now. She also wished that she had thought to go to the bathroom before the session started. Maybe it was nervousness, maybe it was anticipation, but she felt a growing internal discomfort.
“Salisbury.” Jack addressed a thin man with a black, drooping mustache and liquid dark eyes. “Is it there in the analog?”
The Ogre was more polite than Milly had ever seen him. He seemed cool, almost abstracted, until you noticed the left hand in the pocket and heard the constant jingle of keys or coins.
Salisbury nodded. “If it’s there in the digital, it’s there in the analog.”
That was a guarded, conservative answer. It represented an approach that Milly was learning to appreciate. The basic signals from space, either radio waves or neutrino pulses, arrived in analog form. They went through an analog-to-digital conversion before computer analysis and display. All the usual problems of A-to-D might be introduced in the process. You could get clipping effects from using an insufficient number of digital bits, or you could get aliasing, a frequency shift caused by the use of the wrong sampling rate. You could lose information, or you could create spurious “information” when none was present. Tim Salisbury was not saying there was or was not a signal — that was not his area of expertise. He was merely saying that the presence or absence of a signal was not the consequence of analog/digital conversion.
“Right.” Jack didn’t offer his usual third-degree interrogation, but turned to the woman on Milly’s right. “Tankard?”
Milly decided that rank had its privileges, even here. Hannah Krauss, Milly’s usual supervisor, was noticeable by her absence. These were Jack Beston’s most senior and trusted workers, and they looked like they didn’t take shit from anyone. As for Pat Tankard, if she had once been a vulnerable junior employee, Milly doubted that she had ever been troubled by the Ogre’s unwanted sexual advances. Tankard’s dark hair was cropped to less than an inch, she wore gold bands on the ring fingers of both hands, and her muscular left biceps carried a holographic tattoo that read from one angle, “Ellen,” and from another displayed the image of a slender long-haired blonde.
“If there are artifacts in the data, they are not the result of anything that Milly Wu did.” Pat Tankard smiled at Milly in a reassuring way. Her voice was a honeyed baritone, which Milly now realized she had heard in the shower rooms, crooning old-fashioned romantic ballads. Tankard went on, “I applied every operator in my own preferred order, which was generally not commutative with the order applied yesterday. If there was a signal, there is still a signal. Whatever was there, is there.”
The order in which you performed operations could generate the illusion of a meaningful signal. Something as simple as a change from Cartesian to polar coordinates in a two-D array might produce “meaningful” patterns that went away when you made the conversion at a different point in the processing.
It was one step nearer to detection. Milly ought to be feeling some reassurance. Instead she experienced a rising tension, and the pressure in her bladder was definitely uncomfortable. She also felt a queasiness, like that of the first few minutes in zero-gee, when the stomach rose to push up against the diaphragm. How much longer could she sit here in order to hear Jack Beston’s final decision?
Milly decided that before she would leave, she would sit until she threw up or her bladder burst. The precedent for the latter was not promising. Tycho Brahe, the last of the great pre-telescope astronomers, and an eccentric task-master far more formidable than Jack Beston, had been unable for reasons of protocol to rise and leave a court banquet before the duke did so. He had suffered a burst bladder as a result, and died a few days later.
“Kruskal?”
Jack’s voice broke into Milly’s thoughts. The woman across from her nodded. “If it derives from a process of natural origin, it is one unknown to science.” She was squat, olive-skinned, and plump, with an accent that suggested that she had arrived at the Jovian L-4 station from somewhere in the Inner System — probably Earth, and probably from one of the observatories still situated on the Andean cordillera.
Erma Kruskal went on, “Moreover, any natural process that generated such a signal would have to be, in most senses of the word, most unnatural. The entropy rises and falls, exactly as one would expect if a high-entropy repeated message were separated by long low-entropy start and stop pointers. Of course, this tells us nothing concerning verification and interpretation.”
Everyone was showing the same caution, bending over backwards to avoid too much optimism. Milly told herself that was the right way to do it — you mustn’t get too excited or too hopeful. All the same, she could feel her knees trembling. She pressed them tightly together.
Beston turned to the second man in the group. Arnold Rudolph was frail and tiny and looked older than God. Milly wasn’t sure of his actual age — neither Hannah nor anyone else seemed to know it — but there were rumors that he had been present at the closing of the great radio dish at Arecibo, and had been a major force in producing the first spaceborne SETI interferometric arrays.
Rudolph nodded amiably to Jack Beston, but he seemed in no hurry to begin. After a wait that brought Milly to the edge of her seat, he said, “The history of SETI goes back long before human space colonization, or even the launch of the first artificial Earth satellite. It is, of course, a history filled with false positives, which urges upon us extreme caution.” He didn’t look at Milly, which she read as a bad sign.
He went on, “The human mind has an incredible ability to detect patterns, or to impose patterns where none is present. Thousands of years ago, our earliest ancestors named the constellations because they saw patterns in the stars. More than two hundred years ago, Schiaparelli believed that he saw linear features on the surface of Mars, channels which Percival Lowell in turn interpreted as ‘canals’ and as evidence of intelligent life. With better images, channels and canals both vanished. Seventy years ago, the Hobart hoax fooled every SETI worker for more than a year.”
He paused. Milly wanted to scream, to shout at Arnold Rudolph, “Get on with it, we know all that.” No one moved or spoke, and Milly literally held her water.
“However.” Rudolph paused again, and stared around the little room that represented an antechamber to Jack Beston’s personal quarters. This time his look included Milly. “However, I do not believe that this anomaly is an example of spurious pattern recognition. Something is there. It would be premature to speculate on what that something might be, or even whether it will survive the necessary verification process. But something is there. The anomaly is real. It would be foolish of me to try to contain my own excitement at the possible significance of this discovery.”
His apparent lack of excitement was so obvious that Milly had to think twice before she realized what Rudolph was saying.
It was real! It was a signal! Jack Beston’s top assistants were convinced that this was a genuine discovery.
Jack himself, as calm as Arnold Rudolph, was nodding. “I think that takes us as far as we can go on detection. Let’s move on to verification. First, however, I have something else to report. Earlier today I prepared a message. On the basis of what I have heard, I propose to send it ciphered tight-beam to the Ganymede Office of Records, to be sealed there until we approve its release. The message announces the discovery of a signal, believed to be from an extra-solar source and of artificial rather than natural origin. It establishes our claim to precedence. The same message will be sent tight-beam to the Odin Project at Jovian L-5. Now, let’s get on to the preliminary stages of verification.” He turned to Zetter. “Your analysis?”
“The direction of origin of the potential signal is known to within five arc minutes.” Zetter spoke like a zombie, her voice a flat monotone. Milly wondered, nature or practice?
Zetter went on, “I have examined every possible signal source of human origin, past or present, to see if any lie within a cone of angle five arc minutes. The potential signal has been operating for at most three months. I allowed for our own motion during that period, adjusting for receiver parallax effects. My conclusion is that no known ship, with or without crew, can be the source of the potential signal. However.” At last, a word with some slight stress on it. “This does not rule out all possibilities. We could be receiving a signal from a residue.”
While the others nodded, Milly struggled to recall the briefing manuals. Was a residue the same as a remnant, some form of artifact left over from the Great War?
“To take one example,” Zetter continued, “consider a blinded Seeker, flying outward at maximum thrust until its fuel ran out and then coasting. In a third of a century it could be as much as half a light-year from Sol. No test made using data from this station’s receivers alone can distinguish such a source from one at true stellar distances.”
“Which is what I thought. We need extra-solar verification. That’s why I’m sending word to the Bastard. All
