by Carl Sagan
“Well, the Vega signal looks as if it has polarization modulating. We’re busy checking it out right now. But Dave found that there wasn’t an equal amount of the two sorts of polarization. It wasn’t left polarized as much as it was right polarized. It’s just possible that there’s another message in the polarization that we’ve missed so far. That’s why I’m suspicious about your friend. Kitz isn’t just giving me general gratuitous advice. He knows we may be onto something else.”
“Ellie, take it easy. You’ve hardly slept for four days. You’ve been juggling the science, the administration, and the press. You’ve already made one of the major discoveries of the century, and if I understand you right, you might be on the verge of something even more important. You’ve got every right to be a little on edge. And threatening to militarize the project was clumsy of Kitz. I don’t have any trouble understanding why you’re suspicious of him. But there’s some sense to what he says.”
“Do you know the man?”
“I’ve been in a few meetings with him. I can hardly say I know him. Ellie, if there’s a possibility of a real message coming in, wouldn’t it be a good idea to thin out the crowd a little?”
“Sure. Give me a hand with some of the Washington deadwood.”
“Okay. And if you leave that document on your desk, someone’ll be in here and draw the wrong conclusion. Why don’t you put it away somewhere?”
“You’re going to help?”
“If the situation stays anything like what it is now, I’ll help. We’re not going to make our best effort if this thing gets classified.”
Smiling, Ellie knelt before her small office safe, and punched in the six-digit combination, 314159. She took one last glance at the document that was titled in large black letters THE UNITED STATES VS. HADDEN CYBERNETICS, and locked it away.
• • •
It was a group of about thirty people—technicians and scientists associated with Project Argus, a few senior government officials, including the Deputy Director of the Defense Intelligence Agency in civilian clothes. Among them were Valerian, Drumlin, Kitz, and der Heer. Ellie was the only woman. They had set up a large television projection system, focused on a two-meter-by-two-meter screen set flush against the far wall. Ellie was simultaneously addressing the group and the decryption program, her fingers on the keyboard before her.
“Over the years we’ve prepared for the computer decryption of many kinds of possible messages. We’ve just learned from Dr. Drumlin’s analysis that there’s information in the polarization modulation. All that frenetic switching between left and right means something. It’s not random noise. It’s as if you’re flipping a coin. Of course, you expect as many heads as tails, but instead you get twice as many heads as tails. so you conclude that the coin is loaded or, in our case, that the polarization modulation isn’t random; it has content… Oh, look at this. What the computer has just now told us is even more interesting. The precise sequence of heads and tails repeats. It’s a long sequence, so it’s a pretty complex message, and the transmitting civilization must want us to be sure to get it right.
“Here, you see? This is the repeating message. We’re now into the first repetition. Every bit of information, every dot and dash—if you want to think of them that way—is identical to what it was in the last block of data. Now we analyze the total number of bits. It’s a number in the tens of billions. Okay, bingo! It’s the product of three prime numbers.”
Although Drumlin and Valerian were both beaming, it seemed to Ellie they were experiencing quite different emotions.
“So what? What do some more prime numbers mean?” a visitor from Washington asked.
“It means—maybe—that we’re being sent a picture. You see, this message is made of a large number of bits of information. Suppose that large number is the product of three smaller numbers; it’s a number times a number times a number. So there’s three dimensions to the message. I’d guess either it’s a single static three-dimensional picture like a stationary hologram, or it’s a two-dimensional picture that changes with time—a movie. Let’s assume it’s a movie. If it’s a hologram, it’ll take us longer to display anyway. We’ve got an ideal decryption algorithm for this one.”
On the screen, they made out an indistinct moving pattern composed of perfect whites and perfect blacks.
“Willie, put in some gray interpolation program, would you? Anything reasonable. And try rotating it about ninety degrees counterclockwise.”
“Dr. Arroway, there seems to be an auxiliary sideband channel. Maybe it’s the audio to go with the movie.”
“Punch it up.”
The only other practical application of prime numbers she could think of was public-key cryptography, now widely used in commercial and national security contexts. One application was to make a message clear to dummies; the other was to keep a message hidden from the tolerably intelligent.
Ellie scanned the faces before her. Kitz looked uncomfortable. Perhaps he was anticipation some alien invader or, worse, the design drawings of a weapon too secret for her staff to be trusted with. Willie looked very earnest and was swallowing over and over again. A picture is different from mere numbers. The possibility of a visual message was clearly rousing unexamined fears and fantasies in the hearts of many of the onlookers. Der Heer had a wonderful expression on his face; for the moment he seemed much less the official, the bureaucrat, the presidential adviser, and much more the scientist.
The picture, still unintelligible, was joined by a deep rumbling glissando of sounds, sliding first up and then down the audio spectrum until it gravitated to rest somewhere around the octave below middle C. Slowly the group became aware of faint but swelling music. The picture rotated, rectified, and focused.
Ellie found herself staring at a black-and-white grainy image of…a massive reviewing stand adorned with an immense art deco eagle. Clutched in the eagle’s concrete talons…
“Hoax! It’s a hoax!” There were cries of astonishment, incredulity, laughter, mild hysteria.
“Don’t you see? You’ve been hoodwinked,” Drumlin was saying to her almost conversationally. He was smiling. “It’s an elaborate practical joke. You’ve been wasting the time of everybody here.”
Clutched in the eagle’s concrete talons, she could now see clearly, was a swastika. The camera zoomed in above the eagle to find the smiling face of Adolf Hitler, waving to a rhythmically chanting crowd. His uniform, devoid of military decorations, conveyed a modest simplicity. The deep baritone voice of an announcer, scratchy but unmistakably speaking German, filled the room. Der Heer moved toward her.
“Do you know German?” she whispered. “What’s it saying?”
“The Fuehrer,” he translated slowly, “welcomes the world to the German Fatherland for the opening of the 1936 Olympic Games.”
CHAPTER 6
Palimpsest
And if the Guardians are not happy, who else can be?
—ARISTOTLE
The Politics
Book 2, Chapter 5
AS THE plane reached cruising altitude, with Albuquerque already more than a hundred miles behind them, Ellie idly glanced at the small white cardboard rectangle imprinted with blue letters that had been stapled to her airline ticket envelope. It read, in language unchanged since her first commercial flight, “This is not the luggage ticket (baggage check) described by Article 4 of the Warsaw Convention.” Why were the airlines so worried, she wondered, that passengers might mistake this piece of cardboard for the Warsaw Convention ticket? Why had she never seen one? Where were they storing them? In some forgotten key event in the history of aviation, an inattentive airline must have forgotten to print this caveat on cardboard rectangles and was sued into bankruptcy by irate passengers laboring under the misapprehension that this was the Warsaw luggage ticket. Doubtless there were sound financial reasons for this worldwide concern, never otherwise articulated, about which pieces of cardboard are not described by the Warsaw Convention. Imagine, she
thought, all those cumulative lines of type devoted instead to something useful—the history of world exploration, say, or incidental facts of science, or even the average number of passenger miles until your airplane crashed.
If she had accepted der Heer’s offer of a military airplane, she would be having other casual associations. But that would have been far too cozy, perhaps some aperture leading to an eventual militarization of the project. They had preferred to travel by commercial carrier. Valerian’s eyes were already closed as he finished settling into the seat beside her. There had been no particular hurry, even after taking care of those last-minute details on the data analysis, with the hint that the second layer of the onion was about to unpeel. They had been able to make a commercial flight that would arrive in Washington well before tomorrow’s meeting; in fact, in plenty of time for a good night’s sleep.
She glanced at the telefax system neatly zipped into a leather carrying case under the seat in front of her. It was several hundred kilobits per second faster than Peter’s old model and displayed much better graphics. Well, maybe tomorrow she would have to use it to explain to the President of the United States what Adolf Hitler was doing on Vega. She was, she admitted to herself, a little nervous about the meeting. She had never met a President before, and by late-twentieth-century standards, this one wasn’t half bad. She hadn’t had time to get her hair done, much less a facial. Oh well, she wasn’t going to the White House to be looked at.
What would her stepfather think? Did he still believe she was unsuited for science? Or her mother, now confined to a wheelchair in a nursing home? She had managed only one brief phone call to her mother since the discovery over a week ago, and promised herself to call again tomorrow.
As she had done a hundred times before, she peered out the airplane window and imagined what impression the Earth would make on an extraterrestrial observer, at this cruising altitude of twelve or fourteen kilometers, and assuming the alien had eyes something like ours. There were vast areas of the Midwest intricately geometrized with squared, rectangles, and circles by those with agricultural or urban predilections; and, as here, vast areas of the Southwest in which the only sign of intelligent life was an occasional straight line heading between mountains and across deserts. Are the worlds of more advanced civilizations totally geometrized, entirely rebuilt by their inhabitants? Or would the signature of a really advanced civilization be that they left no sign at all? Would they be able to tell in one swift glance precisely which stage we were in some great cosmic evolutionary sequence in the development of intelligent beings?
What else could they tell? From the blueness of the sky, they could make a rough estimate of Loschmidt’s Number, how many molecules there were in a cubic centimeter at sea level. About three times ten to the nineteenth. They could easily tell the altitudes of the clouds from the length of their shadows on the ground. If they knew that the clouds were condensed water, they could roughly calculate the temperature lapse rate of the atmosphere, because the temperature had to fall to about minus forty degrees Centigrade at the altitude of the highest clouds she could see. The erosion of landforms, the dendritic patterns and oxbows of rivers, the presence of lakes and battered volcanic plugs all spoke of an ancient battle between landforming and erosional processes. Really, you could see at a glance that this was an antique planet with a brand new civilization.
Most of the planets in the Galaxy would be venerable and pretechnical, maybe even lifeless. A few would harbor civilizations much older than ours. Worlds with technical civilizations just beginning to emerge must be spectacularly rare. It was probably the only quality fundamentally unique about the Earth.
Through lunch, the landscape slowly turned verdant as they approached the Mississippi Valley. There was hardly any sense of motion in modern air travel, Ellie thought. She looked at Peter’s still sleeping form; he had rejected with some indignation the prospect of an airline lunch. Beyond him, across the aisle, was a very young human being, perhaps three months old, comfortably nestled in its father’s arms. What was an infant’s view of air travel? You go to a special place, walk into a large room with seats in it, and sit down. The room rumbles and shakes for four hours. Then you get up and walk off. Magically, you’re somewhere else. The means of transportation seems obscure to you, but the basic idea is easy to grasp, and precocious mastery of the Navier-Stokes equations is not required.
It was late afternoon when they circled Washington, awaiting permission to land. She could make out, between the Washington Monument and the Lincoln Memorial, a vast crowd of people. It was, she had read only an hour earlier in the Times telefax, a massive rally of black Americans protesting economic disparities and educational inequities. Considering the justice of their grievances, she thought, they had been very patient. She wondered how the President would respond to the rally and to the Vega transmission, on both of which some official public comment would have to be made tomorrow.
• • •
“What do you mean, Ken, ‘They get out’?”
“I mean, Ms. President, that our television signals leave this planet and go out into space.”
“Just exactly how far do they go?”
“With all due respect, Ms. President, it doesn’t work that way.”
“Well, how does it work?”
“The signals spread out from the Earth in spherical waves, a little like ripples in a pond. They travel at the speed of light—186,000 miles a second—and essentially go on forever. The better some other civilization’s receivers are, the farther away they could be and still pick up our TV signals. Even we could detect a strong TV transmission from a planet going around the nearest star.”
For a moment, the President stood ramrod straight, staring out the French doors into the Rose Garden. She turned toward der Heer. “You mean…everything?”
“Yes. Everything.”
“You mean to say, all that crap on television? The car crashes? Wrestling? The porno channels? The evening news?”
“Everything, Ms. President.” Der Heer shook his head in sympathetic consternation.
“Der Heer, do I understand you correctly? Does this mean that all my press conferences, my debates, my inaugural address, are out there?”
“That’s the good news, Ms. President. The bad news is, so are all the television appearances of your predecessor. And Dick Nixon. And the Soviet leadership. And so are a lot of nasty things your opponent said about you. It’s a mixed blessing.”
“My God. Okay, go on.” The President had turned away from the French doors and was now apparently preoccupied in examining a marble bust of Tom Paine, newly restored from the basement of the Smithsonian Institution, where it had been consigned by the previous incumbent.
“Look at it this way: Those few minutes of television from Vega were originally broadcast in 1936, at the opening of the Olympic Games in Berlin. Even though it was only shown in Germany, it was the first television transmission on Earth with even moderate power. Unlike the ordinary radio transmission in the thirties, those TV signals got through our ionosphere and trickled out into space. We’re trying to find out exactly what was transmitted back then, but it’ll probably take some time. Maybe that welcome from Hitler is the only fragment of the transmission they were able to pick up on Vega.
“So from their point of view, Hitler is the first sign of intelligent life on Earth. I’m not trying to be ironic. They don’t know what the transmission means, so they record it and transmit it back to us. It’s a way of saying ‘Hello, we heard you.’ It seems to me a pretty friendly gesture.”
“Then you say there wasn’t any television broadcasting until after the Second World War?”
“Nothing to speak of. There was a local broadcast in England on the coronation of George the Sixth, a few things like that. Big time television transmission began in the late forties. All those programs are leaving the Earth at the speed of light. Imagine the Earth is here”—der Heer gestured in the air—“and there’s a little s
pherical wave running away from it at the speed of light, starting out in 1936. It keeps expanding and receding from the Earth. Sooner or later, it reaches the nearest civilization. They seem to be surprisingly close, only twenty-six years for the Berlin Olympics to return to Earth. So the Vegans didn’t take decades to figure it out. They must have been pretty much tuned, all set up, ready to go, waiting for our first television signals. They detect them, record them, and after a while play them back to us. But unless they’ve already been here—you know, some survey mission a hundred years ago—they couldn’t have known we were about to invent television. So Dr. Arroway thinks this civilization is monitoring all the nearby planetary systems, to see if any of its neighbors develop high technology.”
“Ken, there’s a lot of things her to think about. Are you sure those—what do you call them, Vegans?—you sure they don’t understand what that television program was about?”
“Ms. President, there’s no doubt they’re smart. That was a very weak signal in 1936. Their detectors have to be fantastically sensitive to pick it up. But I don’t see how they could possibly understand what it means. They probably look very different from us. They must have different history, different customs. There’s no way for them to know what a swastika is or who Adolf Hitler was.”
“Adolf Hitler! Ken, it makes me furious. Forty million people die to defeat that megalomaniac, and he’s the star of the first broadcast to another civilization? He’s representing us. And them. It’s that madman’s wildest dream come true.”
She paused and continued in a calmer voice. “You know, I never thought Hitler could manage that Hitler salute. He never gave it straight on, it was always skewed at some wacko angle. And then there was that fruity bent elbow salute. If anyone else had done his Heil Hitlers so incompetently he would’ve been sent to the Russian front.”
“But isn’t there a difference? He was only returning the salutes of others. He wasn’t Heiling Hitler.”