On Sun, Dec 24, 2017 at 05:14:08AM -0800, shadow at shadowgard.com (via tml list) wrote:
> Reactionless drives don't have that factor. so they will *always*
> violate conservation of energy, conservation of momentum, and even
> conservation of angular momentum in at least one frame of reference.

Yes.  You can get a bit of both worlds if instead of truly
reactionless drives, you have a reaction drive with tachyonic exhaust.
That would satisfy all the usual conservation laws.  There's a
potential problem with causality, but who really needed that anyway?

- Tim