The Galactic Center Companion, page 9
A hollow shuuuung twisted the air by his head. It was a blaring noise-cast, blending infrasonic rumbles at his feet with electromagnetic screeches, ascending to teeth-jarring frequencies.
The Rattler was trying to confuse him, scramble his sensors. He ducked his head reflexively, though it did no good, and made all his receptors go dead. Except for his fast-lurching vision he heard or felt nothing.
A child stumbled ahead. Agaden grabbed her by her shoulder and haunch and lifted her up a sandbank.
Another shuuuung echoed dimly in his sheathed mind. It was so powerful it caught the girl unaware. She crumpled. He bent, sucked in breath. With a rolling motion he took her weight across his back.
Close now, the Rattler sent a feverhot neural spark forking into his leg. The muscles jumped and howled and then went stonecold dead.
Agaden stumbled forward. The mech building ahead loomed. It was tall, imposing, far higher than the usual mechwork.
He wasn’t going to make it.
He staggered. “Agaden!” someone called.
Sand slid beneath his boots. The sky reeled.
He fumbled for his weapon. The Rattler would be on him in a moment. If he could fire sure and quick and steady—
Then the world came rushing in. Sound blared. The Rattler’s crunch and clank was hollow, diminishing.
Someone was pounding him on the back.
The girl’s weight slipped off.
His sensorium flooded with scattershot pricklings, tripped open by some freeing signal.
Agaden turned to confront the Rattler. He saw only the rear of it as massive gray cylinders slid and worked. It was retreating.
Cermo-the-Slow was shouting, “—hadn’t shut down your ears you’da heard it bellow. Right mad it was.”
“Why? Why’d it stop?”
“That li’l thing there.”
A small pyramid poked up through the sandstone shelf they stood on. In flight, Agaden had passed it without noticing.
Agaden blinked at the finely machined thing. “How?”
“Dunno. Musta given the Rattler orders.”
Agaden had heard of such things, but never seen one. The four-sided monument of chromed faces and ornate designs must have told the Rattler to come no closer.
Friends shouted at him joyfully. The girl he’d carried was fine. Considering their terror of only moments before, their glee was permissible, even after the loss of Old Majy.
Exhausted but exultant faces swam in his vision. They brought him up toward the large mech building. Eager friends gave him a drink. Children clapped their hands in glee.
Mechs could not violate a command to leave a mechwork alone. Humans could. Thus they entered with impunity the grounds of the massive construction.
Agaden frowned, puzzled. What was so different about this place?
Ordinarily he ignored whatever mechs built. This thing, though, had saved his life.
It was broad and high. And impossibly shaped.
Atop a huge marble platform sat what Agaden at first thought must be an illusion. Only mechs made mirages; he was on guard. But when he kicked the thing, it gave back a reassuring solid thud.
It was massive, made of plates of ivory stone, yet it seemed to float in air. Pure curves met at enchanting though somehow inevitable angles. Walls of white plaques soared upward as though there were no gravity. Then they bulged outward in a dome that seemed to grow more light and gauzy as the rounded shape rose still more. Finally, high above the gathering Families, the stonework arced inward and came to an upthrusting that pinned the sky upon its dagger point.
The arabesques of gossamer-thin stone, shining white, did not interest Agaden so much as the evident design. He had never seen such craft.
Around him the Family celebrated. The solstice ceremony wound through the plaza. Agaden played his part as leader, dancing, singing, trying not to show that the wondrous building distracted him.
His people retained the old rituals, from a time when the lot of man was different. Agaden knew that era through its songs, though much of the ceremony was a riddle.
Once his forefathers had made food grow from the ground in great fields. Then the solstice had meant much. Now the family scavenged for wild fruit, or stole edible things from mech factories.
His forefathers had survived the Wrecked Times, Agaden knew. The ways founded on love of Vishnu and fear of Shiva had persisted, while all else failed. Once there had been men who did vast, unknown things, but the Wreck had vanquished them. Now the Families of Vishnu and Shiva carried forth. Their legacy was the chips and sensors embedded in them, to afford some measure of protection from the Marauders.
Over this Familial net Agaden sent the final call of the solstice celebration: “And so vanquish the not-flesh! Bring rain and sweetness, O Vishnu!”
The ritual dissolved into festivity. Cermo-the-Slow had gotten into the strong, rough fruit brandy that served both as ritual fluid and as a valued currency among Families. He lurched and grinned, barking at the solemn sky.
Hoarse voices raised in rowdy song. Hands plucked at him. Agaden smiled at the women who beckoned to him, their intentions clear. Their smooth skins, browned by the double suns, could not match the ghostly pale of the stones he crossed. He murmured thanks, stroked their shiny hair, and moved on.
He explored, ignoring the ricocheting voices of celebration. At the borders of the vast square marble platform stood four delicate towers. Agaden walked between them, eyeing their solemn, silent upjut. They stood like sentinels at the monument’s corners, guards against whatever rude forces the world could muster.
He saw that each tower leaned outward at a tiny angle. Something told him the reason. When the towers finally collapsed, they would fall outward. Their demise would not damage the huge, airy building at the center.
On the back of the last marble wall there was a single plate of solid black, a dark eye that gazed out on a land inhospitable.
Yet as Agaden approached, it blinked. A ruby glaze momentarily fogged its surface and into his mind—merging with him instantaneously through his inbuilt receptors and chips—came a steady, chanting voice that spoke of glories gone and names resonantly odd.
Agaden felt the words as crystalline cold wedges of meaning, beyond mere talk. He gaped as he understood.
The thing was, incredibly, not mechmade.
It was instead of human times and ’facture. The mechs had left it untouched.
Agaden listened for a while, comprehending nothing beyond the singular fact of it: that men and women had once made things.
And had done it so well that even machines gave their work tribute and place.
Agaden froze, his mind aswirl. He had led his Family into this fresh territory, opening up new lands. All spoke of him as the best leader they had, within memory. Even allowing for the usual flattery, Agaden himself knew this was true.
But even he wondered what such an astounding revelation could do to the Family. They were a fragile people, steeped in their ways. Shiva and Vishnu ruled, and this was the eternal order.
To tell them that men had been ’facturers themselves...that would awaken troubling thoughts.
Yet he himself could not shake the beautiful mystery of this place. Or stop the awed speculations it called forth.
Dazed, eyes open but unseeing, he did not hear Cermo-the-Slow until a hand clapped on his shoulder.
“Come on! You get first hack.”
“What...?”
“Gone take one these down.”
“One of—”
“Big crash time! Big! Cel’brate!”
Already five of the Family were scrawling marks at the base of one of the slender towers. Cermo-the-Slow tugged Agaden toward them.
“You don’t understand,” Agaden said. “This isn’t a mech building.”
Cermo snickered. “Think’s a hill? Huh?”
“Humans made it.”
Cermo laughed.
“They did! There’s a voice from over there—”
“Hearin’ voices,” Cermo called to the others. “Rattler musta addled him some.” Raucous catcalls answered.
“Humanity built this. That’s why it’s so, so—beautiful.”
“Mechstuff, ’s all.” Cermo walked to the foot of the tower.
“No! Long time ago, somebody—some of us—did such work. Just look at it.”
Agaden was slow to see the seeds of revolt. Cermo had the others with him, faces smirking and chuckling and preparing in their bleary way to do what men and women did whenever they found undefended mechwork.
“More damn foul mechstuff, ’s what it is,” Cermo said with a touch of irritation. “You don’t want part of it, we’ll take it all.”
Two women laughed and handed Cermo a cutter-beam tube, one ripped from the Crafter. Cermo thumbed a button and a ready buzzing came from it.
Agaden shook his head, knowing what he must do.
A fevered mix of fear and rage propelled him forward.
Cermo had half turned to the tower, pointing the cutter-beam at one of the creamy stone plates. The crowd made a murmuring noise of anticipation, highpitched threads of glee racing through it.
Agaden hit him solidly in the back. Cermo lurched. He smacked into the tower. Agaden caught him with a roundhouse kick in the side. The cutter fell from his fingers.
“You—” Cermo blurted. Agaden kicked the buzzing cutter away.
Cermo ducked down and lumbered away. Agaden tripped him. The big man struck a broad stone plate and groaned.
“Leave it! It’s ours.”
A woman called, “You protectin’ mech garbage? I—”
“People way back did this. People—different from us.”
The woman bared her gray teeth. “Who cares? They prob’ly made mechs, too. Anybody’d do thing like this, they were crazy! We don’t need respect mechs, or mech-makers!”
“Not going argue with you. Pick up your packs! We’re movin’.”
Agaden stared at them, stony and redfaced, eyes wide.
Slitted eyes regarded him, assessing chances of taking him in a fight.
Hands grasped at air, eager for the weight of a weapon.
Wind whistled among the high bright towers.
And the moment passed. The crowd shuffled to the side, mumbling, eyes averted. They went to find packs and discarded boots.
Agaden helped Cermo sit up, brought him water. Then he stood and watched thin cirrus skate across the sky, framed by the towers and the enchantment of the great curving dome.
Again he listened to the ancient hollow voice and its singsong chant. Then his Family was ready.
He shook his head and tapered the voice down to a dim dry warble. Around him Family grumbled, but he knew it was best that they move on. They would all like to rest here for a while. To grieve for Old Majy. To fest. To relive through story and celebration the pillage of the Crafter and the humiliation of the Rattler.
Most of them would never believe that the place to which they owed their lives was not merely another mech factory or inexplicable waystation. And they would be horrified if they did.
Agaden frowned again. Even he still had a trace of doubt. Incredible, that humans once shared the hated traits of the mechs: permanence, rigid lines, dwarfing cities, the idea of owning and not simply passing through.
Humanity lived lightly on the land; mechs belabored it. That was nature’s balance and eternally ordained conflict.
This beautiful place was impressive, yes, but it shared some disquieting principles with the mech ways. Agaden felt awed and yet uncomfortable here.
If mechs honored this human place, then humans should too. Of that he was sure.
But they could honor it by leaving it. By not allowing this strange place to disturb their ways.
“March!” he called. “Flanks out. Go!”
They left the flat plaza in good marching order.
It felt good to feel soil and rock underfoot. Agaden set the pace. He liked the steady sway and rhythms of voyaging, of movement, of the perpetual mystery that lurked beyond the far horizon. This was humanity’s role.
He paused at the lip of the next rutted canyon.
Glancing back, he was startled by a sudden intuition. Seen from afar, the shape struck a deeply resonant chord in him, a sense of what the melancholy sweep and curve of stone meant.
It was a place to honor the dead. Perhaps it contained a body, or even many.
His language had no word for a tomb, but the idea itself came to him, wrinkling his brow.
The proud rise spoke of humanity—itself summoned forth from matter and too soon cast down—and its sorrow at knowing this destiny.
A tomb. His quick eyes traced patterns in the broad, sculpted plain. Water had shaped it. Crumbled bluffs and dry pebbled washes spoke of a wide river that had flowed here in the old, lush times. The river had once hugged the shelf below the tomb.
Slow erosion—or had it been the hand of man?—had made the snaky waterway meander away from the bluff, so it would not undercut the lonely building.
That had been unimaginably long ago. The river itself had dwindled and died, its strength carried off by thirsty winds.
Who the place had honored he could not guess. But its lines said things to him, murmuring in his heart of sorrow and love and the sad sway of time.
That such things could live in brute stone made Agaden shiver, swept by ancient emotions.
To encase human feelings that way...
Slowly, the idea filled Agaden with horror.
The essence of human good lay in its fleeting poignancy. Only things mechlike built and shaped. Their kind sought a cold, uncaring permanence.
If humanity had been mechlike in the far past, even to the point of making things of stone that trapped feeling... Agaden curled his lip. If that was true, then he felt no reverence for those benighted ancestors.
He was suddenly glad to live in a holier and wiser time. Humanity today knew the true division between the sweet passing beauties of things human, and the cruel hard mech ways.
The knowledge of certain death, that nothing could be caught, that each fleeting instant had to be savored in its passing—that was the essence of wisdom. Not holding on, but instead, living fully.
If the ancients had confused this, they deserved to be forgotten.
He gazed for a long moment at the monument with a hesitant wistfulness. At last he saw that his thinking was right, that the past meant nothing. He spat derisively. Then he turned and went on and never looked back again.
Galactic Center Astronomy, 2013
The Basics: how the sky looks there
We cannot see the bright central hub of our galaxy because a dark cloud blocks the view in the Sagittarius constellation.
Photo courtesy NASA
The very center is a whirl of gas, strange filaments, and stars whose great waltzing orbits take them around the immense black hole.
A supermassive black hole resides in the bright white area, right of the center. This composite photograph covers about half of a degree of the sky. Most revealing are the strange long filaments in the innermost hundreds of light years of the center, visible to us only in frequencies around a gigahertz—the same region where our cell phones communicate. A gigahertz map shows them:
(This is from arXiv:astro-ph/0701050v1 2 Jan 2007
The Galactic Center Magnetosphere
Mark Morris, UCLA.)
There are also details in a color version:
Because most of the filaments, hundreds of light years long, are roughly perpendicular to the Galactic plane, the implied large-scale geometry of the magnetic field that they lie along is a dipole, like Earth’s—and made by some currents near the central plane.
Credit: Farhad Yusef-Zadeh et al. (Northwestern), VLA, NRAO
Explanation: What causes this unusual structure near the center of our Galaxy? The long parallel rays slanting across the top of the above radio image are known collectively as the Galactic Center Radio Arc and jut straight out from the Galactic plane. The Radio Arc is connected to the Galactic Center by strange curving filaments known as the Arches. The bright radio structure at the bottom right likely surrounds a black hole at the Galactic Center and is known as Sagittarius A*. One origin hypothesis holds that the Radio Arc and the Arches have their geometry because they contain hot plasma flowing along lines of constant magnetic field. Recent images from the Chandra X-ray Observatory appear to show this plasma colliding with a nearby cloud of cold gas.
Perhaps the oddest structure is the Snake:
http://iopscience.iop.org/0067-0049/155/2/421/fulltext/59954.fg11.html
There’s also a remarkable, large-scale, helically wound structure with two threads—a double helix in the galactic center sky.
Strange weather
There’s dynamic action, too. A massive object called G2, a large gas cloud first identified in 2011, will pass by the massive black hole in March 2014. As the black hole’s gravity draws the gas cloud closer, it spins and stretches. To quote from a recent paper (http://arxiv.org/pdf/1201.1414.pdf), “While passing the super massive black hole, G2 will break up into a string of droplets that within the next 30 years mix with the surrounding hot gas and trigger cycles of Active Galactic Nuclei activity.” It could strike other objects near the black hole, too, such as orbiting small stars or small black holes. There may very well be enhanced activity due to a bow shock the cloud develops, which we’ll see as radio and microwave radiation. (The same spectral bands in which we see the filaments a hundred light years long.)
From a simple model of a tidally shearing gas cloud as the black hole stretches the cloud, we get images like these:
The picture below, with blue orbits, shows the elliptical orbits other stars follow in this dense, energetic region. The cloud will sweep by on a tight ellipse. Its orbit eccentricity is highly puzzling, because in a random distribution of orbits the value of the cloud’s—0.966, nearly a straight line, not a comfortable sloped curve as, say, most stars move on around the hole—would only have a probability of 6.7%. So what makes this cloud follow a doomed orbit, sure to be shredded? (I have my own ideas: the high magnetic fields exert strong forces on big clouds, which are partially ionized. That will flatten orbits and draw clouds inward. G2 could be just the latest example of a class.)
