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.

This episode is brought to you by Skillshare.

If aliens exist, there may come a day when we live and work alongside them, and if the internet

has taught us anything, far in love with them, too.

Science fiction often shows us busy spaceports and metropolitan planets full of various aliens, probably

most famously the hive of scum and villainy, the Moss Isley Cantina in the original Star Wars film,

and in the most detail in the Babylon 5 series, where the titular space station is essentially

the city in space where all the diplomats of a hundred races gather.

Today we'll explore how likely that is, having many different aliens working and living together, and how it might actually function if it were. Also, since this episode comes out

on Valentine's Day and such settings so often feature half human, half alien hybrids,

I thought we'd explore the notion of falling

love and marrying an alien too. We have to start by stipulating the existence of alien civilizations

and an abundance of them for the scenario of multi-species civilizations to exist, and channel

regulars know that I'm generally skeptical that alien civilizations exist anywhere in our own

galaxy, or even neighboring ones, so for today we will simply assume they are quite common.

We will also explore both scenarios where fast and light travel being possible, as it generally

is in such science fiction, with lots of aliens, and a no-FTR scenario. It should however be noted that some of the

issues discussed here may be present in a potential far future where different groups

of human descendants had diverged greatly, either the old-fashioned way or more rapidly through technology.

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