Грег Иган - Distress

The decorative trace minerals began to fade, not to be wasted at a depth where they’d rarely be seen. Rajendra’s breathing accelerated, and he glanced up toward the surface; some of the people watching the screen called down to him and waved, their arms skinny silhouettes half eaten by the glare from the dazzling circle of sky. He looked away, and then directly down; the grid of the platform was no real obstruction, but neither lantern beams nor sunlight penetrated far. He seemed to grow calm again. I’d considered asking him to provide a running commentary, but I was glad now that I hadn’t; it would have been an unfair burden.

The wall of the tunnel grew visibly moist; Rajendra reached out and trailed his fingers through the chalky fluid. Water and nutrients penetrated every part of the island (even the center, although the dry, hard surface layer was thickest there). It didn’t matter that the rock here would never be mined—and the fact that the tunnel remained unhealed showed that this region had been explicitly programmed against regrowth. The lithophiles were still indispensable; the heartrock could never be allowed to die.

I began to make out tiny bubbles forming in the fluid clinging to the wall—and then, deeper still, visible effervescence. Beyond the edges of the guyot, Stateless was unsupported from below—and a solid limestone overhang forty kilometers long, strengthened by biopolymers or not, would have snapped in an instant. The guyot was a useful anchor, and it bore some of the load, but most of the island simply had to float. Stateless was three-quarters air; the heartrock was a fine, mineralized foam, lighter than water.

The air in the foam was under pressure, though: from the rock above, and—below sea level—from the surrounding water trying to force its way in. Air was constantly being lost to diffusion through the rock; the wind blasting out of this tunnel was the accumulated leakage from hundreds of square meters, but the same thing was happening, less dramatically, everywhere.

The lithophiles prevented Stateless from collapsing like a punctured lung, and sinking like a drowned sponge. Plenty of natural organisms were proficient at making gas, but they tended to excrete products you wouldn’t want wafting out of the ground in vast amounts, like methane or hydrogen sulphide. The lithophiles consumed water and carbon dioxide (mostly dissolved) to make carbohydrates and oxygen (mostly undissolved)—and because they manufactured "oxygen-deficient" carbohydrates (like deoxyribose), they released more oxygen than they took in carbon dioxide, adding to the net increase in pressure.

All of this required energy as well as raw materials; the lithophiles, living in darkness, needed to be fed. The nutrients they consumed and the products they excreted were part of a cycle which stretched out to the reefs and beyond; ultimately, sunlight on distant water powered everything they did.

Soon the surface was frothing and boiling, spraying calcareous droplets toward the camera like spittle. And it finally dawned on me that I’d been utterly mistaken: the dive had nothing to do with Edenite notions of "modern tribalism." Whatever courage it required was incidental; that wasn’t being valued for its own sake. The point was to descend through the palpable exhalation of the rock, and to see with your own eyes what Stateless was: to understand the hidden machinery which kept the island afloat.

Rajendra’s hand appeared at the border of the image as he fitted the mouthpiece and switched on the air supply. Of course: all this seeping liquid would build up at the bottom of the tunnel. He glanced down once, at what looked like a dark, sulphurous pool, boiling with volcanic heat; in fact, it was probably chilly and almost odorless. Munroe had been right about one thing: you really had to be there. What’s more… the tunnel wind would be weaker at this depth than at the surface, because much of the leaking rock contributing to the total airflow was now overhead. Rajendra would have no trouble noticing the difference—but the view, alone, of gas escaping at ever greater pressure, suggested exactly the opposite.

As the camera plunged beneath the surface, the image flickered and then switched to lower resolution. Even through the turbulent, cloudy water, I could still catch occasional glimpses of the tunnel wall—or at least the wall of bubbles streaming out of the rock. It was a weird, disorienting sight—it almost looked as if the water was so acidic that it was dissolving the limestone right before my eyes… but once again, that impression would have been instantly untenable if I’d been down there in person, swimming in the stuff.

The resolution dropped again, and then the frame rate fell; the picture became a series of stills in rapid succession as the camera struggled to maintain contact. Sound came through clearly enough, though I probably wouldn’t have recognized distortion in the noise of bubbles breaking against a scuba mask. Rajendra glanced down; the view showed ten thousand pearls of oxygen streaming up through opalescent water— and nothing more distant than his knees. I thought I heard him inhaling sharply, tensing himself in preparation for touching the bottom—and then I almost sent the notepad tumbling down after him.

One still showed a startled, bright red fish staring straight into the camera. In the next image, it was gone.

I turned to the woman beside me. "Did you see—?" She had, but she didn’t seem at all surprised. The skin tingled all over my body. How thick was the rock we were standing on? How long was the cable?

When Rajendra emerged from the underside of the island, he made a noise which might have expressed anything from exuberance to terror; with a plastic tube in his mouth, and all the other acoustic complications, all I could discern was a muffled choking sound. As he descended through the subterranean ocean, the water around him gradually became clearer. I saw a whole school of tiny, pale fish cross the lantern beam in the distance, followed by a gray manta ray at least a meter wide, mouth stretched open in a permanent, plankton-straining grin. I glanced up from the screen, shaken. This couldn’t be happening beneath my feet.

The winch halted. Rajendra looked up, back toward Stateless, tilting the lantern on its pivot, swinging it back and forth.

Milky water roiled in a layer that clung to the underside. Fine particles of limestone? I was confused; why didn’t they simply fall? Even from strobed stills, I could see that this haze was in constant motion, surging rhythmically toward the hidden rock. I could also make out bubbles of gas, dragged down a few meters in some kind of undertow, before finally escaping back into the haze. Rajendra played the beam back and forth, improving his control; the lantern was obviously difficult to manipulate accurately, and I could sense his frustration—but after a few minutes his persistence paid off.

A stronger-than-average surge mixed an updraft of clear water into the milky layer above, parting the curtain for an instant. Beam and camera transfixed the event, exposing lumpy rock sparsely populated with barnacles and pale, frond-mouthed anemones. In the next frame, the image was blurred—not yet obscured by the haze of white particles, but crinkled, distorted by refraction. At first, we’d seen the rock through pure water; now we saw it through water and air.

There was a thin layer of air constantly trapped against the underside, maintained by the steady stream of oxygen escaping from the foamed rock.

This air gave the water a surface which could carry waves. Every wave which crashed on the distant reefs would send a twin diving beneath the island.

No wonder the water was cloudy. The underside of Stateless was being constantly scraped by a vast, wet, jagged file. Waves eroded the shoreline, but at least that stopped at the high-tide mark. This assault was going on beneath dry land, all the way to the rim of the guyot.