repeated string. That string always contained the same twenty binary digits, and it could indicate an actual number but more likely stood for a symbol of some kind. Milly gave it a name. Call it the 20-bit “connector.” Each block of connector-number-connector had its own start and stop codes, separating it from other blocks.
Milly substituted the word “connector” in the data set in place of the 20-bit strings, put decimal numbers in place of their binary integer equivalents, and read the result.
On the face of it, she didn’t have much. Here was eight-connector-six-connector-eight, followed by the end- of-block marker. Here was eight-connector-seven-connector-eight, which was numerically almost the same, and another block end marker. But next to that sat the group one-connector-eight-connector-one, and then the more mysterious one-one-connectorconnector-six-connectorconnector-one-one.
Signifying?
Milly concentrated until the numbers and words swam and wandered and wobbled in front of her eyes. Pattern recognition was what humans did well, better than any computer so far built.
There had to be a pattern, right?
Right! So recognize it!
The display sneered back at her, Right! If you can!
Milly closed her eyes, took a deep breath, and sat motionless for a long time. At the conscious level, she seemed to be drifting from thought to random thought. But when she opened her eyes she was changing the word “connector” on the display to the symbolic ” — “.
The section she had been looking at became: 8 — 6 — 8, 8 — 7 — 8, 1 — 8 — 1, 1,1 — –6 — –1,1. If anything, that was more confusing than before.
And then, suddenly, it was not confusing at all. Milly shivered and rubbed her eyes. How dense could you get? Before she started, she had told herself the order in which a rational being would try to construct meaningful messages: mathematics, then physics, then chemistry. When that was done, you could consider interpreting biology and language.
Mathematics they had, at least at the level of the integers. It might be months or years before they advanced to complex variables and algebraic topology and the theory of continuous groups, but you did not need all those for a start on other subjects.
In physics and chemistry, what was the most obvious and fundamental information a message might offer? The periodic table was a basic building block, invariant across the universe. Hydrogen came first, helium second, lithium third, and so on right up through all the stable elements. Carbon was sixth, nitrogen seventh, oxygen eighth, and you had absolutely no choice in those assignments.
So now:
8 — 6 — 8: carbon dioxide, complete with the symbol for a chemical bond.
8 — 7 — 8: nitrous oxide.
1 — 8 — 1: hydrogen-oxygen-hydrogen — water. If you were a human, you would have placed that first. Did it occur more frequently than the other symbols? Milly would have to go back and check.
And 1,1 — –6 — –1,1? The dash was a clumsy notation for a two-or three-dimensional bond, but the reader was presumed to be intelligent. This one was methane, CH4, carbon with single bonds to four hydrogen atoms. Maybe the 2-D or 3-D representation would be found elsewhere in the signal, but meanwhile this would suffice. Scanning the whole sequence, Milly could see more complex patterns. She was reading a tutorial in elementary chemistry, one which confirmed at the same time that the natural numbers represented the elements.
It wasn’t a great discovery, maybe it was just one small step up the mountain of understanding involved in deciphering an alien message. But it was her step, one that no one else had ever taken. Milly didn’t just want to post it on the Puzzle Network displays. She wanted to tell somebody, shout it to the world before her brain burst and the information was lost.
She stood up quickly, swayed, and grabbed the edge of the console. She came close to blacking out and had to drop back into her seat to save herself.
As dizziness receded she glanced over to see what time it was. Well past midnight. At once she knew what was happening. It was her old problem. She had sat alone in her cubicle, oblivious to everything but the displays and her own thoughts, for more than half a day. Now that she was again aware of her body, her mouth was dry and her throat felt as though it could not swallow. She needed a drink, and she needed to go to the bathroom — and both those things took priority over the table of the elements.
She stood up, more carefully this time, and eased her way to the cubicle door and out into the corridor. She did not know where the bathroom was, but instinct told her that there must be one close to a conference room. She moved slowly along the corridor to the end, supporting herself with a hand on the wall and glad now that all the doors were closed.
In the bathroom she relieved herself, then drank from a faucet and splashed cold water over her face and wrists.
She went back out into the deserted corridor. In her muddled-headed condition she had not noticed before how quiet and dark it was. Everyone else in the Puzzle Network team must have gone to bed long ago, and she should do the same. Her brain was not going to burst. She would post her discovery tomorrow.
Milly walked back toward the entrance, slowly and wearily. Halfway there, her nose picked up a faint and infinitely attractive aroma. Someone had been cooking, and in her starved state the smell was ambrosial.
She tracked the food scent to a particular closed door, and stood in front of it. Every tissue in her body called out for instant nourishment. If there happened to be leftovers, surely the person who had prepared the dish would not begrudge them to Milly? She would leave a note, explaining what had happened and promising to replace whatever she ate.
Her mouth, dry five minutes ago, was watering. She eased open the door of the cubicle. The lighting inside was at a low setting, but she could see the food stand and a big brown crockpot sitting on top of it. The handle of a ladle pointed invitingly to Milly.
She had taken two quick paces and was reaching out a hand when she realized that the room was not empty after all. A huge person, big enough to obscure half the cubicle’s display screens, squatted on a flat padded chair. As Milly dropped back a step, the black-clad hulk turned toward her.
28
“Is this it?” Uncle Karolus placed a closed transparent container the size and shape of a small thimble on the table. “I wanted to be sure we were talking about the same thing before I go ahead and give it to’ the test team.”
It was the middle of the night in Alex’s living quarters. Karolus, black-caped and hooded, had entered without warning to be greeted by a sleepy and startled Kate wearing only a short nightie. He gave her an appreciative leer before Alex appeared from the bedroom and she could retire into it.
Alex blinked in the brighter light of the living-room and picked up the miniature vial. He lifted it close to his eyes, peering at the contents. It contained a dark-gray liquid that moved sluggishly as he tilted it.
“It doesn’t look right,” he said. “The way it was described to me, there should be a lot of little balls in there.”
“There are. At least, one of the Ligon techs took a quick look with a microscope and said there were. They’re real tiny, so they move around as though they’re a liquid.”
“Then I guess this is what we need. Did you have to come here in the middle of the night?”
“I thought we agreed this whole thing should be completed as fast as possible. Does your fat friend still say he’ll assign Pandora to us?”
“For a full year, as soon as the tests are finished and we deliver the results. He’s grumbling a lot, but he already vacated Pandora and came to Ganymede. He wants the Ops Center finished before he goes back.”
“Then let’s get the tests over and done with, before he changes his mind. Who has the list?”
“Nobody. Bat described one series of experiments that I already passed on to Bengt Suomi, but he wants our people to feel free to add any more physical tests they can think of. He’s convinced that when the right experiment
