sci.physics.relativity

"John C. Polasek" wrote
> On Fri, 24 Aug 2007 15:58:39 GMT, "Androcles"
> wrote:
> >"John C. Polasek" wrote
> >: On Fri, 24 Aug 2007 13:37:04 +0200, "qbit" wrote:
> >:
> >: >FACT #1:
> >: > A photon emitted at the Earth surface (ignoring air-resistance)
> >: > and going up vertically into the space is SLOWER than a photon
> >: > going straightforward in vacuum space; ie. slower than c.
> >: > Reason: attraction by the Earth gravity.
> >
> >: Not at all. A "photon"'s velocity increases as it leaves the gravity
> >: well, thus stretching the WL and maintining constant frequency.

Hmm. how is that possible? A photon cannot accellerate on itself.
It just can keep its initial speed. Only if it gets into the direction of
the center of a G-field then it will accellerate, and if the G-field gets
weaker then it cannot accellerate as it means the center of gravity
is behind the photon's path.
So a photon's velocity can in this case not increase. Don't you agree?

> >Not at all. A "photon"'s velocity DECreases as it leaves the gravity
> >well, thus shrinking the WL and maintAining constant frequency.
>
> No, that would be a blue shift but we see a red shift.
> It's like clapping with one hand to ascribe all kinds of hijinks to
> photons, when the interesting stuff occurs with the *generator* of
> photons, namely an atomic oscillator.
>
> The oscillator frequency is reduced in gravity, by the same proportion
> that c is reduced in gravity, (that being a low-energy regime) so it
> retains its native wavelength unchanged, in or out.
> Upon emission the reduced frequency "photon" with its native WL
> emerges with the WL stretching as c INCREASES on the way out. It
> retains its low energy frequency unchanged by the climb.
> If c gains 1%, and WL gains 1%, frequency = c/WL remains constant.

Hmm. you say "c is reduced in gravity". This is IMO not exact as
it depends on the direction of the path of the photon, ie. whether
it goes into the direction of the center of the gravity (then v_photon becomes >c),
or to the opposite direction (then v_photon becomes
> >: >FACT #2:
> >: > A photon emitted in vacuum space and falling down vertically
> >: > to the surface of the Earth (ignoring air-resistance) is FASTER
> >: > than a photon going straightforward in vacuum space; ie. faster than c.
> >: > Reason: attraction by the Earth gravity.
> >:
> >: The velocity and clock frequency of its light is reduced in a gravity well.
> >
> >Not at all. The velocity of its light is reduced in a gravity
> >well, the frequency is invariant.

We are talking of the velocity of the photon towards the center of a gravity field
(here v_photon becomes >c), and off a gravity field (here v_photon becomes
> Clap with two hands. The CLOCK frequency is reduced in gravity 1% and
> c is reduced 1%, so the WL = c/F is the same up or down.
> >:
> >: >Ergo, FACT #3:
> >: > In gravitational fields the real speed of light differs from c.
> >: > It can be even faster than c! The direction is important, see above.
> >: > (Remember: c is just a manmade definition of a constant!).
> >
> >: Always slower, gaining as it leaves the well.
> >
> >Not at all. See Sagnac.
> >
> Always slower, see Shapiro.

Always slower than c, yes, but the second part of your saying
("gaining as it leaves the well") does not hold.

> >: >Ergo, FACT #4:
> >: > Due to the equivalence principle (accelleration/deceleration is like
> >: > gravity and vice versa), the speed of light in accellerated/decelerated
> >: > frames differs from c. It can be even faster than c! It depends on
> >: > accelleration/deceleration and of course on the direction of the
> >emitted light.
> >: > (Remember: c is just a manmade definition of a constant!).
> >: >
> >: >Ergo, FACT #5:
> >: > What's valid for photons is of course also valid for anything else!
> >: > (except that each particle type and macroscopic objects can have
> >: > their own characteristic MaxSpeed, even beyond c).
> >: >
> >: >Ergo, FACT #6:
> >: > Everybody who says different is a charlatan.
> >: > These facts speak for itself. We ordinary people call this kind of
> >reasoning
> >: > LOGIC, something that seems like from outer space to most Relativists!
> >:-)
> >:
> >: You have everything all wrong.

I don't think so.
All what is said in these FACTs is IMO very logical and true.