David Brin - Earth

“Uh-huh. They aren’t truly funnel-things drawn in circles, of course. There’s a limit to how well you can represent…” Alex sighed. “It’s hard to describe this without math.”

“I know math,” George grumbled.

“Mm, yes. Excuse me, George, but the tensors you use, searching for deep methane, wouldn’t help a lot with this.”

“Maybe I understand more’n you think, white boy.” Hutton’s dialect seemed to thicken for a moment. “Like I can see what your cosmic string’s got that black holes don’t. Holes got no dimensions deep inside. But strings have length.”

George Hutton kept doing this — play-acting the “distracted businessman,” or “ignorant native boy,” then coming back at you when your guard was down. Alex accepted the rebuke.

“Good enough. Only strings, just like black holes, are unstable. They dissipate too, in a colorful way.”

At a spoken word, a new display formed.

The rubber sheet was gone. Now they watched a loop in space, glowing red from infalling matter, and white from a halo-fringe of new particles, showering into space. Inflow and outgo.

“Now I’ll set the simulation in motion, stretching time a hundred-million-fold.”

The loop began undulating, turning, whirling.

“One early prediction was that strings would vibrate incredibly fast, influenced by gravitational or magnetic…”

Two sides collided in a flash, and suddenly a pair of smaller loops replaced the single large one. They throbbed even faster than before.

“Some astronomers claim to see signs of gigantic cosmic strings in deep space. Perhaps strings even triggered the formation of galaxies, long ago. If so, the giant ones survived because their loops cross only every few billion years. Smaller, quicker strings cut themselves to bits…”

As he spoke, both little loops made lopsided figure eights and broke into four tinier ones, vibrating madly. Each of these soon divided again. And so on. As they multiplied, their size diminished and brightness grew — bound for annihilation.

“So,” George surmised. “Small ones still aren’t dangerous.”

Alex nodded. “A simple, chaotic string like this couldn’t explain the power curves at Iquitos. So I went back to the original cavitron equations, fiddled around with Jones-Witten theory a bit, and came up with something new.

“This is what I thought I’d made, just before Pedro Manella set off his damned riot.”

The tiny loops had disappeared in a blare of brilliance. Alex uttered a brief command, and a new object appeared. “I call this a tuned string.”

Again, a lambent loop pulsed in space, surrounded by white sparks of particle creation. Only this time the string didn’t twist and gyre chaotically. Regular patterns rippled round its rim. Each time an indentation seemed about to touch another portion, the rhythm yanked it back again. The loop hung on, safe from self-destruction. Meanwhile, matter continued flowing in from all sides.

Visibly, it grew.

“Your monster. I remember from when you first arrived. I may be drunk, Lustig, but not so I’d forget this terrible taniwha .”

Watching the undulations, Alex felt the same mixed rapture and loathing as when he’d first realized such things were possible… when he first suspected he had made something this biblically terrible, and beautiful.

“It creates its own self-repulsion,” he said softly, “exploiting second- and third-order gravities. We should have suspected, since cosmic strings are superconducting—”

George Hutton interrupted, slapping a meaty hand onto Alex’s shoulder. “That’s fine. But today we proved you didn’t make such a thing. We sent waves into the Earth, and echoes show the thing’s dissipating. It’s dying. Your string was out of tune!”

Alex said nothing. George looked at him. “I don’t like your silence. Reassure me again. The damned thing is for sure dying, right?”

Alex spread his hands. “Bloody hell, George. After all my mistakes, I’d only trust experimental evidence, and you saw the results today.” He gestured toward the mighty thumper. “It’s your equipment. You tell me.”

“It’s dying.” George said, flat out. Confident.

“Yes, it’s dying. Thank heaven.”

For another minute the two men sat silently.

“Then what’s your problem?” Hutton finally asked. “What’s eating you?”

Alex frowned. He thumbed a control, and once again a cutaway view of the Earth took shape. Again, the dot representing his Iquitos singularity traced lazy precessions among veins of superheated metal and viscous, molten rock.

“It’s the damn thing’s orbit.” Equations filed by. Complex graphs loomed and receded.

“What about its orbit?” George seemed transfixed, still holding the bottle in one hand, swaying slightly as the dot rose and fell, rose and fell.

Alex shook his head. “I’ve allowed for every density variation on your seismic maps. I’ve accounted for every field source that could influence its trajectory. And still there’s this deviation.”

“Deviation?” Alex sensed Hutton turn to look at him again.

“Another influence is diverting it. I think I’ve got a rough idea of the mass involved…”

The bigger man swung Alex around bodily. The Maori’s right hand gripped his shoulder. All signs of intoxication were gone from Hutton’s face as he bent to meet Alex’s eyes.

“What are you telling me? Explain!”

“I think…” Alex couldn’t help it. As if drawn physically, he turned to look back at the image in the tank.

“I think something else is down there.”

In the ensuing silence, they could hear the drip-drip of mineral-rich water, somewhere deeper in the cave. The rhythm seemed much steadier than Alex’s heartbeat. George Hutton looked at the whiskey bottle. With a sigh, he put it down. “I’ll get my men.”

As his footsteps receded, Alex felt the weight of the mountain around him once more, all alone.

□ In ages past, men and women kept foretelling the end of the world. Calamity seemed never farther than the next earthquake or failed harvest. And each dire happening, from tempest to barbarian invasion, was explained as wrathful punishment from heaven.

Eventually, humanity began accepting more of the credit, or blame, for impending Armageddon. Between the world wars, for instance, novelists prophesied annihilation by poison gas. Later it was assumed we’d blow ourselves to hell with nuclear weapons. Horrible new diseases and other biological scourges terrified populations during the Helvetian struggle. And of course, our burgeoning human population fostered countless dread specters of mass starvation.

Apocalypses, apparently, are subject to fashion like everything else. What terrifies one generation can seem obsolete and trivial to the next. Take our modern attitude toward war. Most anthropologists now think this activity was based originally on theft and rape — perhaps rewarding enterprises for some caveman or Viking, but no longer either sexy or profitable in the context of nuclear holocaust! Today, we look back on large-scale warfare as an essentially silly enterprise.

As for starvation, we surely have seen some appalling local episodes. Half the world’s cropland has been lost, and more is threatened. Still, the “great die-back” everyone talks about always seems to lie a decade or so in the future, perpetually deferred. Innovations like self-fertilizing rice and super-mantises help us scrape by each near-catastrophe just in the nick of time. Likewise, due to changing life-styles, few today can bear the thought of eating the flesh of a fellow mammal. Putting moral or health reasons aside, this shift in habits has freed millions of tons of grain, which once went into inefficient production of red meat.