russ_hensel
- Joined Jan 11, 2009
- 825
All current theories that I am aware of still assign mass to photons ( and/or e and m waves ) Just no rest mass. The biggest change that I have seen is that the neutrino was thought to have 0 rest mass and is now believed to be small but non-zero.......
One of the arguments is they responded to acceleration and gravity pretty much the same way as conventional matter. Now I'm told it is massless. <shrug> OK, whatever.
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And since GR gravity has not be a force, but an aspect of curved space-time.