On Sep 16, 4:06*pm, John Smith wrote:
Art Unwin wrote:
...
Radiation has no mass? You just made that up

Yes, that would seem to break the law of "'E' equals mc squared", and
its' opposite, counterpart ... I mean, if you really think about it ... ;-)

Regards,
JS

John, the danger in using mc squared is that it has not stood the test
of time. I have difficulty with it as the motion of an observer
acheiving the speed of light seems like standing on a sand spar
waiting for the tide to come in. Same goes with Feynman diagrams
as it just replaces an unknown with another unknown! Are these both
emporers with no clothes surrounded by Lemmings?
Art