Polaris Adrift

Not in the brochures.

The princess threw up.

“I didn’t think you had it in you, what with how you’ve eaten recently. Or haven’t.”

“You do well by respecting my countenance. But another quip about my zero-G nausea, and you’ll be breathing vacuum. Or won’t.”

Casey smiled. It was good to poke the boss. The regent didn’t care enough for interplanetary shipping; it was Her Highness’s influence that made it happen. Someday, the orphan would be Queen of the Federation, and they’d get some proper ships . . .

“Best get used to it, ‘red-top’. The Hohmann transfer to Mars takes months. Your next birthday will be in zero-G.”

“By the end of this trip, I’m sure I’ll be a first-class spacer. And a Martian! I feel a little better. Let’s go see the control deck.”

But the next day, the princess threw up again.

Orbit Guard

Kratocide or capitalism?

“Don’t tell me you’re busy?”

“Crushingly. Important?”

“No. I’ll be back later.”

The U.F.P. Justice hung in null-G, poised, as its burdened commander labored over the ship’s supercomputer terminal. Two hours ago, the call had come in: “Unauthorized asteroid deflection burn, Dec. -5.419°, R.A. 41.17°, class ξ asteroid 1999 RQ36 ‘Bennu’. Deflection Δv = 0.26±0.03 m/s.”

Small deflections make big changes. Even the emission of absorbed heat makes asteroids move unpredictably, unless their surfaces are mapped in detail. But with literally millions of asteroids, the Yarkovsky effect is not worth the bother.

But now someone has gone and moved one of them. A pretty big one, maybe half a kilometer on edge. That would probably utterly destroy one of Earth’s megacities, should it hit one.

Which means someone landed on it, did a thermographic survey, plotted its orbit to high precision, and then nudged it deliberately, in a particular direction, an exact amount.

So, the question—was it some unhinged terrorist bent on the obliteration of Los Angeles? Or a miner secretly moving a motherlode of priceless volatiles back to base?

In 51 years, he’d know for sure. For now, there’d be only guessing.

A Monte-Carlo Simulation

Because really, how long is “short” for a galaxy?

“We’re alone.”

“Hmm?”

“Ran a sim. It’s really obvious. I don’t know why I didn’t think of it before. See these green dots?”

The visualization in front of her swam with millions—probably billions—of green fireflies.

“Yeah hmm?”

“Each is a planet in the sim. 1011-ish. Let’s say there are 103 civilizations, starting within 108 years of each other, technologically. Once a civilization attains spaceflight, each of their planets colonizes a vacant one every 500 years.”

“So how long does it take?”

“12 500 years for half the galaxy, and no one else has even started. See where I’m going?”

“Exponential growth is a bitch?”

“Ha. Try again.”

“It seems to me that if you pick a random point in time, chances are, either the galaxy will be empty, or else full. 20 000 years should be enough to colonize the whole thing, and that’s a very short time in galactic terms.”

“Exactly. So the fact we still haven’t heard from anyone?”

“It means either we’re alone, or we’re the first.”