Killeen cast about for some idea, some fleeting hope. The walls were nearly dark now, the radiance of the hoop somehow absorbed by the rock beyond. Smoldering orange-brown wedges shot past—lava trapped in underground vaults, great oceans of livid, scorching rock.
I would suppose that the hoop-tube is left to stand empty at times. Perhaps the cyborgs are now working on some minor repairs. Or perhaps they simply pause to let the orbited teams which are fashioning the first batch of core metal do their work. In any case, assuming the cyborg above did not simply throw us in to see us boiled away by a gusher of iron, there is another fate.
Killeen tried to calm himself and focus on Arthur’s words. The walls seemed closer as he fell, the tube narrowing before him. He pulled himself rigid and straight, arms at his sides, feet down toward the yellow disk below that grew steadily. He blinked back sweat and tried to see better.
I believe we have passed through the crust and are now accelerating through the mantle. Note that the occasional lava lakes are getting larger and more numerous. Temperature increases here by about 10 degrees centigrade every kilometer we fall. This will continue until the temperature exceeds the melting point of simple silicate rocks. Then—drawing on studies of similar planets—we will enter an increasingly dense and hot core. At this point the rocks will be fluid and at about 2,800 degrees centigrade.
“Howcome rock doesn’t fill up this tube?”
The hoop pressure, which is truly immense. Grey calculates—
“And the heat? The hoop stops that?” Killeen asked, seeking reassurance, though he already suspected the answer.
Heat is infrared electromagnetic radiation. The hoop is transparent to it. All light passes through it—which is why we see now the dark rock beyond. Soon, though, the silicates will begin to glow with the heat of their compression.
“What’ll we do?”
The heat radiation exerts a pressure. But this is symmetric, of course, acting equally in all directions. So it cannot push us toward one wall in preference to another. But it will cook us quite thoroughly.
“How…how long?”
Passage through the core…about 9.87 minutes.
“My suit—it’ll silver up for me.”
True, it already has. And I calculate we might survive one entire passage if we seal up completely, close your helmet visor, damp all inputs. Perhaps the cyborg understood that; it may know a good deal about our technology. Yes, yes…I am beginning to see its devilish logic.
Killeen shut down his suit inputs. He left only a slight lightpipe for optical images. His suit skin reflected the blur of thickening light around him with a mirror finish. The walls rushing past were turning ruddy, sullen. “Where are we?”
We must be approaching the boundary at which iron melts. This reddening probably signals the transition from the mantle to the outer core. We can expect some varying magnetic fields now, since this is the region—so theory says—where the planet’s field is born. Large currents of molten metal eddy about, carrying electrical currents, like great wires in a generator station. New Bishop’s spin serves to wrap these around, creating current vortexes, which in turn stir up magnetic whorls.
“Damn, it’s getting hot already.”
External temperature is 2,785 degrees centigrade.
Killeen clicked down his visor. He fell in complete blackness. He wondered if he could stand the heat in utter isolation, plunging faster, faster, ever faster….
Again he struggled to slow his breathing. If he was to live through even the next few minutes he would have to think clearly. The dark might help that as long as he could keep his natural reactions from running away.
Luckily, the added speed imparted by the cyborg will take us through that much faster. I register external temperature now at well over 3,000 centigrade. Here—one of the suit’s lightpipes will give us a faint image, which is all we need in such a place.
“Damnall, think!”
I am. I simply do not see any way out of our dilemma.
“There’s gotta be some way—”
The existence of a well-defined problem does not imply the existence of a solution.
“Damn you!”
Years before, Killeen had suppressed his Aspects when they threatened to overwhelm him. Now he felt the risk in that. Arthur was a disconnected intelligence, serving as a mere consultant mind. Without nature’s primitive surges of alarm, like adrenaline, Arthur remained aloof. Still, his coolness kept the less-used Aspects and Faces from intruding on Killeen with their panics.
“Look, we get through this, we’ll be back outside, yeasay?”
Yes. But that is the devilish nature of this cyborg’s trick. We are participating in an ancient schoolboy’s homework problem—a shaft through the planet, with us as the harmonically oscillating test mass.
“What…”
Killeen suddenly saw what Arthur meant. He watched as in his eye the blue dot shot through the core and on, out through the other side of the red tube. It rose toward the surface, its velocity dwindling in gravity’s grip, then broke free above the surface, still slowing. After hesitating at the peak it began falling again, to execute another long plunge through the heart of the spitted planet.
We can perhaps survive this one passage. But another, and another?—so on, ad infinitum?
“There must be a way out.”
Killeen said this with absolute conviction, even though he had no knowledge of the physics underlying Arthur’s colorful display. Even if a gargantuan alien had made this incinerating rattrap, it could have made a mistake, left some small unnoticed exit.
He had to believe that or the panic which squeezed his throat would overwhelm him. He would die like a pitiful animal, caught on the alien’s spit and roasted to a charred hulk. He would end as a cinder, bobbing endlessly through the central furnace.
We might possibly try something at the very high point, when the hoop begins to curve over far above the pole. We should come to rest there for a brief instant.
“Good. Good. I can maybe pump some this cooling stuff—”
Refrigerant fluids, yes, I see. Use them in our thruster. But that would not be enough to attain an orbit.
“How about the hoop? Maybe I could bounce off it up there, where it’s spinning. I could pick up some vector, get free.”
Killeen felt Arthur’s strangely abstract presence moving, pondering, consulting Ling and Grey and some Faces, as though this were merely some fresh problem of passing interest. Falling in absolute blackness, he felt his stomach convulse. He clamped his throat shut and gulped back down a mouthful of acid bile.
