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.t.v.t.v.

And use my code, Isaac Arthur.

In the future, humanity may travel to many strange new worlds and make homes on them,

but we may also build giant space habitats for humanity to call home.

Probably one of the most popular topics on this channel is space habitat,

but usually we're

either discussing one specific type out of mini, like an or a cylinder, or just mentioning

them in passing as this sort of inevitable future for all mankind.

Folks coming to the channel can be surprised sometimes how we talk about them less

as things we might build a few of, and more as a mass manufactured

archipelago that will eventually house the supermajority of humans, instead of planets

being their main homes.

Space habitats are very different from a basic space station like those we have now, and

are cost prohibitive until we have a much larger presence in space, like mines and forges

on the moon, as well as greater energy abundance and better automation that is able to handle

much of the production, so humans aren't individually welding each plate of the habitats

floor together by hand. It is very likely, though though that we will reach those benchmarks inside this

century, in which case much as high rises and skyscrapers become economical with cheap steel,

enormous cylinder and ring-shaped habitats, spinning to produce artificial gravity,

...