sci.physics.particle

On Feb 26, 3:28=A0pm, Cosmik de Bris
wrote:
> pmbwrote:
> > On Feb 25, 2:16 am, Eric Gisse wrote:
> >> On Feb 24, 9:28 pm, "Y.Porat" wrote:
>
> >>> On Feb 24, 11:25 pm, "chu...@gmail.com" wrote:
> >>>> Ok...so I've been wondering how on earth does gravity bend light, I
> >>>> mean I read all about how Einstein's General Relativity describes
> >>>> space-time, and when there's a mass in space-time it creates a
> >>>> curve(Bowling ball on a sheet or something), and that curve is
> >>>> Gravity, and when light passes through the curve it bends....but why?=

> >>> --------------------
> >>> just forget about curved spacetime
> >>> light bends next topthe sun
> >>> becuase of the most simple reason
> >>> LIGHT HAS MASS !!!
> >> You are amazingly sure of this despite not having one shred of
> >> evidence to support your claim. Then again, it is more important to be
> >> original than be right, eh?
>
> >>> (even Einstein ddint know to read his momentous formula
> >>> E=3Dmc^2
> >> Show us the calculation of the deflection angle given the assumption
> >> that photons have mass.
>
> > The reason that all text particles fall at the same rate given the
> > same inititial conditions is because the gravitational mass equals the
> > inertial mass and therefore the mass cancelts out in the equatuions of
> > motion. Einstein predicted that light is deflected in a gravitational
> > field because light has energy and energy has mass.
>
> You are still propagating this myth. Energy and mass are equivalent that
> doesn't mean that energy has mass.

I disagree. And its not a myth at all. The true myth is believing
otherwise. Anything which has inertial mass has energy and anything
which has energy has energy has inertial mass. As Feynman wrote in the
"Feynman Lectures" Vol -I page 7-11, Section entitled Gravitation and
Relativity
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One feature of this new law is quite easy to understand is this: In
Einstein relativity theory, anything which has energy has mass -- mass
in the sense that it is attracted gravitationaly. Even light, which
has energy, has a "mass". When a light beam, which has energy in it,
comes past the sun there is attraction on it by the sun.
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Or as Einstein wrote in "The Evolution of Physics," page 221. Einstein
is responding to the assertion regarding an observer in an
accelerating elevator "The inside observer, who believes in the
gravitational field acting on all objects in his elevator, would say:
there is no accelerated motion of the elevator, but only the action of
the gravitational field. A beam of light is weightless and, therefore,
will not be affected by the gravitational field."
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But there is, unfortunately, a grave fault in the reasoning of the
inside observer, which saves our previous conclusion. He said : "A
beam of light is weightless and, therefore, it will not be affected by
the gravitational field." This cannot be right! A beam of light
carries energy and energy has mass. But every inertial mass is
attracted by the gravitational field as inertial masses and
gravitational masses are equivalent. A beam of light will bend in a
gravitational field exactly as a body would if thrown horizontally
with a velocity equal to that of light. If the inside observer has
reasoned correctly and had taken into account the bending of light
rays in a gravitational field, then his results would have been
exactly the same as those of an outside observer.
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I understand that people may disagree with this since there is a
tendancy to confuse inertial mass (which is non-zero for light) and
inertial mass (which is zero for light). If you believe that you can
prove otherwise then please do. Thanks.

Best wishes

Pete