After receiving her doctorate, Ellie accepted an appointment as research associate at the Arecibo Observatory, a great bowl 305 meters across, fixed to the floor of a karst valley in the foothills of northwestern Puerto Rico. With the largest radio telescope on the planet, she was eager to employ her maser detector to look at as many different astronomical objects as she could–nearby planets and stars, the center of the Galaxy, pulsars and quasars. As a full-time member of the Observatory staff, she would be assigned a significant amount of observing time. Access to the great radio telescopes is keenly competitive, there being many more worthwhile research projects than can possibly be accommodated. So reserved telescope time for the resident staff is perquisite beyond price. For many of the astronomers, it was the only reason they would consent to live in such godforsaken places.
She also hoped to examine a few nearby stars for possible signals of intelligent origin. With her detector system it would be possible to here the radio leakage from a planet like Earth even if it was a few light-years away. And an advanced society, intending to communicate with us, would doubtless be capable of much greater power transmissions than we were. If Arecibo, used as a radar telescope, was capable of transmitting one megawatt of power to a specific locale in space, then a civilization only a little bit in advance of ours might, she thought, be capable of transmitting a hundred megawatts or more. If they were intentionally transmitting to the Earth with a telescope as large as Arecibo but with a hundred-megawatt transmitter, Arecibo should be able to detect them virtually anywhere in the Milky Way Galaxy. When she thought carefully about it, she was surprised that, in the search for extraterrestrial intelligence, what could be done was so far ahead of what had been done. The resources that had been devoted to this question were trifling, she thought. She was hard pressed to name a more important scientific problem.
The Arecibo facility was known to the locals as “El Radar.” Its function was generally obscure, but it provided more than a hundred badly needed jobs. The indigenous young women were sequestered from the male astronomers, some of whom could be viewed at almost any time of day or night, full of nervous energy, jogging along the circumferential track that surrounded the dish. As a result, the attentions directed at Ellie upon her arrival, while not entirely unwelcome, soon became a distraction from her research.
The physical beauty of the place was considerable. At twilight, she would look out the control windows and see storm clouds hovering over the other lip of the valley, just beyond one of the three immense pylons from which the feed horns and her newly installed maser system were suspended. At the top of each pylon, a red light would flash to warn off any airplanes that had improbably strayed upon this remote vista. At 4 A.M., she would step outside for a breath of air and puzzle to understand a massed chorus of thousands of local land frogs, called “coquis” in imitations of their plaintive cry.
Some astronomers lived near the Observatory, but the isolation, compounded by ignorance of Spanish and inexperience with any other culture, tended to drive them and their wives toward loneliness and anomie. Some had decided to live at Ramey Air Force Base, which boasted the only English-language school in the vicinity. But the ninety-minute drive also heightened their sense of isolation. Repeated threats by Puerto Rican separatists, convinced erroneously that the Observatory played some significant military function, increased the sense of subdued hysteria, of circumstances barely under control.
Many months later, Valerian came to visit. Nominally he was there to give a lecture, but she knew that part of his purpose was to check up on how she was doing and provide some semblance of psychological support. Her research had gone very well. She had discovered what seemed to be a new interstellar molecular cloud complex, and had obtained some very fine high time-resolution data on the pulsar at the center of the Crab Nebula. She had even completed the most sensitive search yet performed for signals from a few dozen nearby stars, but with no positive results. There had been one or two suspicious regularities. She observed the stars in question again and could find nothing out of the ordinary. Look at enough stars, and sooner or later terrestrial interference or the concatenation of random noise will produce a pattern that for a moment makes your heart palpitate. You calm down and check it out. If it doesn’t repeat itself, you consider it spurious. This discipline was essential if she was to preserve some emotional equilibrium in the face of what she was seeking. She was determined to be as tough-minded as possible, without abandoning the sense of wonder that was driving her in the first place.
From her scant supply in the community refrigerator, she had made a rudimentary picnic lunch, and Valerian sat with her along the very periphery of the bowl-shaped dish. Workmen repairing or replacing the panels could be seen in the distance, walking on special snowshoes so they did not tear the aluminum sheets and plunge through the ground below. Valerian was delighted with her progress. They exchanged bits of gossip and current scientific tidbits. The conversation turned to SETI, as the search for extraterrestrial intelligence was beginning to be called.
“Have you ever though about doing it full time, Ellie?” he asked.
“I haven’t thought about it much. But it’s not really possible, is it? There’s no major facility devoted to SETI full-time anywhere in the world, as far as I know.”
“No, but there might be. There’s a chance that dozens of additional dishes might be added to the Very Large Array, and make it into a dedicated SETI observatory. They’d do some of the usual kind of radio astronomy also, of course. It would be a superb interferometer. It’s only a possibility, it’s expensive, it needs real political will, and it’s years away at best. Just something to think about.”
“Peter, I’ve just examined some forty-odd nearby stars of roughly solar spectral type. I’ve looked in the twenty-one centimeter hydrogen line, which everybody says is the obvious beacon frequency–because hydrogen is the most abundant atom in the universe, and so on. And I’ve done it with the highest sensitivity ever tried. There’s not a hint of a signal. Maybe there’s no one out there. Maybe the whole business is a waste of time.”
“Like life on Venus? That’s just disillusionment talking. Venus is a hellhole of a world; it’s just one planet. But there’s hundreds of billions of stars in the Galaxy. You’ve looked at only a handful. Wouldn’t you say it’s a little premature to give up? You’ve done on-billionth of the problem. Probably much less than that, if you consider other frequencies.”
“I know, I know. But don’t you have the sense that if they’re anywhere, they’re everywhere? If really advanced guys live a thousand light-years away, shouldn’t they have an outpost in our backyard? You could do the SETI thing forever, you know, and never convince yourself that you’d completed the search.”
“Oh, you’re beginning to sound like Dave Drumlin. If we can’t find them in his lifetime, he’s not interested. We’re just beginning SETI. You know how many possibilities there are. This is the time to leave every option open. This is the time to be optimistic. If we lived in any previous time in human history, we could wonder about this all our lives, and we couldn’t do a thing to find the answer. But this time is unique. This is the first time when anybody’s been able to look for extraterrestrial intelligence. You’ve made the detector to look for civilizations on the planets of millions of other stars. Nobody’s guaranteeing success. But can you think of a more important question? Imagine them out there sending us signals, and nobody on Earth is listening. That would be a joke, a travesty. Wouldn’t you be ashamed of your civilization if we were able to listen and didn’t have the gumption to do it?”
* * *
Two hundred fifty-six images of the left world swam by on the left. Two hundred fifty-six images of the right world glided by on the right. He integrated all 512 images into a wraparound view of his surroundings. He was deep in a forest of great waving blades, some green, some etiolated, almost all larger than me. But he had no difficulty clambering up and over, occasionally balancing precariously on a bent blade, falling to the gentle cushion of horizontal blades below, and then continuing unerringly on his journey. He could tell he was centered on the trail. It was tantalizingly fresh. He would think of nothing, if that’s where the trail led, of scaling an obstacle a hundred or a thousand times as tall as he was. He needed no pylons or ropes; he was already equipped. The ground immediately before him was redolent with a marker odor left recently, it must be, by another scout of his clan. It would lead to food; it almost always did. The food would spontaneously appear. Scouts would find it and mark the trail. He and his fellows would bring it back. Sometimes the food was a creature rather like himself; other times it was only an amorphous or crystalline lump. Occasionally it was so large that many of his clan would be required, working together, heaving and shoving it over the folded blades, to carry it home. He smacked his mandibles in anticipation.