Recently I read a sci-fi describing a species living in a closed hollow space in a planet. An earlier answer suggested that such structures could exist but will not be stable, if only effected by self gravity.
What would happen if I were to fall into a massive hollow planet?
Hence, I was wondering whether there could exist celestial bodies that:
- are at least about the size of a planet (~$1000km$)
- at stable equilibrium, admit a closed hollow space with dimension near the size of the whole object (diameter~$0.1 \times$ planet radius)
Can this be done by applying electric charge, spin, or placing other celestial bodies nearby?
