I think they have Eric, if you put a bunch of photons in a reflective box, the resistance to acceleration of the box is increased by the presence of the photons just consider the blue/red shifting of the energy of the reflecting photons.
And I believe it is considered likely that photons also create a gravity field, indeed it seems it must. And so it is tricky to work out what definition of mass is there where photons don't have any? John On Wed, Feb 4, 2015 at 5:42 PM, Eric Walker <eric.wal...@gmail.com> wrote: > On Tue, Feb 3, 2015 at 7:54 AM, David Roberson <dlrober...@aol.com> wrote: > > It would have been a surprise to find that nanovortices did not have mass >> since they obviously have energy. > > > Mass is a tricky thing. Photons have no rest mass, for example, even > though they can carry as much energy as you can put into them. But they do > follow the contours of spacetime, almost as if they had mass. (I wonder, > here, whether physicists have gotten themselves into another language game > with this one.) > > Eric > >
