sci.physics.particle

On Mar 16, 4:39 pm, The Speaking Clock
wrote:
> On 17 Mar, 01:04, BradGuth wrote:
>
>
>
> > On Mar 16, 1:41 pm, The Speaking Clock
> > wrote:
>
> > > On 16 Mar, 20:30, BradGuth wrote:
>
> > > > On Mar 16, 9:14 am, Tom Roberts wrote:
>
> > > > > The Speaking Clock wrote:
> > > > > > On 15 Mar, 08:57, Pentcho Valev wrote:
> > > > > >> [... his usual nonsense]
>
> > > > > > Would the speed of light be a non wiggly constant at the very edge of
> > > > > > the universe - bending around it?
>
> > > > > The speed of light is a constant, c, for any LOCAL measurement anywhere
> > > > > in the universe. I guess that includes "non wiggly". It also includes
> > > > > essentially all measurements of light speed here on earth. At least that
> > > > > is what GR predicts, and there are no observations that contradict it.
>
> > > > > [Ignore Valev when he brings up Pound-Rebka and similar
> > > > > experiments -- they do not measure speed.]
>
> > > > > But if you want to see light "bending around the universe" then that
> > > > > would certainly require a non-local path, and there's no solid
> > > > > prediction of the result (given the uncertainties in the physical
> > > > > situation you have in mind).
>
> > > > > It is rather difficult to perform a non-local measurement of the speed
> > > > > of light, but it has been done by sending radar waves across the solar
> > > > > system to reflect back from mars and venus. By measuring the round-trip
> > > > > delay repeatedly over several years, and fitting to the planetary
> > > > > orbits, one can deduce the round-trip speed of light for these paths.
> > > > > That speed varies, depending on how close to the sun the path passes;
> > > > > look up "Shapiro time delay". The results are in excellent agreement
> > > > > with the predictions of GR.
>
> > > > > Some people claim this is due to the solar atmosphere.
> > > > > They are wrong: by doing this for multiple wavelengths the
> > > > > effect of the solar atmosphere can be identified, and is
> > > > > found to be negligible. Of course it would be highly
> > > > > unlikely that such a different effect could mimic the GR
> > > > > dependence on path. Indeed, measurements using pulsars
> > > > > agree with the GR predictions for paths that never go
> > > > > inside earth's orbit, and we know what the solar
> > > > > atmosphere is out here.
>
> > > > > Tom Roberts
>
> > > > But photons clearly represent mass, thus the solar atmosphere of
> > > > photons does offer mass for other passing photons to interact with.
> > > > . -BradGuth- Hide quoted text -
>
> > > > - Show quoted text -
>
> > > My physics friend says - "what about the underlying noise of the
> > > universe caused by the discrete nature of the photon/s in time, and
> > > how does that contribute to the total 1/f energy of the universe?"
>
> > > And then he changed the subject because light speed and it's constant
> > > interacting with what he talked about is something to do with space
> > > travel and I'm a buddhist. lol. Although - this is just my surmise;)
>
> > Don't exclude anything unless you know for certain otherwise.
> > . - Brad Guth- Hide quoted text -
>
> > - Show quoted text -
>
> *nodding like the churchill dog*
>
> My physics friend also says that photons have a *theoretical* mass.
> Whatever that means. To a buddhist - everything looks largely
> theoretical. :)
>
> Physists don't agree on anything - not the shape of the universe,
> whether light has a constant, why it bends. Ask a simple question -
> get a complex argument. Ah well - as long as people have fun. :)

This anti-think-tank of a Usenet from hell is a good example, of
supposedly smart folks not hardly in agreement on much of anything,
especially if such rocks their mainstream status quo good ship
LOLLIPOP.

I like the zero-mass dump-truck as representing a photon, that which
can haul a wee bit of mass.
. - Brad Guth