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.

Imagine a vast, self-sustaining habitat floating in the depths of space, where entire

communities could live, work, and flourish in a garden park world tailored to their needs

and desires.

The Bonoos. and desires. The Bernal sphere is one of the earliest and most iconic visions of a space habitat, conceptualized by John Desmond Bernal in 1929.

This bold idea presented a self-sustaining, rotating spherical structure 10 miles wide,

designed to house thousands of people in space.

The sphere's rotation would create artificial gravity on its inner surface, enabling residents

to live and work in an earth-like environment, with provisions for agricultural zones,

living quarters and energy systems that

harness solar power, the Bernersphere offered a comprehensive approach to human settlement

beyond Earth, addressing fundamental needs such as food production, atmosphere control, and

radiation protection.

Burner's concept inspired future space architects and science fiction creators by presenting the vision

of a permanent, habitable outpost in space.

It laid the groundwork for later, more complex designs like Gerard-Kale-Hale's space habitats

and influenced the broader discussion on space colonization.

The Bernal sphere embodies the ambition of expanding human civilization to the stars,

envisioning not just survival but the possibility of thriving in the cosmos.

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