From: Dr J R Stockton on
In sci.astro message <VOidnddJvPuxG8DR4p2dnAA(a)giganews.com>, Sat, 7 Aug
2010 11:13:32, Tom Roberts <tjroberts137(a)sbcglobal.net> posted:

>
>This last is just plain wrong. In GR, light always follows a null
>geodesic, which means that a local measurement of a light ray's speed
>will always yield c (measurement made in a locally-inertial frame using
>standard clocks and rulers). This is completely independent of where
>the light ray was emitted or where the measurement is made.

That is not really meaningful. Consult BIPM's site. The standard clock
exists in essence; its rate is given by a transition frequency of
Caesium. But length is now defined by setting the speed of light to
299792458 m/s exactly. Therefore, the speed of light can no longer me
measured. The experiment can be performed; but the result is a
calibration of the local ruler.

AFAICS, all that can really be said is that a photon cannot overtake
another along the same path; and that if nothing else changes then two
photons on the same path maintain a constant separation in time.

But something must be added about the size of the photon and the nature
of the environment; a visible photon can pass along the centre of an
ordinary, but evacuated, long metal water-pipe, whereas a photon of AM
radio should not.

--
(c) John Stockton, near London. *@merlyn.demon.co.uk/?.?.Stockton(a)physics.org
Web <URL:http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
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From: Pentcho Valev on
PREMISE: By increasing the perimeter of a rotating disc while keeping
the linear speed of the periphery constant, one converts clocks fixed
on the periphery into VIRTUALLY INERTIAL clocks (the "gravitational
field" they experience is reduced to zero).

CONCLUSION: In accordance with Einstein's 1905 light postulate, a
clock at rest situated outside the disc, close to the periphery, will
be seen running SLOWER than the virtually inertial clocks passing it.
Another prediction based on Einstein's 1905 light postulate is that
the clock at rest will be seen running FASTER than the virtually
inertial clocks passing it ( http://www2.bartleby.com/173/23.html ).
Clearly we have REDUCTIO AD ABSURDUM showing that Einstein's 1905
light postulate is false.

Pentcho Valev
pvalev(a)yahoo.com
From: Pentcho Valev on
PREMISE (Einstein's 1905 light postulate):
http://www.fourmilab.ch/etexts/einstein/specrel/www/
"...light is always propagated in empty space with a definite velocity
c which is independent of the state of motion of the emitting body."

CONCLUSION: In the bug-rivet scenario described below an observer
travelling with the rivet will see the bug being squashed. Observers
at rest relative to the bug will see it alive and kicking. Clearly we
have REDUCTIO AD ABSURDUM showing that Einstein's 1905 light postulate
is false.

http://hyperphysics.phy-astr.gsu.edu/Hbase/Relativ/bugrivet.html
"The bug-rivet paradox is a variation on the twin paradox and is
similar to the pole-barn paradox.....The end of the rivet hits the
bottom of the hole before the head of the rivet hits the wall. So it
looks like the bug is squashed.....All this is nonsense from the bug's
point of view. The rivet head hits the wall when the rivet end is just
0.35 cm down in the hole! The rivet doesn't get close to the
bug....The paradox is not resolved."

Pentcho Valev wrote:

PREMISE: By increasing the perimeter of a rotating disc while keeping
the linear speed of the periphery constant, one converts clocks fixed
on the periphery into VIRTUALLY INERTIAL clocks (the "gravitational
field" they experience is reduced to zero).

CONCLUSION: In accordance with Einstein's 1905 light postulate, a
clock at rest situated outside the disc, close to the periphery, will
be seen running SLOWER than the virtually inertial clocks passing it.
Another prediction based on Einstein's 1905 light postulate is that
the clock at rest will be seen running FASTER than the virtually
inertial clocks passing it ( http://www2.bartleby.com/173/23.html ).
Clearly we have REDUCTIO AD ABSURDUM showing that Einstein's 1905
light postulate is false.

Pentcho Valev
pvalev(a)yahoo.com
From: Pentcho Valev on
The formula:

(frequency) = (speed of light)/(wavelength)

has always been a nightmare in Einsteiniana. This formula makes the
obvious fact "Both the frequency and the speed of light vary with the
speed of the observer", a fact consistent with both Maxwell's theory
and Newton's emission theory of light (but not with Divine Albert's
Divine Special Relativity), too obvious. That is, even in
Einsteiniana's schizophrenic world, where any idiocy is welcome, the
formula might prove dangerous for Einstein's 1905 false light
postulate. So Einsteinians fiercely teach that it is the wavelength
that varies with the speed of the observer:

http://sampit.geol.sc.edu/Doppler.html
"Moving observer: A man is standing on the beach, watching the tide.
The waves are washing into the shore and over his feet with a constant
frequency and wavelength. However, if he begins walking out into the
ocean, the waves will begin hitting him more frequently, leading him
to perceive that the wavelength of the waves has decreased."

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/big_bang/index.html
John Norton: "Here's a light wave and an observer. If the observer
were to hurry towards the source of the light, the observer would now
pass wavecrests more frequently than the resting observer. That would
mean that moving observer would find the frequency of the light to
have increased (AND CORRESPONDINGLY FOR THE WAVELENGTH - THE DISTANCE
BETWEEN CRESTS - TO HAVE DECREASED)."

Similarly, when confronted with Hubble redshift, Einsteinians fiercely
teach that the allegedly EXPANDING universe somehow "stretches" the
wavelength and so the constancy of the speed of light is saved.
However one is entitled to assume that this "stretching" is just as
silly as the variation of the speed of light with the speed of the
observer and advance the following argument:

PREMISE 1: The frequency of light coming from distant sources
decreases proportionally to the distance (Hubble redshift).

PREMISE 2: "Stretching" of the wavelength does not occur.

CONCLUSION: In our STATIC universe, the speed of light coming from
distant sources decreases proportionally to the distance.

Pentcho Valev wrote:

PREMISE 1: The wavelength of light cannot vary with the speed of the
observer.

PREMISE 2: (frequency) = (speed of light)/(wavelength)

CONCLUSION: The speed of light varies with the speed of the observer,
that is, Einstein's 1905 light postulate is false.

Pentcho Valev
pvalev(a)yahoo.com
From: Pentcho Valev on
Pentcho Valev wrote:
> However one is entitled to assume that this "stretching" is just as
> silly as the variation of the speed of light with the speed of the
> observer and advance the following argument...

Mistake: I wrote "speed of light" instead of "wavelength". Here is the
corrected text:

The formula:

(frequency) = (speed of light)/(wavelength)

has always been a nightmare in Einsteiniana. This formula makes the
obvious fact "Both the frequency and the speed of light vary with the
speed of the observer", a fact consistent with both Maxwell's theory
and Newton's emission theory of light (but not with Divine Albert's
Divine Special Relativity), too obvious. That is, even in
Einsteiniana's schizophrenic world, where any idiocy is welcome, the
formula might prove dangerous for Einstein's 1905 false light
postulate. So Einsteinians fiercely teach that it is the wavelength
that varies with the speed of the observer:

http://sampit.geol.sc.edu/Doppler.html
"Moving observer: A man is standing on the beach, watching the tide.
The waves are washing into the shore and over his feet with a constant
frequency and wavelength. However, if he begins walking out into the
ocean, the waves will begin hitting him more frequently, leading him
to perceive that the wavelength of the waves has decreased."

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/big_bang/index.html
John Norton: "Here's a light wave and an observer. If the observer
were to hurry towards the source of the light, the observer would now
pass wavecrests more frequently than the resting observer. That would
mean that moving observer would find the frequency of the light to
have increased (AND CORRESPONDINGLY FOR THE WAVELENGTH - THE DISTANCE
BETWEEN CRESTS - TO HAVE DECREASED)."

Similarly, when confronted with Hubble redshift, Einsteinians fiercely
teach that the allegedly EXPANDING universe somehow "stretches" the
wavelength and so the constancy of the speed of light is saved.
However one is entitled to assume that this "stretching" is just as
silly as the variation of the wavelength with the speed of the
observer and advance the following argument:

PREMISE 1: The frequency of light coming from distant sources
decreases proportionally to the distance (Hubble redshift).

PREMISE 2: "Stretching" of the wavelength does not occur.

CONCLUSION: In our STATIC universe, the speed of light coming from
distant sources decreases proportionally to the distance.

Pentcho Valev wrote:

PREMISE 1: The wavelength of light cannot vary with the speed of the
observer.

PREMISE 2: (frequency) = (speed of light)/(wavelength)

CONCLUSION: The speed of light varies with the speed of the observer,
that is, Einstein's 1905 light postulate is false.

Pentcho Valev
pvalev(a)yahoo.com