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.

In a grim and dark future among the vast ocean of our galaxy, there may be worlds where humanity

treats its members as little more than cogs in a machine or ants in a hive.

But what would such worlds truly be like?

Yeah. be like. So welcome to another sci-fi Sunday here on SFIA, where we look at concepts popular in science fiction and ask how realistic they are or how they might operate if they came to

fruition.

And today we'll be looking at the concept of hive cities and hive worlds, the grim and dark

urban settings of so many sci-fi stories.

They are bleak places where you always wonder how anyone survives and where all the food

comes from, which we'll be spending a fair amount of time discussing today, as getting

food and energy in, along with waste and heat out, are the big bottlenecks of these depressing

places where the only laughter is cruel or dark humor, and we have a fair amount of that

in today's episode too, but as many the administrator of a hive city can tell you, dark humor

is like food.

Not everyone gets it.

There are many settings that talk about enormous megacities, and indeed we even did an episode

on megacities some years back, but not very many books or shows really go into detail,

especially on the truly enormous cities.

To really look at the idea in detail, ever since we started seeing the big migration

...