off and be replaced by something else, something very rich, the real message. We just have to keep on listening.”
This was the hardest part to explain to the press, that the signals had essentially no content, no meaning— just the first few hundred prime numbers in order, a cycling back to the beginning, and again the simple binary arithmetic representations: 1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31… Nine wasn't a prime number, she'd explain, because it was divisible by 3 (as well as 9 and 1, of course). Ten wasn't a prime number because 5 and 2 went into it (as well as 10 and 1). Eleven was a prime number because it was divisible only by 1 and itself. But why transmit prime numbers? It reminded her of an idiot savant, one of those people who might be grossly deficient in ordinary social or verbal skills but who could perform mindboggling feats of mental arithmetic—such as figuring out, after a moment's thought, on what day of the week June first in the year 11,977 will fall. It wasn't for anything; they did it because they liked doing it, because they were able to do it.
She knew it was only a few days after receipt of the message, but she was at once exhilarated and deeply disappointed. After all these years, they had finally received a signal—sort of. But its content was shallow, hollow, empty. She had imagined receiving the Encyclopedia Galactica.
We've only achieved the capacity for radio astronomy in the last few decades, she reminded herself, in a Galaxy where the average star is billions of years old. The chance of receiving a signal from a civilization exactly as advanced as we are should be minuscule. If they were even a little behind us, they would lack the technological capability to communicate with us at all. So the most likely signal would come from a civilization much more advanced. Maybe they would be able to write full and melodic mirror fugues: The counterpoint would be the theme written backwards. No, she decided. While this was a kind of genius without a doubt, and certainly beyond her ability, it was a tiny extrapolation from what human beings could do. Bach and Mozart had made at least respectable stabs at it.
She tried to make a bigger leap, into the mind of someone who was enormously, orders of magnitude, more intelligent than she was, smarter than Drumlin, say, or Eda the young Nigerian physicist who had just won the Nobel Prize. But it was impossible. She could muse about demonstrating Fermat's Last Theorem or the Goldbach Conjecture in only a few lines of equations. She could imagine problems enormously beyond us that would be old hat to them. But she couldn't get into their minds; she couldn't imagine what thinking would be like if you were much more capable than a human being. Of course. Nor surprise. What did she expect? It was like trying to visualize a new primary color or a world in which you could recognize several hundred acquaintances individually only by their smells…. She could talk about this, but she couldn't experience it. By definition, it has to be mighty hard to understand the behavior of a being much smarter than you are. Buy even so, even so: Why only prime numbers?
The Argus radio astronomers had made progress in the last few days. Vega had a known motion—a known component of its velocity toward or away from the Earth, and a known component laterally, across the sky, against the background of more distant stars. The Argus telescopes, working together with radio observatories in West Virginia and Australia, had determined that the source was moving with Vega. Not only was the signal coming, as carefully as they could measure, from where Vega was in the sky; but the signal also shared the peculiar and characteristic motions of Vega. Unless this was a hoax of heroic proportions, the source of the prime number pulses was indeed in the Vega system. There was no additional Doppler effect due to the motion of the transmitter, perhaps tied to a planet, about Vega. The extraterrestrials had compensated for the orbital motion. Perhaps it was a kind of interstellar courtesy.
“It's the goddamnedest most wonderful thing I ever heard of. And it's got nothing to do with our shop,” said an official of the Defense Advanced Research Projects Agency, preparing to return to Washington.
As soon as the discovery had been made, Ellie had assigned a handful of the telescopes to examine Vega in a range of other frequencies. Sure enough, they had found the same signal, the same monotonous succession of prime numbers, beeping away in the 1420 megahertz hydrogen line, the 1667 megahertz hydroxyl line, and at many other frequencies. All over the radio spectrum, with an electromagnetic orchestra, Vega was bleating out prime numbers.
“It doesn't make sense,” said drumlin, casually touching his belt buckle. “We couldn't have missed it before. Everybody's looked at Vega. For years. Arroway observed it from Arecibo a decade ago.
Suddenly last Tuesday Vega starts broadcasting prime numbers? Why now? What's so special about now?
How come they start transmitting just a few years after Argus starts listening?”
“Maybe their transmitter was down for repairs for a couple of centuries,” Valerian suggested, “and they just got it back on-line. maybe their duty cycle is to broadcast to us just one year out of every million.
There are all those other candidate planets that might have life on them, you know. We're probably not the only kid on the block.” But Drumlin, plainly dissatisfied, only shook his head.
Although his nature was the opposite of conspiratorial, Valerian thought he had caught an undercurrent in Drumlin's last question: could all this be a reckless, desperate attempt by Argus scientists to prevent a premature closing down of the project? It wasn't possible. Valerian shook his head. As der Heer walked by, he found himself confronted by two senior experts on the SETI problem silently shaking their heads at one another.
Between the scientists and the bureaucrats there was a kind of unease, a mutual discomfort, a clash of fundamental assumptions. One of the electrical engineers called it an impedance mismatch. The scientists were too speculative, too quantitative, and too casual about talking to anybody for the tastes of many of the bureaucrats. The bureaucrats were too unimaginative, too qualitative, too uncommunicative for many of the scientists. Ellie and especially der Heer tried hard to bridge the gap, but the pontoons kept being swept downstream.
This night, cigarette butts and coffee cups were everywhere. The casually dressed scientists, Washington officials in light-weight suits, and an occasional flag-rank military officer filled the control room, the seminar room, the small auditorium, and spilled out of doors, where, illuminated by cigarettes and starlight, some of the discussions continued. But tempers were frayed. The strain was showing.
“Dr. Arroway, this is Michael Kitz, Assistant Secretary of Defense for C3I.”
Introducing Kitz and positioning himself just a step behind him, der Heer was communicating…
what? Some unlikely mix of emotions. Bemusement in the arms of prudence? He seemed to be appealing for restraint. Did he think her such a hothead? “C3I”—pronounced cee-cubed-eye—stood for Command, Control, Communications, and Intelligence, important responsibilities at a time when the United States and the Soviet Union were gamely making major phased reductions in their strategic nuclear arsenals. It was a job for a cautious man.
Kitz settled himself in one of the two chairs across the desk from Ellie, leaned forward, and read the Kafka quote. He was unimpressed.
“Dr. Arroway, let me come right to the point. We're concerned about whether it's in the best interest of the United States for this information to be generally known. We were not overjoyed about your sending that telegram all over the world.”
“You mean to China? To Russia? To India?” Her voice, despite her best effort, had a discernible edge to it. “You wanted to keep the first 261 prime numbers secret? Do you suppose, Mr. Kitz, the extraterrestrials intended to communicate only with Americans? Don't you think that a message from another civilization belongs to the whole world?”
“You might have asked our advice.”
“And risk losing the signal? Look, for all we know, something essential, something unique might have been broadcast after Vega had set her in New Mexico but when it was high in the sky over Beijing.
These signals aren't exactly a person-to-person call to the U. S. of A. They're not even a person-to-person call to the Earth. It's station-to-station to any planet in the solar system. We just happened to be lucky enough to pick up the phone.”
Der Heer was radiating something again. What was he trying to tell her? That he liked that elementary analogy, but ease up on Kitz?
“In any case,” she continued, “it's too late. Everybody knows now that there's some kind of intelligent life in the Vega system.”
“I'm not sure it's too late, Dr. Arroway. You seem to think there'll be some information-rich transmission, a
