One of the younger peepers shivered. But Spivey met her eyes in shared understanding. They each had priorities. It was far more important they respect than like each other.
Back at her console, she watched the bottom portion of the station come into view — a cluster of bulbous tanks and plumbing hanging from a silvery line. Far above, other station components glittered like jewels strung far apart on a very long necklace. Most distant, and invisible except by radar, lay Farpoint Cluster, where Jason worked on things she still knew next to nothing about.
They were passing over the Alps now, a battered, crumpled range, whose bomb craters were only now emerging from winter’s coating of snow. It was an awesome juxtaposition, showing what both natural and man-made forces could do, when angry.
But Teresa had no time for sightseeing. Her attention focused on Nearpoint — hanging like a pendulum bob, closest to the Earth.
Just below the fluid-pumping station hung a boom that flexed and stretched as its operator played out line like a fisherman, casting for the big one.
Teresa’s eyes roamed over her instruments, the station, the stars, absorbing them all. Moments like this made all the hard work worthwhile. Every part of her felt unified, from the hands lightly flexing Pleiades’ vernier controls to the twin hemispheres of her brain. Engineer and dancer were one.
For the present all anxieties, all worries, vanished. Of the countless jobs one could have, on or off the world, this one gave her what she needed most.
“We’re coming in,” she whispered.
Teresa knew exactly where she was.
“Once upon a time, the great hero Rangi-rua lost his beautiful Hine-marama. She died, and her spirit went to Rarohenga, the land of the dead.
“Rangi-rua was beset with grief. Inconsolable, he declared that he would follow his wife into the underworld and fetch her back again to Ao-marama, the world of light.
“With Kaeo, his ever-faithful companion, Rangi-rua came to the swirling waters guarding the entrance to Rarohenga. There, he and Kaeo dove into the mouth of hell, down where the heartbeat of Manata sends shivers through the earth. Against this power they swam and swam until, at last, they reached the other bank, where the spirit of Rangi-rua’s lovely wife awaited him.
“Now, to be fair it must be said that Rangi-rua and Kaeo may not have been the only mortals to accomplish this feat. For the pakeha tell a similar story of one called Orpheus, who did the very same thing for the sake of his lover — and it is said he even managed the crossing on his own.
“But Rangi-rua outdid Orpheus in the most important thing.
For when Rangi-rua emerged again into the light of father sun, both his friend and his lover were at his side.
“But Orpheus failed because, like all pakeha, he just couldn’t keep his mind on one thing at a time.”
• CORE
Sitting in front of his holographic display — sole illumination in the deserted lab — Alex recalled George Hut-ton’s performance at the celebration, earlier in the evening, reciting Maori legends to the tired but happy engineers by firelight. Especially appropriate had been the tale of Rangi-rua’s, speaking as it did of fresh hope, snatched from the very gates of hell.
Later, though, Alex found himself drawn back to the underground laboratory. All the machinery, so busy earlier in the day, now lay dark and dormant save under this pool of light, which spilled long shadows onto the nearby limestone walls.
Rangi’s legend had touched Alex, all right. It might apply to his present state of mind.
Don’t look back. Pay attention to what’s in front of you.
Right now what lay before him was a depiction of the planet, in cutaway view. A globe sliced like an apple, revealing peel and pulp, stem and core.
And seeds, Alex thought, completing the metaphor.
The eye couldn’t make out Earth’s slight deviations from a sphere. Mountain ranges and ocean trenches — exaggerated on commercial globes — were mere dewy ripples on this true-scale representation. So thin was the film of water and air compared to the vast interior.
Inside that membrane, concentric shells of brown and red and pink denoted countless subterranean temperatures and compositions. With a word, or by touching the holo’s controls, Alex could zoom through mantle and core, following rocky striations and myriad charted rivers of magma.
Okay. George, he thought. Here’s a pakeha allegory for you. We’ll start by cutting a hole straight through the Earth.
From the surface of the globe, he caused a narrow line to stab inward, through the colored layers. Drill a tunnel, straight as a laser, with mirror-smooth walls. Cover both ends and drop a ball inside.
It was an exercise known to generations of physics students, illustrating certain points about gravity and momentum. But Alex played the scenario in earnest.
Assuming that inertial and gravitational mass balance, as they tend to do, anything dropped at Earth’s surface accelerates nine point eight meters per second, each second.
His ringers stroked knobs, releasing a blue dot from the outer rim. It fell slowly at first, even with the time rate magnified. A millimeter here stood for an awful lot of territory in the real world.
But after the ball falls a good distance, acceleration has changed.
In 1687, Isaac Newton took several score pages to prove what smug sophomores now demonstrated on a single sheet — ah, but Newton did it first! — that only the spherical portion “below” a falling object continues to apply net gravity, until acceleration stops altogether as the ball hurtles through the center at a whizzing ten kilometers per second.
It can’t fall any farther than that. Now it’s streaking upward.
(Answer a riddle — where is it you can continue in a straight line, yet change directions at the same time?)
Now more and more mass accumulates “below” the rising ball. Gravity clings, draining kinetic energy. Speed slackens till at last — neglecting friction, coriolis effects, and a thousand other things — our ball lightly bumps the door at the other end.
Then it falls again, hurtling once more past sluggish, plasti-crystal mantle layers, past the molten dynamo of the core, plummeting then climbing till finally it arrives “home” once more, where it began.
Numbers and charts floated near the giant globe, telling Alex the round trip would take a little over eighty minutes. Not quite the schoolboy perfect answer, but then schoolboys don’t have to compensate for a real planet’s varying density.
Next came the neat trick. The same would be true of a tunnel cut through the Earth at any angle! Say, forty-five degrees. Or one drilled from Los Angeles to New York, barely skimming the. magma. Each round trip took about eighty minutes — the period of a pendulum with the same span as the Earth.
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It’s also the period of a circular orbit, skimming just above the clouds.
Alex soon had the cutaway pulsing with blue dots, each falling at a different angle, swiftly along the longer paths, slowly along shorter ones. Besides straight lines there were also ellipses, and many-petaled flower trajectories. Still, to a regular rhythm, they all recombined at the same point on the surface, labeled PERU.
Of course, things change when you include Earth’s rotation… and the pseudo-friction of a hot object pushing against material around it…