: Of course you can have a wave that moves through nothing. - that's exactly what a light wave does. A light wave is a transverse self -sustaining oscillation of electric and magnetic fields. The oscillating electric field creates the magnetic field and the oscillating magnetic field creates the electric field as clearly described by Maxwell's equations - ever here of him??? This is basic first year physics for God's sake. Also as I have said before the attractive force of gravitation has nothing to do with a gravity wave. A gravity wave by it's very nature cannot have any attractive force whatsoever.

Light is material thing.