A hollow planet
65737
What would happen if I were to fall into a massive hollow planet?
76615
A story about Earth in far future with a civilization centered around a huge tree
110960
ID a book about a mirror world and 4th dimension
89194
Potential at Center of Earth
12720
Short Sci-fi story about a sentient planet/creature that exists to seed the universe with life
92591
Could a Dyson Sphere-like object be made to encase a black hole without collapsing?
116300
Electric Potential produced by Hollow Sphere
141434
Why is the field inside a hollow sphere zero?
22184
Planet where humans fight for access to algae
131274
Earthlings create and interact with a pocket universe; universe inhabitants eventually desire to escape
132722
Why was this item left relatively unguarded on a barren planet?
46739
Dark Energy saving the world
141399
Throwing a ball from the surface of the earth so that it ends up in a circular orbit
111401
Short sci-fi story about Earth blockaded by other human colonies
54446
Story about living planet linked to skin lesions
87913
Could there be a star orbiting around a planet?
144344
Book: Female protagonist transformed into alien on alien planet