[Spaceships] Your preferences regarding plausible/playable Reactionless Drives

[Anthony]

Actually, ramscoops that hang around soon-to-go-supernova stars might have some uses.

[teviet]

Originally Posted by Anthony

General relativity forbids perfect stiffness. The maximally stiff medium discussed above is the maximum permitted by GR.

Also follows from special relativity. Speed of a wave generally goes as sqrt(stiffness/density), so maximally stiff means that waves travel at lightspeed.

The EM field is of course a maximally stiff medium. Solid materials are far from maximally stiff: their densities are much too high.

TeV