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Article #16173

Re: Why does light bend under gravity?

#16173
From: BradGuth
Date: Thu, 27 Mar 2008 20:01
87 lines
6016 bytes
On Mar 27, 10:33 am, critico <pierre.r...@numericable.fr> wrote:
> On 16 mar, 20:22, BradGuth <bradg...@gmail.com> wrote:
>
>
>
> > On Mar 11, 11:21 pm, Pentcho Valev <pva...@yahoo.com> wrote:
>
> > > On Mar 11, 5:27 am, Tom Roberts <tjroberts...@sbcglobal.net> wrote in
> > > sci.physics:
>
> > > > Tom wrote:
> > > > > The speed of light varies depending on the strength of the
> > > > > gravitational field. Einstein said that.
>
> > > > He said that in 1911, early on the then-unfinished journey to General
> > > > Relativity. GR itself does not really have this property -- the _LOCAL_
> > > > speed of light is everywhere c. When measured over non-local paths the
> > > > speed of light can vary, but there is no definite dependence on
> > > > "strength of the gravitational field", it's rather that one must compute
> > > > an integral over the path to obtain the theoretical value for such a
> > > > speed measurement.
>
> > > >         Yes, as one prolific idiot around here is fixated on,
> > > >         in the APPROXIMATION of weak fields and restriction to
> > > >         paths at fixed gravitational potential, for Newtonian
> > > >         coordinates one can express the non-local COORDINATE
> > > >         speed of light in terms of the gravitational potential.
> > > >         In 1911 Einstein did not understand all the caveats
> > > >         mentioned here, but certainly did by 1915; this idiot
> > > >         still does not understand them.
>
> > > The year is 1920 Roberts Roberts and Divine Albert still believes that
> > > the speed of light "varies with position" in a gravitational field, as
> > > Superior Brother Steve Carlip explains to you:
>
> > >http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_o...
> > > Superior Brother Steve Carlip: "Einstein went on to discover a more
> > > general theory of relativity which explained gravity in terms of
> > > curved spacetime, and he talked about the speed of light changing in
> > > this new theory.  In the 1920 book "Relativity: the special andgeneral theory" he wrote: ". . . according to the general theory of
>
> > > relativity, the law of the constancy of the velocity of light in
> > > vacuo, which constitutes one of the two fundamental assumptions in the
> > > special theory of relativity [. . .] cannot claim any unlimited
> > > validity.  A curvature of rays of light can only take place when the
> > > velocity of propagation of light varies with position."  Since
> > > Einstein talks of velocity (a vector quantity: speed with direction)
> > > rather than speed alone, it is not clear that he meant the speed will
> > > change, but the reference to special relativity suggests that he did
> > > mean so.  THIS INTERPRETATION IS PERFECTLY VALID AND MAKES GOOD
> > > PHYSICAL SENSE, but a more modern interpretation is that the speed of
> > > light is constant in general relativity."
>
> > > In a sense, Superior Brother Steve Carlip is less dishonest (or more
> > > naive) than you Roberts Roberts.
>
> > > Pentcho Valev
> > > pva...@yahoo.com
>
> > Interesting, but why does light reflect off a mirror, or get refracted
> > by an atmosphere?
>
> > Perhaps photons do not actually bend, but merely interact with other
> > matter, be it regular or dark matter.
> > . - Brad Guth-
>
> Bravo les artistes !  57 interventions et pas un mot en Français .
> On est bien sur un groupe fr. n'est-ce pas ?
> Alors, pour ceux qui ne maîtrisent pas l'englich, il est très
> difficile de repérer les conneries, car il doit y en avoir un tas , of
> course...
> Sans rancune, mais avec un pointe d'mamertume.

?

Primary photons are not the same as secondary photons, and so forth.
. - Brad Guth
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From: BradGuth <bradguth@gmail.com>
Newsgroups: sci.physics,sci.physics.relativity,sci.physics.particle,fr.sci.physique,sci.astro
Subject: Re: Why does light bend under gravity?
Date: Thu, 27 Mar 2008 13:01:16 -0700 (PDT)
Organization: http://groups.google.com
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