Terran wrote:Source of the post If you just took a homogeneous gas or material with a high density and encased a localized region of spacetime, then leave a void in the middle, you should essentially have a region of negative curvature when compared to the shell.

Assuming spherical symmetry to this setup, then the space-time geometry of the void will be flat (described exactly by special relativity), and the region outside it will obey the Schwarzschild metric. Unfortunately, no part of this looks like a wormhole metric. Otherwise we could build wormholes quite easily.

To make a wormhole, the popular description is to connect the singularities of two Schwarzschild metrics to each other (how to achieve

*that* is an exercise left for the forum). But this connection is violently unstable. It requires something which is gravitationally repulsive to keep it open, which means a negative energy density in a manner which violates the energy conditions -- and this is very likely an unphysical solution to the equations.

Another form of wormhole that can appear in the mathematics is for a charged or rotating black hole. Either effect (or both) generates a region of space-time where space flows back outwards -- into a new universe, perhaps. However, there are again clues that such solutions are unphysical.

There's nothing inherently wrong about putting wormholes in SE -- the mathematics describing such a thing exists. It's just a question of programming feasibility and one's stance on including speculative / sci-fi realms of physics. Alcubierre drives are already in Space Engine and those are just as unphysical as wormholes.