laid throughout the ship, from the command ‘deck with its
fifteen-foot-wide display screen, through the control rooms, living
quarters, and hospital, to the cargo holds and the tiers of cages
that had contained the animals. The primary energy-convertor and
generator section was as imposing and as complex as the inside of a
thermonuclear power station. Beyond it, they passed through a
bulkhead and found themselves dwarfed beneath the curves of the
exposed portions of a pair of enormous toroids. The engineer
leading them pointed up at the immense, sweeping surfaces of metal.
“The walls of those outer casings are sixteen feet thick,” he
in-formed them. “They’re made from an alloy that would cut
tungsten-carbide steel like cream cheese. The mass concentration
inside them is phenomenal. We think they provided closed paths in
which masses of highly concentrated matter were constrained in
circulating or oscillating resonance, interacting with strong
fields. It’s possible that the high rates of change of gravity
potential that this produced were somehow harnessed to induce a
controlled distortion in the space around the ship. In other words,
it moved by continuously falling into a hole that it created in
front of itself- kind of like a four-dimensional tank track.”
“You mean it trapped itself inside a space-time bubble, which
propagated somehow through normal space?” somebody offered.
“Yes, if you like,” the engineer affirmed. “I guess a bubble is as
good an analogy as any. The interesting point is, if it did work
that way, every particle of the ship and everything inside it would
be subjected to exactly the same acceleration. Therefore there
would be no G effect. You could stop the ship dead from, say, a
million miles an hour to zero in a millisecond, and nobody inside
would even know the difference.”
“How about top speed?” someone else asked. ‘Would there have been a
relativistic limit?”
“We don’t know. The theory boys up in Jupiter Four have been losing
a lot of sleep over that. Conventional mechanics wouldn’t apply to
any movement of the ship itself, since it wouldn’t be actually
moving in the local space inside the bubble. The question of how
the bubble propagates through normal space is a different ball game
altogether. A whole new theory of fields has to be
worked out. Maybe completely new laws of physics apply-as I said
before, we just don’t know. But one thing seems clear: Those
photon-drive starships they’re designing in California might turn
out to be obsolete before they’re even built. If we can figure out
enough about how this ship worked, the knowledge could put us
forward a hundred years.”
By the end of the day Hunt’s mind was in a whirl. New information
was coming in faster than he could digest it. The questions in his
head were multiplying at a rate a thousand times faster than they
could ever be answered. The riddle of the Ganymean spaceship grew
more intriguing with every new revelation, but at the back of it
there was still the Lunarian problem unresolved. He needed time to
stand back and think, to put his mental house in order and sort the
jumble into related thoughts that would slot into labeled boxes in
his mind. Then he would be able to see better which question
depended on what, and which needed to be tackled first. But the
jumble was piling up faster than he could pick up the pieces.
The banter and laughter in the mess after the evening meal soon
became intolerable. Alone in his room, he found the walls
claustrophobic. For a while he walked the deserted corridors
between the domes and buildings. They were oppressive; he had lived
in metal cans for too long. Eventually he found himself in the
control tower dome, staring out into the incandescent gray wall
that was produced by the floodlights around the base soaking
through the methane-ammonia fog of the Ganymedean night. After a
while even the presence of the duty controller, his face etched out
against the darkness by the glow from his console, became an
intrusion. Hunt stopped by the console on his way to the stairwell.
“Check me out for surface access.”
The duty controller looked across at him. “You’re going outside?”