That’s why I said engineerable. If it takes the mass-energy of Jupiter it’s likely something that could never be done since no material could contain or control

That’s why I said engineerable. If it takes the mass-energy of Jupiter it’s likely something that could never be done since no material could contain or control such energy in an organized way. This paper does not offer an engineerable solution but it does argue that negative mass, which may not exist, may not be required. That brings us closer. Are there solutions that require less energy? Are they physical or just math artifacts? Get the energy down to LHC levels and it becomes testable if even at submicroscopic scale. Show it at any scale and it’s a physics revolution and front page news and loads of money starts being spent. Going to the moon was once dismissed by many scientists as requiring silly amounts of energy until we figured out a bunch of things like modern rocket engines and staged rockets.