Experiment

“This isn’t really safe, is it.”

“That’s good on paper. What about practice?”

“Of course, we won’t know anything until we try.” John shot her a quizzical look, then went on: “It’s not like the academy is fully cognizant of the potential significance of this work.”

“They’re barely cognizant of their own financial security, which, by the way, is still rather tenuous. Research cuts, you know.”

“Don’t I know it.”

“Well let’s try it, then. We’ve been ready for a while. Months, really.”

John nodded. And, without further ceremony, a small red button was pushed. Somewhere, machinery hummed, and two enormous drums of titanium alloy began spinning in a perfect vacuum.

Faster and faster the enormous drums spun, until sheer strength was insufficient to hold them together, and the radial artificial gravity fields began crushing them inward.

Their outer surfaces were racing past each other now at thousands of kilometers per second, separated by a tiny vertical strip just millionths of a meter wide. To the naked eye, the two atomically perfect, titanic disks touched in a single, unbroken line.

But of course no human would risk his life from being so near to such contained energy. And of course, the Earth couldn’t be risked either, so that was far away too.

“We should see something by now,” Casey observed, searching without success for that something.

“Well, frame dragging is within predicted measures.” said John.

“The cylinders are warping spacetime past 0.5 c. Something’s going to have to give, and it’d better be space. There’s already more than a quadrillion joules of kinetic energy in those wheels.”

Nothing.

“It’s a wash, then.”

“3 trillion , wasted.”

“Wasted?” Casey smiled furtively. “No; we’ve only just begun.”

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.”