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

we're asked at 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.

Stars give warmth of light to planets and make life possible until they run out of fuel and die themselves, but could these dead stars still enable life to dwell around them?

There are hundreds of billions of stars in this galaxy and most are smaller than our sun,

and even of those that are bigger, virtually all will expand to a red giant one day,

then shuck off their outer layers and collapse inward into a burned-out husk called a white dwarf.

This is the fate of 97% of all stars, including our own, and so it

stands to reason that we might want to have a game plan for living around them. Indeed,

even though most stars that have ever formed are still alive, we still have around 10 billion

white dwarfs in our galaxy already, including over a dozen in our nearby interstellar

neighborhood out to about 30 light years.

So while every civilization probably needs to have a plan for living around white dwarfs

eventually, it probably behooves them, and us, to have a plan even sooner.

We will also be exploring some new megastructures and variants that work well around white dwarfs,

and brown dwarfs too for that matter, such as strip wards or solar bracelets, so our

journey today is going to take us to the heights of mega engineering and the depths of deep

time, which means we'll be here for a bit, and a drink and a snack might be

a good idea, and don't forget to hit the like and subscribe buttons while you're at it.

Now our goal today is not to rehash the basics of what white dwarfs are or how they come

to exist, I think most people do know that, but a lot of times that's about where that

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