[THERMAL mass transfer]: Gerald L. O'Barr wrote: -=-
In m
I know they say a photon **doesn't** have a [REST] mass.
Tom Roberts wrote: -=-SNiP-=- -=- eV/c^2. -=-
$$ The GUESS iSS test REST mass is, eM/c^2. [Brackets mine.]

Gerald L. O'Barr globarr comments: -=-
In SR [& GR], they have changed the meaning of the word, 'mass.'
[Conspiring with SOME economically-associated collaborates, etc.]

Mass no longer means mass, as it is used in all other
sciences. In SR [and GR], they today only allow the word
'mass' to mean 'rest mass.' Those in SR [and GR] are too weak
to use mass the way everyone [General Science] else uses this
word [mass].
-=-
So a photon, never being at rest, still has to have
mass, as it is defined in all other [GENERAL] sciences.
And a photon will always have such mass, since it is always
moving. Therefore, a photon is a real particle of mass, as
others [General Science] would say it.

wrote:
But do we know the amount of energy a single
photon can produce [as ABSORBED] and then use E=mc^2
thus [EQUiVALENT] m = E/c^2 [as ABSORBED mass.] -=-

$$ THERMAL mass transfer (Radiation light).
$$ A photon EMiTTED with energy h*f, subs ..h*f/c^2, mass.
$$ A photon ABSORBED with energy h*f adds ..h*f/c^2, mass.
$$ Think of this as you would poking MARBLEs through tube.
$$ [So ONE's Loss Marble is ANOTHER's gain, by increment].

$$ Fridge magnet = suction cup equation, next.
$$ Think of a Regrigerator Magnet as a Fridge Suction Cup.
$$ Each must do WORK in OVERcoming friction, or FALL down.
$$ Refrigerator Magnet = Fridge Suction Cups of Trembling.

$$ Hope this helps, ```Brian A M Stuckless, Ph.T (Tivity).

Tom [He between his error-bars] Roberts wrote: -=-
E single photon has energy E=hv, where h is Planck's constant,
and v is the frequency [as MEASURED] of the [says Tom] source.

-=- deletes Thanks for reading.
Gerald L. O'Barr Remove three dots
is there a "theoretical" mass for a photon ???
THERMAL mass transfer. End of POST.