Thread:Ghelæ/@comment-5080468-20170728205943/@comment-47205-20170728211652

Extrapolating technological development, especially with fictional physics, is really educated guesswork at best.

Fusion bombs are out of the question: they're far too weak; a planet-destroying one would have to be comparable to the planet itself in size. For a small planet or large moon, you're easily dealing with about 1030 J gravitational binding energy, or around 1013 kg (ten billion tonnes). This means that even an antimatter bomb, miraculously managing to transfer all of its mass into planet-busting energy with complete efficiency, would need to weigh at least that order of magnitude.

So destroying a planet is not going to be a matter of improving on simple technology like fusion bombs or antimatter containment. It's going to require developing something entirely new. So the answer to "could they do that in 200 years" is, "erm, maybe?".