Diamonds in the Sky

by Mike Brotherton, Ed.

  Closer, I notice an even odder effect. The sweeping stars detour smoothly around the bubble of blackness, but very close to the bubble, there are other stars, stars which actually move in the opposite direction, a counterflowing river of stars. It takes me a long time (microseconds perhaps) before my physicist persona tells me that I am seeing the image of the stars in the Einstein mirror. The entire external universe is mirrored in a narrow ring outside the black hole, and the mirror image flows along with a mirror of my own motion.

  In the center of the ring there is nothing at all.

  Five thousand kilometers, and I am moving fast. The gravitational acceleration here is over ten million gees, and I am still fifty times the Schwarzschild radius from the black hole. Einstein’s correction is still tiny, though, and if I were to do nothing, my orbit will whip around the black hole and still escape into the outside world.

  One thousand kilometers. Perimelasma, the closest point of my elliptical orbit. Ten times the Schwarzschild radius, close enough that Einstein’s correction to Newton now makes a small difference to the geometry of space. I fire my engines. My speed is so tremendous that it takes over a second of my engine firing at a million gravities to circularize my orbit.

  My time sense has long since speeded up back to normal, and then faster than normal. I orbit the black hole about ten times per second.

  My god, this is why I exist, this is why I’m here.

  All my doubts are gone in the rush of naked power. No biological could have survived this far; no biological could have even survived the million-gee circularization burn, and I am only at the very beginning. I grin like a maniac, throb with a most unscientific excitement that must be the electronic equivalent of an adrenaline high.

  Oh, this ship is good. This ship is sweet. A million-gee burn, smooth as magnetic levitation and I barely cracked the throttle. I should have taken it for a spin before dropping in, should have hot-rodded Huis Clos around the stellar neighborhood. But it had been absolutely out of the question to fire the main engine close to the wormhole station. Even with the incredible efficiency of the engine, that million-gee perimelasma burn must have lit up the research station like an unexpected sun.

  I can’t wait to take Huis Clos in and see what it will really do.

  My orbital velocity is a quarter of the speed of light.

  The orbit at nine hundred kilometers is only a parking orbit, a chance for me to configure my equipment, make final measurements and, in principle, a last chance for me to change my mind. There is nothing to reconnoiter that the probes have not already measured, though, and there is no chance that I will change my mind, however sensible that may seem.

  The river of stars swirls in a dance of counterflow around the blackness below me. The horizon awaits.

  The horizon below is invisible, but real. There is no barrier at the horizon, nothing to see, nothing to feel. I will be even unable to detect it, except for my calculations.

  An event horizon is a one-way membrane, a place you can pass into but neither you nor your radio signals can pass out of. According to the mathematics, as I pass through the event horizon, the directions of space and time change identity. Space rotates into time; time rotates into space. What this means is that the direction to the center of the black hole, after I pass the event horizon, will be the future. The direction out of the black hole will be the past. This is the reason that no one and nothing can ever leave a black hole; the way inward is the one direction we always must go, whether we will it or not: into the future.

  Or so the mathematics says.

  The future, inside a black hole, is a very short one.

  So far the mathematics have been right on. But nevertheless, I go on. With infinitesimal blasts from my engine, I inch my orbit lower.

  The bubble of blackness gets larger, and the counterflow of stars around it becomes more complex. As I approach three times the Schwarzschild radius, 180 km, I check all my systems. This is the point of no rescue: inside three Schwarzschild radii, no orbits are stable, and my automatic systems will be constantly thrusting to adjust my orbital parameters to keep me from falling into the black hole or being flung away to infinity. My systems are all functional, in perfect form for the dangerous drop. My orbital velocity is already half the speed of light. Below this point centrifugal force will decrease toward zero as I lower my orbit, and I must use my thrusters to increase my velocity as I descend, or else plunge into the hole.

  When I grew up, in the last years of the second millennium, nobody thought that they would live forever. Nobody would have believed me if I told them that, by my thousandth birthday, I would have no concept of truly dying.

  Even if all our clever tricks fail, even if I plunge through the event horizon and am stretched into spaghetti and crushed by the singularity, I will not die. You, my original, will live on, and if you were to die, we have made dozens of back-ups and spin-off copies of myselves in the past, some versions of which must surely still be living on. My individual life has little importance. I can, if I chose, uplink my brain-state to the orbiting station right at this instant, and reawake, whole, continuing this exact thought, unaware (except on an abstract intellectual level) that I and you are not the same.

  But we are not the same, you and I. I am an edited down version of you, and the memories that have been edited out, even if I never happen to think them, make me different, a new individual. Not you.

  On a metaphorical level, a black hole stands for death, the blackness that is sucking us all in. But what meaning does death have in a world of matrix back-ups and modular personality? Is my plunge a death wish? Is it thumbing my nose at death? Because I intend to survive. Not you. Me.

  I orbit the black hole over a hundred times a second now, but I have revved my brain processing speed accordingly, so that my orbit seems to me leisurely enough. The view here is odd. The black hole has swollen to the size of a small world below me, a world of perfect velvet darkness, surrounded by a belt of madly rotating stars.

  No engine, no matter how energetic, can put a ship into an orbit at 1.5 times the Schwarzschild radius; at this distance, the orbital velocity is the speed of light, and not even my total-conversion engine can accelerate me to that speed. Below that there are no orbits at all. I stop my descent at an orbit just sixty kilometers from the event horizon, when my orbital velocity reaches 85% of the speed of light. Here I can coast, ignoring the constant small adjustments of the thrusters that keep my orbit from sliding off the knife-edge. The velvet blackness of the black hole is almost half of the universe now, and if I were to trust the outside view, I am diving at a slant downward into the black hole. I ignore my pilot’s urge to override the automated navigation and manually even out the trajectory. The downward slant is only relativistic aberration, nothing more, an illusion of my velocity.

  85% of the speed of light is as fast as I dare orbit; I must conserve my fuel for the difficult part of the plunge to come.

  In my unsteady orbit 60 kilometers above the black hole, I let my ship’s computer chat with the computer of the wormhole station, updating and downloading my sensor’s observations.

  At this point, according to the mission plan, I am supposed to uplink my brain state, so that should anything go wrong further down the well, you, my original, will be able to download my state and experiences to this point. To hell with that, I think, a tiny bit of rebellion. I am not you. If you awaken with my memories, I will be no less dead.

  Nobody at the wormhole station questions my decision not to upload.

  I remember one other thing now. “You’re a type N personality,” the psychologist had said, twitching her thumb to leaf through invisible pages of test results. The gesture marked her era; only a person who had grown up before computer hotlinks would move a physical muscle in commanding a virtual. She was twenty-first century, possibly even twentieth. “But I suppose you already know that.”

  “Type N?” you asked.

  “Novelty-seeking,” she said. �
��Most particularly, one not prone to panic at new situations.”

  “Oh,” you said. You did already know that. “Speaking of novelty seeking, how do you feel about going to bed with a type N personality?”

  “That would be unprofessional.” She frowned. “I think.”

  “Not even one who is about to jump down a black hole?”

  She terminated the computer link with a flick of her wrist, and turned to look at you. “Well—”

  * * *

  From this point onward, microsecond timing is necessary for the dance we have planned to succeed. My computer and the station computer meticulously compare clocks, measuring Doppler shifts to exquisite precision. My clocks are running slow, as expected, but half of the slowness is relativistic time dilation due to my velocity. The gravitational redshift is still modest. After some milliseconds — a long wait for me, in my hyped-up state — they declare that they agree. The station has already done their part, and I begin the next phase of my descent.

  The first thing I do is fire my engine to stop my orbit. I crack the throttle to fifty million gees of acceleration, and the burn takes nearly a second, a veritable eternity, to slow my flight.

  For a moment I hover, and start to drop. I dare not drop too fast, and I ramp my throttle up, to a hundred megagee, five hundred, a billion gravities. At forty billion gravities of acceleration my engine thrust equals the gravity of the black hole and I hover.

  The blackness has now swallowed half of the universe. Everything beneath me is black. Between the black below and the starry sky above, a spectacularly bright line exactly bisects the sky. I have reached the altitude at which orbital velocity is just equal to the speed of light, and the light from my rocket exhaust is in orbit around the black hole. The line I see around the sky is my view of my own rocket, seen by light that has traveled all the way around the black hole. All I can see is the exhaust, far brighter than anything else in the sky.

  The second brightest thing is the laser beacon from the wormhole station above me, shifted from the original red laser color to a greenish blue. The laser marks the exact line between the station and the black hole, and I maneuver carefully until I am directly beneath the orbiting station.

  At forty billion gravities, even my ultrastrong body is at its limits. I cannot move, and even my smallest finger is pressed against the form-fitting acceleration couch. But the controls, hardware interfaced to my brain, do not require me to lift a finger to command the spacecraft The command I give Huis Clos is: down.

  Inward from the photon sphere, the bright line of my exhaust vanishes. Every stray photon from my drive is now sucked downward.

  Now my view of the universe has changed. The black hole has become the universe around me, and the universe itself, all the galaxies and stars and the wormhole station, is a shrinking sphere of sparkling dust above me.

  Sixty billion gravities. Seventy. Eighty.

  Eighty billion gravities is full throttle. I am burning fuel at an incredible rate, and only barely hold steady. I am still twenty kilometers above the horizon.

  There is an unbreakable law of physics: incredible accelerations require incredible fuel consumption. Even though my spaceship is, by mass, comprised mostly of fuel, I can maintain less than a millisecond worth of thrust at this acceleration. I cut my engine and drop.

  It will not be long now. This is my last chance to uplink a copy of my mind back to the wormhole station to wake in your body, with my last memory the decision to upload my mind.

  I do not.

  The stars are blueshifted by a factor of two, which does not make them noticeably bluer. Now that I have stopped accelerating, the starlight is falling into the hole along with me, and the stars do not blueshift any further. My instruments probe the vacuum around me. The theorists tell that the vacuum close to the horizon of a black hole is an exotic vacuum, abristle with secret energy. Only a ship plunging through the event horizon would be able to measure this. I do, recording the results carefully on my ship’s on-board recorders, since it is now far too late to send anything back by radio.

  There is no sign to mark the event horizon, and there is no indication at all when I cross it. If it were not for my computer, there would be no way for me to tell that I have passed the point of no return.

  Nothing is different. I look around the tiny cabin, and can see no change. The blackness below me continues to grow, but is otherwise not changed. The outside universe continues to shrink above me; the brightness beginning to concentrate into a belt around the edge of the glowing sphere of stars, but this is only an effect of my motion. The only difference is that I have only a few hundred microseconds left.

  From the viewpoint of the outside world, the light from my spacecraft has slowed down and stopped at the horizon. But I have far outstripped my lagging image, and am falling toward the center at incredible speed. At the exact center is the singularity, far smaller than an atom, a mathematical point of infinite gravity and infinite mystery.

  Whoever I am, whether or not I survive, I am now the first person to penetrate the event horizon of a black hole. That’s worth a cheer, even with nobody to hear. Now I have to count on the hope that the microsecond timing of the technicians above me had been perfect for the second part of my intricate dance that might, if all goes well, allow me to survive this feat.

  Above me, according to theory, the stars have already burned out, and even the most miserly red dwarf has sputtered the last of its hydrogen fuel and grown cold. The universe has already ended, and the stars have gone out. I still see a steady glow of starlight from the universe above me, but this is fossil light, light that has been falling down into the black hole with me for eons, trapped in the infinitely stretched time of the black hole.

  For me, time has rotated into space, and space into time. Nothing feels different to me, but I cannot avoid the singularity at the center of the black hole any more than I can avoid the future. Unless, that is, I have a trick.

  Of course I have a trick.

  At the center of the spherical universe above me is a dot of bright blue-violet; the fossil light of the laser beacon from the orbiting station. My reaction jets have kept on adjusting my trajectory to keep me centered in the guidance beam, so I am directly below the station. Anything dropped from the station will, if everything works right, drop directly on the path I follow.

  I am approaching close to the center now, and the tidal forces stretching my body are creeping swiftly toward a billion gees per millimeter. Much higher and even my tremendously strong body will be ripped to spaghetti. There are only microseconds left for me. It is time.

  I hammer my engine, full throttle. Far away, and long ago, my friends at the wormhole station above dropped a wormhole into the event horizon. If their timing was perfect—

  From a universe that has already died, the wormhole cometh.

  Even with my enhanced time sense, things happen fast. The laser beacon blinks out, and the wormhole sweeps down around me like the vengeance of God, far faster than I can react. The sparkle-filled sphere of the universe blinks out like a light, and the black hole — and the tidal forces stretching my body — abruptly disappears. For a single instant I see a black disk below me, and then the wormhole rotates, twists, stretches, and then silently vanishes.

  Ripped apart by the black hole.

  My ship is vibrating like a bell from the abrupt release of tidal stretching. “I did it,” I shout. “It worked! God damn it, it really worked!”

  This was what was predicted by the theorists, that I would be able to pass through the wormhole before it was shredded by the singularity at the center. The other possibility, that the singularity itself, infinitesimally small and infinitely powerful, might follow me through the wormhole, was laughed at by everyone who had any claim to understand wormhole physics. This time, the theorists were right.

  But where am I?

  There should be congratulations pouring in to my radio by now, teams of friends and technicians swarming
over to greet me, cheering and shouting.

  “Huis Clos,” I say, over the radio. “I made it! Huis Clos here. Is anybody there?”

  In theory, I should have reemerged at Wolf-562. But I do not see it. In fact, what I see is not recognizably the universe at all.

  There are no stars.

  Instead of stars, the sky is filled with lines, parallel lines of white light by the uncountable thousands. Dominating the sky, where the star Wolf-562 should have been, is a glowing red cylinder, perfectly straight, stretching to infinity in both directions.

  Have I been transported into some other universe? Could the black hole’s gravity sever the wormhole, cutting it loose from our universe entirely and connect it into this strange new one?

  If so, it has doomed me. The wormhole behind me, my only exit from this strange universe, is already destroyed. Not that escaping through it could have done me any good — it would only have brought me back to the place I escaped, to be crushed by the singularity of the black hole.