I would see several of them within real world physics, but none of thematpollard said:To turn from the well kicked tires of economics for a moment, are there any thoughts on possible 'Engineering' deal killers?
within the physics behind the Third Imperium technology (e.g. reaction-
less drives).
As for terraforming, I would expect the creation of entire ecosystems and
biospheres "from scratch", including the use of genetically engineered spe-
cies designed for specific purposes, to become possible around late TL 9 /
early TL 10.