[Professor Mega-Mind (OP)]

...........Reply #17 - Colin 2b
Take the principles laid out here .  Now imagine ~infinitely hard , extremely light , flat waves bobbing up and down extremely fast .  One intercepts a heavier , ~infinitely hard , unmoving particle .  The highly-oblique angle of interception knocks the particle forward at great speed , while the waves bobbing (oscillating) motion is instantly reduced and reversed .  This interaction is very similar to many billiard-ball collisions , but is actually representative of photon/electron collisions .  Since light is throw-away imitation matter , it could be possible to create a recoil/thrust imbalance , and thus ride an electro-magnetic wave , in place of the impossible-to-use gravity wave .
Surf it , Franklin !
P.M.