Redshift - Does wavelength change?
James Clark
changes in the gravitational redshift experiment?
Vesselin Petkov
Jackie
>
> Does anyone know why it is believed that the wavelength of a photon
> changes in the gravitational redshift experiment?
It has been observed.
I don't know why it's believed.
Barry
Jackie
>
> Does anyone know why it is believed that the wavelength of a photon
> changes in the gravitational redshift experiment?
Physics doesn't answer "why" questions.
You need to go to a philosophy or psychology news group.
Barry
and...@ibm.net
>
> James Clark wrote:
> >
> > Does anyone know why it is believed that the wavelength of a photon
> > changes in the gravitational redshift experiment?
>
>
> I don't know why it's believed.
Isn't physics an experimental science?
Or are you claiming that the experimental
results are wrong?
John Anderson
Jackie
> Jackie wrote:
> > It has been observed.
> > I don't know why it's believed.
> Isn't physics an experimental science?
Let me change this a bit.
Question:
Does anyone know why it is believed that the sky is blue?
My Answer:
The sky has been observed to be blue.
I don't know why it is believed that the sky is blue.
Does that make what I wrote any clearer?
Observations are interpreted within a particular belief system of the
observer. That seems clear and it may be the way that the human mind
must work.
I do not know why an intelligent, educated mind, knowing this, can
_believe_ it's particular interpretation.
That is why I am an agnostic in science, as well as in religion.
That is why I am bemused and somewhat critical of belief and certainty.
> Or are you claiming that the experimental
> results are wrong?
An experimental result _can_ be wrong. The experiment can be wrongly set
up, it can be wrongly measured or it can be wrongly interpreted. It is
the latter error which is the most difficult to ferret out.
For example, the sky as a whole is approximately sun coloured, not blue.
What we call the sun is not the sun, it is merely the solar light which
was scattered the least. In "reality", the "blue sky" is just as much a
part of the sun as is the bright disc that we see and think is the sun.
Barry
Joe Fischer
: Does anyone know why it is believed that the wavelength of a photon
In the tower experiment, the results are the
same as if the tower were accelerating upward.
So, as the tower accelerates, an emitted
particle must travel farther before being received,
so the number of particles being received are less
than the number emitted.
This makes the wavelength (distance between
crests) longer, and the frequency slower.
If the experiment is done in the opposite
direction, the reverse happens.
I really don't understand why some say
time slows or speeds up. :-)
Joe Fischer
ryk...@my-dejanews.com
Rod: The wavelength _appears_ to have changed to an observer .
Rod Ryker...
--== Sent via Deja.com http://www.deja.com/ ==--
---Share what you know. Learn what you don't.---
Vesselin Petkov
> James Clark wrote:
> >
> > Does anyone know why it is believed that the wavelength of a photon
> > changes in the gravitational redshift experiment?
>
>
> I don't know why it's believed.
>
>
I used the exact word "believed". It is NOT measured. What is measured is
the frequency.
Vesselin
Vesselin Petkov
> Vesselin Petkov wrote:
> >
> > Does anyone know why it is believed that the wavelength of a photon
> > changes in the gravitational redshift experiment?
>
>
> You need to go to a philosophy or psychology news group.
>
> Barry
>
and Snider, and (ii) to think a little more before offering advice on who
should go where.
This question is much more serious than you can imagine. First, try to
explain why you BELIEVE that lambda changes (because this is a belief;
you cannot prove it) and then I will give you more details.
Again, in all experiments it has been observed that frequency (NOT
lambda) changes.
Vesselin
Vesselin Petkov
> Vesselin Petkov (vpe...@alcor.concordia.ca) wrote:
> : Does anyone know why it is believed that the wavelength of a photon
> : changes in the gravitational redshift experiment?
>
> same as if the tower were accelerating upward.
> So, as the tower accelerates, an emitted
> particle must travel farther before being received,
> so the number of particles being received are less
> than the number emitted.
> This makes the wavelength (distance between
> crests) longer, and the frequency slower.
>
> If the experiment is done in the opposite
> direction, the reverse happens.
> I really don't understand why some say
> time slows or speeds up. :-)
>
> Joe Fischer
>
the gravitational redshift effect from the viewpoint of an inertial
reference frame I falling in a gravitatianal field (or in the case of an
accelerating tower from the viewpoint of a frame I moving with constant
velocity). In I the redshift effect is NOT a gravitational phenomenon
since there is no gravitational field in I. It is simply a Doppler effect
in I; that is why the wavelength changes there along with the frequency
(the velocity of light being constant in I).
The gravitational redshift is a gravitational effect only in a non-
inertial frame N supported in a gravitational field. So, if we are in a
tower and try to explain the frequency shift observed there we cannot say
that the wavelength changes along with the frequency since there is no
Doppler effect in N (i.e. in the tower). Even if we put aside the
question of whether or not the wavelength canges it is a fact in general
relativity (GR) that the velocity of light is not constant in a
gravitational field; this means that if the wavelength were to change
(for unknown reasons) the correct frequency shift cannot be obtained.
In short, it is the local velocity of light that changes when frequency
changes in the gravitational redshift experiment. This is an important
result that has been overlooked; it contradicts the curved-spacetime
interpretation of GR which requires that the local velocity of light is
always c. (For more on this you can have a look at:
http://xxx.lanl.gov/abs/gr-qc/9810030
Vesselin
Ken H. Seto
(Vesselin Petkov) wrote:
>In article <3745F803...@netcom.ca>, ja...@netcom.ca says...
>> Vesselin Petkov wrote:
>> >
>> > Does anyone know why it is believed that the wavelength of a photon
>> > changes in the gravitational redshift experiment?
>>
>> Physics doesn't answer "why" questions.
>>
>> You need to go to a philosophy or psychology news group.
>>
>> Barry
>>
>Unfortunately, you need (i)to read the original papers of Pound, Rebka
>and Snider, and (ii) to think a little more before offering advice on who
>should go where.
>
>This question is much more serious than you can imagine. First, try to
>explain why you BELIEVE that lambda changes (because this is a belief;
>you cannot prove it) and then I will give you more details.
>
>Again, in all experiments it has been observed that frequency (NOT
>lambda) changes.
Frequency change as measured by one clock is due to a change in the
state of absolute motion of the observer or the source or both.
The assumed change in lambda is due to the assumption that the one way
speed of light is constant in all inertial frames. Actually this is
true if you use a clock second to measure light speed. But if you use
a defined absolute second to measure light speed then the speed of
light will vary in different inertial frames. In that case the wave
length will remain constant in all inertial frames.
Ken Seto
Vesselin Petkov
Once the standard Einstein convention (epsilon = 1/2, i.e. equal back and
forth light velocities) is assumed, the velocity of light is constant in
all inertial frames.
What is involved in the gravitational redshift is the speed of light in a
non-inertial frame N. The velocity of light changes in N which means that
frequency shift cannot be obtained.
V. Petkov
Jackie
>
>
> Unfortunately, you need (i)to read the original papers of Pound, Rebka
> and Snider, and (ii) to think a little more before offering advice on who
> should go where.
>
> This question is much more serious than you can imagine. First, try to
> explain why you BELIEVE that lambda changes (because this is a belief;
> you cannot prove it) and then I will give you more details.
>
> Again, in all experiments it has been observed that frequency (NOT
> lambda) changes.
Unfortunately, you didn't understand my answer, in which I was
"agreeing" with you.
I don't BELIEVE that lamda changes, others may. Why they BELIEVE that is
a matter of debate outside of science, since the BELIEF is not rational,
as you are pointing out.
They are taught that (i) c = fl and that (ii) c is a constant so (iii)
if f decreases, l must increase. To BELIEVE anything else involves
dropping either (i) or (ii) which is not possible in their BELIEF
system.
Remember, in their minds, both (i) and (ii) are proven unquestionable
facts.
Barry
Jackie
> > It has been observed.
> > I don't know why it's believed.
> > Barry
> I used the exact word "believed". It is NOT measured. What is measured is
> the frequency.
Again, you misunderstand me.
I meant "observed" in the BELIEF system where (i) c = fl and (ii) c is a
constant.
In that belief system, an observation (measurement) that f changes is
_the same_ as an observation (measurement) that l changes.
BELIEVE me, it is difficult (for all of us) to change those belief
systems.
Barry
Vesselin Petkov
That is the whole point - it is implicitely assumed that c is constant
and then inevitably lambda changes if frequency changes. This is true but
only in inertial frames. However, the velocity of light is not constant
in a non-inertial frame N. Although this is a fact in general relativity
(GR) no special attention has been paid to it.
The gravitational redshift can be properly described only in N (it does
not matter whether N is supported in a gravitational field or
accelerating in flat spacetime). But the velocity of light is not
constant in N; that is why lambda does not change in N. Lambda does
change if the redshift is described in an inertial frame I (the redshift
is measured in N and only described in I; there is no redshift in I). In
the inertial frame, however, the described frequency shift is NOT a
gravitational effect (there is no gravitational field in I) but a Doppler
shift. That is why the gravitational redshift is relevantly described
only in N.
The fact that the local velocity of light is not c (as the redshift
experiment shows) has profound implications for the interpretation of GR.
Vesselin
JM Albuquerque
Vesselin Petkov <vpe...@alcor.concordia.ca> wrote:
>
> In short, it is the local velocity of light that changes when frequency
> changes in the gravitational redshift experiment. This is an important
> result that has been overlooked; it contradicts the curved-spacetime
> always c.
>
> Vesselin
This is an atomic bomb on physics.
If this is true it will change a lot of misunderstanding we have today on
physics.
There have been other observation on light speed changing due to (perhaps)
gravitational field.
The text bellow is not mine. It is from some one else that believes the
changing is due to electromagnetic fields.
I'm only interested in the fact that light speed seam's to change.
Regards,
JM Albuquerque
««« There is a glaring problem with the phenomenon called superluminal
sources,
or high red shift quasars which are obviously visibly interacting with a
neighboring galaxy, a neighboring galaxy which is at a much lower red shift
than the quasar, meaning that the energy being transferred in the
interaction with the quasar and the neighboring galaxy must travel at speeds
far in excess of the speed of light, which of course is impossible.
Supraluminal quasar-galaxy interactions are a strong clue that quasars must
have an inherent mechanism that red shifts light leaving them because in
supraluminal quasar-galaxy interactions, the quasar is far more red shifted
than the galaxy with which it is obviously interacting. The interaction is
obvious as you can see a trial of matter being dragged from the low red
shift galaxy and being drawn into the high red shift quasar. The quasar and
the galaxy simply cannot be a great cosmological distance apart and have a
physical interaction. There must be a mechansim whereby the photons exiting
the quasar have some energy removed from them which makes the quasar appear
to be at a greater red shift.
The superluminal sources are direct evidence that there must be a mechanism
in quasars that causes exiting photons to be red shifted because the two
star systems are obviously interacting and cannot be separated by a vast
cosmological distance.
Since it is proposed that the flow of the background of matter is magentic
flux and since magnetic fields around quasars are known to interact with the
exiting photons removing energy from photons and causing additional red
shift above that of cosmological expansion alone, it is proposed that
quasars are like hurricanes compared to goalaxies which are like tropical
storms. Quasars are proposed to be low 'low pressure' cells with high winds
(strong magnetic fields) compared to regular galaxies with normal 'low
pressure' winds. The stronger than widely expected magnetic fields around
quasars driven by a lower pressure is a known process which could be causing
an additional red shift to exiting photons.
Physicists have been reluctant to believe in magnetic fields of that
magnitude. It is a speculative proposal that quasars magnetic fields strong
enough to remove energy from exiting photons, but magnetic fields are a
known mechansim and there must be a quasar dependent force causing
additional red shift as evidenced by the supraluminal sources..
There is no way to explain a quasar interacting with another galaxy over a
vast cosmological distance which requires the energy to travel at speeds in
excess of the speed of light. The distance separating the objects must be as
it appears in the visible picture and there must be a process which red
shifts the photons exiting the quasar to make it have the greater red shift
compared to its neighbor galaxy.
Supraluminal sources indicate a direct physical link of the flow of matter
from an apparently close low red shift companion galaxy to an apparently far
high red shift quasar.
Since the companion galaxy does have a great red shift and the quasar
does, and since there is a physical causal connection as indicated by the
flow of matter, there must be some inherent mechanism within the quasar
which causes red shift of exiting photons.
Therefore, there must be two red shift mechanisms, one mechanism pertaining
to quasar redshift, and one of cosmic redshift. Quasars must have some
inherent mechanism causing red shift.
There is a proposed mechanism for a quasar to interacting with photons
leaving the quasar and remove energy from them, namely the interaction with
the immense magnetic fields generated by the quasar.»»»
Vesselin Petkov
says...
>
> Vesselin Petkov <vpe...@alcor.concordia.ca> wrote:
> >
> > In short, it is the local velocity of light that changes when frequency
> > changes in the gravitational redshift experiment. This is an important
> > result that has been overlooked; it contradicts the curved-spacetime
> > interpretation of GR which requires that the local velocity of light is
> > always c.
> >
> > Vesselin
>
> This is an atomic bomb on physics.
> If this is true it will change a lot of misunderstanding we have today on
> physics.
>
> There have been other observation on light speed changing due to (perhaps)
> gravitational field.
>
> The text bellow is not mine. It is from some one else that believes the
> changing is due to electromagnetic fields.
>
> I'm only interested in the fact that light speed seam's to change.
>
> Regards,
> JM Albuquerque
>
speed of light depends on the diference of the gravitational potentials
(delta Phi) of the source and observation points:
c' = c[1 + (delta Phi)/c^2]. (1)
However, in 1911 this formula lead Einstein to a wrong value of the
deflection angle of a light ray being deflected by the Sun. In 1916
Einsten got it right using the coordinate velocity of light. Since then
formula (1) has been neglected. But it is this velocity that is involved
in any calculations verifying the principle of equivalence.
May I ask you about the source of the text you attached in your message?
It is exactly the case that the velocity of light at a point ultimately
depends on the strength of the EM fields at that point. The anisotropy of
light propagation around massive objects fully accounts for the
gravitational interaction. I cannot explain it here in one or two
sentences but if you are interested you can look at:
http://xxx.lanl.gov/abs/physics/9805028
and
http://xxx.lanl.gov/abs/gr-qc/9810030
Regards,
V. Petkov
JM Albuquerque
Vesselin Petkov <vpe...@alcor.concordia.ca> wrote:
>
> May I ask you about the source of the text you attached in your message?
It is here:
http://www.starlight-pub.com/Matter/PartIII/III15BigBang.html
It belongs here:
http://www.starlight-pub.com/Matter/PartIII.html
It begins here:
http://www.starlight-pub.com/Matter/tableofcontents.html
> I cannot explain it here in one or two
> sentences but if you are interested you can look at:
> http://xxx.lanl.gov/abs/physics/9805028
> and
> http://xxx.lanl.gov/abs/gr-qc/9810030
>
> Regards,
> V. Petkov
Thanks, I'm reading.
Regards,
JM Albuquerque
Joe Fischer
: Joe Fischer wrote:
: > Vesselin Petkov (vpe...@alcor.concordia.ca) wrote:
: > : Does anyone know why it is believed that the wavelength of a photon
: >
: > In the tower experiment, the results are the
: > same as if the tower were accelerating upward.
: > So, as the tower accelerates, an emitted
: > particle must travel farther before being received,
: > so the number of particles being received are less
: > than the number emitted.
: > This makes the wavelength (distance between
: > crests) longer, and the frequency slower.
: >
: > If the experiment is done in the opposite
: > direction, the reverse happens.
: > I really don't understand why some say
: > time slows or speeds up. :-)
: Your explanation is perfectly correct. However, this is a description of
: reference frame I falling in a gravitatianal field (or in the case of an
: accelerating tower from the viewpoint of a frame I moving with constant
: velocity).
I don't think so, it is direct counts of emitted
and received particles where they are emitted or received,
and since the entire tower may be considered to be
accelerating upward, there is no reason to mention
inertial frames, reference frames, or even gravitational
fields (any differences due to gradients in a span of
30 meters being ignored).
: In I the redshift effect is NOT a gravitational phenomenon
: since there is no gravitational field in I. It is simply a Doppler effect
Yes, and did you ever hear the song "Is that all
there is?"? Not only do I believe in a literal interpretation
of the Principle of Equivalence, I work with a model of
gravitation that is a literal interpretation of the PoE.
Therefore I consider any other explanation for
gravitational redshift not to be as acceptable as simply
Doppler, although it might be a complex, or relativistic
Doppler.
: in I; that is why the wavelength changes there along with the frequency
: (the velocity of light being constant in I).
I understand what you are saying, I just don't
spend any time thinking of the velocity of light not
being constant. I think I can get away with this,
in this case, because if the entire tower is accelerating
upward, then even if the speed of light is different
from c, it is different the same amount at both ends
of the tower.
: The gravitational redshift is a gravitational effect only in a non-
: inertial frame N supported in a gravitational field.
Call it what you like, but I am unable to think
of gravity as a "field", poor me, even though I think
I understand what the external gravitational "field"
is in General Relativity. (I am trapped in the PoE)
: So, if we are in a tower and try to explain the frequency shift
: observed there we cannot say that the wavelength changes along with the
: frequency since there is no Doppler effect in N (i.e. in the tower).
My opinion is that you are carrying the reference
frames too far, any point on the 30 meter tower should
be considered to be local, the speed of light should be
constant (even though possibly slightly different from c),
and the tower should be considered to be accelerating
upward, where there is no gravitational "field",
If General Relativity is approached with the
attitude that "we can detect a gravitational field
by gradients", then it isn't General Relativity any more.
: Even if we put aside the question of whether or not the
: wavelength canges it is a fact in general relativity (GR)
: that the velocity of light is not constant in a gravitational field;
:
: this means that if the wavelength were to change
: (for unknown reasons) the correct frequency shift cannot be obtained.
The frequency changes _IF_ the wavelength changes,
_BECAUSE_ c is constant, regardless of it's value in this
case. If c varied, there would be no definitive ratio
of wavelength to frequency.
: In short, it is the local velocity of light that changes when frequency
: changes in the gravitational redshift experiment. This is an important
: result that has been overlooked; it contradicts the curved-spacetime
: interpretation of GR which requires that the local velocity of light is
: always c. (For more on this you can have a look at:
: http://xxx.lanl.gov/abs/gr-qc/9810030
I don't know much about the curved-space-time
interpretation of GR, but I am not inclined to search
for contradictions.
Things do get overlooked, but in this case,
the tower is so short, both ends are accelerating together,
and the speed of light should be measured the same at both ends,
so it is a very simple experiment except for the difficulty
in precision.
It is enough for me to accept the wavelength
differences between the two ends as due to acceleration
in compliance with the Principle of Equivalence, and
to be satisfied with that.
I do not think of changes in rate of flow of
time, or variation in the speed of light.
Regards,
Joe Fischer
Vesselin Petkov
> If General Relativity is approached with the
> attitude that "we can detect a gravitational field
> by gradients", then it isn't General Relativity any more.
If there is no diference in the gravitational potentials of the source
and observation points in the gravitational redshift, there is no
redshift at all. See for instance H. Ohanian and R. Ruffini, Gravitation
and Spacetime, 2nd ed., p.181.
> I understand what you are saying, I just don't
> spend any time thinking of the velocity of light not
> being constant. I think I can get away with this,
> in this case, because if the entire tower is accelerating
> upward, then even if the speed of light is different
> from c, it is different the same amount at both ends
> of the tower.
Of course, it is up to you whether or not you spend time on the velocity
of light. But this does not change the fact that a photon has different
velocities at both ends of the tower. See A. Einstein's paper "On the
influence of gravitation on the propagation of light" - you can easily
find this paper in The Principle of Relativity, Dover, 1952, p. 107.
Or, if you like, you can calculate it yourself - consider the famous
Einstein elevator, do the calculations and you will see whether the
velocity of light is the same at both ends.
The use of inertial and non-inertial frames is both inevitable and
crucial but I would rather not discuss this now.
It is a problem that you consider the PE in this way. The PE itself needs
explanation; it does not provide explanation. Forget for a moment about
the accelerating tower and try to explain the gravitational redshift in
the tower on the Earth.
Regards,
V Petkov
and...@ibm.net
>
> Vesselin Petkov <vpe...@alcor.concordia.ca> wrote:
> >
> > In short, it is the local velocity of light that changes when frequency
> > changes in the gravitational redshift experiment. This is an important
> > result that has been overlooked; it contradicts the curved-spacetime
> > interpretation of GR which requires that the local velocity of light is
> > always c.
> >
>
> This is an atomic bomb on physics.
> If this is true it will change a lot of misunderstanding we have today on
> physics.
The important word here is "if". The second thing to realize
is that I can't tell from what you quoted from the original
poster whether his/her claim is that there's an experiment
that unambiguously supports this claim, or whether the claim
is based on an interpretation of an experiment.
Lorentz ether theory is an alternative explanation of some
of the experiments that SR explains. that doesn't mean
that EITHER of them is wrong. It just means that you need
to do an experiment that can eliminate one of them to show
that one is wrong.
John Anderson
Joe Fischer
: (Joe Fischer) wrote:
: > Vesselin Petkov (vpe...@alcor.concordia.ca) wrote:
: > : Does anyone know why it is believed that the wavelength of a photon
: > : changes in the gravitational redshift experiment?
: >
: > In the tower experiment, the results are the
: > same as if the tower were accelerating upward.
: > So, as the tower accelerates, an emitted
: > particle must travel farther before being received,
: > so the number of particles being received are less
: > than the number emitted.
: > This makes the wavelength (distance between
: > crests) longer, and the frequency slower.
: >
: > If the experiment is done in the opposite
: > direction, the reverse happens.
: > I really don't understand why some say
: > time slows or speeds up. :-)
:
: Rod Ryker...
The wavelength does change in the tower experiment,
with a corresponding change in frequency.
The number of particles received at the top of
the tower are less than the number of particles
emitted at the bottom, and that is a natural result
of thought experiments using the Principle of
Equivalence.
It would maybe seem that this can not be a
situation that could continue indefinitely,
but it is.
Joe Fischer
ryk...@my-dejanews.com
Rod: I have to disagree re freq. changing . It only
appears to have changed to an observer . If the observer
is a wavelength he will not see a change . Therefore the
the wavelength doesn't change but it is observed to have
to an observer outside his frame . All of this I'm
sure you already know . Give me a url to a web site wrt
the tower exp. if you know of one please .
Joe Fischer
: Rod: I have to disagree re freq. changing . It only
: appears to have changed to an observer .
No observer is needed, the experiment uses a
radioactive element that emits particles at regular
intervals.
In one experiment the source is placed at the
bottom of a 30 meter tower, and a detector is placed
at the top. The count of received particles _is_
less than the number of emitted particles.
: If the observer
: is a wavelength he will not see a change . Therefore the
: the wavelength doesn't change but it is observed to have
: to an observer outside his frame .
What "wavelength" means is distance beteeen
events, the emitted particles in this case.
All this is meaningless unless it is related
to an identical experiment with a tower accelerating
in gravity free space. The results should be identical.
: All of this I'm
: sure you already know . Give me a url to a web site wrt
: the tower exp. if you know of one please .
No observers here, the finite speed of light
affects some observations, but not in this case,
as no distant observers are needed, and counts are
made locally.
I think some details of the experiment are
in good books on General Relativity, but I don't
know about web sites.
Regards,
Joe Fischer
Joe Fischer
: The issue here is not the velocity of light in an inertial frame.
: all inertial frames.
But both ends of the tower are subjected to
essentially the same acceleration, and any change
in the speed of light should be the same for both.
: What is involved in the gravitational redshift is the speed of light in a
: non-inertial frame N. The velocity of light changes in N which means that
: if the wavelength were to change (for unknown reasons) the correct
: frequency shift cannot be obtained.
Well, that gets complicated if you measure the
redshift of light from various parts of the disk of the sun.
The center of the disk has a different redshift
than the edge or limb. The center has less redshift
than the limb, and I suspect there is good reason for
this, and it probably isn't reference frames.
I appreciate the experiments where observer
dependent data occurs, but not all experiments have
inertial frames and non-inertial frames, or observers
distant enough for the speed of light to affect the
data.
This sorts out those who are able to what the
difference is. I am not sure I even see what an
observer is needed for, unless the experimenter
needs to account for a time delay for light travel
time. I accept gravitational redshift as Doppler,
and I think this helps explain why stars do not
have very evident redshifts proportional to their
mass.
Joe Fischer
Vesselin Petkov
is not correct. Some people do think that the Lorentz-Fitzgerald
ether theory is an alternative one to SR but this is not the c
ase for the majority of relativists. It is clear to them that
in the ether theory, effects such as the Lorentz-Fitzgerald
contraction are absolute whereas the same effects in SR are
relative (reciprocal). That is why the ether theory is simply
wrong.
And one final note. Are you really saying that an experiment
as such (without interpretation) can prove or disprove anything
or I misunderstood you? If you meant that, just recall for how
many centuries the motion of the Sun as observed from the Earth
had been misinterpreted. An experiment without interpretation
means nothing. Some physicists think that interpretation of
experiments is not as serious as carrying out experiments or
calculations. And we all are paying the price for this.
Risking to start a new discussion I will mention only two cases.
(i) If more effort and time had been spent on the interpretation
of Galileo's experiments SR would have been formulated much
earlier; LOGICALLY it could have been discovered in the 17th
century (hold your smile until you see this for yourself;
very serious physics is involved here, not speculations).
(ii) The proper interpretation of the consequences of SR is not
completed. How many people know that all kinematic effects of SR
are possible only if reality is a "frozen", timeless four-dimensional
world? Most physicists would say "Of course, the world is
four-dimensional - that is the Minkowski space" but in most of the
cases they continue to think in 3+1 (space+time, not spacetime) terms.
The proper interpretation of the consequences of SR is crucial for
the future development of physics.
Regards,
V. Petkov
Vesselin Petkov
I have already started to doubt what the purpose of such
discussions might be. Everyone spends time with these groups for three
basic reasons, I believe - (i) to learn more, (ii) to try to convince
others in new results, or (iii) to be convinced. And now I find it quite
discouraging. Everyone tries to convince the others. Only few people seem
to be ready to even seriously consider others' ideas. In your case not
only was I eager to have your objections, but I was willing to understand
them. Unfortunately, you have not provided a single piece of evidence.
Here are several examples:
> But both ends of the tower are subjected to
> essentially the same acceleration, and any change
> in the speed of light should be the same for both.
>
You continue to claim that the speed of light is the same at both ends
despite the fact that I gave you a reference (Einsten's paper) and
suggested that you calculate it to see for yourself. What matters here is
not the acceleration; it is the potential.
> Well, that gets complicated if you measure the
> redshift of light from various parts of the disk of the sun.
> The center of the disk has a different redshift
> than the edge or limb. The center has less redshift
> than the limb, and I suspect there is good reason for
> this, and it probably isn't reference frames.
That is true but completely irrelevant for this discussion. The Pound -
Rebka - Snider experiments are terestrial experiments.
>
> I accept gravitational redshift as Doppler,
> and I think this helps explain why stars do not
> have very evident redshifts proportional to their
> mass.
>
There are three things here:
1. By claiming that the gravitational redshift is a Doppler effect you
are missing the whole point of this discussion. The redshift is a Doppler
shift ONLY if described in an inertial frame; it is not necessary to
believe me, if you cannot see the point yourself see W. Rindler,
Essential Relativity, 2nd ed, p. 117. In any case I will not try to
change your mind on this any more.
2. It is simply not true that viewing the redshift as Doppler effect
helps explain why the redshift from stars is not proportional to their
mass. Try to show this mathematically to see why your statement is wrong.
3. I cannot understand why you are saying that the redshift from stars is
not proportional to their mass. First, that is plain wrong - look at any
book on GR. Second, you contradict yourself:
> The center of the disk has a different redshift
> than the edge or limb.
V Petkov
Tom Roberts
> But this does not change the fact that a photon has different
That depends upon what you mean by "velocity" -- i.e. how you measure it.
If you use local inertial standard coordinates, you will get c at each end of
the tower. If you use global coordinates (i.e. the same coordinates at top and
bottom) then you are correct.
Remember this is a _coordinate_ velocity, and it has no global significance.
In the Pound and Rebka experiment, what is of global significance is their
counting rates. In GR one can use several different coordinate systems and
obtain several different values for "the speed of light at top and at bottom",
but they all predict/compute the same counting rates, which is what is actually
measured. The various "speeds of light" are merely different _interpretations_
using different coordinate systems....
Tom Roberts tjro...@lucent.com
and...@ibm.net
[snip]
> I apologize for intervening here but you state something which
> is not correct. Some people do think that the Lorentz-Fitzgerald
> ether theory is an alternative one to SR but this is not the c
> ase for the majority of relativists. It is clear to them that
> in the ether theory, effects such as the Lorentz-Fitzgerald
> contraction are absolute whereas the same effects in SR are
> relative (reciprocal). That is why the ether theory is simply
> wrong.
>
I don't believe in LET myself. But the kinematic predictions
of SR are also predicted by LET. The interpretations of the
theories are different, but if they both agree with experiments
you can't eliminate one just because you don't like the interpretation.
> And one final note. Are you really saying that an experiment
> as such (without interpretation) can prove or disprove anything
> or I misunderstood you?
Experiments can disprove theories. They can't prove them.
> If you meant that, just recall for how
> many centuries the motion of the Sun as observed from the Earth
> had been misinterpreted. An experiment without interpretation
> means nothing. Some physicists think that interpretation of
> experiments is not as serious as carrying out experiments or
> calculations. And we all are paying the price for this.
If you're trying to say that I can choose between two theories
that both agree with experiments using some other criteria, then
I agree with that. but that doesn't mean that you have eliminated
the other theory.
John Anderson
ryk...@my-dejanews.com
Rod: It's apples and oranges then . However your point on the tower
experiment is well taken . Gravity appears to be the culprit here
or are you suggesting otherwise ? I don't see wavelength as an issue
here , only gravity .
Joe Fischer
: I have already started to doubt what the purpose of such
: discussions might be.
They help me. I do admit that I was too ready
to consider only the accelerated tower and not the
one in the gravitational "field" used in the experiment.
: Everyone spends time with these groups for three
: basic reasons, I believe -
: (i) to learn more,
Some will, most won't.
: (ii) to try to convince others in new results, or
Unmoderated newsgroups are really not that
formal, but original articles are preferred to
casual discussions, at least by me.
: (iii) to be convinced. And now I find it quite
: discouraging. Everyone tries to convince the others.
Yes, and most have warped ideas, if not worse.
My ideas are warped, and I admit it, so I will try to
finish at least the rest of this response thinking of
General Relativity and experiments relating to it.
: Only few people seem
: to be ready to even seriously consider others' ideas.
Sorry. I get a lot of email about alternate
theories, and most of them are either ether, or photons
or heat causes gravity.
This means a lot to me, as gravity is my primary
interest, but it is a casual interest.
: In your case not
: only was I eager to have your objections, but I was willing to understand
: them. Unfortunately, you have not provided a single piece of evidence.
You are correct, I would like to be able to
cut and paste references, or snippets from books or
formal papers.
: Here are several examples:
: Joe Fischer wrote:
: > But both ends of the tower are subjected to
: > essentially the same acceleration, and any change
: > in the speed of light should be the same for both.
:
: You continue to claim that the speed of light is the same at both ends
: despite the fact that I gave you a reference (Einsten's paper) and
: suggested that you calculate it to see for yourself.
I was working under the assumption that 30 meters
is not enough to to affect the speed of light in the low
potential of Earth gravity.
I assumed it was at least on the order of
30 / 300000000 but if I am wrong, I will appreciate
being corrected.
I am also very weak on varying time flow,
it makes my head hurt, all I found in descriptions
of the tower experiment was the emission counts.
: What matters here is
: not the acceleration; it is the potential.
Do you mean difference in gravitational potential
between the top and bottom of the tower, or do you see
where the difference between the two ends really have
different geometries or something.
I hope you will stay around long enough to help
me sort this out, as I see nothing about the speed of
light or clocks and rate of time flow involved, _as_long_as
all counts or observations are made where they are received.
: > Well, that gets complicated if you measure the
: > redshift of light from various parts of the disk of the sun.
: > The center of the disk has a different redshift
: > than the edge or limb. The center has less redshift
: > than the limb, and I suspect there is good reason for
: > this, and it probably isn't reference frames.
:
: That is true but completely irrelevant for this discussion. The Pound -
: Rebka - Snider experiments are terestrial experiments.
I feel all aspects of gravitational redshift
should be studied together.
I also feel that "forces" and "acceleration
of light" should not be considered. I would like
to read more about the experiment, but haven't been
able to.
: > I accept gravitational redshift as Doppler,
: > and I think this helps explain why stars do not
: > have very evident redshifts proportional to their
: > mass.
:
: There are three things here:
:
: 1. By claiming that the gravitational redshift is a Doppler effect you
: are missing the whole point of this discussion. The redshift is a Doppler
: shift ONLY if described in an inertial frame; it is not necessary to
: believe me, if you cannot see the point yourself see W. Rindler,
: Essential Relativity, 2nd ed, p. 117. In any case I will not try to
: change your mind on this any more.
Ok, I admit, gravitational redshift is either
Doppler shift, or gravitational redshift. Counting
emitted particles is a pretty simple thing to do with
the right equipment.
Are you saying that the rate of time flow
is different at the different ends of the tower,
or that the speed of light is different.
I think I wasn't able to see what the speed
of light has to do with it, but this is my deficiency.
: 2. It is simply not true that viewing the redshift as Doppler effect
: helps explain why the redshift from stars is not proportional to their
: mass. Try to show this mathematically to see why your statement is wrong.
I wasn't aware of any good data on gravitational
redshift of distant stars, in fact I understood there is
NO gravitational redshift seen in distant stars.
But I have been at this so long, new technology
may have provided new data, and I would be anxious to
see it.
: 3. I cannot understand why you are saying that the redshift from stars is
: not proportional to their mass. First, that is plain wrong - look at any
: book on GR. Second, you contradict yourself:
Does MTW "Gravitation" show data on distant stars.
If you can give me a page number, I have it at my fingertips.
But it is getting kind of old, if you have a better
reference, and I don't have it, I will buy it.
: > The center of the disk has a different redshift
: > than the edge or limb.
There is a measured gravitational redshift
of sunlight, and it is as I describe (I think),
but the sun isn't a distant star.
I will be looking for any mention of the
speed of light in the tower experiment, and
rechecking to find if any distant star now
exhibits a gravitational redshift.
Regards,
Joe Fischer
Vesselin Petkov
>
> Remember this is a _coordinate_ velocity, and it has no global significance.
>
>
The coordinate velocity is involved in the calculation of the deflection
angle of light passing near a star. The gravitational redshift involves
the local (proper) velocity of light. On the one hand, in the standard
curved-spacetime interpretation of GR the local velocity of light is c.
On the other hand, however, in his 1911 paper on how gravity influences
the propagation of light Einstein derived the expression for the proper
(not coordinate) velocity of light in a gravitational field which
demonstrates that the local velocity of light depends on the
gravitational potentials of the source and observation points (the
coordinate velocity involves only one potential). The whole point of this
discussion is that the gravitational redshift makes use of that velocity;
thus proving that the local velocity of light is not always c.
V Petkov
Joe Fischer
: The coordinate velocity is involved in the calculation of the deflection
: the local (proper) velocity of light. On the one hand, in the standard
: the propagation of light Einstein derived the expression for the proper
: (not coordinate) velocity of light in a gravitational field which
: coordinate velocity involves only one potential). The whole point of this
: discussion is that the gravitational redshift makes use of that velocity;
I just looked at the 1911 paper (it is my favorite
because it spends a lot of time on the Principle of Equivalence).
And you are right, there is a lot about gravitational
redshift. But that paper is not GR, and it was off by a
factor of one on the bending of starlight, so I don't see
how it "proves" anything. Have you compared the 1911
discussion of redshift with what the 1916 "Foundations
of The General Theory of Relativity" says?
I don't know of a way to measure the local velocity
of light as anything but c. But I will enjoy reading the
part of the 1911 paper on redshift again, thanks.
Regards,
Joe Fischer
Vesselin Petkov
> I just looked at the 1911 paper (it is my favorite
> because it spends a lot of time on the Principle of Equivalence).
> And you are right, there is a lot about gravitational
> redshift. But that paper is not GR, and it was off by a
> factor of one on the bending of starlight, so I don't see
> how it "proves" anything. Have you compared the 1911
> discussion of redshift with what the 1916 "Foundations
> of The General Theory of Relativity" says?
>
> I don't know of a way to measure the local velocity
> of light as anything but c. But I will enjoy reading the
> part of the 1911 paper on redshift again, thanks.
>
> Regards,
>
> Joe Fischer
>
>
This is really an unbelievable case in physics. In general relativity the
speed of light depends on the diference of the gravitational potentials
(delta Phi) of the source and observation points:
c' = c[1 + (delta Phi)/c^2]. (1)
However, in 1911 this formula lead Einstein to a wrong value of the
deflection angle of a light ray being deflected by the Sun. In 1916
Einsten got it right using the coordinate velocity of light. Since then
formula (1) has been neglected. But it is this velocity that is involved
in any calculations verifying the principle of equivalence.
------------------
Formula (1) gives you the local velocity of light. As you can easily
check the local velocity of light is c ONLY when delta Phi = 0, i.e. when
source and observation points coincide. In several messages I gave a
reference to a paper of mine that deals with this; it can be found at:
http://xxx.lanl.gov/abs/gr-qc/9810030
In order to convince yourself that this is the correct local velocity try
to verify the PE (your field!) by calculating the potential and EM field
of a charge in an accelerating RF and in a RF supported in a
gravitational field. If you like you can try to calculate the self-force
acting upon a charge in both RF as well (this is much more complicated).
You can find more on this at:
http://xxx.lanl.gov/abs/physics/9805028
I do not know whether I will be able to answer all of your questions from
your previous message since in less than a month I am going to a
conference and I am late with my paper. But here are two references:
1. Redshift values for Sirius and Eridani are given in H Ohanian and R.
Ruffini, Gravitation and Spacetime, 2nd ed, p 185.
2. What is crucial in the gravitational redshift is the potential
difference. Without it there is no redshift; there is no gravitational
acceleration either. The proper times at both ends of the tower are
different (even for a height of 22.6 m as in the Pound and Rebka
experiment). On this see again Ohanian and Ruffini, p 181 (this can be
found in other books too). Proper times and proper distances using
accelerated RF are calculated in L I Schift, Am J Phys, 28 (1960) p 340.
However, be careful - the idea in this paper is brilliant but the time
dilation and length contraction calculations are wrong (they are
reversed).
Regards,
V Petkov
Joe Fischer
: Perhaps you have not seen my message to JM Albuquerque:
I did, and I also captured it.
[snip]
: Formula (1) gives you the local velocity of light. As you can easily
: check the local velocity of light is c ONLY when delta Phi = 0, i.e. when
: source and observation points coincide. In several messages I gave a
: reference to a paper of mine that deals with this; it can be found at:
: http://xxx.lanl.gov/abs/gr-qc/9810030
I will read it, thanks.
: In order to convince yourself that this is the correct local velocity try
: to verify the PE (your field!) by calculating the potential and EM field
: of a charge in an accelerating RF and in a RF supported in a
: gravitational field. If you like you can try to calculate the self-force
: acting upon a charge in both RF as well (this is much more complicated).
: You can find more on this at:
: http://xxx.lanl.gov/abs/physics/9805028
This too.
: I do not know whether I will be able to answer all of your questions from
: your previous message since in less than a month I am going to a
: conference and I am late with my paper. But here are two references:
:
: 1. Redshift values for Sirius and Eridani are given in H Ohanian and R.
: Ruffini, Gravitation and Spacetime, 2nd ed, p 185.
:
: 2. What is crucial in the gravitational redshift is the potential
: difference. Without it there is no redshift; there is no gravitational
: acceleration either. The proper times at both ends of the tower are
: different (even for a height of 22.6 m as in the Pound and Rebka
: experiment). On this see again Ohanian and Ruffini, p 181 (this can be
: found in other books too). Proper times and proper distances using
: accelerated RF are calculated in L I Schift, Am J Phys, 28 (1960) p 340.
: However, be careful - the idea in this paper is brilliant but the time
: dilation and length contraction calculations are wrong (they are
: reversed).
Ok, thanks. But I would like to suggest that
you approach this with questioning, rather than definite
truth.
The very reason we have had a discussion is the
fact that you seem to consider a gravitational field
to be something like a magnetic field or EM field.
The gravitational field is merely a description
of a gradient acceleration field.
This is different than a uniform accelerating
reference frame, or an accelerating plane surface.
And this fact is what imposes the requirement
to use complex geometry in General Relativity.
Your approach is mainstream physics, mine
is not, but I feel mine is compatible with GR,
while not _all_ of mainstream phyics is.
And GR is not complete, although I really
believe nothing will replace it, and nothing is
needed to replace it, it just must be understood
better, as gravity needs to be understood better.
But I don't want to distract you from your
effort, maybe when you have time we can discuss
the true nature of gravity more.
Regards,
Joe Fischer
Joe Fischer
: Rod: It's apples and oranges then . However your point on the tower
: experiment is well taken . Gravity appears to be the culprit here
: or are you suggesting otherwise ? I don't see wavelength as an issue
: here , only gravity .
Right, gravity is an acceleration gradient field,
where the coordinate system itself is dynamic, and is
not Euclidean.
But it is not particles or forces that cause
gravity, it is a process involving matter, and the
relative measurements of distance/length and time.
The tower experiment involves counts of
received particles and counts of emitted particles.
Any motion of the tower will affect counts,
and in an acceleration gradient field, the motion
is also changing. It is "called" gravity, and
it is more than simply "relativity".
Regards,
Joe Fischer
ryk...@my-dejanews.com
Rod: I believe GR people will say the earth while accelerating
= GR . You are making a seperation between the two I know .
And of course you are right concerning the count . It will be
different since the earth (and the lot) are accelerating .
I thought waves of particles were measured in this experiment ,
thanks for a clearer unerstanding . I still see no time dilation ,
which of course you agree .
and...@ibm.net
> Rod: I believe GR people will say the earth while accelerating
> = GR . You are making a seperation between the two I know .
> And of course you are right concerning the count . It will be
> different since the earth (and the lot) are accelerating .
> I thought waves of particles were measured in this experiment ,
> thanks for a clearer unerstanding . I still see no time dilation ,
> which of course you agree .
>
Jesus Murphy!!!!!!!! What a load of verbal diarrhea.
Mangled ideas expressed in incoherent sentences.
John Anderson
ryk...@my-deja.com
Rod: Well , hello ande452 !
1. Is or does the earth accelerate ?
2. Wouldn't two objects on a collision course collide more quickly ?
3. Time dilation for me means an actual change in time . Relativity
only proves time _appears_ to change to distant observers . Doppler ,
doesn't prove time is warped , it only supports Relativity . Now , if
you can keep Mr. Hyde locked up long enough to respond - please do .
--
Tom Roberts
> This is really an unbelievable case in physics. In general relativity the
> speed of light depends on the diference of the gravitational potentials
> (delta Phi) of the source and observation points:
>
> c' = c[1 + (delta Phi)/c^2]. (1)
This depends upon what you mean by "velocity of light". Normally when
that phrase is used, one implicitly or explicitly means using standard
coordinates, and under inertial conditions, or in a local region, or
some similar restrictions. In GR, an unconstrained "velocity of light"
can have any value whatsoever, and is not very interesting.
That's what is happening here, and in your paper "Gravitational redshift
contradicts the curved-spacetime interpretation of general relativity"
(gr-qc/9810030) Equation 1. You are computing a velocity over a non-local
path, and the velocity of light over such a path is also unconstrained.
In your paper you claim to contradict the curved-spacetime interpretation
of GR, because the speed of light you calculate is not c -- your argument
fails because only the _LOCAL_ speed of light need be c, and for
calculations such as yours it is unconstrained.
In physics a local region is a region of spacetime small enough
such that the effects of spacetime curvature are negligible
compared to one's measurement accuracy. Applied to your Eq. 1,
this means one will measure c to within one's measurement
accuracy -- that means the path must be short enough so that
((delta Phi)/c^2) is small compared to one's fractional
measurement accuracy.
Nobody expects the velocity of light must be c over a non-local path.
And even in a flat spacetime, an accelerated system can have a velocity
of light different from c. All that is required is that a _local_
measurement of the speed of light in an _inertial_ system using
_standard_ coordinates must yield c. Your claim does not affect this.
You claim to show that a photon's speed at a given point in spacetime
depends upon its prior history. You also did not show that. Your Eq. 1
is a computation for an _average_ speed over the non-local path, and
not a computation of its instantaneous (local) speed at the point in
question.
Tom Roberts tjro...@lucent.com
and...@ibm.net
>
> In article <374B7E...@ibm.net>,
> and...@ibm.net wrote:
> > ryk...@my-dejanews.com wrote:
> > > Rod: I believe GR people will say the earth while accelerating
> > > = GR . You are making a seperation between the two I know .
> > > And of course you are right concerning the count . It will be
> > > different since the earth (and the lot) are accelerating .
> > > I thought waves of particles were measured in this experiment ,
> > > thanks for a clearer unerstanding . I still see no time dilation ,
> > > which of course you agree .
> > >
> >
> > Jesus Murphy!!!!!!!! What a load of verbal diarrhea.
> > Mangled ideas expressed in incoherent sentences.
> >
> > John Anderson
>
> Rod: Well , hello ande452 !
> 1. Is or does the earth accelerate ?
Yes. But what is the collection of words
(I can't call it a sentence) "I believe GR people will say the earth
while accelerating = GR " supposed to mean? And don't
tell me that the "GR people" need to explain it. Those are your
words, not theirs.
> 2. Wouldn't two objects on a collision course collide more quickly ?
More quickly than what? Than if they aren't on a collision
course? If they aren't then they won't collide ever.
> 3. Time dilation for me means an actual change in time . Relativity
> only proves time _appears_ to change to distant observers . Doppler ,
> doesn't prove time is warped , it only supports Relativity . Now , if
> you can keep Mr. Hyde locked up long enough to respond - please do .
>
Relativity doesn't prove that "time _appears_ to change to distant
observers". Science doesn't prove things at all. It eliminates
theories that are inconsistent or which disagree with experiment.
It disproves things. Experimental Doppler shifts support relativity.
So they support it, but they don't prove it as you point out.
But, since no theory can be proven, so what?
Also the "_appears_ to change" and "distant observer" references
are vague. If you have a valid objection to relativity,
then that would imply that you understand the theory well
enough to pinpoint a real flaw as opposed to just having
an opinion. When you write things that don't really
indicate that you understand relativity very well,
it leads me to believe that your objection is based
on your opinion only.
If you have an alternative explanation of the Doppler shift
that agrees with experiments then it's supported by them
also. Does it make predictions about other experiments
like relativity does? Does it agree with the other experiments?
You can call me Mr Hyde if you want but, frankly, most of your
postings are incoherent. They're expressed in recognizable
sentence structure. And they make claims about relativity
that seem to be wrong (I said "seem to be" because it's
really hard to understand what you're saying).
John Anderson
ryk...@my-deja.com
and...@ibm.net wrote:
> ryk...@my-deja.com wrote:
> >
> > In article <374B7E...@ibm.net>,
> > and...@ibm.net wrote:
> > > ryk...@my-dejanews.com wrote:
> > > > Rod: I believe GR people will say the earth while accelerating
> > > > = GR . You are making a seperation between the two I know .
> > > > And of course you are right concerning the count . It will be
> > > > different since the earth (and the lot) are accelerating .
> > > > I thought waves of particles were measured in this experiment ,
> > > > thanks for a clearer unerstanding . I still see no time dilation
,
> > > > which of course you agree .
> > > >
> > >
> > > Jesus Murphy!!!!!!!! What a load of verbal diarrhea.
> > > Mangled ideas expressed in incoherent sentences.
> > >
> > > John Anderson
> >
> > Rod: Well , hello ande452 !
> > 1. Is or does the earth accelerate ?
>
> Yes. But what is the collection of words
> (I can't call it a sentence) "I believe GR people will say the earth
> while accelerating = GR " supposed to mean? And don't
> tell me that the "GR people" need to explain it. Those are your
> words, not theirs.
Rod: Happy to see you've toned down ande452 ! :)
Check the FAQ re GR ->gravity , acceleration etc.
> > 2. Wouldn't two objects on a collision course collide more quickly ?
>
> More quickly than what? Than if they aren't on a collision
> course? If they aren't then they won't collide ever.
Rod: Correct again ! 2 for 2 . I think it's quite simple actually .
> > 3. Time dilation for me means an actual change in time . Relativity
> > only proves time _appears_ to change to distant observers . Doppler
,
> > doesn't prove time is warped , it only supports Relativity . Now ,
if
> > you can keep Mr. Hyde locked up long enough to respond - please do .
> >
>
> Relativity doesn't prove that "time _appears_ to change to distant
> observers". Science doesn't prove things at all. It eliminates
> theories that are inconsistent or which disagree with experiment.
> It disproves things. Experimental Doppler shifts support relativity.
> So they support it, but they don't prove it as you point out.
> But, since no theory can be proven, so what?
Rod: I disagree , SR experiments prove an appearance in time changing
in different frames . Proves , supports , the words don't
change results .
> Also the "_appears_ to change" and "distant observer" references
> are vague. If you have a valid objection to relativity,
> then that would imply that you understand the theory well
> enough to pinpoint a real flaw as opposed to just having
> an opinion. When you write things that don't really
> indicate that you understand relativity very well,
> it leads me to believe that your objection is based
> on your opinion only.
Rod: Vague ? We talking about time differences wrt frames .
I believe that using the Lorentz transforms wrt the , stationary
frame / moving frame experiments , may be an error . I get totally
different results using my formula . Of which I'm sure someone-
else can claim .
> If you have an alternative explanation of the Doppler shift
> that agrees with experiments then it's supported by them
> also. Does it make predictions about other experiments
> like relativity does? Does it agree with the other experiments?
Rod: The problem I have is time dilation . I say time is not
warped (time doesn't actually change) based on doppler data .
> You can call me Mr Hyde if you want but, frankly, most of your
> postings are incoherent. They're expressed in recognizable
> sentence structure. And they make claims about relativity
> that seem to be wrong (I said "seem to be" because it's
> really hard to understand what you're saying).
Rod: Next time I'll post in an unrecognizable sentence structure
when I converse with you . :)
> John Anderson
--
Rod Ryker...
Sent via Deja.com http://www.deja.com/
Vesselin Petkov
> Vesselin Petkov wrote:
> > This is really an unbelievable case in physics. In general relativity the
> > speed of light depends on the diference of the gravitational potentials
> > (delta Phi) of the source and observation points:
> >
> > c' = c[1 + (delta Phi)/c^2]. (1)
>
> This depends upon what you mean by "velocity of light". Normally when
> that phrase is used, one implicitly or explicitly means using standard
> coordinates, and under inertial conditions, or in a local region, or
> some similar restrictions. In GR, an unconstrained "velocity of light"
> can have any value whatsoever, and is not very interesting.
>
> That's what is happening here, and in your paper "Gravitational redshift
> contradicts the curved-spacetime interpretation of general relativity"
> (gr-qc/9810030) Equation 1. You are computing a velocity over a non-local
> path, and the velocity of light over such a path is also unconstrained.
>
> In your paper you claim to contradict the curved-spacetime interpretation
> of GR, because the speed of light you calculate is not c -- your argument
> fails because only the _LOCAL_ speed of light need be c, and for
> calculations such as yours it is unconstrained.
>
What is calculated in my paper is the local velocity of light. Perhaps
it's my fault that I did not stress that despite the fact that two points
S (source point) and O (observation point) are involved, equation (1)
gives the velocity of light at point O (see the 1911 Einstein paper cited
in my manuscript; Einstein chooses the potential at the source point to
be zero). So, equation (1) determines the velocity of light at one POINT
(not even a local region).
By "velocity of light" I mean what Einstein meant in his paper. Equation
(1) gives the local velocity of light at point O and it cannot have
different values (given that the standard Einstein convention epsilon =
1/2 is assumed). This is not a coordinate velocity; equation (1) is the
local or proper velocity of light since it involves proper times and
distances. It is determined in a non-inertial frame (supported in a
gravitational field or accelerating). It is this velocity that is
http://xxx.lanl.gov/abs/physics/9805028)
> You claim to show that a photon's speed at a given point in spacetime
> depends upon its prior history. You also did not show that. Your Eq. 1
> is a computation for an _average_ speed over the non-local path, and
> not a computation of its instantaneous (local) speed at the point in
> question.
>
> Tom Roberts tjro...@lucent.com
>
c' = c[1 + (1/2)(delta Phi)/c^2].
--------------------------------
The gravitational redshift proves that the local velocity of light is not
always c (it is c only when points S and O coincide). And this is an
irrefutable argument against the curved-spacetime interpretation of GR.
V Petkov