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 ad-free, plus hours of bonus content,

check out go.nebula.tv slash Isaac Arthur and use my code, Isaac Arthur.

The Stanford Torres is a vast space habitat design intended to allow thousands to dwell safely

and comfortably in space, but how do we build such a structure?

Today we're looking at the Stanford Taurus Space Habitat, one of the best known designs

for a spin-gravity space station designed as a long-term dwelling for an entire community

of humans and a true ecology.

An enormous donut, often a mile wide in designs, this wheel shape can be combined with

other wheels of the same size or not, around a central

axis with minimal artificial gravity, while those inside the hoop benefit from full gravity

caused by rotation of the hoop.

The spinning wheel design, in its most well-known incarnation, would have a diameter of

7090 meters or 1.11 miles, mass at least 10 megatons,

mostly in radiation shielding, and housed an estimated 10,000 people, an estimated 67 square

meters or 721 square feet per person. Bigger designs are possible, as are smaller ones, as this radius, 895 meters or 2,936

feet, was selected for it and other designs, as is the radius that spinning object can

have while rotating exactly once per minute, 1 RPM, and producing the 9.8 meters per second per second that we call

normal gravity. Today we'll be both looking at the basics for folks who don't know it,

and deep-diving some aspects for the folks who are already quite familiar with it,

so no prior knowledge is needed, but it doesn't hurt either. While not the first design by any means,

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