters further there are millions of frequencies that a signal could be received on. It may be that we just haven't looked in the right place at the right time yet.