Re: Please explain where you get e=mc^2 from 1905 paper

On Oct 14, 1:44 am, "CWatters" <colin.watt...@xxxxxxxxxxxxxxxxxxx>
wrote:
<frankli...@xxxxxxxxx> wrote in message

news:1192340864.849836.301840@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

How do you get E=mc^2 from any of this?

Proof in about 6 lines..

http://www.drphysics.com/syllabus/energy/energy.html

so easy he wasn't the first...

http://www.guardian.co.uk/international/story/0,,253524,00.html

"Olinto De Pretto, an industrialist from Vicenza, published the equation
E=mc2 in a scientific magazine, Atte, in 1903, said Umberto Bartocci, a
mathematical historian. "

:-)

Thank you for the references as this makes much more sense than
Einstein's orginal 1905 paper. But this has NOTHING to do with how
Einstein derived E=mc^2.

This also does bring up the point that E=mc^2 was derived before
Einstein and that you don't need relativity to do it. I would be much
more likely to accept Henri Poincaré's 1900 discovery of E=mc2
described in:

http://uk.arxiv.org/ftp/physics/papers/0608/0608289.pdf

"If c designates the speed of light in vacuum and E the
electromagnetic energy, then the radiation energy flux is S=Ec.
Poincaré now introduced a strong innovation: he assumed that the
emitted radiation carries a momentum, p. By Poynting's Theorem, this
momentum must be equal to S/c2. By Descartes's formula, one must also
have p=mv. Setting v=c, since the emitted radiation travels at the
speed of light, and combining p=mc=S/c2 with S=Ec, Poincaré readily
obtained a result he expressed in these terms: "We can regard
electromagnetic energy as a fictitious fluid of density K0J which
moves in space in accordance with Poynting's laws."

All this leads me to believe that while E=mc^2 may be a correct
physical law, Einstein's derivation of it was completely corrupt,
possibly by stealing it from someone else. This is why he uses such
vague logic as "From this equation, it directly follows that:" You
have got to be sure that when you hear words like this, that it most
certainly does not follow.

.