The problem isn’t really the need for exotic matter in enormous quantities (apparently we have a negatively curved universe where dark energy serves exactly tha

The problem isn’t really the need for exotic matter in enormous quantities (apparently we have a negatively curved universe where dark energy serves exactly that purpose), but rather the aspect of causal disconnection: everything inside the bubble is disconnected from everything outside it, so it’s difficult to envision how the spacecraft inside could be generating, steering, or even shutting down the warp bubble outside itself.