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.t.v.t.v.

And use my code, Isaac Arthur.

The Industrial Revolution saw the rise of factories so big, they often grew entire towns or cities around them to operate,

but in the future, entire planets might be used to fuel the Titanic projects for conquering the stars themselves.

The Projects for conquering the Stars themselves. Welcome back to Science and Futurism with Isaac Arthur for another sci-fi Sunday here on SFIA,

where we examine popular concepts in science fiction and ask how realistic they are and

what a future with them might truly look like. One of the common themes of science fiction

is the idea of a giant city full of factories, and often these are dark and grungy places,

where even the homes workers come back to after 12-hour shifts are dirty and grimy.

There are no gardens or parks, except maybe the occasional crime-ridden one with a few

petrified and ash-covered trees left over.

These sorts of factory cities are portrayed as bleak places and draw heavily on the gloomier

moments of the Industrial Revolution for inspiration,

like the London smog, it isn't much of a stretch to imagine that repeating itself in the

future, or even worse, especially if translated up to the planetary scale.

We will discuss some of the reasons why a planet, devoted to industry, might not be a trash

heap, but this is a case where fiction might be close to right.

This episode is also an informal sequel to our episode Hive Worlds, our sci-fi Sunday episode

episode back in May of this year, where we tried to imagine what cities covering a whole planet

...