“Maybe they do it on purpose,” signed Captain Curling-Sixth-Finger. Palm-Up-Middle-Fingers-Splayed was grateful for the zero gravity; if they’d been on a planet’s surface, Curling-Sixth-Finger would have towered over him, just as most adult females towered over most males. But here, with them both floating freely, the difference in size was much less intimidating.
“Do what?” signed Palm-Up-Middle-Fingers-Splayed.
“Maybe they cultivate their own predators,” replied Curling-Sixth-Finger, “specifically to keep their population in check. There are—what?” She peered at the binary numbers beneath the blocky drawings. “Six billion of the terrestrial forms? But only a few million of the aquatic adults.”
“So it would seem,” said Palm-Up-Middle-Fingers-Splayed. “It’s interesting that their adult form returns to the water; on the world of that last star we visited, the larvae were aquatic and the adults were land-dwellers.” He paused, then pointed at the right-hand figure’s horizontally flattened tail. “They resemble the ancestral aquatic forms of our own kind from millions of years ago—even down to the horizontal tail fin.”
Curling-Sixth-Finger spread her fingers in agreement. “Interesting. But, enough chat; there are important questions we have to ask these aliens.”
Darren Hamasaki had just checked in at the Air Canada booth at the Las Vegas airport and was on his way to the Star Alliance lounge—his trip last year to see the eclipse in Europe had got him enough points to earn entry privileges—when Karyn Jones, one of Mayor Rivers’s assistants, caught up with him.
“Darren!” she wheezed, touching his arm, and buying herself a few seconds to catch her breath.
“What is it?” said Darren, raising his eyebrows. “Did I forget something?”
“No, no, no,” said Karyn, still breathing raggedly. “There’s been a reply.”
“Already?” asked Darren. “But that’s not possible. Groombridge 1618 is 4.9 parsecs away.”
Karyn looked at him as though he were speaking a foreign language. After a moment, she simply repeated, “There’s been a reply.”
Darren glanced down at his boarding pass. Karyn must have detected his concern. “Don’t worry,” she said. “We’ll get you another flight.” She touched his forearm again. “Come on!”
Of course, many observatories now routinely watched Groombridge 1618; it was under twenty-four hour surveillance from ground stations, and was frequently examined by Hubble, as well—not that a reply was expected soon, but there was always the possibility that the aliens would send another message of their own volition, prior to receiving a response from Earth. Even so, few in the astronomical community seriously believed the Groombridgeans would ever see the Las Vegas light show, and the United Nations was still debating whether to build a big laser to send an official reply.
And so, Darren saw the alien’s response the same way most of the world did: on CNN.
And a response it surely was, for in layout and design it precisely matched the message Mayor Rivers had arranged to be sent. The aliens were bipedal, with broad, flat tails like those of beavers; Tailiens was a word the CNN commentator was already using to describe them. Their heads sported V-shaped mouths, and arms projected from either side of the head. There was something strange about their abdomens, though: a single column of zero bits—blank pixels—ran down the length of the chest; what it signified, Darren had no idea.
CNN took away the graphic of the message and replaced it with the anchor’s face. “Do you have it on videotape?” asked Darren. “I want to examine the message in detail.”
“No,” said Karyn. “But it’s on the CNN web site.” She pointed to an iMac sitting across the room; sure enough, the graphic was displayed on its screen. Darren bounded over to it. He was still trying to take it all in, trying to discern whatever details he could. In the background, he could hear the CNN anchor talking to a female biologist: “As you can see,” the scientist said, “the aliens presumably evolved from an aquatic ancestor, not unlike our own fishy forebears. Our limbs are positioned where they are because those were the locations of the pectoral and pelvic fins of the lobe-finned fish we evolved from. This creature’s ancestors presumably had its front pair of fins further forward, which is why the arms ended up growing out of the base of the head, instead of the shoulders, and…”
Darren tried to shut out the chatter. His attention was caught by the string of pixels beneath the alien figure.
The very long string of pixels…
The crew of the Ineluctable hadn’t bothered to send an image of a juvenile of their kind alongside the adult; unlike the strange beings they were now communicating with, they had no larval form—babies looked just like miniature adults.
Palm-Up-Middle-Fingers-Splayed and the others didn’t wait for another reply from the denizens of the third planet before flashing a series of additional pictures at them. These were standard images, already prepared, showing details of
And then they could determine whether these people and the members of
“They’re not at Groombridge 1618,” Darren said to Mayor Rivers, when His Honor arrived shortly after midnight; the mayor’s toupee had been hastily perched and now sat somewhat askew atop his head. “They can’t be. Assuming they responded immediately upon receipt of our message, they’re only a few light-hours away—about the distance Pluto is from the Earth, although, of course, they’re well above the plane of the solar system.” Darren frowned. “They must be in a spaceship, but…but, no, no, that can’t be right. Every observatory on Earth has been taking the spectra of the laser flashes, and they’re dead on the D1 sodium line, which can’t be a coincidence. The senders are using a line that’s weak in their home star but very strong in our own sun’s spectrum to signal us. But, like I said, it’s dead on that line, meaning there’s no Doppler shift. But if the ship was coming towards us, the light from the laser would be blue-shifted, and—”
“And if it were a-flyin’ away from us,” said Mayor Rivers, “it would be red-shifted.”
Darren looked at His Honor, surprised. Rivers lifted his shoulders a bit. “Hey, we’re not all hicks down here, you know.”
Darren smiled. “But if the light isn’t undergoing a Doppler shift, then—”
“Then,” said Rivers, “the starship must be holdin’ station, somewhere out there near the edge of the solar system.”
Darren nodded. “I wonder why they don’t come closer?”
The next night, Darren found himself flipping channels in his hotel room—they’d put him back in the Hilton. Letterman did a top-ten list of people who would make the best ambassadors to visit the aliens (“Number four: Robert Downey, Jr., because he’s been damn near that high already”). And Leno did a “Jay Walking” segment, asking people on the street basic questions about space; Darren was appalled that one person said the sun revolved around the Earth, and that another declared that Mars was “millions of light-years” away.
After that, though, he switched to Nightline, which had some more-serious discussion of the aliens. Ted Koppel was interviewing a guy named Quentin Fawcett, who was billed as an “astrobiologist.”
“I’ve been studying the anatomical charts that the Tailiens sent us,” said Fawcett, whose long hair was tied into a ponytail. “I think I’ve figured out why they don’t use radio.”
Koppel played the stooge well. “You figured that out from anatomical charts? What’s anatomy got to do with it?”
“Can we have the first slide?” asked Fawcett. A graphic appeared on the monitor between Koppel and Fawcett, and, a second later, the image on Hamasaki’s hotel-room TV filled with the same image, as the
director cut to it. “Look at this,” said Fawcett’s voice.
“That’s the one they’re calling three-dash-eleven, isn’t it?” said Koppel. “The eleventh picture from the third group of signals the Tailiens sent.”
“That’s right. Now, what do you see?”
The TV image changed back to a two-shot of Koppel and Fawcett, both looking at their own monitor. “It’s the Tailien head,” said Koppel. And indeed it was, drawn out like an alligator’s.
“Look carefully at the mouth,” said Fawcett.
Koppel shook his head. “I’m sorry; I’m not getting it.”
“That’s not a picture of the head, you know. It’s a picture of the Tailien cranium—the skull.”
“Yes?”
“It’s all one bone,” said Fawcett triumphantly. “There’s no separate mandible, no movable jaw. The mouth is just a boomerang-shaped opening in a solid head.”
Koppel frowned. “So you’re saying they couldn’t articulate? I guess it would be hard to talk without a hinged jaw.” He nodded. “No talking, no radio.”
“No, it’s not the ability to make sounds that depends on the advent of jaws. It’s the ability to hear sounds, or, at least, to hear them clearly and distinctly.”
Koppel waited for Fawcett to go on. “I’ve got TMJ—temporomandibular-joint syndrome,” said Fawcett, tapping his temple. “Discomfort where the jaw articulates with the temporal bone; it’s pretty common. Well, last winter, I had an infection in my ear canal—‘swimmer’s ear,’ they called it. Except I didn’t know it for the longest time; I thought the pain was from my TMJ. Why? Because our ears are located right over our jaw joints—and that’s no coincidence. The small bones in our inner ear—the hammer, the anvil, and the stirrup—make our acute hearing possible, and they exist precisely because the skull splits there into the cranium and the jaw. Our earliest vertebrate ancestors were jawless fish—fish with heads very much like the Tailiens still seem to have, consisting of one solid piece of bone.”
Koppel was coming up to speed. “So…so, what? They take in soft food through permanently open mouths? No chewing?”
“Perhaps,” said Fawcett. “Or maybe that slit that runs down their torsos is a feeding orifice. But, either way, I’m willing to bet that they don’t depend on sound for communication.”
Darren worked with an illustrator from the Las Vegas Review-Journal and a doctor from the UNLV Medical Center coding a series of human-anatomy diagrams, but no one quite knew how to send them. It would take more than a day of flashing the city’s lights on and off—the power could only be cycled so quickly—to send even one of these high-resolution images, and the casinos wouldn’t stand for it. Every minute the power was off cost them tens of thousands of dollars in betting revenues.
But, before they’d figured out how to reply, a new set of messages—batch number four—arrived from the Tailiens.
Palm-Up-Middle-Fingers-Splayed personally supervised the sending of the next messages, since he’d been the one who had coded them. They were designed to convey a series of simple multiple-choice questions. The messages consisted of 23 rows of 79 columns, much smaller than the anatomical charts. Fist-Held-Sideways had opined that bandwidth might be a problem for the third planet in sending similar messages, which is presumably why no response had yet been received.
The top part of each message showed a simple math problem, and the bottom part showed three possible answers, one of which was correct. The boxes containing these answers were labeled, from left to right, with one pixel, two pixels, and three pixels respectively in their upper right-hand corners.
Palm-Up-Middle-Fingers-Splayed, Fist-Held-Sideways, and the rest awaited the answers from the third planet; nothing less than a perfect score on the test would be morally acceptable before they asked the most important question of all.
The aliens seemed to have no trouble reading the flashing of Las Vegas’s lights, and so the responses to the math problems were sent by that city winking itself on and off. Many of the hundred thousand people who had come to Nevada to be part of the first signaling effort were still in town, thrilled that an actual dialogue between humans and aliens seemed to be opening up.
Fortunately for the croupiers and pit bosses, the math problems only took seconds to reply to; all that had to be sent was the number of the box containing the correct answer: one flash, two flashes, or three flashes.
“There’s no doubt,” signed Palm-Up-Middle-Fingers-Splayed to Captain Curling-Sixth-Finger, “that the aliens understand our syntax. They clearly know how to give the correct response to a multiple-choice question—and they got all the answers right, even the one about division by zero.”
“Very well,” said Curling-Sixth-Finger, her fingers moving slowly, deliberately. She clearly was steeling herself, in case she had to repeat the action she’d been forced to take at the last star system. “Ask them the big one.”
The next message was, in the words of Larry King, who had Darren Hamasaki on his show to talk about it, “a real poser.”
“It looks,” said King, leaning forward on his desk, his red suspenders straining as he did so, “like they’re asking us something about DNA, isn’t that right, Mr. Hamasaki?”
“That does seem to be the case,” said Darren.
“Now, I don’t know much about genetics,” said King, and he looked briefly into the camera, as if to make clear that he was speaking on behalf of his viewing audience in confessing this ignorance, “but in USA Today this morning there was an article saying that it didn’t make sense that the aliens were talking to us about DNA. I mean, DNA is what life on Earth is based on, but it isn’t necessarily what alien life will be based on, no? Aren’t there other ways to make life?”
“Oh, there might very well indeed be,” said Darren, “although, you know, try as we might, no one has come up with a good computer model for any other form of self-replicating biochemistry. But I don’t think it matters. Life didn’t begin on Earth, after all. It was imported here, and—”
“It was?” King’s eyebrows shot up toward his widow’s peak. “Who says so?”
“Lots of biologists—more and more each day. You know, the initial problem with Darwin’s theory of evolution was this: it was clear that the process of natural selection would take a long time to develop complex life forms—but there was no evidence that the Earth was particularly old; we didn’t have any proof that it was old until the discovery of radioactivity. Then, when we found that Earth was billions of years old, it seemed that there was plenty of time for evolution. But now we’ve run into another not-enough-time problem: the oldest known fossils are 4.0 billion years old, and they’re reasonably complex, which means if life were indigenous to Earth, the first self-replicating molecules would have had to appear only a few hundred million years after the solar system was born, 4.5 billion years ago.”
“We’re going to get letters, I know it,” said King, “from people disputing those age claims. But go on.”
“Well, that early on, Earth was still being bombarded by meteors and comets; extinction-level events would have been common. Earth simply wouldn’t have presented a stable environment for life.”
“So you think life came here from outer space?”
“Almost certainly. Some biologists believe that it arose first on Mars—Mars was much drier than Earth, even back then. A comet or asteroid impact has a much greater destabilizing effect on the climate if it hits water than it does if it hits dry land. But the original DNA on Earth could have also come from outside the solar system—meaning, in fact, that these Tailiens might be our distant, distant relatives. All life in this part of the galaxy might share a common ancestor, if you go back far enough.”
“Fascinating,” said King. “Now, what about this latest message from the Tailiens? Can you take us through that?”
“Well, the top picture shows what looks to be a snippet of DNA, three codons long.”
“Codons?”
“Sorry. Words in the D
NA language. We read the language a letter at a time: A, C, G, or T. And since A and T always bond together, and G always bonds with C, we can just read the letters off one half of the DNA ladder and know automatically what the letters down the other side will be.”
King nodded.
“Well,” continued Darren, “each group of three letters—ACG, say, or TAT—is a word, specifying one amino acid, and amino acids are the building blocks of life. What we have in the first picture is a snippet of DNA consisting of nine letters, or three words. Next to that, there’s space for another snippet of DNA the same length, see? As if you were supposed to place one of the strings from the lower section up here beside this one.”
“And how do we choose which one should go there?”
Darren frowned. “That’s a very good question, Larry.” It was cool getting to call him Larry. He looked at his cheat-sheet on the desktop. “The sequence in the top part of the message is CAC, TCA, and GTC, which codes, at least here on Earth, for the amino acids histidine, serine, and valine.”
“Okay,” said King.
“And the three possible replies are below. Two of them are strings of DNA. The first one—in answer box one—is a string of DNA very similar to the one above. It reads as CAC—the same as before; TTA—which is one nucleotide different from the string on the top, so it codes for, umm, let me see, for leucine instead of serine; and then there’s GTC again, which is valine, just as before.”
“So it differs by only one-ninth from the specimen at the top,” said Larry. “A close relative, you might say.”
Darren nodded. “Exactly. And that brings us to the second possible response. Like the first possible response, it consists of nine codons, but here the codons don’t match at all—the sequence is completely different from the one above. And, if you look carefully, you’ll see it’s not just frameshifted out of synch from the sample above; it really has nothing in common with it. Nor could it be a possible match for the other side of the DNA ladder, because it doesn’t have the same pattern of duplicated letters.”
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