EINSTEIN:  THE PHOTON HAS MASS


To all those who believe the fable about the photon having no mass,
let me tell you the story Einstein tells. And then we shall see.


                             -<*>-


We have a "body"  popping along at a goodly pace. Therefore, it has a 
kinetic energy and is subject to the Lorentz transform which we will
designate here as R.

Now, here comes a photon that slams into the body and is, in Einstein's
own words, "absorbed".

Einstein gives the energy of the photon as E_0. (He refers to it as
"radiation".)


Now the body, in absorbing the photon, does *not* -- by stipulation -- 
increase in velocity (This is important) but *does* increase in kinetic 
energy by  -- not E_0 but by  E_0/R.                      

                                     
                                         E_0
                                    (m + --- ) c^2
                                         c^2
     The new energy of the body is  ==============    
                                          R


Einstein:

                                                          E_0
"Thus the body has the same energy as a body of mass (m + --- ) moving
                                                          c^2
                                                         
with velocity v"  (the same continuing velocity)

"Hence we can say: If a body takes up an amount of energy  E_0, then
its inertial mass increases by an amount E_0/c^2 ; the inertial mass
of a body is not a constant, but varies according to the change in the
in the energy of the body. The law of the conservation of the mass of 
a system becomes identical with the law of the conservation of energy,
and is only valid provided the system neither takes up nor sends out 
energy."

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That's what Vergon has been saying all along!
In addition this scenario fits my description of the Compton scattering
experiment.

I've used quotes here because Einstein said it -- and said it much better 
than I could have.

In my words:

In short, we have a body moving at a high velocity absorbing a photon
without increasing its velocity. The mass of the body increases, increasing
the kinetic energy. The increased mass has to be that of the photon.

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Comments?


V.V.     The Ugly Duckling