 |
|
| Science Forum Index » Physics - Research Forum » Spacecraft earth-flyby data reveals dynamical... |
|
Page 1 of 1 |
|
| Author |
Message |
| Tom Roberts... |
 Posted: Thu Aug 20, 2009 9:33 am |
|
|
|
Guest
|
Surfer wrote:
[quote:4741db27f5]Combining NASA/JPL One-Way Optical-Fiber Light-Speed Data with
Spacecraft Earth-Flyby Doppler-Shift Data to Characterise 3-Space Flow
Reginald T Cahill (Flinders University)
http://arxiv.org/abs/0906.5404
[/quote:4741db27f5]
That is written by Cahill, who simply does not understand error
analysis. You'll note his claims in the abstract are all without
errorbars. He lists 8 experiments at the end of the abstract, claiming
they all "determined light speed anisotropy". In fact, the first six of
those did nothing of the sort and are all consistent with the isotropy
predicted by SR. Cahill does not understand this because he ignores the
error analysis that MUST accompany such experiments.
I discuss five of the six here:
http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html#Experiments_not_consistent_with_SR
The sixth, DeWitte, is unpublished; I have a copy of
his data and KNOW that Cahill's claims are wrong.
Those six experiments all averaged data to obtain the "signal" that
Cahill claims. As I discussed in http://arxiv.org/abs/physics/0608238,
such averaging is a comb filter and invariably does not do what the
experimenter wished to do -- often it selects noise and concentrates it
right in the frequency bin where the signal is expected, making the
noise LOOK just like the expected signal should look. Averaging
time-series data like this is a VERY BAD thing to do; one should model
the background and then fit the entire time sequence to
signal+background.
Michelson and Morley, and Miller have an excuse: the
DSP techniques that explicate the comb filter were not
known during their lifetimes, and a quantitative error
analysis was not usual in their day. The modern authors
and experimenters have no such excuse.
Tom Roberts |
|
|
| Back to top |
|
|
|
| Phillip Helbig---remove CLOTHES to reply... |
| Posted: Tue Aug 25, 2009 6:28 am |
|
|
|
Guest
|
In article <RS5RDPB1FakKFwwj at (no spam) charlesfrancis.wanadoo.co.uk>, Oh No
<NotI at (no spam) charlesfrancis.wanadoo.co.uk> writes:
[quote:0f6ce45cd7]In str there is no absolute frame of reference, but in gtr there is the
CMB frame, or the frame in which a synchronous slice is defined by
a(t)=constant, where a(t) is the expansion parameter. I have no idea
whether this frame might be detectable through some suitable experiment,
[/quote:0f6ce45cd7]
Sure: any of the CMB mapping experiments. What one normally sees has
two things removed: a) the galactic contribution (i.e. foreground stuff
from our own galaxy) and the CMB dipole. These two things are much
larger than the actual signal one is usually interested in (i.e.
fluctuations in the CMB). Our velocity vector with respect to the CMB
is just the dipole which is removed. (This agrees reasonably well with
prior, independent estimates of what our proper motion with respect to
relatively nearby galaxies, galaxy clusters etc should be.) |
|
|
| Back to top |
|
|
|
| Surfer... |
| Posted: Wed Aug 26, 2009 4:47 am |
|
|
|
Guest
|
On Tue, 18 Aug 2009 10:55:04 +0200 (CEST), Andreas Most
<Andreas.Most at (no spam) nospam.invalid.de> wrote:
[quote:32d796196c]
The Flyby anomaly is probably explained by a transverse Doppler effect
which has not been taken into account (arxiv:0809.1888). There is
probably no new physics in this data.
I had a look at this paper:[/quote:32d796196c]
Special relativity may account for the spacecraft flyby anomalies
http://arxiv.org/abs/0809.1888v1
But I can see a potential problem with the right hand side of vector
equation (4), which is:
2 (V_infinity_i - V_infinity_o) . V_E/c^2
Here the V_... variables are vectors and . is the dot product.
V_E is the rotational velocity vector of the ground based antenna wrt
the geocentric reference frame.
Doppler radar measurements of Vinfinity_i and Vinfinity_o must be
made at different times (before the flyby starts and after the flyby
finishes)
But since V_E varies with earth rotation, there is no guarantee that
V_E will have the same direction at those different times.
So the RHS of equation 4 would seem in need of correction to something
like:
2 (V_infinity_i . V_E_i - V_infinity_o . V_E_o) /c^2
But that might invalidate the rest of the argument.
Regards,
Surfer |
|
|
| Back to top |
|
|
|
| Juan R.... |
| Posted: Wed Aug 26, 2009 4:50 am |
|
|
|
Guest
|
Jonathan Thornburg [remove -animal to reply] wrote on Wed, 26 Aug 2009
09:29:08 +0100:
[quote:559e075e08]Oh No <NotI at (no spam) charlesfrancis.wanadoo.co.uk> wrote:
[/quote:559e075e08]
(...)
[quote:559e075e08]Of course, it still remains possible that special relativity is wrong.
[/quote:559e075e08]
Of course, no. Ignoring now that words as right/wrong are deprecated in
modern epistemology [#], what you claim cannot happen!
Special relativity describes very well a broad range of experiments/
observations, thus it cannot be 'wrong'. At the best it can be
*incomplete*, which would be showed if it failed to explain future
outcomes of experiments or some of the actually considered dubidous.
[[Mod. note -- That's what I meant by my (admittedly somewhat sloppy)
use of the word "wrong".
-- jt]]
Then a new theory, explaining the new observations, would be developed.
This new theory would explain the current observations as well as SR does
today. As a consequence, SR will continue to be used within its range of
applicability the same that today we use Newtonian mechanics for its
respective range [%].
[quote:559e075e08]Ultimately this is a question to be settled by experiment. So far, the
experimental status of special relativity is *very* healthy, with many
high-precision experiments confirming it nicely. See
http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html
for outlines of, and references to, many of these experiments.
ciao,
[/quote:559e075e08]
Regards.
[#]
We say theories apply or do not to certain kind of phenomena, not that are
absolutely right or wrong.
[%]
In fact I have heard too often in USENET that relativity proved "Newtonian
theory wrong", which is not true and reason which Newtonian theory
continue being taught at schools and continue being used by astronomers,
physicists, enginners... for the important kind of (non-relativistic
classical) problems for which we know it works.
--
http://www.canonicalscience.org/ |
|
|
| Back to top |
|
|
|
| Hendrik van Hees... |
| Posted: Wed Aug 26, 2009 7:29 am |
|
|
|
Guest
|
Oh No wrote:
[quote:34162fbd22]I have had a three responses so far (thanks Philip, Hendrik, Jonathon)
and I don't think any of them have seen quite what I was getting at. I
wasn't referring to "looking out the window" at the CMBR, though the
CMBR frame is, in practice, the same as the one I was trying to
describe. Rather I was referring to the Friedmann equation, in which
the expansion parameter a(t) defines a particular frame. Of course we
have no practical way of measuring the expansion parameter, let alone
measuring a synchronous hypersurface, a(t)=const. However, as a matter
purely of principle, it seems to me that this hypersurface exists even
in a local context.
[/quote:34162fbd22]
I guess, what you mean is that there is a class of preferred reference
frames in FLRW space time defined as the set of local observers for
whom space looks homogeneous and isotropic. This is true for our
universe to a high degree of accuracy in the large-scale average.
I'm not an expert in cosmology, but if I understood it right, according
to the standard cosmological model the restframe of the CMBR (i.e.,
the "heat-bath frame" I wrote about earlier today) is identical with
this theoretical frame of the cosmological standard model.
--
Hendrik van Hees Institut für Theoretische Physik
Phone: +49 641 99-33342 Justus-Liebig-Universität Gießen
Fax: +49 641 99-33309 D-35392 Gießen
http://theory.gsi.de/~vanhees/faq/ |
|
|
| Back to top |
|
|
|
| Phillip Helbig---remove CLOTHES to reply... |
| Posted: Sat Aug 29, 2009 10:10 pm |
|
|
|
Guest
|
In article <XThPW0AFmPlKFwIh at (no spam) charlesfrancis.wanadoo.co.uk>, Oh No
<NotI at (no spam) charlesfrancis.wanadoo.co.uk> writes:
[quote:a306139d4f]I have had a three responses so far (thanks Philip, Hendrik, Jonathon)
and I don't think any of them have seen quite what I was getting at. I
wasn't referring to "looking out the window" at the CMBR, though the
CMBR frame is, in practice, the same as the one I was trying to
describe. Rather I was referring to the Friedmann equation, in which the
expansion parameter a(t) defines a particular frame. Of course we have
no practical way of measuring the expansion parameter, let alone
measuring a synchronous hypersurface, a(t)=const. However, as a matter
purely of principle, it seems to me that this hypersurface exists even
in a local context.
[/quote:a306139d4f]
I don't see a big difference; you can define the frame such that the
locally measured CMB temperature is everywhere the same. This will give
you your hypersurface. |
|
|
| Back to top |
|
|
|
| eric gisse... |
| Posted: Sun Aug 30, 2009 9:00 pm |
|
|
|
Guest
|
Oh No wrote:
[...]
[quote:e9cd0db0ee]This defines a "preferred" frame. As you say, preferred in the sense of
B, in that the Friedmann equation makes sense. Incidentally, it seems
clear that we do not have Poincaré invariance - but then we shouldn't
really expect Poincaré invariance because we are talking about general,
not special relativity.
[/quote:e9cd0db0ee]
Remember, Poincare invariance is invariance under Lorentz transformations
*and* translations.
[quote:e9cd0db0ee]
The frame has other interesting properties - so much so that I don't
know why aetherists don't make more of it. For example the radial speed
of light is a constant.
[/quote:e9cd0db0ee]
Some of them do. Fortunately, people who are capable of digesting the
concept without too much trouble are capable of understanding why the aether
is rejected by 21st (and 20th...) century physics.
[...]
Tom's reply encapsulates my thoughts well enough to not deserve a followup. |
|
|
| Back to top |
|
|
|
| Surfer... |
| Posted: Fri Sep 04, 2009 6:10 am |
|
|
|
Guest
|
On Sat, 29 Aug 2009 08:08:34 -0800, eric gisse
<jowr.pi.nospam at (no spam) gmail.com> wrote:
[quote:1b8df47427]
Then why aren't there independent confirmations that do not suffer from the
same issues Tom raises?
Because in sci.physics.relativity Tom recently stated:[/quote:1b8df47427]
"no measurements can possibly identify the ether frame of LET"
That is a position based on idealism (rather than realism), but it is
apparently what Tom believes.
Therefore Tom will raise issues with every confirmation of Miller's
result.
[quote:1b8df47427]
Miller's result is TAINTED.
I have to say, use of the word "tainted" in this context, seems[/quote:1b8df47427]
another example of idealism :-)
[quote:1b8df47427]
Regardless of what the original
experiments did or did not show, the followup experiments have decidedly
fallen on the side of "there is no aether",
I don't believe so. Here is why:[/quote:1b8df47427]
Combining NASA/JPL One-Way Optical-Fiber Light-Speed Data with
Spacecraft Earth-Flyby Doppler-Shift Data to Characterise 3-Space Flow
Reginald T. Cahill (Flinders University)
http://arxiv.org/abs/0906.5404
<Start extract>
[[Mod. note -- 43 excessively-quoted lines snipped. -- jt]]
Here we combine data from two high precision NASA/JPL experiments:
(i) the one-way speed of light experiment using optical fibers:
Krisher et al. [19], and
(ii) the spacecraft earth- flyby doppler shift data: Anderson et al.
[21],
to give the solar-system galactic 3-space average speed of 486 km/s in
the direction RA= 4.29 h, Dec= -75 deg.
Turbulence effects (gravitational waves) are also evident.
Various data reveal the 30 km/s orbital speed of the earth and the sun
inflow component of 615 km/s near the sun, and 42 km/s at 1AU, and for
the first time, experimental evidence of the 3-space inflow of the
earth, which is predicted to be 11.2 km/s at the earth's surface.
The optical-fiber and restricted flyby data give, at this stage, only
an average of 12.4 +/- 5 km/s for the earth inflow - averaged over the
spacecraft orbits, and so involving averaging wrt distance from earth
and RF propagation angles wrt the inflow.
The optical fiber - flyby data is in remarkable agreement with the
spatial flow characteristics as determined in other light speed
anisotropy experiments, such as Michelson-Morley (1887), Miller
(1933), DeWitte (1991), Torr and Kolen (1981), Cahill (2006), Munera
(2007), Cahill and Stokes (2008) and Cahill (2009).
The NASA data enables an independent calibration of detectors for use
in light speed anisotropy experiments and related gravitational wave
detectors. These are turbulence effects in the flowing 3-space. These
fluctuations are in essence gravitational waves, and which were
apparent even in the Michelson-Morley 1887 data [1, 2, 22].
<End extract>
Regards,
Surfer |
|
|
| Back to top |
|
|
|
| Surfer... |
| Posted: Mon Sep 07, 2009 4:11 am |
|
|
|
Guest
|
On Sun, 6 Sep 2009 09:59:42 +0000 (UTC), eric gisse
<jowr.pi.nospam at (no spam) gmail.com> wrote:
[quote:33ed0c3973]
LET's ether frame can not be detected, even in principle.
That would only be true if Nature perfectly complied with this man[/quote:33ed0c3973]
made theory.
[quote:33ed0c3973]
If you think otherwise, a short explanation and/or literature reference (that isn't
Cahill) would be sufficient.
I don't believe that Nature perfectly complies with any man made[/quote:33ed0c3973]
theory.
[quote:33ed0c3973]
Of course you'll have to explain why every search for violations of Lorentz
invariance have come up empty, though.
In the photon sector the various MM experiments show that:[/quote:33ed0c3973]
1) Lorentz invariance holds for MM experiments
with light paths passing through vacuum.
2) Lorentz invariance does not hold for MM experiments
with light paths passing through air or gas.
Modern MM experiments generally search for violations only for the
case of vacuum light paths.
[quote:33ed0c3973]
Therefore Tom will raise issues with every confirmation of Miller's
result.
As well he should, given the rather large preponderance of evidence to the
_contrary_.
There is little evidence to the contrary because MM experiments with[/quote:33ed0c3973]
light paths through vacuum cannot provide evidence about MM
experiments with light paths through gas.
[quote:33ed0c3973]
Combining NASA/JPL One-Way Optical-Fiber Light-Speed Data with
Spacecraft Earth-Flyby Doppler-Shift Data to Characterise 3-Space Flow
Reginald T. Cahill (Flinders University)
http://arxiv.org/abs/0906.5404
to give the solar-system galactic 3-space average speed of 486 km/s in
the direction RA= 4.29 h, Dec= -75 deg.
Turbulence effects (gravitational waves) are also evident.
Laughably wrong. Any gravitational wave signal strong enough to alter the
course of a spacecraft would be blindingly, screamingly obvious to all
up to and including the lunar
ranging group.
[/quote:33ed0c3973]
No, because:
1) "turbulence effects" refers to effect on light speed, not to
effect on spacecraft course.
2) The effects are below the frequency response range of
current Earth bound gravitational wave observatories. |
|
|
| Back to top |
|
|
|
| Surfer... |
| Posted: Sun Sep 13, 2009 9:14 am |
|
|
|
Guest
|
On Tue, 18 Aug 2009 10:55:04 +0200 (CEST), Andreas Most
<Andreas.Most at (no spam) nospam.invalid.de> wrote:
[quote:47727d04b7]
The Flyby anomaly is probably explained by a transverse Doppler effect
which has not been taken into account (arxiv:0809.1888).
After thinking further I doubt thats the case.[/quote:47727d04b7]
The transverse Doppler effect is caused by time dilation of a
transmitter relative to a receiver. It therefore shouldn't occur for
Doppler radar, because the transmitter and receiver are not in
relative motion in that case.
-- Surfer |
|
|
| Back to top |
|
|
|
| Surfer... |
| Posted: Thu Sep 24, 2009 7:32 am |
|
|
|
Guest
|
On Tue, 22 Sep 2009 22:11:00 +0100 (BST), Tom Roberts
<tjroberts137 at (no spam) sbcglobal.net> wrote:
[quote:6ddba1ffb7]Surfer wrote:
We have a key difference in that:
1) You calculated errorbars from Miller's data BEFORE
removal of drift and noise, whereas,
Not true. I calculated the errorbars on his reduced data for each run,
INCLUDING the "removal of drift and noise", USING THE METHOD MILLER
USED.
[/quote:6ddba1ffb7]
I am not sure why you say "Not true". You may have calculated the
errorbars "on his reduced data....", but to do so you used his raw
data from which drift and noise had NOT BEEN removed.
[quote:6ddba1ffb7]
READ section II of my paper, and LOOK at Fig. 5 of my paper:
that's how I plot them, as errorbars on the "signal" he found in his
reduced data, because that's what they are -- errorbars for his entire
data reduction algorithm.
But your errorbars are never the less calculated from the raw data.
2) I believe its more reasonable to calculate errorbars
from Miller's data AFTER removal of drift and noise.
But you must calculate them CORRECTLY, and you do not. Removing the
drift introduces ENORMOUS correlations in the resulting data points,
and your computation fails to take that into account.
I have been looking into that.[/quote:6ddba1ffb7]
But it turns out that since linear drift is subtracted from full
turns, the effects of the correlations have a period of a full turn.
As a result they cancel out when half turns are averaged by the last
step of Miller's algorithm.
[quote:6ddba1ffb7]
You have argued that 2) is inappropriate because Miller
".....ASSUMED the background is linear; it isn't...."
You don't even get my argument right. I have repeatedly argued that (2)
is inappropriate because IT IS NOT WHAT MILLER DID.
I don't think you wrote what you intended here. Miller calculated his[/quote:6ddba1ffb7]
probable error AFTER using his data reduction algorithm to remove
drift and noise. That is exactly what (2) says is reasonable :-)
[quote:6ddba1ffb7]This is so very basic I don't understand why it is so hard for you to
understand: in order to accept Miller's result, you must accept WHAT HE
DID.
[/quote:6ddba1ffb7]
I think its more sensible to focus on the EFFECT of what Miller did.
His data reduction algorithm differs from a modern DSP algorithm, but
I am satisfied that its overall EFFECT is sufficiently similar that
the difference doesn't matter.
[quote:6ddba1ffb7]
We now know that WHAT HE DID does not include computing the
errorbars due to his averaging, and those errorbars completely dwarf the
"signal" that he found.
I have established though, that Miller's algorithm can be rearranged[/quote:6ddba1ffb7]
to do the averaging last, after removal of drift and noise, with no
change to the final results.
When the averaging is done last, the errorbars due to the averaging
are smaller than the signal.
Regards,
Surfer |
|
|
| Back to top |
|
|
|
| Tom Roberts... |
| Posted: Thu Sep 24, 2009 8:09 pm |
|
|
|
Guest
|
Surfer wrote:
[quote:62ef0e7cbc]On Tue, 22 Sep 2009 22:11:00 +0100 (BST), Tom Roberts
tjroberts137 at (no spam) sbcglobal.net> wrote:
Surfer wrote:
We have a key difference in that:
1) You calculated errorbars from Miller's data BEFORE
removal of drift and noise, whereas,
Not true. I calculated the errorbars on his reduced data for each run,
INCLUDING the "removal of drift and noise", USING THE METHOD MILLER
USED.
I am not sure why you say "Not true".
[/quote:62ef0e7cbc]
I said "not true" because what you said is indeed not true.
[quote:62ef0e7cbc]You may have calculated the
errorbars "on his reduced data....", but to do so you used his raw
data from which drift and noise had NOT BEEN removed.
[/quote:62ef0e7cbc]
You need to READ THE PAPER. In it you will find a description of the
errorbar computation. It is indeed, AS I SAID, the errorbars on his
reduced data, the last line of his Fig. 8 (my Fig. 1), which he plotted
to show the "signal".
[quote:62ef0e7cbc]But your errorbars are never the less calculated from the raw data.
[/quote:62ef0e7cbc]
That has been my descriptions on USENET, including this and other
newsgroups, because the difference is negligible and it's much easier to
describe. But the calculation in the paper is on his reduced data,
appropriate for the algorithm he used.
For example, the data that were averaged to compute the
value in the first column of his last line consists of:
a) the 20 values at Marker 1
b) the 20 values at Marker 9 plus 1.5
The histogram in Fig. 4 has that 0.15 fringe added to the
Marker 9 values, and the sigma of that histogram is the
errorbar on this point because it is almost completely
systematic (see text). Even if one ignores the systematic
pattern of the variations, closes his eyes and holds his
nose (needed because this is incredibly ugly and stinks),
and divides the errorbar by sqrt(40), it is STILL larger
than the "signal" that Miller found.
Now look at Fig 4 and ask yourself: how important is
0.15 added to the values of marker 9 compared to the
variance of the histogram? -- NOT VERY (it's smaller
than the bin width). That's why I have not bothered to
explain this detail around here.
[quote:62ef0e7cbc]2) I believe its more reasonable to calculate errorbars
from Miller's data AFTER removal of drift and noise.
But you must calculate them CORRECTLY, and you do not. Removing the
drift introduces ENORMOUS correlations in the resulting data points,
and your computation fails to take that into account.
I have been looking into that.
But it turns out that since linear drift is subtracted from full
turns, the effects of the correlations have a period of a full turn.
As a result they cancel out when half turns are averaged by the last
step of Miller's algorithm.
[/quote:62ef0e7cbc]
Not true. That would be true ONLY if the drift had a perfect period of 1
turn. It doesn't -- not even close.
You REALLY need to learn about error analysis; essentially random values
like Miller's "drift" never cancel out. Just LOOK at the data to see how
ludicrous your claim is.
[quote:62ef0e7cbc]You have argued that 2) is inappropriate because Miller
".....ASSUMED the background is linear; it isn't...."
You don't even get my argument right. I have repeatedly argued that (2)
is inappropriate because IT IS NOT WHAT MILLER DID.
I don't think you wrote what you intended here. Miller calculated his
probable error AFTER using his data reduction algorithm to remove
drift and noise. That is exactly what (2) says is reasonable 
[/quote:62ef0e7cbc]
<sigh> Miller did not include the errorbar associated with his averaging
when he claimed a "probable error" -- that errorbar completely dwarfs
what he called "probable error". TODAY we know about this, and it is a
standard and necessary component of an error analysis; in Miller's day
it was not very common at all.
[quote:62ef0e7cbc]This is so very basic I don't understand why it is so hard for you to
understand: in order to accept Miller's result, you must accept WHAT HE
DID.
His data reduction algorithm differs from a modern DSP algorithm, but
I am satisfied that its overall EFFECT is sufficiently similar that
the difference doesn't matter.
[/quote:62ef0e7cbc]
They are not similar at all, and your claim is just plain wrong.
And I repeat: YOU MUST COMPUTE ERRORBARS CORRECTLY. If you apply a DSP
filter, you must include the correlations that it produces among its
output data, and that is problematical.
[quote:62ef0e7cbc]When the averaging is done last, the errorbars due to the averaging
are smaller than the signal.
[/quote:62ef0e7cbc]
Only when you compute the errorbars incorrectly.
And I repeat for the zillionth time: IF YOU WANT TO ACCEPT MILLER'S
RESULT, YOU MUST ACCEPT WHAT HE DID. WHAT HE DID has errorbars much
greater than the "signal" he found, which completely negates his results.
You are just repeating yourself and displaying your unwillingness to
actually read my paper and understand it. Don't expect me to continue.
Tom Roberts |
|
|
| Back to top |
|
|
|
|
|
All times are GMT - 5 Hours
The time now is Sat Nov 28, 2009 5:42 am
|
|