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 ad-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 Brilliant.

One day we hope to journey to new worlds, but once we are there, how will we travel around them?

So a few months back, one of our newer editors, Jason Snyder pointed out that while

we spent a lot of time talking about how to travel to other worlds beyond our own, we generally

don't spend much time talking about how we were actually travel around those places once there.

And in my suggestion he submitted an excellent outline

that serves as the basis for today's script. All chance to see how folks in the future might

make their way around their distant homes. This was also about the same time my wife and

I started taking flight lessons and like a lot of folks I often enjoy the journey to places

as much as the destination. Those long trips in a car, and like a lot of folks, I often enjoy the journey to places as much as the destination.

Those long trips in a car, chatting with a friend or listening to an audiobook and seeing the

scenery are some of the most pleasant and relaxing times, all at the same time, flying through

the air can be exhilarating. Of course, many planets have no air and while they might one day have roads, they don't now.

So we'll be focusing on different techniques and circumstances, whether it's traveling in

a vacuum or by blimp on Venus, or subglacial bullet trains or complex tether and orbital

ring systems.

We will approach it by looking at unique challenges and opportunities on each world, beginning

with Mercury, then we'll move out, world to world until we get to the Kuiper Belt and Pluto,

...