Okay, what’s a Petrovascope? Best guess: a telescope and/or camera that looks specifically for the IR light that Astrophage emit. It looks for the Petrova line via the Petrova wavelength so it’s a Petrovascope and we really need to stop putting “Petrova” in front of everything.

Why can’t I use it when the spin drive is active?

I don’t how a spin drive works, or why it’s called a spin drive, but I do know I have one in the back of the ship and it’s consuming Astrophage as fuel. So it’s my engine. It probably activates enriched Astrophage to use them as thrust.

Ah… that would mean there’s a ridiculous amount of IR light coming out the back of the ship right now. Like… enough to vaporize a battleship or something. I’d have to do the math to know for sure but—I can’t help it, I want to do the math right now.

The engines consume 6 grams of Astrophage per second. Astrophage stores energy as mass. So basically, the spin drive converts 6 grams of mass into pure energy every second and spits it out the back. Well, it’s the Astrophage doing the work, but whatever.

I bring up the “Utility” panel on a smaller screen to my right. It has a bunch of familiar applications, all ready to go. One of them is a calculator. I use it to calculate the mass-conversion energy of that 6 grams… good Lord. It’s 540 trillion Joules. And the ship is emitting that much energy every second. So it’s 540 trillion watts. I can’t even fathom that amount of energy. It’s considerably more than the surface of the sun. Literally. Like… you would get hit by less energy if you were on the surface of the sun than if you were standing behind the Hail Mary at full thrust.

I’m decelerating right now. Have to be. The plan is to come to rest in the Tau Ceti system. So I’m probably pointed away from the star and slowing down—having spent a really long time at near light speed during the trip.

Okay, so all that light energy will hit dust particles, ions, and anything else between me at Tau Ceti as I plug along. Those poor little particles will be brutally vaporized. And that’ll scatter some IR light back at the ship. Not much compared to the engine output, but it would be blinding to the Petrovascope, which is finely tuned to look for trace amounts of that exact frequency.

So no using the Petrovascope with the engine on.

But man. I would love to know if Tau Ceti has a Petrova line.

Theoretically, any star infected with Astrophage should have one, right? The little blighters need carbon dioxide to breed. Can’t get that from the star (unless you go way into the core, and I don’t know if even Astrophage could survive those temperatures).

If I see a Petrova line, it means that Tau Ceti has an active Astrophage population that, for some reason, hasn’t grown out of control like it has everywhere else. And that line will lead to a planet that has carbon dioxide. Maybe there’s some other chemical in that atmosphere that impedes the Astrophage? Maybe the planet has a weird magnetic field that messes with their ability to navigate? Maybe the planet has a bunch of moons that the Astrophage physically collides with?