"Old Man" writes:

Gordon D. Pusch wrote in message
...
"Old Man" writes:
[...]
Rest mass of a single photon is zero, and a single
photon doesn't have a rest frame. However, observe that two
photons, with identical energy, E, but with appositely directed
momentum, E / c = p1 = -p2, have total rest energy of 2*E wherein
the gravitational mass of the two photon system is M = 2*E / c^2.
In the center of momentum system, total energy gravitates. If
the two photons are travling in the same direction, such that
p1 = p2, then the total rest energy is zero because, in this case,
it is impossible to define a center of momentum frame.

The "rest frame energy" (actually, "Center of Momentum frame energy")
is not "zero" in the "parallel" case, but rather =UNDEFINED=, because
_NO SUCH "REST FRAME" EXISTS_.

And in any event, such hand-waving attempts to make naive analogies
between Einsteinian and newtonian physics are at best ill-justified,
and at worst, JUST PLAIN =WRONG=. Newtonian physics is the "weak field,
slow motion" approximation to General Relativity --- and photons CANNOT
be considered "slow moving" in any Einsteinian sense !!!

Pusch suffers from delusions of competence. [Old Man]

"{Old Man]" suffers from projection of his own delusions of competence on
others, as well as some VERY peculiar notions regarding how relativistic
physics works --- no doubt because he is largely self-taught (as I believe
he has admitted in this forum), and has not interacted sufficiently with
other physicists during this process to correct his own conceptual errors.
I strongly suggest he crack the books again, because he is quite, quite
wrong in this case.


-- Gordon D. Pusch

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