I've had this strange theory for a long time. If a free floating proton has a tiny amount of mass, wouldn't excelating it to near C increase its mass or energy nearly infinitely? If this is so, if we run a wire and fire electrons down its length lets say 100 times per second. Then fire protons through a field to reverse their magnetic charge, then wouldn't they adhere to the electron and effectively piggyback up to near C? Couldn't this produce a large amount of thrust? And nearing the end of the wire there would be another field to reverse the protons charge so it would "let go" of the electron and fly away? I've wondered for a long time if this could work out to be a sort of "solid state" propulsion. Electricity In, thrust out, no moving parts. What say you?