#WorldBuilding #WritingPrompt:

Alternate reality where Earth's gravity is upside down.

Life evolved in cave systems.

What happened when the first humans made their way out of the caves?

Did they ever develop structures to live on the "ground?"

How?

What is their religion like?

What does outer space look like with negative gravity? (Is it negative only on earth?)

Is space travel unidirectional?

What is architecture like?