"Mysteriously, five spacecraft that flew past the Earth have each displayed unexpected anomalies in their motions.
These newfound enigmas join the so-called "Pioneer anomaly" as hints that unexplained forces may appear to act on spacecraft.
A decade ago, after rigorous analyses, anomalies were seen with the identical Pioneer 10 and 11 spacecraft as they hurtled out of the solar system. Both seemed to experience a tiny but unexplained constant acceleration toward the sun.
A host of explanations have been bandied about for the Pioneer anomaly. At times these are rooted in conventional science — perhaps leaks from the spacecraft have affected their trajectories. At times these are rooted in more speculative physics — maybe the law of gravity itself needs to be modified.
Now Jet Propulsion Laboratory astronomer John Anderson and his colleagues — who originally helped uncover the Pioneer anomaly — have discovered that five spacecraft each raced either a tiny bit faster or slower than expected when they flew past the Earth en route to other parts of the solar system."
I have suggested already in 2006 on my web page http://www.physicsmyths.org.uk/pioneer.htm (and my corresponding usenet and forum posts) that the earth's rotation is responsible for this (which is now John Anderson's conclusion as well).
>I have suggested already in 2006 on my web page >http://www.physicsmyths.org.uk/pioneer.htm > (and my corresponding usenet and forum posts) that the earth's > rotation is responsible for this (which is now John Anderson's > conclusion as well).
> Thomas
It is not so much the Earth's rotation that is causing the anomalous accelerations. It is due to the cracks in General Relativity that are showing themselves as we attempt to measure speed from a rotating reference frame.
Thomas Smid wrote: > I have suggested already in 2006 on my web page http://www.physicsmyths.org.uk/pioneer.htm > (and my corresponding usenet and forum posts) that the earth's > rotation is responsible for this (which is now John Anderson's > conclusion as well).
How about more exotic conclusions? Such as Dark Matter or the newly formed theory about Dark Fluid (unified Dark Matter & Energy)?
>It is not so much the Earth's rotation that is causing the anomalous >accelerations. It is due to the cracks in General Relativity that are >showing themselves as we attempt to measure speed from a rotating reference >frame.
Thomas Smid <thomas.s...@gmail.com> writes: > I have suggested already in 2006 on my web page http://www.physicsmyths.org.uk/pioneer.htm > (and my corresponding usenet and forum posts) that the earth's > rotation is responsible for this (which is now John Anderson's > conclusion as well).
Careful, you are mixing two different "anomalies." The Pioneer-related anomaly is most definitely *not* related directly to earth rotation. If, as you supposed on your website, the problem were a mis-accounting of the station position, then the resulting anomaly would be *diurnal*, not linear in time.
For that matter, station positions can be treated as "solve-for" parameters, and yet this does not resolve the anomaly.
<craigm...@REMOVEcow.physics.wisc.edu> wrote: > Thomas Smid <thomas.s...@gmail.com> writes: > > I have suggested already in 2006 on my web page >> http://www.physicsmyths.org.uk/pioneer.htm > > (and my corresponding usenet and forum posts) that the earth's > > rotation is responsible for this (which is now John Anderson's > > conclusion as well).
> Careful, you are mixing two different "anomalies." ThePioneer-relatedanomalyis most definitely *not* related directly to > earth rotation. If, as you supposed on your website, the problem were > a mis-accounting of the station position, then the resultinganomaly > would be *diurnal*, not linear in time.
As pointed out on my web page already, there should be a net anomaly (of the observed magnitude) as one observes only half of the diurnal cycle (naturally, no data are obtained when the spacecraft is below the horizon). And since the data are batch averages over several days, any wrong assumption about the exact value of the earth's rotational acceleration will result in an apparent net acceleration of the space craft towards the earth.
> For that matter, station positions can be treated as "solve-for" > parameters, and yet this does not resolve theanomaly.
I am sure that if the numerical values for the earth's rotational velocity and radius are suitably adjusted (within the error limits), the anomaly will disappear.
Thomas <thomas.s...@gmail.com> writes: > On 2 Mar, 03:12, Craig Markwardt > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > Thomas Smid <thomas.s...@gmail.com> writes: > > > I have suggested already in 2006 on my web page > >> http://www.physicsmyths.org.uk/pioneer.htm > > > (and my corresponding usenet and forum posts) that the earth's > > > rotation is responsible for this (which is now John Anderson's > > > conclusion as well).
> > Careful, you are mixing two different "anomalies." The > > *Pioneer-related* anomalyis most definitely *not* related directly > > to earth rotation. If, as you supposed on your website, the > > problem were a mis-accounting of the station position, then the > > resultinganomaly would be *diurnal*, not linear in time.
> As pointed out on my web page already, there should be a net anomaly > (of the observed magnitude) as one observes only half of the diurnal > cycle (naturally, no data are obtained when the spacecraft is below > the horizon).
Actually, this claim is not "pointed out" on your web page already.
In any case, while it is true that the spacecraft is only visible by (either) station when it is above the horizon, the resulting residual would still be diurnal in nature, and this is not the nature of the actual "anomaly."
> ... And since the data are batch averages over several days, > any wrong assumption about the exact value of the earth's rotational > acceleration will result in an apparent net acceleration of the space > craft towards the earth.
You are incorrect. While a "batch-sequential" analysis was used by one research group, this does *not* mean that the signal was averaged over several days (but rather that the anomalous acceleration was estimated in batches from finer data). Also, my own work was a global analysis of 60-second sample intervals (no batching), and the main anomaly was definitely *not* diurnal.
> > For that matter, station positions can be treated as "solve-for" > > parameters, and yet this does not resolve theanomaly.
> I am sure that if the numerical values for the earth's rotational > velocity and radius are suitably adjusted (within the error limits), > the anomaly will disappear.
Your surety is misplaced. (a) The "earth radius" is irrelevant since the stations are not on the equator. (b) Station positions *were* allowed to vary in the analysis, and this did not correct the anomaly. (c) The uncertainty in earth angular rate you quote (ref. IERS site), is actually the uncertainty in the *mean* rate since the earth is not a perfect rotator. (d) *However*, the actual earth rotation angles (and hence rates) are known precisely to the millisecond all times during the Pioneer flight, so the mean rate is irrelevant. Thus, your comments are irrelevant as well.
In any case, the same stations, the same technologies, and the same instruments are used to successfully track GPS satellites, quasars, and lunar retro-reflectors, all to mm-cm type precision. Station positions are *very* well tied to the earth, and the properties of earth rotation are very well known.
CM
[ Incidentally, your other explanation for the Pioneer "anomaly" -- a failure to account for spacecraft motion during the light travel time -- is also erroneous. Spacecraft motion *was indeed* accounted for during the light time. ]
> >It is not so much the Earth's rotation that is causing the anomalous > >accelerations. It is due to the cracks in General Relativity that are > >showing themselves as we attempt to measure speed from a rotating reference > >frame.
"Mysteriously, five spacecraft that flew past the Earth have each displayed unexpected anomalies in their motions.
These newfound enigmas join the so-called "Pioneer anomaly" as hints that unexplained forces may appear to act on spacecraft.
--------------------------------------------------------------------------- ----- tobygr - 08:17am Mar 2, 2008 GMT (#1 of 11) ""I am feeling both humble and perplexed by this," said Anderson, who is now working as a retiree. "There is something very strange going on with spacecraft motions. We have no convincing explanation for either the Pioneer anomaly or the flyby anomaly."
In the one probe the researchers did not confirm a noticeable anomaly with, MESSENGER, the spacecraft approached the Earth at about latitude 31 degrees north and receded from the Earth at about latitude 32 degrees south. "This near-perfect symmetry about the equator seemed to result in a very small velocity change, in contrast to the five other flybys," Anderson explained -- so small no anomaly could be confirmed.
The five other flybys involved flights whose incoming and outgoing trajectories were asymmetrical with each other in terms of their orientation with Earth's equator.
For instance, the NEAR mission approached Earth at about latitude 20 south and receded from the planet at about latitude 72 south. The spacecraft then seemed to fly 13 millimeters per second faster than expected. While this is just one-millionth of that probe's total velocity, the precision of the velocity measurements was 0.1 millimeters per second, carried out as they were using radio waves bounced off the craft. This suggests the anomaly seen is real -- and one needing an explanation.
The fact this effect seems most evident with flybys most asymmetrical with respect to Earth's equator "suggests that the anomaly is related to Earth's rotation," Anderson said.
As to whether these new anomalies are linked with the Pioneer anomaly, "I would be very surprised if we have discovered two independent spacecraft anomalies," Anderson told SPACE.com. "I suspect they are connected, but I really do not know."
--------------------------------------------------------------------------- ----- pgboys - 08:45am Mar 2, 2008 GMT (#2 of 11) I saw an Horizon once that seemed to suggest that (crudely) "spinning objects slow time".
Proper scientists had even got funding to build something that should send information back in time (at least back to the point when it was turned on), allowing the future to communicate with the past.
--------------------------------------------------------------------------- ----- ironE - 08:52am Mar 2, 2008 GMT (#3 of 11) Could this not be related to some kind of small possible variation in the relative ambient gravitation, as a body approaches the equatorial zone? Or is the gravitational "pull" perfectly constant across all latitudes?
--------------------------------------------------------------------------- ----- coshipi - 09:05am Mar 2, 2008 GMT (#4 of 11) pgboys
That's a consequence of General Relativity. The funding wasn't to build something that could send information back in time, but to investigate the theory in sufficient detail to determine whether such a device was in principle possible. Last I heard the state of play was "we're not sure yet, but probably not".
I presume that NASA's calculations allow for General Relativity not just Special Relativity.
ironE
Variations in the gravity of the Earth, both with latitude and in a complicated pattern caused by the mass distribution (mainly to do with differences between oceanic and continental crust, and incomplete post- glacial isostatic recovery) are well known. Again, if NASA haven't included this in their calculations I'd be very surprised.
--------------------------------------------------------------------------- ----- MalcolmMcm - 09:41am Mar 2, 2008 GMT (#5 of 11) Hmm.. if the 'brane theory idea that the relative weakness of gravity is down to "leakage" in some gravity-only dimension holds water you might expect some deviation from inverse square at short ranges, which would be invisible at the solar system level.
I wonder if anyone's looked for a gravition vs. distance curve that would account for such anomilies e.g. a small inverse cube component.
--------------------------------------------------------------------------- ----- ironE - 09:50am Mar 2, 2008 GMT (#6 of 11) Earth does have her quirks, though, the ones mentioned above as well as the dense, spinning core inside a likewise rotating mantle - there must be massive energy discharge associated, which perhaps hasn't fully been brought to light because until these probes flew by there hadn't been a 'detection system' capable of picking up the small variations - now, with this effect on objects travelling very long paths, the math is revealing such a (possible) rotatio-gravitational anomaly?!
Of course that's pure conjecture based on very sparse information...
I suppose there'll be sleepless nights for a good many astrophysicists until this one's sorted out
--------------------------------------------------------------------------- ----- pgboys - 10:05am Mar 2, 2008 GMT (#7 of 11) Ah, cheers coshipi - I hoped I hadn't just imagined it.
--------------------------------------------------------------------------- ----- aegian - 11:29am Mar 2, 2008 GMT (#8 of 11) It must be frustrating that the anomaly is so small. Any smaller and it wouldn't be there. Much bigger and we'd be looking for something that accounts for it with more confidence. It's like Yossarian not quite having jaundice at the start of Catch-22...
--------------------------------------------------------------------------- ----- ironE - 11:36am Mar 2, 2008 GMT (#9 of 11) Did he exhibit a wobble as well?
--------------------------------------------------------------------------- ----- coshipi - 03:36pm Mar 2, 2008 GMT (#10 of 11) ironE
The difference in spin rates between the mantle and the core is extremely small - you're looking at a whole Earth angular velocity of ~2pi/day, with a difference between core and mantle of the order (0.000 000 000 01)/day. (That was ten to the minus eleven.) I don't think this is going to account for anything like as big an anomaly as they're seeing.
Much more significant would be an error in our estimates of the variation of the Earth's density with distance from the centre, and such an error is possible. Our estimate of the mass of the Earth is based on celestial mechanics, so any error in that cancels itself out when you're doing celestial mechanics - but any error in our estimate of the radial variation of density on General Relativistic effects doesn't cancel itself out in the same way. And we don't have any very good method of estimating the density of the mantle and core as a function of radius. All our information about the mantle and core is derived from propagation of seismic waves, and we don't know enough about the properties of matter at the temperatures and pressures inside the Earth to work anything out very accurately. Even the temperature and pressure estimates could be quite a long way out.
--------------------------------------------------------------------------- ----- CaptPugwash - 05:46pm Mar 2, 2008 GMT (#11 of 11)
On Mar 1, 10:41 am, Thomas Smid <thomas.s...@gmail.com> wrote:
> I have suggested already in 2006 on my web pagehttp://www.physicsmyths.org.uk/pioneer.htm > (and my corresponding usenet and forum posts) that the earth's > rotation is responsible for this (which is now John Anderson's > conclusion as well).
> Thomas
Of rotation as well as for the interactive gravitation/tidal factors associated with our massive moon should be causing some kind of "anomaly".
So, put it all into the impressive NASA supercomputer and run off a few thousand or even millions of simulations. . - Brad Guth
> --------------------------------------------------------------------------- ----- > tobygr - 08:17am Mar 2, 2008 GMT (#1 of 11) > ""I am feeling both humble and perplexed by this," said > Anderson, who is now working as a retiree. "There is > something very strange going on with spacecraft > motions. We have no convincing explanation for either > the Pioneer anomaly or the flyby anomaly."
Well, "tobygr" (and apparently you too) was not aware that in 2006, Anderson wrote a paper that explained the flyby anomaly and GR did this too. Be careful what you pick up in chatrooms.
<craigm...@REMOVEcow.physics.wisc.edu> wrote: > Thomas <thomas.s...@gmail.com> writes: > > On 2 Mar, 03:12, Craig Markwardt > > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > > Thomas Smid <thomas.s...@gmail.com> writes: > > > > I have suggested already in 2006 on my web page > > >>http://www.physicsmyths.org.uk/pioneer.htm > > > > (and my corresponding usenet and forum posts) that the earth's > > > > rotation is responsible for this (which is now John Anderson's > > > > conclusion as well).
> > > Careful, you are mixing two different "anomalies." The > > > *Pioneer-related* anomalyis most definitely *not* related directly > > > to earth rotation. If, as you supposed on your website, the > > > problem were a mis-accounting of the station position, then the > > > resultinganomaly would be *diurnal*, not linear in time.
> > As pointed out on my web page already, there should be a net anomaly > > (of the observed magnitude) as one observes only half of the diurnal > > cycle (naturally, no data are obtained when the spacecraft is below > > the horizon).
> Actually, this claim is not "pointed out" on your web page already.
Well, I did not exactly point it out with these words, but in case there were ambiguities in this respect, I have now slightly re-edited my page for clarification.
> In any case, while it is true that the spacecraft is only visible by > (either) station when it is above the horizon, the resulting residual > would still be diurnal in nature, and this is not the nature of the > actual "anomaly."
There will be a diurnal component, but there will also be a non- diurnal component (if you average only over the positive halves of a sinusoidal signal, this will not average to zero but produce a net result).
> > ... And since the data are batch averages over several days, > > any wrong assumption about the exact value of the earth's rotational > > acceleration will result in an apparent net acceleration of the space > > craft towards the earth.
> You are incorrect. While a "batch-sequential" analysis was used by > one research group, this does *not* mean that the signal was averaged > over several days (but rather that the anomalous acceleration was > estimated in batches from finer data). Also, my own work was a global > analysis of 60-second sample intervals (no batching), and the main > anomaly was definitely *not* diurnal.
> > > For that matter, station positions can be treated as "solve-for" > > > parameters, and yet this does not resolve theanomaly.
> > I am sure that if the numerical values for the earth's rotational > > velocity and radius are suitably adjusted (within the error limits), > > the anomaly will disappear. > Your surety is misplaced. (a) The "earth radius" is irrelevant since > the stations are not on the equator.
The (average) radius of the earth is as relevant as any other model parameter entering the calculations (in fact more relevant as some of the others, as it is a constant figure).
> (b) Station positions *were* > allowed to vary in the analysis, and this did not correct the > anomaly.
Do you have any reference for this claim? I can not see anything in the original analysis of Anderson et al. for instance ( http://arxiv.org/abs/gr-qc/0104064 ) that would indicate this. On the contrary, from what they say there it seems that the ephemerides and earth (IERS) data have been assumed as invariable input data, and no attempt has been made to reversely model the latter such as to minimize the anomaly. This is for instance evident from pages 40-42 in this paper where they discuss the apparent annual and diurnal anomalies in the data. Qualitative suggestions are made to explain these, but in the end the authors leave it open how these originate, apparently as they are not interested in the periodic anomalies anyway. The point is that, as indicated above, an erroneous figure for the rotational acceleration of the earth does not only produce a sinusoidal diurnal anomaly but also a constant one, due to the fact that data can only be obtained when the spacecraft is above the horizon.
(c) The uncertainty in earth angular rate you quote (ref. IERS
> site), is actually the uncertainty in the *mean* rate since the earth > is not a perfect rotator. (d) *However*, the actual earth rotation > angles (and hence rates) are known precisely to the millisecond all times > during the Pioneer flight, so the mean rate is irrelevant. Thus, your > comments are irrelevant as well.
One millisecond/day would about be the error that produces the Pioneer anomaly.
> In any case, the same stations, the same technologies, and the same > instruments are used to successfully track GPS satellites, quasars, > and lunar retro-reflectors, all to mm-cm type precision. Station > positions are *very* well tied to the earth, and the properties of > earth rotation are very well known.
A relative location does not suffice here. What one would need for an unambiguous interpretation of the Pioneer anomaly is a figure for the rotational acceleration of the observing station with a relative accuracy much better than 10^-8, and already the main parameters of the earth (the average radius and the average rotation rate) are not specified with a sufficient accuracy.
> [ Incidentally, your other explanation for the Pioneer "anomaly" -- a > failure to account for spacecraft motion during the light travel time > -- is also erroneous. Spacecraft motion *was indeed* accounted for > during the light time. ]
The question is not whether the spacecraft motion is being taken into account or not, but whether the 'light distance' is equal to the actual spacecraft distance (when the signal is received): traditional theory assumes that (as judged from the ground station) the light travel time is t=x/(c-v) for a spacecraft receding with velocity v and at distance x when the signal is sent out. But if you consider it from the spacecraft, it should only only take t=x/c as the travel time of the light signal should not depend on whether the earth recedes from it or not when the signal is emitted (assuming c is invariant, i.e. independent of the velocity of the source).
This means that with the first assumption the 'light distance' (ct=c*x/ (c-v)) is equal to the spacecraft distance when the signal is received ( x+v*t=x+v*x/(c-v)=x*(1+v/(c-v))=x*((c-v+v)/(c-v))=c*x/(c-v) ), but with second the light distance (ct=x) is shorter than the actual spacecraft distance x+vt=x+v*x/c=x*(1+v/c) by an amount -x*v/c.
By the way, I had actually a closer look at the 'planetary flyby anomaly' paper now (which basically appears to have been published already a while ago under http://arxiv.org/abs/astro-ph/0608087 ): the reported velocity anomalies for the earth flybys are actually much larger (about 1-2 orders of magnitude) than the Pioneer anomaly. So this suggests to me that this is a different effect unrelated to the earth rotation issue I suggested for the Pioneer results. Maybe the different results for the different spacecraft (which Anderson suggests might have something to do with the earth's rotation) are just associated with the different velocity and line of sight vectors in each case, but it is difficult to tell without knowing the exact observational geometry for each flyby (at least I have not been able to work this out yet from the orbital parameter table in the paper).
Is there an actual scientific article on this yet? Or even a preprint?
-- Steve Willner Phone 617-495-7123 swill...@cfa.harvard.edu Cambridge, MA 02138 USA (Please email your reply if you want to be sure I see it; include a valid Reply-To address to receive an acknowledgement. Commercial email may be sent to your ISP.)
Thomas Smid <thomas.s...@gmail.com> writes: > On 2 Mar, 16:44, Craig Markwardt > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > Thomas <thomas.s...@gmail.com> writes: > > > On 2 Mar, 03:12, Craig Markwardt > > > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > > > Thomas Smid <thomas.s...@gmail.com> writes: > > > > > I have suggested already in 2006 on my web page > > > >>http://www.physicsmyths.org.uk/pioneer.htm > > > > > (and my corresponding usenet and forum posts) that the earth's > > > > > rotation is responsible for this (which is now John Anderson's > > > > > conclusion as well).
> > > > Careful, you are mixing two different "anomalies." The > > > > *Pioneer-related* anomalyis most definitely *not* related directly > > > > to earth rotation. If, as you supposed on your website, the > > > > problem were a mis-accounting of the station position, then the > > > > resultinganomaly would be *diurnal*, not linear in time.
> > > As pointed out on my web page already, there should be a net anomaly > > > (of the observed magnitude) as one observes only half of the diurnal > > > cycle (naturally, no data are obtained when the spacecraft is below > > > the horizon).
> > Actually, this claim is not "pointed out" on your web page already. > Well, I did not exactly point it out with these words, but in case > there were ambiguities in this respect, I have now slightly re-edited > my page for clarification.
> > In any case, while it is true that the spacecraft is only visible by > > (either) station when it is above the horizon, the resulting residual > > would still be diurnal in nature, and this is not the nature of the > > actual "anomaly." > There will be a diurnal component, but there will also be a non- > diurnal component (if you average only over the positive halves of a > sinusoidal signal, this will not average to zero but produce a net > result).
However, since the data were *not* averaged over positive halves of the diurnal cycle, your supposition is largely irrelevant.
> > > ... And since the data are batch averages over several days, > > > any wrong assumption about the exact value of the earth's rotational > > > acceleration will result in an apparent net acceleration of the space > > > craft towards the earth.
> > You are incorrect. While a "batch-sequential" analysis was used by > > one research group, this does *not* mean that the signal was averaged > > over several days (but rather that the anomalous acceleration was > > estimated in batches from finer data). Also, my own work was a global > > analysis of 60-second sample intervals (no batching), and the main > > anomaly was definitely *not* diurnal.
I note no response.
> > > > For that matter, station positions can be treated as "solve-for" > > > > parameters, and yet this does not resolve theanomaly.
> > > I am sure that if the numerical values for the earth's rotational > > > velocity and radius are suitably adjusted (within the error limits), > > > the anomaly will disappear.
> > Your surety is misplaced. (a) The "earth radius" is irrelevant since > > the stations are not on the equator. > The (average) radius of the earth is as relevant as any other model > parameter entering the calculations (in fact more relevant as some of > the others, as it is a constant figure).
However, since the (equatorial) radius of the earth is *not* a parameter of the model, your supposition continues to be irrelevant.
> > (b) Station positions *were* > > allowed to vary in the analysis, and this did not correct the > > anomaly. > Do you have any reference for this claim? I can not see anything in > the original analysis of Anderson et al. for instance ( > http://arxiv.org/abs/gr-qc/0104064 ) that would indicate this. ...
Anderson et al. 2002. Section VII. G.
"... Our analysis indicates that at most these [station-dependent] effects would produce a distance and/or time-dependent drifts that would be easily noticeable in the radio Doppler data. What is more important is that none of the effects would be able to produce a constant drift in the Doppler residuals of Pioneers over such a long time scale. ..."
... deletion ...
> (c) The uncertainty in earth angular rate you quote (ref. IERS > > site), is actually the uncertainty in the *mean* rate since the earth > > is not a perfect rotator. (d) *However*, the actual earth rotation > > angles (and hence rates) are known precisely to the millisecond all times > > during the Pioneer flight, so the mean rate is irrelevant. Thus, your > > comments are irrelevant as well. > One millisecond/day would about be the error that produces the Pioneer > anomaly.
Actually, I meant one millisecond of hour-angle arc. I.e. the earth orientation -- polar axes and rotation angles -- are known in an absolute sense to this level or better [*]. A unmodeled drift rate of 1 millisecond per day would be caught very quickly.
> > In any case, the same stations, the same technologies, and the same > > instruments are used to successfully track GPS satellites, quasars, > > and lunar retro-reflectors, all to mm-cm type precision. Station > > positions are *very* well tied to the earth, and the properties of > > earth rotation are very well known.
> A relative location does not suffice here. What one would need for an > unambiguous interpretation of the Pioneer anomaly is a figure for the > rotational acceleration of the observing station with a relative > accuracy much better than 10^-8, and already the main parameters of > the earth (the average radius and the average rotation rate) are not > specified with a sufficient accuracy.
Since -- as pointed out above -- neither the average earth radius nor the *average* earth rotation rate [*] are involved in the Pioneer doppler analysis, your comment is again irrelevant. And this is all irrelevant since the unaveraged anomaly is *not* a diurnal signal (as pointed out several times, but you continue to ignore).
[*] of course, as also pointed out, the *instantaneous* earth orientation and rotation are used, and are known very accurately.
> > [ Incidentally, your other explanation for the Pioneer "anomaly" -- a > > failure to account for spacecraft motion during the light travel time > > -- is also erroneous. Spacecraft motion *was indeed* accounted for > > during the light time. ]
> The question is not whether the spacecraft motion is being taken into > account or not, but whether the 'light distance' is equal to the > actual spacecraft distance (when the signal is received): traditional > theory assumes that (as judged from the ground station) the light > travel time is t=x/(c-v) for a spacecraft receding with velocity v and > at distance x when the signal is sent out. But if you consider it from > the spacecraft, it should only only take t=x/c as the travel time of > the light signal should not depend on whether the earth recedes from > it or not when the signal is emitted (assuming c is invariant, i.e. > independent of the velocity of the source).
Huh? This is by no means a "traditional" theory. If you are assuming relativity is true (as indicated by "c" being universal in all frames), then you must also transform distances and times the proper way, using Lorentz transformations [*]. Since you did not, your suppositions would be erroneous. If on the other hand you are not assuming relativity, then your "theory" is not traditional, and thus it is irrelevant as the straw man you are using it for.
[*] even in that case, the time measured by a clock on the spacecraft would be different than the time measured on earth. This is immaterial since the spacecraft clock is not used in the analysis.
... deletion ...
> By the way, I had actually a closer look at the 'planetary flyby > anomaly' paper now (which basically appears to have been published > already a while ago under http://arxiv.org/abs/astro-ph/0608087 ): the > reported velocity anomalies for the earth flybys are actually much > larger (about 1-2 orders of magnitude) than the Pioneer anomaly. So > this suggests to me that this is a different effect unrelated to the > earth rotation issue I suggested for the Pioneer results. Maybe the > different results for the different spacecraft (which Anderson > suggests might have something to do with the earth's rotation) are > just associated with the different velocity and line of sight vectors > in each case, but it is difficult to tell without knowing the exact > observational geometry for each flyby (at least I have not been able > to work this out yet from the orbital parameter table in the paper).
A paper by Antreasian & Guinn in 1998 (AIAA 98-4287) shows the flyby geometries of NEAR and Galileo quite well.
<craigm...@REMOVEcow.physics.wisc.edu> wrote: > Thomas Smid <thomas.s...@gmail.com> writes: > > On 2 Mar, 16:44, Craig Markwardt > > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > > Thomas <thomas.s...@gmail.com> writes: > > > > On 2 Mar, 03:12, Craig Markwardt > > > > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > > > > Thomas Smid <thomas.s...@gmail.com> writes: > > > > > > I have suggested already in 2006 on my web page > > > > >>http://www.physicsmyths.org.uk/pioneer.htm > > > > > > (and my corresponding usenet and forum posts) that the earth's > > > > > > rotation is responsible for this (which is now John Anderson's > > > > > > conclusion as well).
> > > > > Careful, you are mixing two different "anomalies." The > > > > > *Pioneer-related* anomalyis most definitely *not* related directly > > > > > to earth rotation. If, as you supposed on your website, the > > > > > problem were a mis-accounting of the station position, then the > > > > > resultinganomaly would be *diurnal*, not linear in time.
> > > > As pointed out on my web page already, there should be a net anomaly > > > > (of the observed magnitude) as one observes only half of the diurnal > > > > cycle (naturally, no data are obtained when the spacecraft is below > > > > the horizon).
> > > Actually, this claim is not "pointed out" on your web page already. > > Well, I did not exactly point it out with these words, but in case > > there were ambiguities in this respect, I have now slightly re-edited > > my page for clarification.
> > > In any case, while it is true that the spacecraft is only visible by > > > (either) station when it is above the horizon, the resulting residual > > > would still be diurnal in nature, and this is not the nature of the > > > actual "anomaly." > > There will be a diurnal component, but there will also be a non- > > diurnal component (if you average only over the positive halves of a > > sinusoidal signal, this will not average to zero but produce a net > > result).
> However, since the data were *not* averaged over positive halves of > the diurnal cycle, your supposition is largely irrelevant.
As I said already, because you can observe the spacecraft only when it is above the horizon, only one half of the diurnal acceleration cycle of the observing station can be observed, and this never changes sign. If you would Fourier transform this signal you would not only have a peak at the diurnal frequency buts also a constant offset.
> > > > ... And since the data are batch averages over several days, > > > > any wrong assumption about the exact value of the earth's rotational > > > > acceleration will result in an apparent net acceleration of the space > > > > craft towards the earth.
> > > You are incorrect. While a "batch-sequential" analysis was used by > > > one research group, this does *not* mean that the signal was averaged > > > over several days (but rather that the anomalous acceleration was > > > estimated in batches from finer data). Also, my own work was a global > > > analysis of 60-second sample intervals (no batching), and the main > > > anomaly was definitely *not* diurnal.
> I note no response.
> > > > > For that matter, station positions can be treated as "solve-for" > > > > > parameters, and yet this does not resolve theanomaly.
> > > > I am sure that if the numerical values for the earth's rotational > > > > velocity and radius are suitably adjusted (within the error limits), > > > > the anomaly will disappear.
> > > Your surety is misplaced. (a) The "earth radius" is irrelevant since > > > the stations are not on the equator. > > The (average) radius of the earth is as relevant as any other model > > parameter entering the calculations (in fact more relevant as some of > > the others, as it is a constant figure).
> However, since the (equatorial) radius of the earth is *not* a > parameter of the model, your supposition continues to be irrelevant.
"Previously they [the model values] were combined into a common publication by either the International Earth Rotation Service (IERS) or by the United States Naval Observatory (USNO). Currently this information is provided by the ICRF. JPL's Earth Orientation Parameters (EOP) is a major source contributor to the ICRF. ...... Both JPL's ODP and The Aerospace Corporation's CHASMP use the JPL/ Earth Orientation Parameters (EOP) values. This could be a source of common error. However the comparisons between EOP and IERS show an insignificant difference. Also, only secular terms, such as precession, can contribute errors to the anomalous acceleration. Errors in short period terms are not correlated with the anomalous acceleration " [and the latter is exactly the erroneous assumption here due to the fact that only half of the diurnal acceleration cycle goes into the data]
But anyway, whatever your earth rotation model is, if you would change the parameters such that it corresponds to a reduction of the rotational acceleration of the observing station by about 5*10^-8 cm/ sec^2, then the anomaly must disappear.
> > > (b) Station positions *were* > > > allowed to vary in the analysis, and this did not correct the > > > anomaly. > > Do you have any reference for this claim? I can not see anything in > > the original analysis of Anderson et al. for instance ( > >http://arxiv.org/abs/gr-qc/0104064) that would indicate this. ...
> Anderson et al. 2002. Section VII. G.
> "... Our analysis indicates that at most these [station-dependent] > effects would produce a distance and/or time-dependent drifts that > would be easily noticeable in the radio Doppler data. What is more > important is that none of the effects would be able to produce a > constant drift in the Doppler residuals of Pioneers over such a long > time scale. ..."
As pointed out already, the uncertainty of the main IERS model parameters is such that they can explain the anomaly. If the authors only check the dependence on irrelevant parameters, then obviously they won't see any effect.
> > (c) The uncertainty in earth angular rate you quote (ref. IERS > > > site), is actually the uncertainty in the *mean* rate since the earth > > > is not a perfect rotator. (d) *However*, the actual earth rotation > > > angles (and hence rates) are known precisely to the millisecond all times > > > during the Pioneer flight, so the mean rate is irrelevant. Thus, your > > > comments are irrelevant as well. > > One millisecond/day would about be the error that produces the Pioneer > > anomaly.
> Actually, I meant one millisecond of hour-angle arc. I.e. the earth > orientation -- polar axes and rotation angles -- are known in an > absolute sense to this level or better [*]. A unmodeled drift rate of > 1 millisecond per day would be caught very quickly
It *has* been caught in form of the Pioneer anomaly, and it is also confirmed by the IERS data (see http://maia.usno.navy.mil/lod.gif ) where a constant offset of about 1 ms is apparent for the length of a day (apart from fluctuations of a similar magnitude).
> > > In any case, the same stations, the same technologies, and the same > > > instruments are used to successfully track GPS satellites, quasars, > > > and lunar retro-reflectors, all to mm-cm type precision. Station > > > positions are *very* well tied to the earth, and the properties of > > > earth rotation are very well known.
> > A relative location does not suffice here. What one would need for an > > unambiguous interpretation of the Pioneer anomaly is a figure for the > > rotational acceleration of the observing station with a relative > > accuracy much better than 10^-8, and already the main parameters of > > the earth (the average radius and the average rotation rate) are not > > specified with a sufficient accuracy.
> Since -- as pointed out above -- neither the average earth radius nor > the *average* earth rotation rate [*] are involved in the Pioneer > doppler analysis, your comment is again irrelevant. And this is all > irrelevant since the unaveraged anomaly is *not* a diurnal signal (as > pointed out several times, but you continue to ignore).
As pointed out already, we are not dealing with full diurnal cycles but only half cycles. This results in a constant anomaly apart from a diurnal signal.
> [*] of course, as also pointed out, the *instantaneous* earth > orientation and rotation are used, and are known very accurately.
As quoted above, according to Anderson et al., essentially the IERS parameters (which have the errors as indicated under http://hpiers.obspm.fr/eop-pc/models/constants.html ) are used to model the rotation and orientation of the earth.
> > > [ Incidentally, your other explanation for the Pioneer "anomaly" -- a > > > failure to account for spacecraft motion during the light travel time > > > -- is also erroneous. Spacecraft motion *was indeed* accounted for > > > during the light time. ]
> > The question is not whether the spacecraft motion is being taken into > > account or not, but whether the 'light distance' is equal to the > > actual spacecraft distance (when the signal is received): traditional > > theory assumes that (as judged from the ground station) the light > > travel time is t=x/(c-v) for a spacecraft receding with velocity v and > > at distance x when the signal is sent out. But if you consider it from > > the spacecraft, it should only only take t=x/c as the travel time of
>> --------------------------------------------------------------------------- --- >> -- >> tobygr - 08:17am Mar 2, 2008 GMT (#1 of 11) >> ""I am feeling both humble and perplexed by this," said >> Anderson, who is now working as a retiree. "There is >> something very strange going on with spacecraft >> motions. We have no convincing explanation for either >> the Pioneer anomaly or the flyby anomaly."
>Well, "tobygr" (and apparently you too) was not aware that in >2006, Anderson wrote a paper that explained the flyby anomaly and >GR did this too. Be careful what you pick up in chatrooms.
>David A. Smith
Forwarded to alt.astronomy, where the saucerheads love to dream that the Pioneer anomaly is evidence of their "flowing space model" and the cabal of mainstream science hiding the real truth about the universe.
-- Supreme Leader of the Brainwashed Followers of Art Deco
Thomas Smid <thomas.s...@gmail.com> writes: > On 4 Mar, 05:19, Craig Markwardt > <craigm...@REMOVEcow.physics.wisc.edu> wrote: > > Thomas Smid <thomas.s...@gmail.com> writes: > > > On 2 Mar, 16:44, Craig Markwardt > > > <craigm...@REMOVEcow.physics.wisc.edu> wrote: ... > > > > In any case, while it is true that the spacecraft is only visible by > > > > (either) station when it is above the horizon, the resulting residual > > > > would still be diurnal in nature, and this is not the nature of the > > > > actual "anomaly." > > > There will be a diurnal component, but there will also be a non- > > > diurnal component (if you average only over the positive halves of a > > > sinusoidal signal, this will not average to zero but produce a net > > > result).
> > However, since the data were *not* averaged over positive halves of > > the diurnal cycle, your supposition is largely irrelevant. > As I said already, because you can observe the spacecraft only when it > is above the horizon, only one half of the diurnal acceleration cycle > of the observing station can be observed, and this never changes sign. > If you would Fourier transform this signal you would not only have a > peak at the diurnal frequency buts also a constant offset.
Since the analysis (and the anomaly) involve *neither* averaging *nor* Fourier transformation, your speculations are still irrelevant. In fact, a diurnal Doppler error signal due to incorrect station positions would been readily visible in the residuals, and could have been corrected by adjusting the station positions (along with any corresponding biases, if any). No reasonable adjustment of the station positions could resolve the anomaly (ref. Anderson et al.; Markwardt 2002).
[ Your entire argument is actually a canard, because the real observables are the Doppler *frequencies* which tend to have both positive and negative diurnal excursions. ]
> > > > > ... And since the data are batch averages over several days, > > > > > any wrong assumption about the exact value of the earth's rotational > > > > > acceleration will result in an apparent net acceleration of the space > > > > > craft towards the earth.
> > > > You are incorrect. While a "batch-sequential" analysis was used by > > > > one research group, this does *not* mean that the signal was averaged > > > > over several days (but rather that the anomalous acceleration was > > > > estimated in batches from finer data). Also, my own work was a global > > > > analysis of 60-second sample intervals (no batching), and the main > > > > anomaly was definitely *not* diurnal.
> > > > > > For that matter, station positions can be treated as "solve-for" > > > > > > parameters, and yet this does not resolve theanomaly.
> > > > > I am sure that if the numerical values for the earth's rotational > > > > > velocity and radius are suitably adjusted (within the error limits), > > > > > the anomaly will disappear.
> > > > Your surety is misplaced. (a) The "earth radius" is irrelevant since > > > > the stations are not on the equator. > > > The (average) radius of the earth is as relevant as any other model > > > parameter entering the calculations (in fact more relevant as some of > > > the others, as it is a constant figure).
> > However, since the (equatorial) radius of the earth is *not* a > > parameter of the model, your supposition continues to be irrelevant.
> "Previously they [the model values] were combined into a common > publication by either the International Earth Rotation Service (IERS) > or by the United States Naval Observatory (USNO). ...
This comment is irrelevant. If you had bothered to read the preceding text, "We include models of precession, nutation, sidereal rotation, polar motion, tidal effects, and tectonic plates drift. Model values of the tidal deceleration, nonuniformity of rotation, polar motion, Love numbers, and Chandler wobble..." you would have seen that *all* of these components are *angles*, and do not require knowledge of the mean equatorial radius of the earth. The IERS Conventions describe many practices related to earth observing. The Pioneer-type doppler analysis definitely does not require knowledge of the radius of the earth.
... snip ...
> But anyway, whatever your earth rotation model is, if you would change > the parameters such that it corresponds to a reduction of the > rotational acceleration of the observing station by about 5*10^-8 cm/ > sec^2, then the anomaly must disappear.
This claim continues to be erroneous. First, earth orientation parameters are nailed down by huge numbers of observations, so they shouldn't be "changed" without invalidating all of those observations. Second, any diddling of these numbers would produce distinct diurnal Doppler signatures, which would *not* reflect a constant acceleration.
> > > > (b) Station positions *were* > > > > allowed to vary in the analysis, and this did not correct the > > > > anomaly. > > > Do you have any reference for this claim? I can not see anything in > > > the original analysis of Anderson et al. for instance ( > > >http://arxiv.org/abs/gr-qc/0104064) that would indicate this. ...
> > Anderson et al. 2002. Section VII. G.
> > "... Our analysis indicates that at most these [station-dependent] > > effects would produce a distance and/or time-dependent drifts that > > would be easily noticeable in the radio Doppler data. What is more > > important is that none of the effects would be able to produce a > > constant drift in the Doppler residuals of Pioneers over such a long > > time scale. ..."
> As pointed out already, the uncertainty of the main IERS model > parameters is such that they can explain the anomaly. If the authors > only check the dependence on irrelevant parameters, then obviously > they won't see any effect.
Whether or not you pointed it out already, it's still erroneous. Neither of the "IERS model parameters" you pointed out are used to perform Doppler analysis. And *if* the station positions were in error, this would appear in the residuals as a diurnal error-signal, that could be corrected by allowing the station positions to vary. Doing this definitely did *not* correct the anomaly.
The point still remains: adjustments to the station positions were attempted, and did not solve the anomaly. And, the instantaneous orientation of the earth at any given time is known extremely precisely (to much higher precision than the "mean" values are known).
> > > (c) The uncertainty in earth angular rate you quote (ref. IERS > > > > site), is actually the uncertainty in the *mean* rate since the earth > > > > is not a perfect rotator. (d) *However*, the actual earth rotation > > > > angles (and hence rates) are known precisely to the millisecond all times > > > > during the Pioneer flight, so the mean rate is irrelevant. Thus, your > > > > comments are irrelevant as well. > > > One millisecond/day would about be the error that produces the Pioneer > > > anomaly.
> > Actually, I meant one millisecond of hour-angle arc. I.e. the earth > > orientation -- polar axes and rotation angles -- are known in an > > absolute sense to this level or better [*]. A unmodeled drift rate of > > 1 millisecond per day would be caught very quickly
> It *has* been caught in form of the Pioneer anomaly, and it is also > confirmed by the IERS data (see http://maia.usno.navy.mil/lod.gif ) > where a constant offset of about 1 ms is apparent for the length of a > day (apart from fluctuations of a similar magnitude).
The plot you indicated is irrelevant. That plot shows the *measured excess* of the length of day beyond the standard length. In other words this is *not* an "unmodeled drift" since it is measured.
Perhaps you are arguing under the assumption that a standard fixed-length day is used in the analysis. That assumption would be false, as I have pointed out several times. In fact, the instantaneous length of day, rotation speed/angles, etc. are used. The very measurements you indicated, are used in the analysis.
> Sorry, but I can't make any sense out of this plot. The one given by > me above should anyway show that the errors are in the ms/day range.
Huh? Since the plot you indicated shows the *measurements* and not the errors, your claim is erroneous. The plot *I* indicated shows the measurement scatter about the standard rotational model for all of the major techniques, i.e. a true indication of errors. All of the scatter is smaller than 100 microseconds (more like 20 microseconds).
... snip ...
I note that you continue to make erroneous and irrelevant claims in support of your supposition.
> >> --------------------------------------------------------------------------- --- > >> -- > >> tobygr - 08:17am Mar 2, 2008 GMT (#1 of 11) > >> ""I am feeling both humble and perplexed by this," said > >> Anderson, who is now working as a retiree. "There is > >> something very strange going on with spacecraft > >> motions. We have no convincing explanation for either > >> the Pioneer anomaly or the flyby anomaly."
> >Well, "tobygr" (and apparently you too) was not aware that in > >2006, Anderson wrote a paper that explained the flyby anomaly and > >GR did this too. Be careful what you pick up in chatrooms.
> >David A. Smith
> Forwarded to alt.astronomy, where the saucerheads love to dream that > the Pioneer anomaly is evidence of their "flowing space model" and the > cabal of mainstream science hiding the real truth about the universe.
>> --------------------------------------------------------------------- ------ --- > >> -- > >> tobygr - 08:17am Mar 2, 2008 GMT (#1 of 11) > >> ""I am feeling both humble and perplexed by this," said > >> Anderson, who is now working as a retiree. "There is > >> something very strange going on with spacecraft > >> motions. We have no convincing explanation for either > >> the Pioneer anomaly or the flyby anomaly."
> >Well, "tobygr" (and apparently you too) was not aware that in > >2006, Anderson wrote a paper that explained the flyby anomaly and > >GR did this too. Be careful what you pick up in chatrooms.
> >David A. Smith
> Forwarded to alt.astronomy, where the saucerheads love to dream that > the Pioneer anomaly is evidence of their "flowing space model" and the > cabal of mainstream science hiding the real truth about the universe.
Best explain it first! ~~~~~~~~~~~~~ Deco will have to find the comic book that covers that in order to explain anything.
>Just for the hell of it, let's drag the slushpile for a moment and see >what manner of goosecrap comes up. Well, look-ee here..
Another demonstration that you lie again and again when you claim that you don't read my posts, Bill.
>> Forwarded to alt.astronomy, where the saucerheads love to dream that >> the Pioneer anomaly is evidence of their "flowing space model" and the >> cabal of mainstream science hiding the real truth about the universe.
>Nobody's sayin' the mainstream is intentionally "hiding" anything..
Another lie, the alleged conspiracy of university physicists that hide the real truth and brainwash students has been a favorite subject in alt.astronomy for a long time.
>but rather that it has bought into a false paradigm hook, line and >sinker. Its bedrock axiom of relativity is 'flat', that is, both SR >and GR are describing a universally-isotropic 'void-nothing' >mathematically.
Interesting that you are afraid to post these great truths to real science groups, Bill.
>This works just fine in the absence of any pressure/ >density gradients in the spatial medium. Recognizing these gradients >will bring relativity out of its present 'flat' status, just as >recognizing the curvature of the Earth transcended the flat Earth. >Notice that it subsumed but still _does not negate_ the 'flat' frame.. >just as relativity itself subsumed but did not negate Newton.
Can you derive the force versus distance relationship of the strong nuclear force from these assumptions, Bill?
>The _cosmological density gradient_ for instance, will resolve such >enigmas as the 1a supernova luminosity curve which currently is >interpreted as 'ever-accelerating expansion' of the universe. In so >doing, it will eliminate need for the mythical "dark energy" driving >the perceived acceleration. On the more mundane, local scale, 'tiny' >density gradients in the gravity wells of stars and planets will >explain the Pioneer and Earth-flyby accelerational "anomalies".
Completely ignoring the point of the OP that such leaps of faith into mysticism and metaphysics are not needs and that they can be explaining with real physics.
>Back to the slushpile, idiot. Ker-flooosh!
Who's the idiot, Bill?
-- Supreme Leader of the Brainwashed Followers of Art Deco
> >Just for the hell of it, let's drag the slushpile for a moment and see > >what manner of goosecrap comes up. Well, look-ee here..
> Another demonstration that you lie again and again when you claim that > you don't read my posts, Bill.
> >> Forwarded to alt.astronomy, where the saucerheads love to dream that > >> the Pioneer anomaly is evidence of their "flowing space model" and the > >> cabal of mainstream science hiding the real truth about the universe.
> >Nobody's sayin' the mainstream is intentionally "hiding" anything..
> Another lie, the alleged conspiracy of university physicists that hide > the real truth and brainwash students has been a favorite subject in > alt.astronomy for a long time.
> >but rather that it has bought into a false paradigm hook, line and > >sinker. Its bedrock axiom of relativity is 'flat', that is, both SR > >and GR are describing a universally-isotropic 'void-nothing' > >mathematically.
> Interesting that you are afraid to post these great truths to real > science groups, Bill.
> >This works just fine in the absence of any pressure/ > >density gradients in the spatial medium. Recognizing these gradients > >will bring relativity out of its present 'flat' status, just as > >recognizing the curvature of the Earth transcended the flat Earth. > >Notice that it subsumed but still _does not negate_ the 'flat' frame.. > >just as relativity itself subsumed but did not negate Newton.
> Can you derive the force versus distance relationship of the strong > nuclear force from these assumptions, Bill?
> >The _cosmological density gradient_ for instance, will resolve such > >enigmas as the 1a supernova luminosity curve which currently is > >interpreted as 'ever-accelerating expansion' of the universe. In so > >doing, it will eliminate need for the mythical "dark energy" driving > >the perceived acceleration. On the more mundane, local scale, 'tiny' > >density gradients in the gravity wells of stars and planets will > >explain the Pioneer and Earth-flyby accelerational "anomalies".
> Completely ignoring the point of the OP that such leaps of faith into > mysticism and metaphysics are not needs and that they can be explaining > with real physics.
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