The Best Science Fiction and Fantasy of the Year-Volume Three (40 page)

Still it was a genuine signal from ET, the scientists were jumping up and down, and for a while it was a public sensation. Within days somebody had rushed out a pop single inspired by the message: called "Eagle Song," slow, dreamlike, littered with what sounded like sitars, and very beautiful. It was supposedly based on a Beatles master lost for five decades. It made number two.

But the signal was just a squirt of noise from a long way off. When there was no follow-up, when no mother ship materialised in the sky, interest moved on. That song vanished from the charts.

The whole business of the signal turned out to be your classic nine-day wonder. Wilson invited me in on the tenth day. That was why I was resentful, I guess, as I drove into town that morning to visit him.

The Clarke Institute's ground station was in one of the huge glass follies thrown up along the banks of the Thames in the profligate boom-capitalism days of the noughties. Now office space was cheap enough even for academics to rent, but central London was a fortress, with mandatory crawl lanes so your face could be captured by the surveillance cameras. I was in the counter-terror business myself, and I could see the necessity as I edged past St. Paul's, whose dome had been smashed like an egg by the Carbon Cowboys' bomb of 2018. But the slow ride left me plenty of time to brood on how many more
important
people Wilson had shown off to before he got around to his brother. Wilson never was loyal that way.

Wilson's office could have been any modern data-processing installation, save for the all-sky projection of the cosmic background radiation painted on the ceiling. Wilson sat me down and offered me a can of warm Coke. An audio transposition of the signal was playing on an open laptop, over and over. It sounded like waves lapping at a beach. Wilson looked like he hadn't shaved for three days, slept for five, or changed his shirt in ten. He listened, rapt.

Even Wilson and his team hadn't known about the detection of the signal for a year. The Clarke ran autonomously; the astronauts who built it had long since packed up and come home. A year earlier the telescope's signal processors had spotted the pulse, a whisper of microwaves. There was structure in there, and evidence that the beam was collimated—it looked artificial. But the signal faded after just a second.

Most previous SETI searchers had listened for strong, continuous signals, and would have given up at that point. But what about a lighthouse, sweeping a microwave beam around the Galaxy like a searchlight? That, so Wilson had explained to me, would be a much cheaper way for a transmitting civilisation to send to a lot more stars. So, based on that economic argument, the Clarke was designed for patience. It had waited a whole year. It had even sent requests to other installations, asking them to keep an electronic eye out in case the Clarke, stuck in its crater, happened to be looking the other way when the signal recurred. In the end it struck lucky and found the repeat pulse itself, and at last alerted its human masters.

"We're hot favourites for the Nobel," Wilson said, matter of fact.

I felt like having a go at him. "Probably everybody out there has forgotten about your signal already." I waved a hand at the huge glass windows; the office, meant for fat-cat hedge fund managers, had terrific views of the river, the Houses of Parliament, the tangled wreck of the London Eye. "Okay, it's proof of existence, but that's all."

He frowned at that. "Well, that's not true. Actually we're looking for more data in the signal. It is very faint, and there's a lot of scintillation from the interstellar medium. We're probably going to have to wait for a few more passes to get a better resolution."

"A few more passes? A few more years!"

"But even without that there's a lot we can tell just from the signal itself." He pulled up charts on his laptop. "For a start we can deduce the Eaglets' technical capabilities and power availability, given that we believe they'd do it as cheaply as possible. This analysis is related to an old model called Benford beacons." He pointed to a curve minimum. "Look—we figure they are pumping a few hundred megawatts through an array kilometres across, probably comparable to the one we've got listening on the Moon. Sending out pulses around the plane of the Galaxy, where most of the stars lie. We can make other guesses." He leaned back and took a slug of his Coke, dribbling a few drops to add to the collection of stains on his shirt. "The search for ET was always guided by philosophical principles and logic. Now we have this one data point, the Eaglets six thousand light years away, we can test those principles."

"Such as?"

"The principle of plenitude. We believed that because life and intelligence arose on this Earth, they ought to arise everywhere they can. Here's one validation of that principle. Then there's the principle of mediocrity."

I remembered enough of my studies to recall that. "We aren't at any special place in space and time."

"Right. Turns out, given this one data point, it's not likely to hold too well."

"Why do you say that?"

"Because we found these guys in the direction of the centre of the Galaxy . . . "

When the Galaxy was young, star formation was most intense at its core. Later a wave of starbirth swept out through the disc, with the heavy elements necessary for life baked in the hearts of dead stars and driven on a wind of supernovas. So the stars inward of us are older than the sun, and are therefore likely to have been harbours for life much longer.

"We would expect to see a concentration of old civilisations towards the centre of the Galaxy. This one example validates that." He eyed me, challenging. "We can even guess how many technological, transmitting civilisations there are in the Galaxy."

"From this one instance?" I was practiced at this kind of contest between us. "Well, let's see. The Galaxy is a disc a hundred thousand light years across, roughly. If all the civilisations are an average of six thousand light years apart—divide the area of the Galaxy by the area of a disc of diameter six thousand light years—around three hundred?"

He smiled. "Very
good.
"

"So we're not typical," I said. "We're young, and out in the suburbs. All that from a single microwave pulse."

"Of course most ordinary people are too dumb to be able to appreciate logic like that. That's why they aren't rioting in the streets." He said this casually. Language like that always made me wince, even when we were undergraduates.

But he had a point. Besides, I had the feeling that most people had already believed in their gut that ET existed; this was a confirmation, not a shock. You might blame Hollywood for that, but Wilson sometimes speculated that we were looking for our lost brothers. All those other hominid species, those other kinds of mind, that we killed off one by one, just as in my lifetime we had destroyed the chimps in the wild—sentient tool-using beings, hunted down for bushmeat. We evolved on a crowded planet, and we missed them all.

"A lot of people are speculating about whether the Eaglets have souls," I said. "According to Saint Thomas Aquinas—"

He waved away Saint Thomas Aquinas. "You know, in a way our feelings behind SETI were always theological, explicitly or not. We were looking for God in the sky, or some technological equivalent. Somebody who would care about
us.
But we were never going to find Him. We were going to find either emptiness, or a new category of being, between us and the angels. The Eaglets have got nothing to do with us, or our dreams of God. That's what people don't see. And that's what people will have to deal with, ultimately."

He glanced at the ceiling, and I guessed he was looking towards the Eagle nebula. "And they won't be much like us. Hell of a place they live. Not like here. The Sagittarius arm wraps a whole turn around the Galaxy's core, full of dust and clouds and young stars. Why, the Eagle nebula itself is lit up by stars only a few million years old. Must be a tremendous sky, like a slow explosion—not like our sky of orderly wheeling pinpoints, which is like the inside of a computer. No wonder we began with astrology and astronomy. How do you imagine their thinking will be different, having evolved under such a different sky?"

I grunted. "We'll never know. Not for six thousand years at least."

"Maybe. Depends what data we find in the signal. You want another Coke?"

But I hadn't opened the first.

That was how that day went. We talked of nothing but the signal, not how he was, who he was dating, not about my family, my wife and the boys—all of us learning sign, incidentally, to talk to little Hannah. The Eagle signal was inhuman, abstract. Nothing you could see or touch; you couldn't even hear it without fancy signal processing. But it was all that filled his head. That was Wilson all over.

This was, in retrospect, the happiest time of his life. God help him.

"You want my help, don't you?"

Wilson stood on my doorstep, wearing a jacket and shambolic tie, every inch the academic. He looked shifty. "How do you know?"

"Why else would you come here? You
never
visit." Well, it was true. He hardly ever even mailed or called. I didn't think my wife and kids had seen him since our father's funeral six years earlier.

He thought that over, then grinned. "A reasonable deduction, given past observation. Can I come in?"

I took him through the living room on the way to my home study. The boys, then twelve and thirteen, were playing a hologram boxing game, with two wavering foot-tall prize fighters mimicking the kids' actions in the middle of the carpet. I introduced Wilson. They barely remembered him and I wasn't sure if he remembered
them
. I hurried him on. The boys signed to each other:
What a dork
, roughly translated.

Wilson noticed the signing. "What are they doing? Some kind of private game?"

I wasn't surprised he wouldn't know. "That's British Sign Language. We've been learning it for years—actually since Dad's funeral, when we hooked up with Barry and his wife, and we found out they had a little deaf girl. Hannah, do you remember? She's eight now. We've all been learning to talk to her. The kids find it fun, I think. You know, it's an irony that you're involved in a billion-pound project to talk to aliens six thousand light years away, yet it doesn't trouble you that you can't speak to a little girl in your own family."

He looked at me blankly. I was mouthing words that obviously meant nothing to him, intellectually or emotionally. That was Wilson.

He just started talking about work. "We've got six years' worth of data now—six pulses, each a second long. There's a
lot
of information in there. They use a technique like our own wave-length division multiplexing, with the signal divided into sections each a kilohertz or so wide. We've extracted gigabytes . . . "

I gave up. I went and made a pot of coffee, and brought it back to the study. When I returned he was still standing where I'd left him, like a switched-off robot. He took a coffee and sat down.

I prompted, "Gigabytes?"

"Gigabytes. By comparison the whole
Encyclopaedia Britannica
is just one gigabyte. The problem is we can't make sense of it."

"How do you know it's not just noise?"

"We have techniques to test for that. Information theory. Based on experiments to do with talking to dolphins, actually." He dug a handheld out of his pocket and showed me some of the results.

The first was simple enough, called a "Zipf graph." You break your message up into what look like components—maybe words, letters, phonemes in English. Then you do a frequency count: how many letter As, how many Es, how many Rs. If you have random noise you'd expect roughly equal numbers of the letters, so you'd get a flat distribution. If you have a clean signal without information content, a string of identical letters, A, A, A, you'd get a graph with a spike. Meaningful information gives you a slope, somewhere in between those horizontal and vertical extremes.

"And we get a beautiful log-scale minus one power law," he said, showing me. "There's information in there all right. But there is a lot of controversy over identifying the elements themselves. The Eaglets did
not
send down neat binary code. The data is frequency modulated, their language full of growths and decays. More like a garden growing on fast-forward than any human data stream. I wonder if it has something to do with that young sky of theirs. Anyhow, after the Zipf, we tried a Shannon entropy analysis."

This is about looking for relationships between the signal elements. You work out conditional probabilities: Given pairs of elements, how likely is it that you'll see U following Q? Then you go on to higher-order "entropy levels," in the jargon, starting with triples: How likely is it to find G following I and N?

"As a comparison, dolphin languages get to third- or fourth-order entropy. We humans get to eighth or ninth."

"And the Eaglets?"

"The entropy level breaks our assessment routines. We think it's around order thirty." He regarded me, seeing if I understood. "It is information, but much more complex than any human language. It might be like English sentences with a fantastically convoluted structure—triple or quadruple negatives, overlapping clauses, tense changes." He grinned. "Or triple entendres. Or quadruples."

"They're smarter than us."

"Oh, yes. And this is proof, if we needed it, that the message isn't meant specifically for us."

"Because if it were, they'd have dumbed it down. How smart do you think they are? Smarter than us, certainly, but—"

"Are there limits? Well, maybe. You might imagine that an older culture would plateau, once they've figured out the essential truths of the universe, and a technology optimal for their needs . . . There's no reason to think progress need be onward and upward forever. Then again perhaps there are fundamental limits to information processing. Perhaps a brain that gets too complex is prone to crashes and overloads. There may be a trade-off between complexity and stability."

I poured him more coffee. "I went to Cambridge. I'm used to being with entities smarter than I am. Am I supposed to feel demoralised?"