Analog SFF, July-August 2006

by Dell Magazine Authors

  Torsten realized that he, too, perhaps had a choice. At least for a while, he could be the professional he had always wanted to be, independent of his family, his own person. He was here, with an audience, with what could be the story of the dawn of a new era of history. It was not up to him to make the news. He had only to put everything else aside and report it.

  “In the meantime,” he began, “the research staff appear to be preparing to do the experiment for real. The data now show the beam lines are fully charged again. I am not getting a count but would guess that it will happen soon."

  He had to fill, he realized; there were no more interviews to switch to. “The instrument module still floats suspended at the ends of the largest linear accelerator ever made. In a few moments, despite all the threats, sabotage efforts, and ethical concerns of opponents ranging from the fringe of political activism to sober physicists and interplanetary leaders, those accelerators may fire and lay the groundwork for a technological journey of Promethean significance that, like it or not, we all seem to be on."

  He glanced at another monitor. “We have a count now—twenty seconds. The project staff members have crowded around their windows—windows, I should remind you, that are made of glass dense enough to stop ninety percent of cosmic radiation; you would not want to look at this with unprotected eyes ... seven seconds ... five ... four...” He zoomed in on the vertex module. “...two ... don't blink ... one...” Suddenly, a brilliant white star sprang out of where the spherical instrument module had been. For the tiniest fraction of a second, he thought he saw a beautiful, iridescent hourglass shape expand from the vertex and rush at him, but it blew by almost instantly.

  Did he feel a slight acceleration? Hilda had said there was not that much matter involved, even at its huge energies, compared to the mass of the station's asteroid.

  “That was it! The instrument module has vanished—where the center of the Ten-Ten experiment was, where all the controversy, plans, and plots were focused, there is now nothing. There is nothing at all in that direction...” and he paused a moment as he realized the poetry of what he was about to say, and said it anyway, “...nothing between us and the distant stars."

  “Mr. Ried?” It was a human voice, behind him. The idiot didn't realize he was interrupting a live feed. He held up a hand to indicate he was busy.

  A hand touched his shoulder, lightly. “Mr. Ried."

  What the hell? Well, it was a good place to break anyway. He faded his channel into the pool feed and turned angrily to confront his interrupter.

  The young blond man behind him seemed suitably apologetic. “Please excuse me, Mr. Ried, I'm Simon Kalas, from BHP Central Security. Hilda Kremer, the real Hilda Kremer, said we should talk to you."

  Torsten shut his eyes and took a deep breath. Oh, shit.

  * * * *

  It was Tse Wen and Brad's idea to quietly whisk Hilda and Sarah out to the Marin Headlands for a walk when they landed back on Earth. They wanted to get the group away from protesters and newsmongers who howled for news.

  They walked up the dirt road towards a cliff overlooking the Golden Gate. With each step Hilda felt her muscles adjust to her Earth weight once more.

  “Why such a windy place?” Sarah asked.

  Brad deferred to Tse Wen, who was looking out over the cliff.

  “The wind up here is strong because the topography has forced it up and given it a greater distance to cover. It is also hard on microphones and little things that fly. The wind has much to teach us about the source of strength, don't you think?"

  It was coming from the East today, and was warm. Hilda touched Brad's arm. He shrugged. “Like being in our faces. Hilda, your boyfriend's damage control efforts..."

  Hilda winced. The history of her misjudgments with Torsten Ried now stood between them.

  Brad shook his head. “Sorry Hilda. It's a bloody war of public opinion. Never mind truth."

  “It's always been that way, Brad,” Hilda said. She'd taken a vacation from physics on the voyage in from the asteroid belt, and had read a compilation of the correspondence between two American philosopher-presidents, Adams and Jefferson, that Tse Wen had given her after the bomb attack. “Six hundred years ago, Thomas Jefferson said that ‘the inquisition of public opinion overwhelms in practice the freedoms assured by the laws in theory.’”

  “Jefferson had it right,” Brad said. “It's impossible to prove that anything is absolutely safe, and you'll never kill off all the wowsers. You just have t’ out-argue and outlast ‘em. Anyway, we've won, mates!"

  “We have only won the right to keep trying,” Sarah said. “Lars Ried keeps on stumping his platform and in a few years will be after the Presidency again and who knows how far they will try to reach.” She looked up.

  “You are worried about the other impactor launch sites,” Tse Wen said. “We have people of unquestioned loyalty going out to take charge of those operations. Dr. G. P. Weaver, a former student of mine, is going to Epsilon Eridani. Hilda's sister, Elizabeth Avonford, will go to Lacaille 9352, and Hilda herself is going back to Groombridge 34. Beyond that, a wise combatant makes use of his opponents’ energy."

  Hilda smiled thoughtfully. “Thank you for teaching me that, Tse Wen."

  “There is still no public word about the impostor and Rossov."

  The mention of Rossov still saddened her. There was no proof, of course, but everyone believed he'd been at the vertex when Sarah had triggered the real event. At least his death there would have been as nearly instantaneous as a death could be.

  “Right,” Brad added. “One or both of ‘em are still out there. Hilda, did you know Rossov was sore at you about one of his papers not being accepted?"

  “No, I didn't. All this for a paper?” She had reviewed thousands of papers over the years. She consulted her deep files through the net, “Oh!” A chill went down her.

  “Hilda?” Sarah asked

  “I trashed a paper. ‘Quagma Energy Loss by Advanced Wave Emission,’ submitted to Physika by V. I. Rossov, 2220. But that was thirty years ago!"

  Sarah laughed. “Advanced emission! Then he had a secondary agenda. He was still trying to get people to take his work seriously."

  Tse Wen sighed. “When we made people immortal, we also made grudges immortal. Well, in the end, it would give me peace to think that Dr. Rossov may have killed his grudge the only way possible. I shall consider it a sufficient act of apology."

  Hilda nodded; Rossov had achieved a sort of closure, though she regretted the death greatly.

  A warm gust of wind hit the group as they reached the apex of the hill. They turned their backs to it and looked out towards the Pacific Ocean and the Farallon Islands on the horizon.

  “What do you think you'll miss the most about Earth?” Sarah asked as they got high enough to see most of San Francisco across the water.

  “Besides us mates, o’ course,” Brad said, jokingly.

  “Oh, I'll miss you all! Chaos help me, I will."

  But instead of sadness, Hilda felt a rise of excitement. It was hard to contain. After all these years on Earth, she was finally going home to New Antarctica, to return to where she had been born, home to work with her father. Perhaps Kate Avonford's starship would stop there, too, some day. Too bad she would miss seeing her younger sister, Liz, who was shipping out to manage the impactor launch from Lacaille 9352.

  Hilda picked up a sun-bleached Dungeness crab claw from the roadside where a seagull had dropped it. Playing with it absently, she looked first at Tse Wen, then at Brad. “And the wind,” she said at last.

  Sarah looked at her oddly. “The what?"

  “The wind. New Antarctica is not misnamed. You have to think first about everything you do outside, there.” Particularly with the project on her shoulders, she realized. She would have to make it happen. After Duluth Station, she thought she had that in her, but ... “I'll miss this wonderful warm free wind in my face."

  * * * *

  Torsten Ried glanc
ed at the time display on his work screen. It was 13:24 7 August 2258. He wished he did not know what he knew would happen in three minutes.

  Out in the asteroid belt, the inexorable laws of celestial mechanics would work their will, and one small asteroid would come between the Black Hole Project's main x-ray communications laser and Groombridge 34. The occultation would only be for a few minutes, and the AI had long ago predicted and allowed for it; for an hour or so, it would not transmit, lest its power slice a deep cut in the traversing asteroid's regolith and fog the entire area with droplets of frozen lava. His stomach tightened.

  What the AI running the project's link to Groombridge 34 did not know, and what Torsten did know, was that there was another laser, hidden down that data stream on the occulting rock, that would transmit for about a millisecond on top of the main carrier between the last data and the interruption code. The AI that ran the bogus link knew all the right codes and modulations. It would also have a message, backed by terabytes of bogus experimental data and theoretical calculations, which would direct a delay in launching the Groombridge 34 impactor.

  So Rossov's dark, ironic sense of humor would reach beyond his death. Did Hilda deserve this cruel revenge? Probably not, he thought, tightening his fingers into a grip.

  But if Torsten were to admit knowledge of it now, he would have to admit complicity in the kidnapping and he would betray his family in a way that they might correct very rapidly. He would also, once again, get involved in making news instead of reporting it. He thought of Hilda, Sarah, Lars, Anna, and their Promethean agenda. Were they too big to stop?

  To make the call or not? He opened his mouth to send a warning ... then cleared his throat. Then he looked back at his time display and shook his head. Too late now.

  Copyright 2006 C. Sanford & G. David Nordley

  [Back to Table of Contents]

  * * *

  THE ALTERNATE VIEW: PLANETS OF BINARY STAR SYSTEMS

  by JOHN G. CRAMER

  Illustration by Wolf Read

  * * * *

  An astronomer once told me that Nature really hates to solve the three-body problem, as evidenced by the fact that She avoids it whenever She can. He was referring to the large number of binary star systems in the galaxy (two stars in relatively close orbits), and the relative rarity of triple-star systems (three stars with relatively small mutual separations).

  The three-body problem to which he was referring is a mathematical conundrum that has been around since the time of Newton. While one can easily solve for the orbits of two mutually gravitating bodies like stars, there is no known way of exactly solving the same problem when three bodies are involved. There are good approximations that can be used when one of the bodies is much smaller than the other two, or when one is very far away from the others, but the general problem has no analytic solution.

  One of the approximate three-body solutions, the so-called “Trojan solution,” is of some interest in science fiction. It turns out that when two of the bodies are much more massive than the third, the smaller object can be locked into an orbit such that the three objects always form an equilateral triangle. Nature has used this solution in our own solar system. At the L4 and L5 Lagrange points 60 degrees ahead of and behind position of Jupiter in its orbit around the Sun, there are a collection of “Trojan” asteroids that lead and trail in the orbit of the giant planet. Astronomers decided to name those asteroids ahead of Jupiter with an index number and the name of a Greek hero of the Trojan War (e.g., 588 Achilles, 659 Nestor, 911 Agamemnon, 1143 Odysseus, 1404 Ajax, 1437 Diomedes, etc.) while the asteroids trailing behind Jupiter were named for the combatants from Troy (884 Priamus, 1172 Aneas, 1173 Anchises, etc.) However, because they were named before this convention was established, the Greek-named 617 Patroclus was put in with the Trojans and 624 Hektor was put with the Greeks. These Trojan asteroids are “herded” around the solar system by Jupiter, and the Trojan locations are points of stability, with a restoring force that acts if the asteroid wanders too far away. Perhaps some future planet-faring civilization may find these solutions to the three-body problem to be a useful source of raw materials or a good stable location for man-made space environments.

  Fortunately, the mathematical difficulties of the three-body problem are not a major impediment to the study of planetary orbits. There are good numerical methods for solving the three-body problem to high accuracy, so that with modern computers we can calculate orbits of multi-body systems to whatever precision we are willing to expend the resources to obtain. However, when we do such calculations we find that most of the orbits for close three-body systems are unstable. After a few orbits, one of the bodies is often ejected from the system, leaving behind a simpler two-body system. Also, such solutions are usually “chaotic,” so that minute differences in the initial conditions of the system can produce dramatically different final orbital results.

  The intrinsic instability and chaos of most close three-body orbits raises the question of whether binary star systems can be expected to have planets at all, and in particular, to have Earth-like planets in stable orbits around them. This question is of particular interest because more than half of the stars in our galactic neighborhood are binary or multiple-star systems.

  One leading example is our nearest stellar neighbor, Alpha Centauri, which consists of a close binary of Sol-like stars, with a third smaller companion orbiting much further out. The two primary stars are Alpha Centauri A, a spectral type G2 star (like our Sun) with a mass of 1.09 solar masses, and Alpha Centauri B, a somewhat smaller and dimmer type K1 star with a mass of 0.90 solar masses. Proxima, the third star of the group, is a small type M5 star of about 0.1 solar masses. Alpha Centauri A and B are in an elongated elliptical orbit with a period of 80 years, approaching each other to as close as 11 AU and receding to as far as 35 AU as they orbit. Here, 1 AU (astronomical unit) is defined as the distance from the Sun to the Earth, 11 AU is roughly the distance from our Sun to the orbit of Saturn, and 35 AU is the distance from our Sun to somewhere between the orbits of Neptune and Pluto. Proxima is a lightweight and somewhat unstable “flare star.” It orbits about 13,000 AU (about 1/5 of a light year) from A and B, a distance so large that it is uncertain whether Proxima is even gravitationally bound to its larger companions or whether it will eventually wander away.

  Perhaps the leading question concerning the Alpha Centauri system is whether either Alpha Centauri A or Alpha Centauri B (or both) could have habitable planets in orbit around them. Until recently, conventional wisdom would have answered that question “probably not.” The reason is that, while either major member of the Alpha Centauri system could probably have planets in stable orbits out to about 2 AU before the perturbations of the other star produced chaotic orbits, it was thought that the process of planet formation itself would be greatly impeded in a binary system. The view was that the protoplanetary dust cloud from which planets were formed should collapse inward from distances on the order of 100 AU under the friction of collisions, and the sweeping action of the binary system members would eject material, frustrate this process, and suppress the formation of planets. Moreover, it was expected that shock waves produced in the dust cloud around one star from the passage of the other would heat and vaporize ice crystals, dispersing the cloud and preventing accretion. Now, however, there are reasons to modify these views.

  On the observational front, recent successes in astronomical searches for planets orbiting stars outside our solar system have found a number of examples of Jupiter-like gas giant planets orbiting in binary star systems with separation distances ranging from 12 to 1000 AU. And on the theoretical front, Dr. Alan G. Boss of the Carnegie Institution in Washington, DC, has developed a numerical model of the protoplanetary gas cloud in a binary star system, which removes the artificial viscosity effects of previous models, but includes vertical motion in the disk and convective cooling. His calculations indicate that planet formation may actually be enhanced in a binary star system.
>
  Boss found that the shock wave heating in binary star systems can often be rather weak, and in these cases gas-giant planets can emerge in the planet-forming disk of gas and dust in the same way they do around single stars. Ice grains can combine through the process of core accretion and grow into solid cores of many Earth-mass sizes.

  But in addition to core accretion, there is another planet forming mechanism that may be even more important in binary systems. The disc of gas and dust orbiting a new star, if it is massive enough, is intrinsically unstable to gravitational attraction because once a region of higher-than-average density appears, it tends to grow progressively larger. Boss has shown that in cases where a protoplanetary disc around one of the stars is just massive enough to be on the edge of such an instability, the passage of the binary companion, with a time scale of around 1000 years, can act as a trigger to precipitate planet formation. When the binary system has a minimum separation distance of more than 50 AU, Boss found that the companions each formed protoplanetary disks of around 20 AU that were relatively unaffected by the perturbations of the companion. However, when the binary minimum separation distance is less than 50 AU, the protoplanetary disks of each star formed spiral arms that typically evolved into dense self-gravitating clumps, a major step to planet formation. Thus, planet formation in a binary system may occur under circumstances where no planets would form in a single star system.

  On the basis of Boss’ calculations, there seems to be a distinct difference between the processes of planet formation in single star systems and binary systems, with the latter actually “pumped” toward star formation earlier and perhaps with different location probabilities. Thus, when improved resolution with interferometric techniques, etc. permits us to determine in detail the planetary structure of the star systems in our neighborhood, we may be in for some surprises when we look at binary systems.

  * * * *

  The implications of this work for SF are fairly clear, and it vindicates the work of many SF authors who placed their protagonists on planets of binary star systems. Writers should now have no reservations about placing Earth-like planets around binary star systems, or having scenes with two “suns” in the sky, etc. Moreover, consider the scenario of an elliptical binary system having a long period between close passes (~ 10 AU), and suppose both stars had Earth-like planets with planet-faring civilizations. This setup has interesting socio-political implications, with trade and contact between two planetary civilizations punctuated by close passages and distant retreats with a periodic time scale on the order of a few hundred years. It makes one feel rather lonely to be isolated in a star system with only one Sun and only one Earth-like planet.