[ar0b]

So you could theoretically build a black whole generator by building a sphere that could emit gravitational waves with precision?

[Aelinsaar]

You'd need the sphere to be more than massive enough to collapse under its own gravity, into a black hole; such a structure wouldn't be hypothetically possible. Building black holes with anything other than stars or giant gas clouds (in the early universe) turns out to be hard; your black hole generators inevitably keep collapsing into black holes or at least neutron stars.

[fizx]

> You'd need the sphere to be more than massive enough to collapse under its own gravity, into a black hole; such a structure wouldn't be hypothetically possible.

I don't think that's technically true. You could build a bunch of catapults on the edge of the sphere, and when they all launch rocks at the center of the sphere, they would eventually form a black hole. The catapults could be arbitrarily far from each other as the radius of the sphere increases, such that they would not really do much to each other gravitationally. You'd just have to wait a real long time for the rocks to hit the middle.

> Building black holes with anything other than stars or giant gas clouds (in the early universe) turns out to be hard;

Well yes, galaxy-sized intelligently designed structures don't really happen.

[b34r]

Some A+ structural integrity fields I suppose.

[4ad]

You don't need to emit gravitational waves, you can emit light that converges to a point.