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 add free, plus hours of bonus content,

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

Space is enormous and may be home to many ancient civilizations besides ours.

What do we do if we realize we are no longer alone?

And it turns out, they are not coming here as friends.

One day you wake up and the news is telling us unequivocally that aliens have arrived,

their intent unclear. The next day, their ships are landing, and their intent has become very clear.

As clear as the holes, their disintegration rays are leaving in buildings.

We've been invaded by aliens. Now what?

Of course, the long-standing piece of channel advice on aliens attacking is to get on your knees

and pray, because that's got a better chance of working than any actual defense we might mount,

and if it doesn't work, it leaves you well positioned to either kiss your butt goodbye or welcome on new alien overlords.

But how true is that?

Today we're going to ask what we might do if aliens invaded, and that depends a lot on what their motivation is.

Why have they invaded and what is their goal?

Some of these scenarios give us better chances than others. We'll explore

why aliens might invade, and even consider the possibility that they might already have invaded.

Now, I want to say up front, since this episode is a quasi-sequel to last year's aliens have

contacted us, Now What episode, where some folks folks were confused that while we can discuss the idea

that this may already have occurred, I for one do not think it has.

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