“In our view,” says Professor Morrison, “life on most planets would be maintained by light from its neighboring star, just as Earth life is maintained by light from our star, the sun. Therefore, any scientific civilization would certainly seek to understand the nature of light which is the basis of their life. Once you understand the nature of light, you are led to the whole electromagnetic spectrum of which radio is a necessary part.”
How do we tune in on other worlds? How do we know the right “station” to fix our attention on? After much study, Project Ozma has picked a listening frequency of 21 centimeters (1420 megacycles). This frequency was chosen to cut down on natural interference. The air surrounding planets like Earth cannot be penetrated successfully by signals above 10,000 megacycles. Below 1,000 megacycles, on the other hand, the static from galactic space is too loud. Faced with atmospheric noise on one hand and radio gibberish on the other, the Ozma scientists compromised on the 21-centimeter frequency. They chose it for another reason as welclass="underline" it is the natural vibration most commonly heard on our radio telescopes, the vibration of neutral hydrogen that we get when we study giant hydrogen clouds in the sky.
Neutral hydrogen, we know then, is richly strewn throughout the universe. Other radio-advanced worlds cannot help but note this same truth. Guessing that we will have already tuned in on this natural intergalactic wave-length, intelligent beings on other worlds may be expected to do a most sensible thing: they will probably broadcast at a frequency close to that of the neutral hydrogen band, just as small U.S. radio stations sometimes sneak over and rub shoulders with big-brother radio-station bands in order to pick up stray listeners. So our Ozma scientists, listening to the moronic outbursts of neutral hydrogen, will test both sides of its narrow band, hoping for sounds more intelligent.
By spectroscopic study of starlight, we have decided that seven stars exist within 15 light years of us which have a luminosity and lifetime like that of our own sun. These seven stars are old enough to have given birth to planets from which radio broadcasts could be expected. The stars are: Tau Ceti, Omicron-Two Eridani, Epsilon Eridani, Epsilon Indi, Alpha Centauri, 70 Ophiuchi and 61 Cygni.
Ozma will record all the radio whispers it gets from these most promising star systems and look for some pattern hidden in the whispers. Any sounds repeated, in sequence, would draw our attention. If we heard, for instance, three dots, seven dots, three dots, seven dots, over and over, again and again, we would be alerted immediately.
“Naturally,” Professor Morrison points out, “there is no chance whatever of a common language existing between the broadcasters on separate worlds. But it is easy to see how a common language could be built up during a long period of communication. Starting with a simple arithmetical relations, using our radio pulses as numbers, we could communicate all the symbols for algebra to another world.”
With the algebraical relations established, Morrison believes, it would be a short step to drawing figures geometrically. At our end of the party line we might try translating the pulses we receive into a picture suggested by the mathematics. Once we find a way to make the diagram visible, we will know how to interpret any picture. Through these pictures, traded between worlds like do-it-yourself numbered painting kits, much information could be transferred and even compact languages taught by cross-galactic radio.
The entire process might last out the lives of generations of scientists. If, for example, we heard a recognizable code from Tau Ceti tonight and broadcast our own welcoming salute back at it, it would take our message 11 years, traveling 186,000 miles per second, the speed of light, to reach our possible friends. If they, in turn, heard our first broadcast and wired us congratulations at joining the network, another 11 years would pass before their good wishes hit our radio telescopes. So it would take until 1982 for us just to say “hello” to each other. It would be 2004 before we asked after each other’s health. By 2026, only a few groping, exploratory words or sentences might have been traded.
We would have to wait until the middle of the 21st Century before anything resembling a page of the simplest pictures might change hands. Meantime, death will have harvested and life reseeded both scientific ends of the fantastic long-distance call.
Not that we will wait that long for our first grunts and stutters to clarify themselves. Once we are sure that a specific star system contains intelligent life, we will probably shoot out vast quantities of information about ourselves on various frequencies, utilizing various codes. This information, though unrecognizable, might be recorded by the scientists on another world, to be translated after they solved our code. They might use the same bombardment of information on us, thus saving vast quantities of time once the new interplanetary language is learned.
Once a language is finally established, what will we talk about? Most important, of course, may be the bartering of scientific fact. Technological know-how radioed from Omicron-Two may help us swarm our rockets up in great locust flights across the universe, thousands of years earlier than now expected.
Nostrums for the common cold may be prescribed for us by doctors who may themselves be long dead before their cure reaches Earth. Psychological information, culled by creatures beyond imagining, may be signaled to us. Much of it may be dross, but some of it might contribute to our own fast-growing self-awareness. And ultimately, who can say? A cure may be offered for that most ancient and terrible of our sicknesses: war.
But surprisingly, the first intelligent sounds we hear from far Epsilon Indi may not be code or pulsing signal at all, but rather some Epsilon Indi music that was broadcast, as is ours, to the heedless winds of space. We would not know it as music at first, just as when we hear the Oriental tone-scale it falls strangely on the ear. Yet, with persistent listenings, our first brush with alien minds across the darkness may be the filtering in of a symphony composed by a Beethoven raised in the starshine of 61 Cygni.
But, man being what he is, electronic ears and signals and symphonies will not suffice. We will want to go and see for ourselves. We will not, however, send our first unmanned rockets to one of the seven promising star systems. Instead, the rockets will fire out through our own solar system, among those very planets which we have half neglected with our radio telescopes, simply because they do not appear to offer hope for our kind of life.
Our first robot machines will probably set down on the red planet Mars. From within this knowledgeable rocket, valves and snouts will thrust to suck ore samples into bins deep in the ship. Other airlocks will feed endless rolling tapes of that gelatinous standby of the biologists, the sticky nutrient agar, through the Martian air and back into a laboratory. There, under automatic TV and camera equipment, a historical event will occur: mankind, by remote control, will meet his first Martian—a bacterium jittering under a microscope.
Dr. Joshua Lederberg, at the Stanford University School of Medicine, who suggested the agar-tape equipment, has warned that we must build devices to decontaminate our rockets coming home from Mars. Science fiction is filled with tales of Martians invading Earth. It would be a terrible irony if some alien bacteria, carried back in a robot ship, conquered Earth through our lungs and blood stream.
Having met and been disappointed by our first Martian, the bacterium, what other life forms can we look for? Vegetation, says Clyde W. Tombaugh, one of the nation’s leading astronomers, now working in Las Cruces, N. M. Tombaugh believes the seasonal darkening of Mars’s so-called canals is probably caused by lichens which survive extreme heat, cold and lack of water. The canals themselves are “deep fissures of fractured land caused by asteroid impacts.”