Do atomic clocks falsify the principle of relativity? (Hafele and Keating experiment)
frank...@yahoo.com
not seen a discussion about the actual behavior of atomic clocks in
different inertial frames and how this relates to the principle of
relativity. It looks to me like the behavior of atomic clocks in motion
violate the basic principle of relativity in a trivial manner. I don't
think this could have escaped the attention of scientists, so I was
hoping to find out what is wrong with the following logic.
>From Einstein's paper:
http://www.marxists.org/reference/archive/einstein/works/1910s/relative/ch05.htm
" For owing to the alteration in direction of the velocity of
revolution of the earth in the course of a year, the earth cannot be at
rest relative to the hypothetical system K0 throughout the whole year.
However, the most careful observations have never revealed such
anisotropic properties in terrestrial physical space, i.e. a physical
non-equivalence of different directions. This is very powerful argument
in favour of the principle of relativity. "
I take this as meaning that there have been no experiments which
produce different results depending on the inertial frame that the
experiment is contained in. So if I fire a bullet, it will
experimentally react exactly the same, not matter what the original
inertial frame was, so we cannot tell any difference between any
inertial frames and there are no "special" frames with unique
properties. Is this correct? Any experiment which does result in a
difference would immediately falsify the principle of relativity. Is
that correct?
Now, there was a famous experiment by Hafele and Keating which flew
atomic clocks on jet airliners in a west and east direction. This
experiment was best known for confirming the accuracy of the special
and general relativity formulas for time dialation. The experiment
revealed that the westward clock ticked the slowest, the earth bound
clock (not travelling) ticked faster than the westward clock and the
eastward clock ticked the fastest. All of this was predicted by the
formulas of special and general relativity to a remarkable accuracy.
But wait! Didn't Einstein say that the principle of relativity required
that the results of ANY experiment should be the same regardless of the
direction of the inertial frame? The Hafele and Keating had 3 atomic
clocks in 3 different inertial frames that produced 3 different
results. Therefore, I conclude that the principle of relativity has
been trivially falsified by the behavior of atomic clocks in differing
inertial frames. If the principle of relativity would have been true,
then it would have predicted that all 3 clocks would have experienced
the same relative slowdown (which of course is impossible and was not
the actual result of the emperical experiment).
So, some special relativity genius please tell me why this isn't true.
To be clear, I am not saying that the formulas describing SR effects
are wrong, I am saying that Einstein's first postulate of the principle
of relativity is wrong by Einstein's own description in the above
quoted paragraph. It is quite possible for the formulas to be correct
and the postulates to be totally wrong.
Also, I know that the atomic clocks in this experiment were not in
truly inertial frames. In this experiment, the center of the Earth was
taken as the point of reference for the inertial frame. All 3 clocks
would be in cirular motion about this point of reference. The time
dialation calculations were based on this arrangement. You might say
that SR/GR need not apply because the clocks are rotating about the
Earth, but then why did the time dialation formulas work so well? No
matter the frame in use, they did appear to act normally according to
SR/GR formulas, so I would think it would be fully applicable. Once
again, SR/GR formulas predict correct experimental result, while
postulate predicts nonsense. fhurelativity
-Please explain
Sue...
The H&K experiment demonstrates (or disproves) the notion
of *time dilation*.
http://www.dipmat.unipg.it/~bartocci/H&KPaper.htm
Shortcomings in principle of relativity are better
demonstrated by considering experiments where the
Coulomb force is acting between moving frames of
reference.
http://arxiv.org/abs/physics/0204034
Sue...
Harry
<frank...@yahoo.com> wrote in message
news:1125984633.0...@g47g2000cwa.googlegroups.com...
Indeed: as far as I know, there has been no experiment reproduced that
falsifies it.
> Now, there was a famous experiment by Hafele and Keating which flew
> atomic clocks on jet airliners in a west and east direction. This
> experiment was best known for confirming the accuracy of the special
> and general relativity formulas for time dialation. The experiment
> revealed that the westward clock ticked the slowest, the earth bound
> clock (not travelling) ticked faster than the westward clock and the
> eastward clock ticked the fastest. All of this was predicted by the
> formulas of special and general relativity to a remarkable accuracy.
> But wait! Didn't Einstein say that the principle of relativity required
> that the results of ANY experiment should be the same regardless of the
> direction of the inertial frame? The Hafele and Keating had 3 atomic
> clocks in 3 different inertial frames that produced 3 different
> results.
Not so: they went around - just like remarked above. If they were all the
time in constant and straight line motion, they couldn't have been brought
back for comparison!
> Therefore, I conclude that the principle of relativity has
> been trivially falsified by the behavior of atomic clocks in differing
> inertial frames. If the principle of relativity would have been true,
> then it would have predicted that all 3 clocks would have experienced
> the same relative slowdown (which of course is impossible and was not
> the actual result of the emperical experiment).
>
> So, some special relativity genius please tell me why this isn't true.
>
> To be clear, I am not saying that the formulas describing SR effects
> are wrong, I am saying that Einstein's first postulate of the principle
> of relativity is wrong by Einstein's own description in the above
> quoted paragraph. It is quite possible for the formulas to be correct
> and the postulates to be totally wrong.
>
> Also, I know that the atomic clocks in this experiment were not in
> truly inertial frames. In this experiment, the center of the Earth was
> taken as the point of reference for the inertial frame. All 3 clocks
> would be in cirular motion about this point of reference. The time
> dialation calculations were based on this arrangement. You might say
> that SR/GR need not apply because the clocks are rotating about the
> Earth, but then why did the time dialation formulas work so well? No
> matter the frame in use, they did appear to act normally according to
> SR/GR formulas, so I would think it would be fully applicable. Once
> again, SR/GR formulas predict correct experimental result, while
> postulate predicts nonsense. fhurelativity
>
> -Please explain
SRT's principle of relativity applies to inertial reference systems.
Harald
Daniel Weston
criticism thereof. Has this article itself been critiqued. If that
article is solid science, its ramifications are extensive. The doctrine
of "Proper Time" as contained in SR, has always troubled me.
Dirk Van de moortel
You quoted a part of an article about special relativity
while H&K is treated in general relativity.
However, the general relativity part can be to an very good
degree approximated by a special relativity part (kinematic)
where the height of the clocks is ignored, plus a pseudo-general
relativity part where the movement of the clocks is ignored.
You'll find some good reading here:
http://www.eftaylor.com/pub/chapter1.pdf
http://www.eftaylor.com/pub/chapter2.pdf
http://www.eftaylor.com/pub/projecta.pdf
The project is about GPS with a time rate between ground
and satellite, but you can apply it twice (first ground/west,
and then ground/east) and then you sort of have the
Hafele-Keating result.
I checked the calculations a while ago in another context.
Perhaps this helps:
http://groups.google.com/group/sci.physics.relativity/msg/0ba81f80d2c9ccad
and a little typo correction
http://groups.google.com/group/sci.physics.relativity/msg/2581429d0b66eb72
You will find the calculation of the kinematic parts in there.
The article we were referring to isn't available as of this writing:
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/airtim.html
Dirk Vdm
Martin Hogbin
Yes but note that this applies to inertial frames only. The Earth's
surface is not an inertial frame because the Earth rotates.
Experiments of Einstein's day, such as that of Michelson and
Morley (the MMX) were sufficiently sensitive to detect the Earth's
motion, due to its orbit round the sun, through the supposed fixed
aether. However, they were not sensitive enough to detect the
Earth's rotation
> Now, there was a famous experiment by Hafele and Keating which flew
> atomic clocks on jet airliners in a west and east direction. This
> experiment was best known for confirming the accuracy of the special
> and general relativity formulas for time dialation. The experiment
> revealed that the westward clock ticked the slowest, the earth bound
> clock (not travelling) ticked faster than the westward clock and the
> eastward clock ticked the fastest. All of this was predicted by the
> formulas of special and general relativity to a remarkable accuracy.
The results agreed well with the predictions of relativity but this was
far from the most sensitive test.
> But wait! Didn't Einstein say that the principle of relativity required
> that the results of ANY experiment should be the same regardless of the
> direction of the inertial frame?
Yes, inertial.
>The Hafele and Keating had 3 atomic
> clocks in 3 different inertial frames that produced 3 different
> results. Therefore, I conclude that the principle of relativity has
> been trivially falsified by the behavior of atomic clocks in differing
> inertial frames. If the principle of relativity would have been true,
> then it would have predicted that all 3 clocks would have experienced
> the same relative slowdown (which of course is impossible and was not
> the actual result of the emperical experiment).
>
The calculations have to take account of the fact that none of
the clocks was in an inertial frame. When this is done the theory
agrees with experiment.
> So, some special relativity genius please tell me why this isn't true.
>
> To be clear, I am not saying that the formulas describing SR effects
> are wrong, I am saying that Einstein's first postulate of the principle
> of relativity is wrong by Einstein's own description in the above
> quoted paragraph. It is quite possible for the formulas to be correct
> and the postulates to be totally wrong.
>
> Also, I know that the atomic clocks in this experiment were not in
> truly inertial frames. In this experiment, the center of the Earth was
> taken as the point of reference for the inertial frame.
So you knew the answer all along.
> All 3 clocks
> would be in cirular motion about this point of reference. The time
> dialation calculations were based on this arrangement. You might say
> that SR/GR need not apply because the clocks are rotating about the
> Earth, but then why did the time dialation formulas work so well? No
> matter the frame in use, they did appear to act normally according to
> SR/GR formulas, so I would think it would be fully applicable. Once
> again, SR/GR formulas predict correct experimental result, while
> postulate predicts nonsense.
The calculations took account of the Earth's rotation. Dirk give some
references which you might like to look at.
Martin Hogbin
Tom Roberts
> Shortcomings in principle of relativity are better
> demonstrated by considering experiments where the
> Coulomb force is acting between moving frames of
> reference.
>
> http://arxiv.org/abs/physics/0204034
The abstract of that paper does not relate to what you said at all.
BTW you do know that J.D.Jackson wrote _Classical_Electrodynamics_,
which has been the textbook of choice for graduate courses in E&M for
>30 years, don't you? In some very real sense, that textbook defines
the modern theory of classical electrodynamics, and includes SR.
Tom Roberts tjro...@lucent.com
Tom Roberts
Yes, several years ago there was a discussion of Kelly's paper in this
newsgroup.
In short: Kelly's arguments and criticisms are fallacious. It is not
"solid" at all.
Tom Roberts tjro...@lucent.com
Tom Roberts
> I have been investigating the subject of special relativity and I have
> not seen a discussion about the actual behavior of atomic clocks in
> different inertial frames and how this relates to the principle of
> relativity.
The measurement errors involved in that would greatly exceed the effects
predicted by SR, for any realistic choices of inertial frames.
Haefle and Keating used airplanes, which are by no means inertial, and
their measurements test GR, not SR.
>>From Einstein's paper:
>
> http://www.marxists.org/reference/archive/einstein/works/1910s/relative/ch05.htm
>
> " For owing to the alteration in direction of the velocity of
> revolution of the earth in the course of a year, the earth cannot be at
> rest relative to the hypothetical system K0 throughout the whole year.
> However, the most careful observations have never revealed such
> anisotropic properties in terrestrial physical space, i.e. a physical
> non-equivalence of different directions. This is very powerful argument
> in favour of the principle of relativity. "
>
> I take this as meaning that there have been no experiments which
> produce different results depending on the inertial frame that the
> experiment is contained in.
Yes. Chief among them is the original Kennedy and Thorndike experiment
(similar to the MMX, but rigidly attached to the earth and rotating with
it), and repetitions -- see the FAQ for references.
> So if I fire a bullet, it will
> experimentally react exactly the same, not matter what the original
> inertial frame was, so we cannot tell any difference between any
> inertial frames and there are no "special" frames with unique
> properties. Is this correct?
Relative to the inertial frame, yes.
> Any experiment which does result in a
> difference would immediately falsify the principle of relativity. Is
> that correct?
Probably, depending on the details.
> Now, there was a famous experiment by Hafele and Keating which flew
> atomic clocks on jet airliners in a west and east direction. This
> experiment was best known for confirming the accuracy of the special
> and general relativity formulas for time dialation. The experiment
> revealed that the westward clock ticked the slowest, the earth bound
> clock (not travelling) ticked faster than the westward clock and the
> eastward clock ticked the fastest. All of this was predicted by the
> formulas of special and general relativity to a remarkable accuracy.
>
> But wait! Didn't Einstein say that the principle of relativity required
> that the results of ANY experiment should be the same regardless of the
> direction of the inertial frame? The Hafele and Keating had 3 atomic
> clocks in 3 different inertial frames that produced 3 different
> results.
None of their clocks were at rest in an inertial frame. They compared
their measurements to the predictions of GR, not SR.
> Also, I know that the atomic clocks in this experiment were not in
> truly inertial frames.
There you go -- so why do you think this has any possibility of refuting
the PoR of SR?
> In this experiment, the center of the Earth was
> taken as the point of reference for the inertial frame. All 3 clocks
> would be in cirular motion about this point of reference.
Not really -- their airplanes did not travel uniformly (they made stops
at airports, and did not travel exactly east/west).
> The time
> dialation calculations were based on this arrangement. You might say
> that SR/GR need not apply because the clocks are rotating about the
> Earth, but then why did the time dialation formulas work so well?
Because they took into account not only the (very roughly) "circular
motion", but also the details of the airplane's altitude and actual
path, and applied GR (not SR).
> No
> matter the frame in use, they did appear to act normally according to
> SR/GR formulas, so I would think it would be fully applicable. Once
> again, SR/GR formulas predict correct experimental result, while
> postulate predicts nonsense.
The postulate does not apply. It specifies inertial frames, and those
clocks aren't at rest in such frames.
The way to test a scientific theory (like SR or GR) is to compute what
the theory predicts the expeirmental measurements should be, based on
the physical situations of the measurements. That's what they did. It's
rather rare to be able to set up a physical situation that directly
tests a postulate.
Tom Roberts tjro...@lucent.com
Sue...
<< The original test results are reproduced for the first time in this
paper; these do not confirm the theory. >>
<< The actual test results, which were not published, were changed by
H & K give the impression that they confirm the theory. Only one clock
(447) had a fairry steady performance over the whole test period;
taking its results gives no difference for the Eastward and the
Westward tests.>>
http://www.dipmat.unipg.it/~bartocci/H&KPaper.htm
Either the notes presented:
[14] Proc. 3rd Dept. Def. PTTI Meeting 261-288 (1971)(USNO)
are genuine or they are fraudulent.
That is the only *science* involved. Do you know of some
assertion that they are fraudulent?
Sue...
frank...@yahoo.com
airplanes were not in a true inertial frame by asking why are the
postulates invalid while the formulas are correct? The formulas are
based on the postulates, so if the postulates are bad, the formulas
should be incorrect as well. Nobody dared to answer this question of
how the postuates can be invalid while the formulas are correct. I
would still like to see some analysis of this question instead of the
blank answer of "SR need not apply". I would presume somebody would
have done an analysis. So far, I have only found analysis which shows
that the rotational frame shouldn't have a net effect since all clocks
are contained within this frame and should be effected in the same
manner. The rotation is not what is contributing to the changed clocks,
it is the predicted SR time dialation - unless someone can show how the
rotation precisely produces the time dialation formulas.
Dirk Van de moortel
<frank...@yahoo.com> wrote in message news:1126073118.1...@g14g2000cwa.googlegroups.com...
> I tried to anticipate the obvious answer that the clocks in the
> airplanes were not in a true inertial frame by asking why are the
> postulates invalid while the formulas are correct? The formulas are
> based on the postulates, so if the postulates are bad, the formulas
> should be incorrect as well. Nobody dared to answer this question of
> how the postuates can be invalid while the formulas are correct. I
> would still like to see some analysis of this question instead of the
> blank answer of "SR need not apply". I would presume somebody would
> have done an analysis. So far, I have only found analysis which shows
> that the rotational frame shouldn't have a net effect since all clocks
> are contained within this frame and should be effected in the same
> manner.
They shouldn't - since they all *move* with respect to each other.
The Earth centered *non-rotating* inertial frame is used to make
the calculations easier. Emphasis on *non-rotating*.
When you want to compare the rates of two clocks that are both
in circular movement around a common centre, the easiest way to
make the SR-calculations, is by working from the centre. The
reason is that w.r.t. centre, the speeds are constant and the
straightforward gamma time dilation expressions can be used and
divided by each other.
> The rotation is not what is contributing to the changed clocks,
> it is the predicted SR time dialation - unless someone can show how the
> rotation precisely produces the time dialation formulas.
I have done exactly that in the message I pointed to:
http://groups.google.com/group/sci.physics.relativity/msg/0ba81f80d2c9ccad
Have you looked at that reply and the pointers?
In short:
One approximation is the so-called Kinematic time rate
Kine(va,vb) = sqrt(1-va^2) / sqrt(1-vb^2)
and it depends on relative motion only. It is an exact result
of special relativity and it is valid in the absence of gravity.
The va and vb are seen in an Earth centered non-rotating
inertial frame.
The reason why this simple equation can be applied, is
because both objects have a constant speeds va and vb
w.r.t. the inertial frame.
The reason why this approximation works when compensated
by the other approximation that would be valid for non
moving clocks that would be "hanging" there subject to gravity,
is the fact that va and vb are small. See the analysis in my
other reply.
Dirk Vdm
Harry
"Tom Roberts" <tjro...@lucent.com> wrote in message
news:J0uTe.486$nt1...@newssvr33.news.prodigy.com...
I remember it differently: his arguments were partly good, so that the HK
experiment should be considered as far from conclusive - but anyway, hardly
ever a single experiment may be considered of being conclusive. A slimmed
down version of it as well as GPS analyses have since been done with similar
results, and also those were discussed in this newsgroup.
Harald
Harry
"Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
in message news:YUmTe.187670$v7.10...@phobos.telenet-ops.be...
Still available through: http://www.archive.org/ .
Thanks,
Harald
Dirk Van de moortel
... and due to the "small" mass of the Earth.
The approximation would not be good for ultra high speeds
and/or for very large or compact masses (like white drawfs
and neutron stars).
Dirk Vdm
Tom Roberts
> I tried to anticipate the obvious answer that the clocks in the
> airplanes were not in a true inertial frame by asking why are the
> postulates invalid while the formulas are correct?
You are intermixing two completely different theories, SR and GR. The
postulate you are worried about is a postulate of SR, and SR simply does
not apply to the H&K experiment. That requires GR, but GR does not use
the PoR, and there's no reason to expect the PoR to apply or be valid here.
> I
> would still like to see some analysis of this question instead of the
> blank answer of "SR need not apply". I would presume somebody would
> have done an analysis.
SR does not apply, because there is gravitation present, and it is
important. One must apply GR to such a physical situation, not SR. No
"further analysis" is either needed or possible.
Note that SR could handle the rotation just fine, but not the
earth's gravitation.
> So far, I have only found analysis which shows
> that the rotational frame shouldn't have a net effect since all clocks
> are contained within this frame and should be effected in the same
> manner.
You seem to be confused.
Consider SR, and a clock on the outer edge of a rotating turntable with
its center at rest in inertial frame S, and an identical clock also at
rest in S located right next to the outer edge. Clearly once per
revolution these two clocks will be adjacent, and we can compare their
readings without complications. Comparing over successive rotations of
the turntable, the rotating clock will lag behind the inertial clock, by
a rate proportional to sqrt(1-v^2/c^2), where v is the velocity of the
turntable clock relative to the inertial frame.
That is a much simplified analogy to the H&K experiment. But if one
ignores the altitudes of the planes (and thus the gravitation of the
earth), their non-uniform speeds, and abstracts out ONLY the rotation
parts of their measurement: the westbound clock rotates slowly relative
to the ECI frame, the earth clock rotates faster, and the eastbound
clock faster still.
ECI frame = Earth Centered Inertial, a non-rotating frame
centered on (moving with) the earth. Due to the revolution of
the earth it is not inertial in the SR sense, but it is locally
inertial in the GR sense, as long as one can ignore gravitation.
For this analogy, the curvature of the earth's motion around the
sun can be ignored, and this is approximately inertial in the
SR sense.
Tom Roberts tjro...@lucent.com
Harry
> airplanes were not in a true inertial frame by asking why are the
> postulates invalid while the formulas are correct? The formulas are
> based on the postulates, so if the postulates are bad, the formulas
> should be incorrect as well. Nobody dared to answer this question of
> how the postuates can be invalid while the formulas are correct.
I pointed out to you that the error was and still is in your question;
In SRT, the PoR postulate applies to uniform rectilinear motion.
> I would still like to see some analysis of this question instead of the
> blank answer of "SR need not apply". I would presume somebody would
> have done an analysis. So far, I have only found analysis which shows
> that the rotational frame shouldn't have a net effect since all clocks
> are contained within this frame and should be effected in the same
> manner.
Probably you read a part about the compensational effects of less
gravitation and higher speed, which in GRT can be accounted for as no effect
at all. Two different lines of reasoning with the same answer - mix them up
and you get confused...
> The rotation is not what is contributing to the changed clocks,
> it is the predicted SR time dialation - unless someone can show how the
> rotation precisely produces the time dialation formulas.
I see that Tom Roberts did so.
Harald
frank...@yahoo.com
something fishy about how you say SR doesn't apply to H&K, yet you
still use SR to predict the relative rates of the clocks in your
simplified analogy to H&K. I will investigate your claims further. But
to get around this, let's just talk about true inertial frames.
To get away from all of this "non-inertial" frame stuff, let's consider
the same experiment done in empty space. Let's take 3 clocks (A,B,C)
and blast them into space free from any significant gravitational
effects. We exactly syncronize the clocks so they all tick at the same
1 second intervals. We then release clocks B and C and use different
sized rockets to make clock C move faster than clock B. We have clocks
B and C radio back a constant beacon to clock A which indicates when
they "tick" a second. We should then be able to compare the ticks
coming from clocks B & C and compare them with A directly. If clock B's
ticks slow down, these should be apparent in the reception of the ticks
by clock A. According to SR time dialation formulas, clock B should be
slower than clock A and clock C should be slower than clock B. Now we
have the same situation as in H&K except that we are using all true
inertial frames. But wait!, we just performed an experiment with clock
B & C in different inertial frames, and they just reported different
results. All that is required to invalidate PoR is a single experiment
which shows that 2 different inertial frames, produce different
experimental results. So how do you explain how this doesn't invalidate
PoR? The very method of applying the SR time dialation formulas
requires this result, which immediately falsifies PoR. Notice that this
experiment doesn't require the clock to return to the same point for
comparison, nor does it rely on anything happening simultaneously.
We're just comparing the constant incoming beacon. The analysis of the
beacon is something we are technically capable of by applying known
effects of doppler, etc. We use such techniques when communicating with
solar probes to determine their position in space. We are technically
capable of doing everything described in the experiment and I would be
curious why anyone hasn't done this very straight forward and direct
test of the PoR postulate.
Another experiment that comes to mind is the measurement of the cosmic
background radiation (CBR). If you do an experiment to determine the
direction of the red-shift, you can determine an absolute speed of an
inertial frame relative to the CBR. Here again is an even more simple
experiment that clearly invalidates PoR since you can experimentally
tell the difference between inertial frames. The only explanation I
have heard for this is that "one frame is more equal than the others".
But really - isn't that nonsense? The presense of any detectable
preferred frame immediately invalidates PoR. Please explain this
without resorting to illogical statements that the CBR frame isn't
special.
Harry
<frank...@yahoo.com> wrote in message
news:1126158281.7...@g44g2000cwa.googlegroups.com...
> Thank's Tom for the more detailed analysis, although there still seems
> something fishy about how you say SR doesn't apply to H&K, yet you
> still use SR to predict the relative rates of the clocks in your
> simplified analogy to H&K. I will investigate your claims further. But
> to get around this, let's just talk about true inertial frames.
I'll read along...
> To get away from all of this "non-inertial" frame stuff, let's consider
> the same experiment done in empty space. Let's take 3 clocks (A,B,C)
> and blast them into space free from any significant gravitational
> effects. We exactly syncronize the clocks so they all tick at the same
> 1 second intervals. We then release clocks B and C and use different
> sized rockets to make clock C move faster than clock B.
Note: Faster wrt the just established reference frame, I presume - and clock
A is still in rest in that frame.
> We have clocks
> B and C radio back a constant beacon to clock A which indicates when
> they "tick" a second. We should then be able to compare the ticks
> coming from clocks B & C and compare them with A directly. If clock B's
> ticks slow down, these should be apparent in the reception of the ticks
> by clock A. According to SR time dialation formulas, clock B should be
> slower than clock A and clock C should be slower than clock B. Now we
> have the same situation as in H&K except that we are using all true
> inertial frames. But wait!, we just performed an experiment with clock
> B & C in different inertial frames, and they just reported different
> results.
From that I conclude that they decided to choose different reference
systems, in which they declare to be in rest and light speed to be
isotropic, instead of that one in which A is resting. Thus, they reported
different conclusions from the same results, based on different and
incompatible assumptions.
> All that is required to invalidate PoR is a single experiment
> which shows that 2 different inertial frames, produce different
> experimental results.
> So how do you explain how this doesn't invalidate PoR?
See above. BTW this was well understood one century ago, but many modern
textbooks don't point it out.
> The very method of applying the SR time dialation formulas
> requires this result, which immediately falsifies PoR. Notice that this
> experiment doesn't require the clock to return to the same point for
> comparison, nor does it rely on anything happening simultaneously.
> We're just comparing the constant incoming beacon. The analysis of the
> beacon is something we are technically capable of by applying known
> effects of doppler, etc. We use such techniques when communicating with
> solar probes to determine their position in space. We are technically
> capable of doing everything described in the experiment and I would be
> curious why anyone hasn't done this very straight forward and direct
> test of the PoR postulate.
>
> Another experiment that comes to mind is the measurement of the cosmic
> background radiation (CBR). If you do an experiment to determine the
> direction of the red-shift, you can determine an absolute speed of an
> inertial frame relative to the CBR. Here again is an even more simple
> experiment that clearly invalidates PoR since you can experimentally
> tell the difference between inertial frames. The only explanation I
> have heard for this is that "one frame is more equal than the others".
You can also determine the average speed of the known universe and call any
speed wrt that "absolute". Then we have multiple "absolute" speeds...
> But really - isn't that nonsense? The presense of any detectable
> preferred frame immediately invalidates PoR. Please explain this
> without resorting to illogical statements that the CBR frame isn't
> special.
It isn't special in the sense that the laws of nature are the same in that
frame - which is what the PoR is about.
Cheers,
Harald
dlzc1 D:cox T:net@nospam.com N:dlzc D:aol T:com (dlzc)
<frank...@yahoo.com> wrote in message
news:1126158281.7...@g44g2000cwa.googlegroups.com...
> Thank's Tom for the more detailed analysis, although there
> still
> seems something fishy about how you say SR doesn't apply to
> H&K, yet you still use SR to predict the relative rates of the
> clocks in your simplified analogy to H&K.
How much work do you expect him to do for you for free? Get a
copy of the paper that reported the results, and review the math
*they* used. Differences in altitude and history of same in
detectably curved space, prevent the application of SR. SR
requires/is based on flat Minkowski spacetime, so detectable
gravitation (aka curvature) "makes SR not apply exactly". SR can
be used for rough estimates, if velocity differences are large.
> I will investigate your claims further.
Excellent.
David A. Smith
Tom Roberts
> Thank's Tom for the more detailed analysis, although there still seems
> something fishy about how you say SR doesn't apply to H&K, yet you
> still use SR to predict the relative rates of the clocks in your
> simplified analogy to H&K.
There's nothing "fishy". In my analogy I SPECIFIED that the center of
rotation is at rest in an inertial frame (which precludes there being
any significant gravitation). But the H&K experiment occured on earth,
and gravitation _IS_ significant. SR only applies when the physical
situation permits inertial frames (to the accuracy of the measurements),
and it therefore does not apply to the H&K experiment.
> To get away from all of this "non-inertial" frame stuff, let's consider
> the same experiment done in empty space. Let's take 3 clocks (A,B,C)
> and blast them into space free from any significant gravitational
> effects. We exactly syncronize the clocks so they all tick at the same
> 1 second intervals.
Synchronization does not affect intervals between ticks, it affects the
setting of the counter within the clock that is counting ticks. Make the
clocks be identical, and they will then tick at the same interval of
_proper_time_ -- no more than that can be done. Synchronize them so at a
specific instant when they are collocated they all display the same time.
> We then release clocks B and C and use different
> sized rockets to make clock C move faster than clock B. We have clocks
> B and C radio back a constant beacon to clock A which indicates when
> they "tick" a second. We should then be able to compare the ticks
> coming from clocks B & C and compare them with A directly. If clock B's
> ticks slow down, these should be apparent in the reception of the ticks
> by clock A. According to SR time dialation formulas, clock B should be
> slower than clock A and clock C should be slower than clock B. Now we
> have the same situation as in H&K except that we are using all true
> inertial frames.
I assume you turn off the rockets before making any comparisons
(otherwise you don't have inertial frames). Now you do NOT have the same
situation as H&K, because those clocks will never again be collocated;
The comparisons you discuss inherently include Doppler shifts, which
dominate.
> But wait!, we just performed an experiment with clock
> B & C in different inertial frames, and they just reported different
> results. All that is required to invalidate PoR is a single experiment
> which shows that 2 different inertial frames, produce different
> experimental results.
Not true. The PoR says the LAWS OF PHYSICS are the same in all inertial
frames, amd does not apply to measurements like this between frames.
Trivially, if (say) a star is at rest in inertial frame A, when you
observe it from inertial frame B you will obtain a different spectrum
from an observation from frame A. The PoR does not preclude Doppler
shifts (etc.).
To apply the PoR to your example, start with a different inertial frame
for clock A, and use the same rockets for B and C -- the PoR says the
measurements should be indepenent of the choice of inertial frame for A.
> Another experiment that comes to mind is the measurement of the cosmic
> background radiation (CBR). If you do an experiment to determine the
> direction of the red-shift, you can determine an absolute speed of an
> inertial frame relative to the CBR.
In the context of SR, this is not "absolute speed", this is merely speed
relative to the dipole=0 frame of the local CMBR.
But in cosmological models based on GR, this is "absolute" in the sense
that the FRW manifolds have a cosmologically preferred frame and the
CMBR is at rest in it. The LAWS OF PHYSICS are not different in that
preferred frame, but the CMBR and galaxies are at rest in it and that is
what makes it preferred.
> Here again is an even more simple
> experiment that clearly invalidates PoR since you can experimentally
> tell the difference between inertial frames.
I repeat: you do not understand what the PoR actually says. OF COURSE
you can distinguish different inertial frames, as you can clearly
measure the velocity of an object at rest in one such frame, and you
will CLEARLY get different answers from other frames. The PoR actually
applies to the LAWS OF PHYSICS, not to measurements between frames.
Tom Roberts tjro...@lucent.com
frank...@yahoo.com
whether H&K falsifies the principle of relativity.
The key is in Tom's last statement that PoR only applies to the laws of
physics measured within the same frame of reference.
The definition of the postulate I have from my standard physics text
is:
"The laws of physics have the same form in all inertial frames"
This does not imply that the results of physical experiments should all
be the same in all inertial frames as I had originally suggested
(although, everyone appeared to agree with that assumption - go
figure). So if you compare results from different inertial frames, this
is not covered by the PoR and this makes sense. Strictly speaking, the
PoR doesn't even require that the you get the same results in all
inertial frames, only that the laws governing the experiments are
invariant.
I don't think the arguments about H&K not being SR because of rotation
are valid. This is just another case of measuring different inertial
frames against one another. SR formulas apply because of the speed
differences between the clocks, but since you are measuring events
happening in multiple inertial frames, PoR doesn't apply.
The arguments about H&K as being a GR rather than a SR is not entirely
valid. If you read the details of the experiment, you find that both
the GR and SR formulas had to be used to predict the result of the
experiment. I would also have to agree that the results of H&K are
questionable due to questions about how the data was gathered and
presented. Although, we do use similar calcualations to keep GPS
syncronized, so I presume the effect is real.
However, none of this precludes the existence of a preferred frame of
reference in which an atomic clock runs the fastest. The H&K showed
that the westward direction had the fastest clock. If we extended this
experiment to include the solar system, we would probably find that a
clock located at the center of the sun would run faster still and if we
included our galaxy, we would find a clock in the center of the galaxy
was even faster. Each of these corresponds to a "slower" inertial
frame. The question is, how slow can you go? Can you go infinitely
slower or at some point do you come to a stop and find an absolute
resting frame? If what I discussed above is true, the PoR would not
precluded the existence of such an absolute resting frame - all laws of
physics would be the same in this frame as in any other. Although this
would seem to be in conflict with other statements that Einstein said.
Can anyone explain that?
dlzc1 D:cox T:net@nospam.com N:dlzc D:aol T:com (dlzc)
<frank...@yahoo.com> wrote in message
news:1126245569.9...@g49g2000cwa.googlegroups.com...
...
> The arguments about H&K as being a GR rather than a SR
> is not entirely valid. If you read the details of the
> experiment,
> you find that both the GR and SR formulas had to be used
> to predict the result of the experiment. I would also have to
> agree that the results of H&K are questionable due to
> questions about how the data was gathered and presented.
> Although, we do use similar calcualations to keep GPS
> syncronized, so I presume the effect is real.
The point is GR becomes SR if there is no (significant) mass
present. You are not "using GR and SR formulas" but applying
"potential" (curvature, GR only) and "kinetic" (motion, GR and
SR) effects to achieve a result.
> However, none of this precludes the existence of a preferred
> frame of reference in which an atomic clock runs the fastest.
> The H&K showed that the westward direction had the fastest
> clock.
... which makes sense, since this craft had a reduction in net
velocity over the other. But is "flying west" a preferred frame?
> If we extended this
> experiment to include the solar system, we would probably
> find that a clock located at the center of the sun would run
> faster still
No. Clocks on the surface of the Sun would run slower than here,
and would run slower still at the center. If our Sun were a dual
of equal masses, and the clock were located at the center between
those two
> and if we included our galaxy, we would find a clock in the
> center of the galaxy was even faster.
No. Black hole there.
> Each of these corresponds to a "slower" inertial
> frame. The question is, how slow can you go?
I am at rest. If Einstein and Mach are right, you could be at
rest wrt the Universe at large, and have the greatest rate of
aging.
> Can you go infinitely
> slower or at some point do you come to a stop and
> find an absolute resting frame?
An "absolute frame" here/now would be moving wrt an "absolute
frame" at some other time or place. Not really absolute, now is
it?
> If what I discussed above is true, the PoR would not
> precluded the existence of such an absolute resting frame
Yes, it does.
> - all laws of
> physics would be the same in this frame as in any other.
> Although this would seem to be in conflict with other
> statements that Einstein said.
> Can anyone explain that?
You heard what you wanted to hear.
David A. Smith
Dirk Van de moortel
> whether H&K falsifies the principle of relativity.
>
> The key is in Tom's last statement that PoR only applies to the laws of
> physics measured within the same frame of reference.
>
> The definition of the postulate I have from my standard physics text
> is:
>
> "The laws of physics have the same form in all inertial frames"
>
> This does not imply that the results of physical experiments should all
> be the same in all inertial frames as I had originally suggested
> (although, everyone appeared to agree with that assumption - go
> figure). So if you compare results from different inertial frames, this
> is not covered by the PoR and this makes sense. Strictly speaking, the
> PoR doesn't even require that the you get the same results in all
> inertial frames, only that the laws governing the experiments are
> invariant.
>
> I don't think the arguments about H&K not being SR because of rotation
> are valid.
Of course they are not valid when you say "because of rotation".
SR can handle rotating bodies perfectly.
The easiest way to calculate accumulated time dilations between
orbiting clocks, is when you compare both of them to one common
inertial frame.
I have shown you that in detail.
Any reason why you obviously didn't look at or comment to it?
> This is just another case of measuring different inertial
> frames against one another.
No, that is the essential part that have got wrong.
This is a case of measuring orbiting (non-inertial!) objects from
one inertial frame, namely the (non-rotating!) Earth centered
(approximately) Inertial frame.
> SR formulas apply because of the speed
> differences between the clocks, but since you are measuring events
> happening in multiple inertial frames, PoR doesn't apply.
>
> The arguments about H&K as being a GR rather than a SR is not entirely
> valid.
Yes they are entirely valid. But see below...
> If you read the details of the experiment, you find that both
> the GR and SR formulas had to be used to predict the result of the
> experiment.
No, they did not *have* to be used. Due to the 'small' mass of
the Earth, and the 'slow' rotation of the Earth and the small
plane velocities that are involved, the separated GR and SR
formulas *can* be used to predict the results, and the only
reason why they *are* used, is the fact that the calculations
are much easier that way.
I have show you that in detail. Is there a reason why you choose
to ignore it? Do you actually understand these calculations?
[I will leave the remainder for someone else to comment on]
Dirk Vdm
Tom Roberts
> Now I think we are getting somewhere in answering the question of
> whether H&K falsifies the principle of relativity.
Perhaps you are "getting somewhere"; the rest uf us have had not problem
here at all.
> The key is in Tom's last statement that PoR only applies to the laws of
> physics measured within the same frame of reference.
> The definition of the postulate I have from my standard physics text
> is:
> "The laws of physics have the same form in all inertial frames"
OK. That's rather loose, but good enough.
> I don't think the arguments about H&K not being SR because of rotation
> are valid.
Sure. SR can handle pure rotations. What it cannot handle is
gravitation, and that is important in H&K.
> The arguments about H&K as being a GR rather than a SR is not entirely
> valid. If you read the details of the experiment, you find that both
> the GR and SR formulas had to be used to predict the result of the
> experiment.
That's just H&K speaking VERY loosely. In fact, a GR computation
includes both terms. That is, one makes ONE computation in GR and gets
agreement with the measurement. H&K spoke that way because back then GR
was not widely understood in their audience. More properly they should
have called these two terms "speed term" and "gravitation term", rather
than misnamed "SR" and "GR". I repeat: GR includes both the speed and
gravitation terms.
> I would also have to agree that the results of H&K are
> questionable due to questions about how the data was gathered and
> presented.
I don't know enough about that to comment. I know there have been some
allegations like that; I also know they came from someone who has
independently proven himself to be incompetent. I have not investigated
them myself.
> However, none of this precludes the existence of a preferred frame of
> reference in which an atomic clock runs the fastest.
Some manifolds have such a frame, some don't. It's not clear whether the
universe we inhabit has such a frame.... probably not; certainly there
is no GLOBAL frame like that, but there could be isolated locations....
Tom Roberts tjro...@lucent.com