Starquake

by Robert L. Forward

  Spheroidal bowls that represented the east and west hemispheres of Egg. They were shaped according to the old-style maps where distances were marked off in tread lengths. They were flat in the regions near the magnetic poles where the cheela treads were of minimum size, and more curved near the magnetic equator where the horizontal component of the magnetic field stretched out the cheela's tread. Now that the cheela had space travel, they realized that Egg was spherical; but the ancient shape was still useful for the crustallogists, for most of the activity in the crust took place near the poles. The maps flickered with lights showing the crust-quake activity. A bright blue spot would appear on the map, then shift down in color as the intensity of the quake died.

  "I was looking for Professor Neutron-Drip," Time-Circle told Eager-Eyes.

  "I'm right here," came a muffled voice. The voice seemed to come from under Eager-Eyes' tread.

  "She's on-site at the East Pole," Eager Eyes explained. "I'll switch the picture to the visual screen on that wall over there. Things are happening fast, so I had better keep working with the touch-and-taste screen."

  "I came over to see if we could have turnfeast together," said Time-Circle. "I didn't realize you had gone."

  "The trip wasn't planned," replied the image of Neutron-Drip. She was moving among an array of acoustic transceivers that were picking up data from the distant seismic instruments buried under the crust around the East Pole.

  "I jumped over early this turn to make sure the transceivers stay on scale. I think there is a big quake coming. But I can't be sure, since this is the first time anyone has tried to record the quakes prior to a big one."

  "Things really started to happen just after last turn-feast," Eager-Eyes reported. "I was watching the signals coming in from the array around the East Pole, when I began to see ring-like patterns."

  "Not only that," said Neutron-Drip. "Although they started small, the magnitude of the quakes has been increasing nearly exponentially for the last ten dothturns as they close in on the root of the East Pole mountains."

  "Exponentially!" Time-Circle was clearly impressed.

  "I expect a 'Trimble-tremblor' anytime soon," said Neutron-Drip. She noticed the confused twitch in his eye-stub pattern. "The East Pole mountains will drop a few millimeters, and the

  length of a turn will increase slightly. The human Nobel Laureate Trimble was the first to predict them accurately from her observations of the Crab nebula neutron star."

  "You might be in danger! You must leave at once!" Time-Circle shouted.

  'Too late now," Neutron-Drip responded. "Keep collecting the data, Eager-Eyes!" she commanded. Suddenly the viewscreen went blank.

  Time-Circle shifted his gaze to the bowl that showed the eastern hemisphere. The East Pole mountains were surrounded by flash after flash of bright blue light. Suddenly the whole East Pole exploded in a blue glare. There was a pause, then a smooth ripple spread out from the focal point. It reached Swift's Climb ... and the display went out.

  Time-Circle now understood why three channels in his time machine were blocked with noise. He raced out of the lab and across the Institute compound. There was one clear back-channel left. If only he could get a message back in time to himself, he might be able to warn the rest of the population on Egg. As he pushed his body through the clinging magnetic fields coming from the crust, he fought off the specter of despair. After all, "he" that was here on this time-line, struggling to reach the time machine, had received no warning message from the future. His present time-line was doomed, but perhaps he could create a paradox—a bifurcation—that would save the "he," and the rest of Egg, on some other time-line. He struggled on.

  Quake!

  06:58:07 GMT TUESDAY 21 JUNE 2050

  Deep within the root of the East Pole mountains, a thick block of crust groaned audibly under the great stress of the billions of tons of matter piled up for centimeters overhead. The stress peaked to the ultimate limit, then with a loud crack, a block of crust broke and a long rip propagated through the striated undercrust. The mountain peaks, now unsupported, dropped a full twenty millimeters in the intense gravity field of Egg. The shock wave from the fall of the mountain range spread out from the East Pole at nearly the speed of light, striking first at the town of Swift's Climb.

  Walls cracked and communications were cut off as the crust lifted and fell. Neutron-Drip felt her eye-stubs flutter as the crust rolled beneath her. She kept watching the overloaded instruments and willing them to get back on scale so they would record the remainder of what had to be the largest crustquake in cheela history.

  A little while later the surface wave passed through the Inner Eye Institute in Bright's Heaven. Time-Circle's already panicked brain-knot screamed mentally as the crust raised up underneath his tread. He slowed to a self-conscious deliberate slide as the wave passed under him and the crust dropped again, having done little to him or the well-constructed compounds of the Inner Eye Institute.

  The magnetic fields of the star, frozen into the moving crust, waved back and forth a little causing electrical currents to flow in Time-Circle's body and exciting the electrons and random nuclei in the tenuous atmosphere until they were moving fast enough to generate electron-positron pairs. The counter-flow

  heat exchangers in the base of his eye-stubs increased their cooling capacity to extract the heat that had been generated in his eye-balls by the flowing electric currents. As his eyes cooled to their normal dark red, he could see the decaying X-ray fluorescence as the remainder of the positrons generated by the atmospheric currents found an electron to annihilate with.

  More slowly now, Time-Circle continued on to the Time-Comm compound to check his machine. Although the crustquake was a large one, he was sure that Cliff-Webb had designed the machine itself to survive the shock. But perhaps the quake had disturbed the control console, and that was what was causing the strange noise signals.

  The lift carrying Heavy-Egg and seven of his crew was passing level 50 when a flare of light from the atmosphere below signaled the start of a crustquake. A couple of methturns later the hum of the up-deflectors changed pitch as the accelerators on the ground compensated for the twenty-millimeter drop of the crust underneath them.

  "That was a big one," Heavy-Egg thought, as his tread felt the change in pitch of the vibrations in the deck.

  There was a loud clang. A pushout, the first in many turns, was hanging in the catcher, the extra strain having proved too much for the ring.

  The shock waves from the crustquake penetrated to the center of the neutron star where they were bounced back and forth by the density differences between the various layers. A number of the bouncing shocks met each other at one of the boundary layers and concentrated their energy in a very small region. The extra pressure was just enough to initiate a phase change in the material, and it shrank in volume. Once started, the phase change spread at nearly the speed of light. An inner layer of star almost a kilometer thick changed density and shrank by two meters, leaving the outer layers of the neutron star unsupported. The outer layers fell, and the crustquake became a Starquake.

  The gigantic Starquake rose to the surface and shook the crust like a Swift shredding a Flow Slow. The crust alternately buckled and spread, sending anything loose moving across the surface at high speed to smash into walls, plants, or cliffs. The

  magnetic fields embedded in the crust shook along with the crust and accelerated the electrons and ions in the thin, tenuous atmosphere. The atmosphere heated up until it reached a temperature of a billion degrees. Electron-positron pairs were created, only to annihilate again to produce a continuing flood of X-rays. The X-rays bounced off the high speed electrons in the super-heated atmosphere and with each bounce increased in energy until they were a deadly, penetrating glare of gamma rays.

  Time-Circle felt the crust drop beneath him once again. Unlike the first time, the dropping motion didn't stop. The whole world around him was dropping and dropping. The gravelectromagnetic fields in
the Time-Comm machine lost control of the spinning black hole at the heart of the machine. The black hole converted back into energy, blowing up the Time-Comm compound and Time-Circle.

  Neutron-Drip had been expecting a second series of shocks as the crustquake circled around Egg and returned again. It returned early. She was still trying to understand why the quake seemed stronger than before, when she found herself sliding helplessly at high speed toward the array of instruments she had been tending. The sharp edges on the instruments cut her to ribbons.

  Zero-Gauss was in her underground laboratory. She was picking up some pellets that had missed the catcher on a fountain plant during the initial crustquake. The starquake hit and she and all the plants and animals were swept across the metal floor to one corner of the room. The support pillars buckled, and the roof fell in.

  A pulsating sheet of fire flickered over the surface of the neutron-star, generating a high-energy blast of radiation that spread out into space. It only took a millisecond for the high-energy ultraviolet, X-rays, and gamma rays to reach Dragon Slayer in its synchronous orbit above Bright's Heaven. The stronger of the gamma rays sheeted through the tough hull of the spacecraft, through the thin protection of Amalita's space-suit, and irradiated her body with three times the lethal dose. The ultraviolet radiation bounced off the star image telescope mirror, burned through the protective filters, and poured unim-

  peded down on the star image table, flooding the Science Deck and Amalita's eyes in an ultraviolet glare.

  Amalita's eyelids closed too late over cloudy-white corneas and started to blister under the intense radiation. Following on the heels of the electromagnetic radiation pulse came a three-pulse burst of kilohertz gravitational radiation that whipped Amalita's body back and forth, breaking three joints and snapping her spinal cord at the neck. The last memory stored in Amalita's dying brain was of the stinging pain in her eyes.

  Qui-Qui was still recuperating from her regeneration and was taking it easy at West Pole mountain resort. She was playing with her new toy, a custom built, high powered, personal flyer. There was less than a dozen on all of Egg, for they cost much more to operate than intercity glide-cars and weren't any faster. A glide-car, however, couldn't go up.

  The flyer had a gravity repulsion drive for operation near the surface, an inertia drive for high altitude, and superconducting wings for gliding on the magnetic field of Egg. It was expensive, it was extravagant, but it was fun!

  She took off from the resort and jumped over some nearby foothills to find a small deserted valley. She took the flyer up to speed on the gravity drive and hit one-twelfth light-speed before she had to switch to inertia drive and zoom up over the mountain at the end of the valley. Turning off the repulsor drive and flipping out the wings, she put it into climb on the inertia drive and watched the energy reserves in her accumulators drop. Her manager would complain about the recharging bill, but she had plenty of stars saved, and there would be lots more now that she was young again.

  Qui-Qui was at 25 meters altitude when the starquake hit. Fortunately, she had been looking up at the West Pole Space Station when the atmosphere lit up. As it was, before she could pull them in under her eyeflaps, two of her eyes had spots that didn't go away for nearly a turn.

  She had trouble believing the altimeter when it varied from 24 to 26 meters every few methturns. All the communicator channels were silent with the exception of some lonely navigation beacon somewhere that proved that her set was working. She knew it was a crustquake because of the glow in the atmosphere, but it must have been a huge one and it was still going strong.

  She would be safe as long as she stayed up out of the atmo-

  sphere while the crust was moving. She set the flyer on autopilot with a minimum power trajectory. The plane slid out its superconducting wings and started gliding slowly down the magnetic field lines, extracting lift when it could from the slow variations in the fields as they followed the motion of the rolling crust below.

  The jumpcraft carrying Admiral Steel-Slicer was starting its jump to orbit when the starquake pulled the support structure out from under the Jump Loop. High-speed ribbon sliced through the outskirts of Bright's Heaven as the pilot fought the jumpcraft clear. The jumpcraft didn't have enough energy to make it into orbit and arced over into a trajectory that ended in the middle of the West Pole mountains. One by one the pilot lost the sight in eight of his twelve eyes from the X-ray glare as he tried to find the West Pole Jump Loopfor an emergency landing. It wasn't there. He snapped out his superconducting wings and, using the last of his onboard emergency propulsion reserves, managed to bounce the jumpcraft off the West Pole magnetic field into an elliptical orbit.

  "Periapsis 5 meters and apoapsis 90 meters, Captain Light-Streak," the copilot, Slippery-Wing, reported. "Coming up on periapsis now."

  The altimeter fluctuated wildly as the undulating crust passed by a few meters below them. Moving at orbital velocities, they shot under a slowly moving flyer high above them. The underside of the flyer glowed brightly from the glare below.

  "I'll circularize the orbit with magnetic lift to give us a chance," Light-Streak said. "But it won't be long before we run out of power and the gravity generators fail, leaving us in free fall."

  Slippery-Wing concentrated on her instruments and tried not to think of what it would be like to die by slow disintegration.

  Speckle-Top felt the bump of the first crustquake, then the ups-and-downs of the big crustquake that came after. The ups-and-downs went on and on. Turnfeast time came, and she was hungry. The big quake was probably keeping the clankers busy, so she started to squirm out of her hiding place. When she reached the rock covering the entrance, she put part of her tread on it and listened. The only noise was that of stones rubbing against one another as the crust moved up and down. She

  pushed the rock aside a little and peeked out. The glare left streaks in her vision. She pulled the rock back and retreated into the blackness, hungry and cursing.

  Heavy-Egg, his senses extra-alert because of the crustquake, tucked his body into the lift console station, formed extra manipulators to take over the controls in case any of the automatics stopped working, and continued to monitor the hum of each of the six deflectors holding up his lift platform. He slowed the speed of their drop to give the deflectors more margin.

  "Snatch that pushout, Metal-Pusher," he said.

  "It's still hot, Boss," Metal-Pusher complained.

  "I said 'snatch it'," said Heavy-Egg. "That was a big quake, and it'll be back around soon. Quality won't like it if you bring them in a pair of bangers."

  There was a grunt, a curse, and a clang as the hot ring was dropped on the deck of the lift.

  The up-deflectors started to change pitch again.

  "Here it comes," Heavy-Egg said, six of his eyes on the instrument panel and six eyes on the six streams of rings above them, glittering in the glow from Egg. The pitch deepened and deepened as the up-going rings came further and further apart. The deck vibrated with anxious murmurs from the crew. Heavy-Egg watched the instruments carefully. The automatics were shifting the load from the troubled up-streams to the stable down-streams. The pitch continued to deepen, then become erratic.

  The up-deflector indicators were fluctuating rapidly as the deflectors attempted to straighten out the ragged stream of rings. There was a clang as another pushout appeared in the catcher. Metal-Pusher was ready and tried to snatch it, but his hook was knocked from his manipulator by another ring that banged loudly into the first. Three more rings followed.

  "We're losing it!" Heavy-Egg shouted.

  The up-going streams slowly pulled away from the down-going streams, destroyed their deflectors, and like three ragged knives, sliced through the triangularly shaped lift. Two of the streams were soon out away from the platform, but the third was making its way right across the middle. Bodies tried to compress to make room on the crowded lift for the deadly stream. A scream of terror turned into a scream of pain as the
rings tore off one side of Yellow-Rock and continued on to cut their way through the platform.

  Three of Heavy-Egg's eyes watched in horror as the platform was cut in two. As the last connection through the decking was severed, the voices of the five members of the crew on the other section were cut off. That section had only one deflector, and with no connection to the computer in the control console, the single deflector couldn't compensate adequately. The section tilted, then fell away to the crust below.

  Heavy-Egg turned his attention to his remaining section. It was the smaller of the two pieces even though it had the control console and two deflectors. Besides the console operator there was only room for two, and one of those was the dying Yellow-Rock. The down-streams now started to show some variations. The automatics reached their limits of control and the platform tilted badly as pushout after pushout banged into the catcher. Yellow-Rock screamed again as he started to slide off the slippery deck.

  "I got you," said Hungry-Pouch. She already had a good grip on the barrier rail with a number of manipulators and now was trying to hold onto Yellow-Rock's limp body by grabbing his eye-stubs and jamming pairs of manipulators into his pouches. Their bodies slid closer to the edge, tilting the platform further.

  "Let him go," Heavy-Egg shouted. "He's good as dead anyway."

  "He's my buddy! We hatched under the same mantle!" Hungry-Pouch explained. "I'm not letting go! You just get this Bright-Afflicted lift level."

  "You can't save him!" Heavy-Egg shouted again, fighting the controls. "Let him go!"

  There was a grunt, a sliding noise, and the deck came back to level. Heavy-Egg was alone on the platform.

  The lift was now down to where Level 30 should have been, but there was nothing there. There were no up-streams anymore, and he was riding on two of the three down-streams. The glare from the ground was becoming brighter, and he had to shield his eyes to watch the controls. He was dropping the lift as fast as he dared, but he needed to know how much down-stream he had left to work with.