> > "They" claim that momentum can have energy without mass,
>
> The equation
>     E^2 = m^2 c^4 + p^2 c^2
> says that when m = 0
>     p = E/c
> giving a relation ship between momentum and energy for
> something without mass. So this shows how
>     "momentum can have energy without mass".
>
Well, of course it does say that, but no mass can equal zero, or if it
does, it is not possible for us to measure it because it is invisible
to us.  We can only see mass when it is more than zero.  Therefore,
your equation is fantasy, or, if it can be said that a "zero mass" can
exist, that can be so only wrt the Uncertainty Principle where we can
only say that there can be an _average_ of zero mass - but not an
actual zero mass.