Einstein's Bridge

by Cramer, John

  Alice stopped typing, yawned, and decided to save the file and go back to bed. An hour ago she had come wide awake and had decided to work on her novel for a while. She shut down the lapstation, turned off the dining room light, opened the door, and padded barefoot back into the darkened bedroom. She dropped her robe on the floor and crawled slowly back into her big bed. She stretched and pulled the sheet over her nakedness. She felt wonderful.

  She could hear George’s soft breathing beside her. She looked at him, sleeping peacefully with a contented smile on his face, and she thought about recent events. He was wonderful. She thought perhaps she was in love with him. It had all been very exciting. It had been romantic too. His delight at finding the Snark had turned to passion. It was fun while it lasted. But realistically, it couldn’t last much longer.

  She had to earn her living by finishing Fire Ants. A great deal of money was at stake, hundreds of thousands of dollars. Their lovemaking had inspired her to write a great new scene. But when George found out why she was really studying life at the SSC so closely, the chances were he would want to have nothing more to do with her. She had come here to Waxahachie under false pretenses, and that fact was likely to sour their blossoming relationship. Nevertheless, she had to tell him. Soon. She sighed and snuggled against him. But not yet.

  Out of the corner of her eye she saw a flash of light from across the room. She rolled over, facing the dresser. George had placed the scintillator bar on the dresser, its open end toward the wall. In the mirror she could see its blue glow. It was flashing. But just as she focused her attention on it, the flashes stopped and there was only the faint and continuous blue glow. She waited, drowsy now. Perhaps she had dreamed the flashes.

  Then, as she was almost dozing off, they came again. Flash. Flash-Flash. Flash-Flash-Flash. Flash-Flash-Flash-Flash-Flash. Flash-Flash-Flash-Flash-Flash-Flash-Flash. Flash-Flash-Flash-Flash-Flash-Flash-Flash-Flash-Flash-Flash-Flash. ... This went on for a while and then stopped again.

  She waited, wide awake now. In a few minutes the flashing began again. This time she counted flashes. 1-2-3-5-7-11-13-17-19-23-29-31. Then it stopped. Twelve numbers. Something was familiar about their sequence. When she had worked as a reporter for the Democrat, Alice had interviewed some Florida State University astronomers about their research. They had been using the Aricibo radio telescope in Puerto Rico to search for extraterrestrial intelligence, “SETI” they had called it. They were searching for radio signals that might have been sent by some hypothetical alien race that lived in another star system.

  After the usual jokes about picking up alien game shows on TV and whether that could be construed as intelligence, Alice had asked about strategies for making the initial contact. How could they be sure that a message they received was not random noise or some natural phenomenon. Or to put it the other way, how would they send a simple radio signal that was clearly a product of an intelligent species. One answer had been to send a sequence of prime numbers, numbers that had no integer divisors. She was sure that the first few primes were 1-2-3-5-7-11-13. The Snark, Alice decided, was trying to send a message. The Snark wasn’t an exotic particle. It was ... something else ... something much more important than that.

  She shook George awake.

  CHAPTER 5.6

  SETI Folk

  ALICE glanced at the wall clock as Roger Coulton arrived at George’s LEM Office. It was just after 9 o’clock on Sunday morning. Roger looked a bit hung-over as he stood in the doorway, unfocused and rather disheveled. He absent-mindedly rubbed a spot on the inside of his thigh.

  “Good morning, Roger,” said Alice. “Sorry we had to abandon you at P.J.’s. I presume George told you about our successful Snark hunt last night.” She didn’t want to advertise the fact that she had been in bed next to him when George had made the call.

  “He certainly did,” Roger said. “Hours ago.” He yawned. “So you two have actually managed to isolate George’s mystery particle, which is now embedded in a scintillation counter. And you’ve discovered that it gives off a blue glow.”

  Alice pointed to the unit on George’s desk. The scintillation cylinder now had a light-tight metal cap mounted on its narrow end. “A blue glow that flashes,” she said.

  “A single wavelength blue glow that flashes,” George added. “I decided we might get a clue from the optical spectrum of the glow, so this morning we looked at the light with a small grating spectrograph. That turned out to be interesting. The thing has only one spectral line: bright blue, with a wavelength of 439.7 nanometers, if I did the calibration right.”

  “What atomic transition makes such a line?” asked Roger.

  “I don’t know,” said George. “I tried looking it up on the Web in an atomic physics database, but there was no match.”

  “Curious,” said Roger.

  “It gets even more curious,” said George.

  “Curiouser and curiouser,” Alice added.

  George frowned at her, then smiled. “To come to the point, Roger, the thing flashes. And this morning we discovered that even when the blue light seems to be continuous, it has a time structure. It’s sending binary code at about ten kilohertz,” he said.

  “What?” Roger turned, studying the two of them. “Is this a joke?”

  “Perhaps it is,” said George, “ but I assure you that it isn’t my joke. Alice first noticed that the flashes came in groups with the sequence 1-2-3-5-7-11-13-17-19-23-29-31, the first 12 prime numbers. And the binary stream gives the first 144 prime numbers in binary code.”

  Alice suddenly had a terrible thought. What if all of this was a joke, a joke on her? Perhaps they had found out that she was here under false pretenses and decided to teach her a lesson by preparing an elaborate hoax, to make the woman science reporter look foolish. It wouldn’t even have to be all that elaborate, a simple battery powered microprocessor concealed in the scintillator thing to make the blue light flashes under the control of a program. George and Roger could both be in on it, and maybe others too. Perhaps even the Snark event had been staged for her benefit.

  She thought more about this possibility, then began to relax. They’d have to be awfully good actors, she decided. And how could anyone know that she would notice the flashes last night? No, it’s probably not a hoax, she decided. In any case, she had no choice but to go along with the thing for the moment, play her assigned role, and watch carefully.

  Alice looked closely at Roger, who had been silent for a while. He now looked much more alert, she thought . Apparently he had recovered from his hangover.

  “Can I have a look at the time structure ?” he asked finally.

  “Thought you’d never ask,” said George. He showed Roger a sheet containing several parallel traces of rectangular peaks and valleys. “I synched this plot at what I think is the starting point. The 1’s and 0’s below the trace are a rendering in binary and hex. That’s the preamble. After the primes, it goes into another mode that we haven’t been able to penetrate.

  “The overall pattern is that it makes the flashes, then the binary primes, then followed by the other stuff. That sequence repeats about every five minutes. The stuff that comes after the binary primes is different each time, though it may repeat too after a while.”

  Roger smiled. “ It’s very likely that the 12 and 144 carry the implication of a base-12 number system. But, ... what the hell could this Snark thing be?”

  George turned to Alice. “You discovered the flashes, and you’ve had as much time to think about this as I have. What’s your guess as to what the Snark is?”

  Alice was caught by surprise by the question. “Calling on the students, Professor George? I detect your academic tendencies surfacing,” she said. She opened her notebook and flipped pages. “But, OK, if you want class participation, here’s my list of what we know about the Snark. It came out of an energetic particle
collision. It seemed to bring along its own energy. Its ionization track shows that it has a big electric charge, and its lack of magnetic deflection indicates that it’s very heavy. It spits quarks as it goes along, which has something to do with color. At rest it emits blue light at a single frequency. It flashes and it sends a series of prime numbers and a lot of additional code. Did I miss anything?”

  “You’re doing fine,” said George. “I might add that the Snark is much more massive than any known particle, but nevertheless it seems to be stable. Continue.”

  “From the flashes I must assume we’re dealing with a signal,” said Alice. “I once did a story on SETI. The claim of the experts I interviewed was that the sequence of primes indicates a message generated by intelligence rather than some product of a natural phenomenon. OK?”

  George shrugged. “We’ll accept that as at least a working hypothesis,” he said. “Keep going.”

  “OK,” said Alice. “The first possibility, it seems to me, is that the Snark might be a tiny mechanism for playing back a prerecorded message.”

  “Wait a moment,” said Roger. “Do we know how large this thing is?”

  “Small,” George said. “We tried looking at it this morning with a good optical system, but all that could be seen was a diffraction-limited blue spot. It’s certainly smaller than the dust grains the system was resolving.”

  “We know it induced those quark jets,” said Roger. “That suggests to me that its size is probably sub-nuclear. So it can’t be a playback device,” he concluded.

  Alice frowned. “How do you know that, Roger?” she asked.

  “Any message must be stored in the form of structure,” he said. “And a structure must be an arrangement of components. What, then, are the components? Atoms? Much too big. Nuclei? Neutrons and protons? Or perhaps quarks or leptons? What forces could possibly fix them in such a structured arrangement? Or read them out and produce a playback. There are no forces that could do that. Conclusion: there is no such structure.”

  “For an open minded theorist, I fear you may be verging on the dogmatic, Roger,” said George. “We’re dealing with a new phenomenon here, and we can’t absolutely rule out previously unknown forces. But I agree with the sense of your conclusion. It seems unlikely that the Snark could be a self-contained playback device.”

  “And I suppose,” said Alice, “ that the same argument also applies to my second alternative, which is that the Snark is a self-contained intelligence that’s trying to communicate with us.”

  “Indeed,” Roger said. “That would require even more structure.”

  “Any other possibilities on your list?” George asked.

  “Just one,” said Alice. “The Snark might be a link to an intelligence located elsewhere. It might be the equivalent of a tiny radio receiver.”

  “That requires structure too,” said George, “but not as much. An optical fiber is considerably less complicated than a compact disk player. Or the musicians who made the music recorded on the CD.”

  “But,” said Roger, “isn’t your Snark a bit, uh, short for an optical fiber link?”

  George spread his hands. “Who can say? At any rate, I agree that a communications link hypothesis is more probable than your other alternatives, Alice. But, is it for one-way communication or for two-way communication?”

  Roger scowled. “Surely,” he said, “two-way communication is not a serious possibility. If the Snark was a link to an extraterrestrial intelligence, which I, for one, am not yet willing to concede, such an intelligence would have to be very far away. Hundreds of light years, perhaps thousands or millions. Even if you did send a message that they were able to receive, you, and perhaps our whole civilization, would have died before the reply message came back. Remember your relativity, people. You can’t beat the speed of light!”

  George looked directly at the theorist and grinned. “Roger, that’s all very logical, but I have a hunch you’re wrong. We have, as they say, a significant difference of opinion. So I’m willing to wager, say, $500 that two way communication is possible using the Snark. You may accept my wager at whatever odds you consider to be fair and equitable. Interested?”

  Roger looked flustered. “Uh, $500? Let me, uh, think about that for a while, George,” he said. “Your intuitions have a certain reputation around here.”

  “Two way communication?” said Alice softly, “I hadn’t thought of that. How would you do it?”

  “Well, “ said George, “our Snark, by dumb luck, is already mounted in an almost ideal system. That lead-glass crystal is optically coupled to a photomultiplier light detector for receiving signals, and it has an on-board light-emitting diode system that makes light flashes in the scintillator for testing. We can use the LED system to transmit light pulses back to the Snark.”

  “If you were going to send the Snark a message, Roger, what would you send?” Alice asked.

  “Hmmm,” said Roger. “The conventional wisdom is that you should send back the same message you received. In this case, though, that might not be such a good idea. It could be interpreted as just a reflection. I’d say, send back a string of primes, perhaps at a different transmission rate, and don’t stop at prime number 144.

  “But I think we must wait a bit before trying to communicate back. There are profound implications of that which need to be considered. I think there are even protocols established by the United Nations for communicating with alien species that should be observed.”

  George turned to the theorist with a look of mock-disappointment. “Do I take it then, Roger old sport, that you don’t want to bet against me?”

  CHAPTER 5.7

  Speckles Revealed

  GEORGE yawned and looked at his wristwatch. It said “June 14, 2004, 06:55 AM.” After the excitement of the weekend, he was glad that he had remembered the appointment to use the microprobe.

  The SSC’s superconducting metallurgy research laboratory was on the West Campus, just across from the administration building. Wolfgang had arrived early, and was already securing his prepared sample of two chips on the polished metal surface of the scanning microprobe stage when George arrived. They had received a brief lesson in how to use the device the previous Friday, and Wolfgang now had the system almost ready to go.

  “Which chips are we testing first?” George asked. He considered the importance of this measurement. It could provide the key to their radiation damage problems, or it could be another blind alley. In either case, at 10 AM he would have to make a report on their progress. He hoped there would be something to report.

  “One is from the new batch that just arrived from the chip foundry,” said Wolfgang, “and the other is one of our problem children. I thought we might learn something from a comparison.” George placed a loop of soft ductile indium wire on the lower vacuum flange and Wolfgang lowered the counterweighted upper part of the apparatus down to meet it. Together they began to clamp down on the flanges, compressing the indium to form a metal-to-metal vacuum seal.

  “Is the bad one the same chip we looked at with the STM?” George asked as he worked.

  “Unfortunately, not,” said Wolfgang. “The STM probe did some surface damage to that one, and I thought it would be better to start fresh. However, this chip was mounted near the other in the pixel detector and shows exactly the same symptoms.” He moused “Start Pumpdown” on the microprobe control computer’s screen. The roughing pump below the apparatus made a chugging sound as it removed air from the microprobe’s inner chamber.

  As they waited for the vacuum to improve, George, still feeling the excitement of the weekend’s developments, began to tell Wolfgang about his recent Snark hunt. Wolfgang seemed interested at first and asked about the tracking and kinematics of the peculiar object. But when George began to describe the repetitive flashes and prime number sequences, Wolfgang’s attitud
e changed. He looked uncomfortable, as if George were describing something private and personal that he did not wish to hear about. Too bad, George thought, considering Wolfgang’s reaction. He had been hoping to recruit him to help with their Snark investigations.

  Wolfgang got up, tapped the mechanical vacuum gauge unnecessarily, moused around the computer screen, and announced that the vacuum was now down below the top operating limit and the microprobe was ready. George nodded and Wolfgang started the imaging sequence. The scanning microprobe produced a beam of electrons that were scanned in a tiny raster pattern across the sample. The viewing screen of the device was scanned with the same raster and modulated in brightness by a current of scattered electrons received on one side of the device. The result was a startlingly realistic and sharply focused microscopic image of the scanned area.

  The sharp image quality of the microprobe, however, was not the reason George and Wolfgang were using it. The scanned electron beam which the device used was unusually energetic, and when it struck individual atoms, it sometimes knocked out their inner-shell electrons, causing them to produce X-rays with an energy characteristic of the producing atom. These X-rays were detected by the device, and their energies used to color the microprobe image that appeared on the screen.

  “Let’s find one of the destroyed FET gates on the bad chip,” said George.

  Wolfgang moused a slide bar on the control screen, and the picture blurred, then stabilized. There was less magnification than the STM had provided, but the gate region was visible. Wolfgang found a gate where the characteristic hour-glass shape had been distorted into two separated pink clumps. Around the ruined gate were clusters of green speckles.

  “Green,” said George. “What does that mean?”