Hi, yes I know how mass 'reacts' to motion and to gravity fields. I wanted a more succint answer of what it actually is, perhaps there isn't one. I've studied how the W and Z bosons receive mass via the Higg's Mechanism but that doesn't help explain what it is. The closest answer I can come up...
Can someone tell me what mass is other than particles with mass react to a gravitational field?
Electrons and photons are quite similar, both are thought at the moment to be elementary particles, both exhibit wave/particle duality. Yet the electron has mass whereas the photon has none. It can't...