Hello, SFIA audio listeners. In this month's Nebula exclusive, big alien theory,

we're asking the reason alien civilizations might be rare is because most aliens are huge.

To hear it and every episode early and ad-free, plus hours of bonus content,

check out go.nebola.tv slash Isaac Arthur and use my code, Isaac Arthur.

As the smoke clears from the mushroom clouds, and the alien saucers hover overhead,

and people grimly ask, what is next?

All I can really say is, I, for one, welcome our new alien overlords.

The war is over. the aliens have won, but humanity still has to live with the aftermath.

We often imagine the day of alien arrival as binary, either they come in peace or they

come in fire. In earlier discussions we looked at aliens have contacted us,

now what, where the great mystery was how we might respond to the simple fact of

intelligent life beyond Earth. Then, and we've been invaded by aliens, now what,

we asked how humanity might fight, resist, and endure a hostile invasion. But let's suppose the alien

invasion is over. The aliens won. Their fleets hang above

our cities, or what's left of them, their banners are planted on our capitals, and their patrols

march through our streets. The old governments are gone, or at least reduced to figureheads,

and the Earth itself is now a client world of an alien empire. So, what comes next?

The good news they probably do not want us for food or labor or debased personal pleasure.

Sci-fi tends to assume one of those three motivations, but they never seem very likely to me.

Unfortunately, that journey leads me to assume an alien would be much more likely to simply

wipe us out, but there are other motives for conquest too.

As those three, let's quickly recap why they are unlikely.

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