Re: .Re: Why all the fascination with E = mc^2 ??

From: Dirk Van de moortel (dirkvandemoortel_at_ThankS-NO-SperM.hotmail.com)
Date: 06/09/04 

Date: Wed, 09 Jun 2004 14:27:26 GMT

"Pmb" <someone@somewhere.com> wrote in message news:Po-dncJ1fJBij1rd4p2dnA@comcast.com...
>
> "John C. Polasek" <jpolasek@cfl.rr.com> wrote
>
> > I scanned your site and have a question.
> >
> > Since you show two photons, A and B, are moving in opposite
> > directions, doesn't that mean that you could substitute 0 for PA +
> > PB? It seems true, but wouldn't that subsitution reduce your finding
> > to a tautology (or something)?
> >
> > I didn't chase the logic far enough to see if it would make any
> > difference.
>
> Here is a much simpler derivation of E = mc^2 based
> on the principle of the conservation of mass and on the
> relationship between energy of radiation and the
> momentum of radiation, E = pc
>
> Let M_i be the initial mass of a box and M_f the final
> mass. Let the box radiate and amount of energy E in
> equal and opposite directions. Define the

[mark the usage of the word "define"]

> mass, m, of the radiation by p = mc. Let the amount
> of radiation of each pulse be U, i.e. U = E/2. The
> relationship between U and p is given by U = pc
> (derived through EM principles. Due to the principle
>of the conservation of mass,

Are you serious about this?

First you *define* something through an equation
p = mc. And you decide to *call* what you have
defined "mass".
And then you apply the "principle of conservation
of" what you have defined.

That does not look like a derivation to me.

Dirk Vdm

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