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Offline Geezer

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Have the Pioneer anomalies also affected other probes?
« Reply #25 on: 26/04/2011 04:11:31 »
Ah! Good. So, what might we conclude?

Well, I think we can say that the speed of light is constant for any observer within their frame of reference. Speed is correct in that sense because it really is the distance travelled in time.

Here's where it might get ugly. We know that the two clocks (the one on the spaceship and the one on earth) are not in agreement. Also, we know that the two vacuum tubes are not really the same length while they have a great difference in relative speed. Soooooo, if you could measure the speed of light on the spaceship using the the Earth clock and the Earth vacuum tube, you would measure a value for c that was different from the official c.


 

 

Offline CPT ArkAngel

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Have the Pioneer anomalies also affected other probes?
« Reply #26 on: 26/04/2011 06:11:09 »
The thing is that all measurements you can do by using the earth's clock and tube will be corrected by the speed of light relating you to the earth...

By the way, i agree with Mike about the blueshift, but i suppose it has already been taking in account and it should be quite small. It may be only a drifting of electronics components... They surely cannot measure it...
« Last Edit: 26/04/2011 06:16:31 by CPT ArkAngel »
 

Offline Geezer

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Have the Pioneer anomalies also affected other probes?
« Reply #27 on: 26/04/2011 07:29:35 »
The thing is that all measurements you can do by using the earth's clock and tube will be corrected by the speed of light relating you to the earth...

Actually, they won't  :D

If the spaceship was orbiting the Earth, you could send it a signal during every orbit so that the spaceship's clock was continuously synchronized with Earth time. Then you would measure a different value for c on the spaceship.

But that does not violate relativity because, in that situation, you would not be measuring the speed of light using the time within the frame of reference of the observer.
 

Offline CPT ArkAngel

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« Reply #28 on: 26/04/2011 07:54:39 »
You're cheating, you forgot the tube...  ;)
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #29 on: 26/04/2011 09:59:16 »
It would seem that I can't stress this enough:-
The speed of light is a constant, is a constant is a constant.

But

The speed of light is a constant because the rate of flow of time is a variable.

Without wishing to get into what time is it has two components, direction and rate of flow.  Obviously time is a product of the universe and its rate of flow must be connected to some particular qualities of the universe, say its a relationship between energy and mass, energy divided by mass.  This ratio is not constant in the universe, nor is it constant on any local volume of space that contains mass.

There is very good reason, known and understood why the speed of light is a constant.  There is nothing that says the rate of flow of time is a constant.  It isn't.  General Relativity states that the passage of time (the rate of flow of time) is relative.  Traveling near to the speed of light or being in a gravity well dilate time.  These are not abstract frame of reference ideas that can't be seen or measured.  Time dilation is real and observable and has been proven to be correct.

"Gravitational time dilation is the effect of time passing at different rates in regions of different gravitational potential; the lower the gravitational potential, the more slowly time passes. Albert Einstein originally predicted this effect in his theory of relativity and it has since been confirmed by tests of general relativity.
This has been demonstrated by noting that atomic clocks at differing altitudes (and thus different gravitational potential) will eventually show different times. The effects detected in such experiments are extremely small, with differences being measured in nanoseconds."
http://en.wikipedia.org/wiki/Gravitational_time_dilation
Gravitational time dilation is minute on the Earth because the Earth in cosmological terms contains little mass.

ArkAngel
It would seem reasonable to assume the blue shift has been taken into account as it is predicted by relativity but honestly, I don't believe it has.

Mike
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #30 on: 26/04/2011 10:08:37 »
Further to comment from ArkAngel:-
As I understand it Newtonian Gravity was used as the model when analysing the Pioneer anomaly.  Newtonian Gravity is obviously lacking for this scenario as it does not take into account gravitational time dilation by our solar system.

Mike
 

Offline JP

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Have the Pioneer anomalies also affected other probes?
« Reply #31 on: 26/04/2011 12:59:51 »
Further to comment from ArkAngel:-
As I understand it Newtonian Gravity was used as the model when analysing the Pioneer anomaly.  Newtonian Gravity is obviously lacking for this scenario as it does not take into account gravitational time dilation by our solar system.

Mike

It would be extremely embarrassing to physicists if the anomaly was as simple as them not using general relativity to do the calculations.  Interestingly, I can't find any description of the model of gravity used in the original papers on it.  See this one, for example: http://arxiv.org/PS_cache/gr-qc/pdf/9808/9808081v2.pdf 

However, some of the attempted explanations involve using general relativity and assuming dark matter/dark energy http://arxiv.org/PS_cache/gr-qc/pdf/0407/0407023v1.pdf, so I assume the effect has been checked with general relativity.  It would be odd to check the anomaly using general relativity with added dark matter/energy and not notice that general relativity without these additions explains the anomaly.

At any rate, I agree with ArkAngel on this one.  Surely they've checked if GR alone predicts the effect, even if I can't find someone explicitly stating that in an article.
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #32 on: 26/04/2011 14:09:05 »
I agree, it would seem odd if they hadn't considered general relativity.  Einstein, when he came up with these theories based much of his work on thought experiments.  I don't know how he would have translated thought experiments into specific as opposed to general mathematical solutions.  Perhaps relativity needs tweaking.

Apart from the Pioneer anomaly there exists the galaxy and associated quasar red shift anomaly and the galaxy rotation anomaly. I am sure that these anomalies are also based around relativity.  Personally I do not believe in dark matter or dark energy.

Anybody care to comment on the speed of light being a constant because the rate of flow of time is a variable.  I think this is what relativity is telling us and I believe my interpretation of this is correct.  However perhaps you know better?

Mike
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #33 on: 26/04/2011 14:32:32 »
"ANOMALOUS GRAVITATIONAL FORCE

A discussion of this phenomenon appears in the 4 October 1999 issue of Newsweek magazine (See also the December 1998 issue of Scientific American.) The mystery of the tiny acceleration towards the sun in the motion of the Pioneer 10, Pioneer 11 and Ulysses spacecraft remains unexplained as of 2006. A team of planetary scientists and physicists led by John Anderson (Pioneer 10 Principal Investigator for Celestial Mechanics) has identified a tiny unexplained acceleration towards the sun in the motion of the Pioneer 10, Pioneer 11, and Ulysses spacecraft. The anomalous acceleration - about 10 billion times smaller than the acceleration we feel from Earth's gravitational pull - was identified after detailed analyses of radio data from the spacecraft. A variety of possible causes were considered including: perturbations from the gravitational attraction of planets and smaller bodies in the solar system; radiation pressure, the tiny transfer of momentum when photons impact the spacecraft; general relativity; interactions between the solar wind and the spacecraft; possible corruption to the radio Doppler data; wobbles and other changes in Earth's rotation; outgassing or thermal radiation from the spacecraft; and the possible influence of non-ordinary or dark matter. After exhausting the list of explanations deemed most plausible, the researchers examined possible modification to the force of gravity as explained by Newton's law with the sun being the dominant gravitational force. "Clearly, more analysis, observation, and theoretical work are called for," the researchers concluded. The scientists expect the explanation when found will involve conventional physics. An article in http://www.space.com/scienceastronomy/mystery_monday_041018.html discusses the current thinking on the acceleration anomaly."
 
http://www.nasa.gov/centers/ames/missions/archive/pioneer.html

Although it mentions general relativity, it talks about modification to Newtons law. We are now talking about three spacecraft with the same anomaly.  One of which is a different design.  It's a very small but consistent anomaly. 

I am absolutely certain that my original explanation is correct.  Either they haven't used general relativity, or they have done the sums wrong or general relativity needs tweaking.

Mike
 

Offline MikeS

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« Reply #34 on: 26/04/2011 15:19:38 »
Iv'e just sent an e.mail to Slava Turyshev at NASA's Jet Propulsion Laboratory who is handling the enquiry.  If I get a rely I will post.

Mike
 

Offline JP

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« Reply #35 on: 26/04/2011 15:26:42 »
Quote
I am absolutely certain that my original explanation is correct.  Either they haven't used general relativity, or they have done the sums wrong or general relativity needs tweaking.

Absolute certainty is a huge leap of faith.  Is it backed up by science?  What evidence makes you so certain that your explanation is right?  

I do happen to agree with you that the idea that GR might need tweaking is a very interesting possibility.  I don't think there's any reason to be certain that it does, though.

By the way, as yor_on posted there was a recent paper claiming that the anomaly could be explained by thermal radiation off an antenna.  It hasn't been double checked.

------------------

As for the speed of light being constant because time is variable, it's usually put the other way.  The speed of light is constant for all observers.  This is from experimental evidence.  In order for that to be correct, the geometry of space-time has to depend on the velocity of observers which means that clocks and measuring sticks moving at different speeds don't match up.

You could come at it the other way, I think.  That clocks and measuring sticks of moving observers don't agree and from measuring exactly how they disagree you could come to the conclusion that the speed of light is constant. 

It's harder to motivate GR that way, though, since you'd have to take a lot of measurements of clocks and measuring sticks in different gravitational situations to construct the theory.  
 

Offline imatfaal

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Have the Pioneer anomalies also affected other probes?
« Reply #36 on: 26/04/2011 16:06:39 »
In the Naked Astronomy podcast (or possible another sci-cast) they mentioned that the recent ideas about a(nother) directional source of thermal radiation causing the anomaly  would cause problems for those who were using the anomaly to tweak GR in their own special way - if they were modifying GR I think you can be certain that they were using GR/SR in their initial calcs.   The JPL orbital calculational engine definitely takes into account some relativistic effects.

Mike - can you actually DO the sums required?  If so, do them and show they are wrong - ie for a start what is the time dilation caused by the gravitational potential of the sun at the position of the earth's orbit, mars', jupiter's etc.  This would at least give you an idea if you were talking in the right magnitude

edit here is a quote giving a rough idea of the methodology used

Quote
The ephemeris programs use equations for point-mass relativistic gravitational accelerations. They are derived from the variation of a time-dependent, Lagrangian action integral that is referenced to a non-rotating, solarsystem, barycentric, coordinate frame. In addition to modeling point-mass interactions, the ephemeris programs contain equations of motion that model terrestrial and lunar figure effects, Earth tides, and lunar physical librations . The programs treat the Sun, the Moon, and the nine planets as point masses in the isotropic, parameterized post-Newtonian, N-body metric with Newtonian gravitational perturbations from large, main-belt asteroid

This is from this paper produced by JPL and others http://arxiv.org/PS_cache/gr-qc/pdf/0104/0104064v5.pdf  I think even this snippet makes it clear that the calculations are not based on solely Newtonian physics.
« Last Edit: 26/04/2011 16:21:41 by imatfaal »
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #37 on: 26/04/2011 17:06:01 »
JP.  I agree, there is nothing scientific about being absolutely certain  but it is still how I feel.
The explanation that I gave, is, the simplest explanation, requires no assumptions, does not require anything new and is the one predicted by general relativity.

"As for the speed of light being constant because time is variable, it's usually put the other way.  The speed of light is constant for all observers.  This is from experimental evidence.  In order for that to be correct, the geometry of space-time has to depend on the velocity of observers which means that clocks and measuring sticks moving at different speeds don't match up"

Yes, I agree but in this instance we are considering gravitational time dilation which is predicted by general relativity and is a proven fact.  Gravity slows down the rate of flow of time. Or to put it another way the speed of light is a constant because the rate of flow of time is a variable.

I have just found this:-
This is an extract from a paper about the pioneer anomaly written by Slava G. Turyshev, Viktor T. Toth
Slava G. Turyshev is the person investigating the anomaly at JPL Pasadena.
"This apparent violation of the Newton's gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained."

"While most of the modern experiments in the solar system do not show disagreements with
general relativity, there are puzzles that require further investigation. One such puzzle was presented by the Pioneer 10 and 11 spacecraft. The radiometric tracking data received from these
spacecraft while they were at heliocentric distances of 20 – 70 astronomical units (AU) have consistently indicated the presence of a small, anomalous, Doppler frequency drift. The drift was
interpreted as a constant sunward acceleration of aP = (8.74 ± 1.33) × 10
−10 m/s
2
experienced by
both spacecraft [15, 18, 391]. This apparent violation of the inverse-square law has become known
as the Pioneer anomaly; the nature of this anomaly remains unexplained."


"Before Pioneer 10 and 11, Newtonian gravity was not measured with great precision over great
distances and was therefore never confirmed. The unique “built-in” navigation capabilities of the
two Pioneers allowed them to reach the levels of ∼ 10
−10 m/s
2
in acceleration sensitivity. Such an
exceptional sensitivity allowed researchers to use Pioneer 10 and 11 to test the gravitational inverse
square law in the largest-scale gravity experiment ever conducted. However, the experiment failed
to confirm the validity of this fundamental law of Newtonian gravity in the outer regions of the
solar system. Thus, the nagging question remains: Just how well do we know gravity?"


"One can demonstrate that beyond 15 AU the difference between the predictions of Newton
and Einstein are negligible. So, at the moment, two forces seem to be at play in deep space:
Newton’s law of gravity and the Pioneer anomaly. Until the anomaly is thoroughly accounted
3for by conventional causes, and can therefore be eliminated from consideration, the validity of
Newton’s laws in the outer solar system will remain in doubt.
This fact justifies the importance
of the investigation of the nature of the Pioneer anomaly"

http://arxiv.org/PS_cache/arxiv/pdf/1001/1001.3686v2.pdf

It would appear that the problem has been analysed from the standpoint of Newtonian gravity and surprise, surprise ..."the validity of Newton’s laws in the outer solar system will remain in doubt."  Let's face it they haven't taken into account gravitational time dilation by mass have they?

Mike
 

Offline JP

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« Reply #38 on: 26/04/2011 17:33:00 »
Quote
"One can demonstrate that beyond 15 AU the difference between the predictions of Newton
and Einstein are negligible.
So, at the moment, two forces seem to be at play in deep space:
Newton’s law of gravity and the Pioneer anomaly. Until the anomaly is thoroughly accounted
3for by conventional causes, and can therefore be eliminated from consideration, the validity of
Newton’s laws in the outer solar system will remain in doubt. This fact justifies the importance
of the investigation of the nature of the Pioneer anomaly"
http://arxiv.org/PS_cache/arxiv/pdf/1001/1001.3686v2.pdf

It would appear that the problem has been analysed from the standpoint of Newtonian gravity and surprise, surprise ..."the validity of Newton’s laws in the outer solar system will remain in doubt."  Let's face it they haven't taken into account gravitational time dilation by mass have they?

Actually, if you read the bolded part above, they did account for general relativity, and noted that the differences from Newtonian gravity is negligible at those distances.  So they ignored time dilation because they considered it and found that it isn't important here. 
 

Offline MikeS

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« Reply #39 on: 26/04/2011 19:06:59 »
imatfaal,

No, I can’t do the maths I wish I could. 

Mathematics  is just another language, the one mostly used by the scientific community.  It is frequently used to prove some theory or another.  There are countless theories on just about everything that can be represented by mathematics, most of them wrong.  Whilst mathematics are capable of telling ultimate truths they are just as capable of deceit, unwitting or otherwise. 

I am always reminded of this quote.
“Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction”.
Albert Einstein

I don’t need to do the maths to know that I am “talking in the right magnitude”.  The anomaly is extremely small but real, just the kind of adjustment that gravitational time dilation should predict.

These are quotes from the paper you mention

“It is also possible to infer the position in the sky of a spacecraft from the Doppler data. This is accomplished by examining the diurnal variation imparted to the Doppler shift by the Earth’s rotation. As the ground station rotates underneath a spacecraft, the Doppler shift is modulated by a sinusoid. The sinusoid’s amplitude depends on the declination angle of the spacecraft and its phase depends upon the right ascension. These angles can therefore be estimated from a record of the Doppler shift that is (at least) of several days duration. This allows for a determination of the distance to the spacecraft through the dynamics of spacecraft motion using standard orbit theory contained in the orbit determination programs”
http://arxiv.org/PS_cache/gr-qc/pdf/0104/0104064v5.pdf


The above programs were written obviously for spacecraft in orbit within the solar system.  It is highly probable that when they were written they did not take into account that they would be used on spacecraft leaving the solar System

“Is there any evidence that some kind of “time acceleration”
http://arxiv.org/PS_cache/gr-qc/pdf/0104/0104064v5.pdf

Although “time acceleration” is mentioned in, the above paper and various methods proposed and discounted.  I could not find any reference to relativistic, gravitational time dilation being seriously considered.

Although the anomaly being discussed is about Pioneers 10 & 11 it seems there may be a total of four that are “probably” affected in the same manner, possibly more.  The anomaly only becomes apparent when spacecraft are leaving the Solar System.  Most explanations have been proposed and discounted.  Gravitational time dilation of photons entering the Solar System remains the simplest and most likely explanation.

JP wrote.

"One can demonstrate that beyond 15 AU the difference between the predictions of Newton
and Einstein are negligible. So, at the moment, two forces seem to be at play in deep space:
Newton’s law of gravity and the Pioneer anomaly. Until the anomaly is thoroughly accounted
3for by conventional causes, and can therefore be eliminated from consideration, the validity of
Newton’s laws in the outer solar system will remain in doubt. This fact justifies the importance
of the investigation of the nature of the Pioneer anomaly"
http://arxiv.org/PS_cache/arxiv/pdf/1001/1001.3686v2.pdf




"One can demonstrate that beyond 15 AU the difference between the predictions of Newton and Einstein are negligible.

In other word below 15AU they are significant right?  The photons from 20AU are being gradually red shifted the closer they get to Earth.

Actually, if you read the bolded part above, they did account for general relativity, and noted that the differences from Newtonian gravity is negligible at those distances.  So they ignored time dilation because they considered it and found that it isn't important here.”

“So they ignored time dilation because they considered it and found that it isn't important here.”

This should read:-

So they ignored time dilation because they didn’t understand it.  See Above

Mike

 

Offline JP

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« Reply #40 on: 26/04/2011 19:38:42 »
I don’t need to do the maths to know that I am “talking in the right magnitude”.  The anomaly is extremely small but real, just the kind of adjustment that gravitational time dilation should predict.

Actually, you do have to do math to know that you're talking about the right order of magnitude.  Orders of magnitude are quantitative.  How do you know you're not of by a factor of 10, 100 or 1000 if you haven't done the math?
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #41 on: 26/04/2011 19:56:21 »
I don’t need to do the maths to know that I am “talking in the right magnitude”.  The anomaly is extremely small but real, just the kind of adjustment that gravitational time dilation should predict.

JP quote
"Actually, you do have to do math to know that you're talking about the right order of magnitude.  Orders of magnitude are quantitative.  How do you know you're not of by a factor of 10, 100 or 1000 if you haven't done the math?"

Point taken.  Let me substitute "ball park" for magnitude.
The fact remains as I said before The anomaly is extremely small but real, just the kind of adjustment that gravitational time dilation should predict.

Mike
 

Offline JP

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« Reply #42 on: 26/04/2011 21:02:17 »
The fact remains as I said before The anomaly is extremely small but real, just the kind of adjustment that gravitational time dilation should predict.

But if the real observations are on the order of 10-9 m/s2, and time dilation ends up being 10-11 m/s2, then it isn't responsible for most of the anomaly.  Can you give any justification that they're on the same order of magnitude other than the fact that time dilation should be "small"?

I doubt you'll change your mind, even faced with these facts.  It is also technically possible that the physicists working on this problem have all made a very basic mistake and that you caught it.   However, it seems a bit extreme to post with absolute certainty you have the answer to the Pioneer anomaly that everyone else missed when you can't provide any numbers to show that the effect you're citing is even the right order of magnitude.
« Last Edit: 26/04/2011 21:08:21 by JP »
 

Offline yor_on

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Have the Pioneer anomalies also affected other probes?
« Reply #43 on: 27/04/2011 01:06:11 »
" During the past 30 years, 2.1 GHz maser signals have been transmitted to the Pioneer 10 and Pioneer 1 spacecraft and coherently transponded back to earth, the frequency shift of the received signal being used to determine the recessional velocity of the spacecraft for the purposes of navigation. However, Anderson et al. report that when the computed velocity is compared to the velocity predicted by orbital  models, a discrepancy is found, even after adjustments are made for all known forces that might act on the spacecraft. They find a frequency blueshift residual that increases linearly with time, or in direct proportion to the increase in the line-of-sight distance the spacecraft. If interpreted as a Doppler effect, this residual implies the presence of an anomalous force accelerating the craft  toward the Sun, which Anderson et al. calculate to be (8.7 ± 1.3) × 10 ^–8 cm/s^2 .

When the propulsive effects of onboard thermal radiation sources are taken into account,  this decreases to a residual acceleration of (6.85 ± 1.3) × 10^-8 cm/s  

If interpreted as an anomalous acceleration, the effect is perplexing since most plausible  forces,  such  as  gravity,  decrease  rapidly with distance whereas the Pioneer apparent acceleration remains relatively constant with time. Moreover, an anomalous acceleration of similar magnitude does not appear to be acting on the planets, given that their orbital periods experience no similar secular change within the accuracy of current determinations."

You know Mike, there seems to be a mountain of theoretical frameworks discussing the underlying physics out on the net :) But to define a new 'physics' on one spacecrafts anomaly seems somewhat drastic. I've seen so many weird explanations now, everything from expecting photons to 'naturally' blue shift (Subquantum kinetics) to the tired light explanation where they 'die out' which in a way seems incorporated in the aforementioned explanation too. And you know what :) They all have tons of math supporting their definitions. Then you have some calling it a redshift instead of a blue shift, finding Andersons et al. definitions and proofs questionable in themselves etc etc.

Let's put a end to this debate. We're not here to judge the best explanation of the Pioneer anomaly and we would need more experiments done to find what it really was/is. The antenna used wasn't that specific (narrowed down) and NASA could neither say with certainty when it was 'closed down' not working, as I understands it. There are so many uncertainties in this material, although I can understand that mathematically inclined physicists threw themselves at the result of the Anderson et all. investigation and started to theorize around it.

And i still have to see how they can define a object moving away from the detector as blue shifted. There has to be an explanation to that idea, I've seen some id* mumbling about accelerating away as explaining it but that one is them mixing the idea of potential energy with red and blue shift.

Take anything moving away, emitting a light, relative you 'standing still'. here is you X and here is the object -- 0 -- when it is still relative you. the '-' is a measure of the lights frequency, the shorter the more energetic/blue shifted here.

Now it starts to move relative you X  ---0- And as you can see :) it will be blue-shifted relative its direction of motion -> and red shifted relative you <--- being 'still'. It's a very simple phenomena basicly. If I assume the Pioneer to have moved apart from us then the blue shift should be in the direction it moved and any red shift should be relative us. To that you can add that any gravitational field will blue shift a incoming photon, as gravity seem to act as an 'accelerator' of energy.

You might assume that the same should be true for a single photon, but it's not. If we assume it to be blue-shifted it will be so, as I see it, from any vector 'observed'. But it will be combined effect of your motion/mass relative the vector/momentum of that photon. Macroscopic objects express a blue and red-shift through their motion relative you, in their waves/photons. But a single photon I believe to have the same 'energy', always. As I see it that is mainly due to two things, We don't see them until they interact, and assuming a 'propagation' any 'photon' will have a direction, and a momentum, (vector=magnitude and direction) directed into what vector they are 'propagating'. That momentum, expressed, and actually created in the 'interaction' with whatever it 'hits', is what will define its final 'energy', not too unlike a ball moving. This does not contradict the idea of a photon having a intrinsic invariant energy though. Just as little as the balls velocity as it smash into you is contradicted by its 'invariant mass', both will have a relevance to the impact. The other reason is that a photon is a 'point particle', not existing inside our SpaceTime other that as a '(wave) packet of energy'.

As photons does not take any 'place', and does not exist until its interaction we can't really say what a photon does in the immediate 'duration' it 'propagates'. One really need to consider the difference between a object of invariant mass (e.g a ball), and also consider it macroscopically to realize that there is a major difference between the idea of a 'photons propagation', as compared to that ball coming at you in the air. the balls trajectory is 'there' for you, you see it before it hits you, translated by the same 'photons' that only exist in their interactions.

To not admit to what is true is one of the worst mistakes one can do. To generalize a propagation of light is well documented and follow laws of physics that allows us to give light a 'invariant speed', but I prefer to look at that as pure constant myself. And as I said, that lights speed is a 'invariant', a 'constant'. That was what Einstein built his theory on relativity on, not 'time pockets' and gravitational 'field' having their own 'time density'. Although I can see how you can think of it that way. 'motion' and 'distance' is relative in Einsteins universe, not light. Light has one same 'speed' in all frames, and as measured from any frame possible. That's actually what makes light unique. Well, there are more things too it, as always. Ask JP :) but that's what he built his theory of relativity on.
==

Had to clear it up some :)
« Last Edit: 27/04/2011 01:41:06 by yor_on »
 

Offline MikeS

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« Reply #44 on: 27/04/2011 10:38:44 »
JP.
Yes, I said “I am absolutely certain that my original explanation is correct.”
This is just my feeling on the subject.  I have already admitted that it is not a scientific approach.  It was never meant to be.  My purpose was to put forth an idea and hope that it would stimulate debate.  The only real debate it seems to have stimulated so far is over my own feelings on the subject and whether I can do the maths.  I have already retracted “magnitude and substituted “ball park”. Whilst I do not want to trivialize the scientific approach, I believe you are “nit picking” and trying to trivialize a much more important issue.  I have already admitted I do not understand the math’s but presumably some amongst you will.  This is an important debate and there is nothing to stop any of you from mathematically investigating the anomaly.


yor_on
Quotes
“If interpreted as an anomalous acceleration, the effect is perplexing since most plausible  forces,  such  as  gravity,  decrease  rapidly with distance whereas the Pioneer apparent acceleration remains relatively constant with time. Moreover, an anomalous acceleration of similar magnitude does not appear to be acting on the planets, given that their orbital periods experience no similar secular change within the accuracy of current determinations."

"Pioneer apparent acceleration remains relatively constant with time."

EXPLANATION  This is because the wavelength of photons emitted by the spacecraft are continually being dilated by gravity as they enter the Solar System.  The dilation is progressive, the further the spacecraft, the more the dilation.  Once the spacecraft is ‘effectively’ outside the gravity of the solar system, the dilation will no longer be progressive but constant.

"Moreover, an anomalous acceleration of similar magnitude does not appear to be acting on the planets, given that their orbital periods experience no similar secular change within the accuracy of current determinations."

EXPLANATION  Of course, it does not affect the planets or anything else within the Solar System as the strength of gravity within the Solar System remains fairly constant

“You know Mike, there seems to be a mountain of theoretical frameworks discussing the underlying physics out on the net :) But to define a new 'physics' on one spacecrafts anomaly seems somewhat drastic. I've seen so many weird explanations now, everything from expecting photons to 'naturally' blue shift (Subquantum kinetics) to the tired light explanation where they 'die out' which in a way seems incorporated in the aforementioned explanation too. And you know what :) They all have tons of math supporting their definitions. Then you have some calling it a redshift instead of a blue shift, finding Andersons et al. definitions and proofs questionable in themselves etc etc.”

"But to define a new 'physics' on one spacecrafts anomaly seems somewhat drastic."

CORRECTION  It’s at least three very similar spacecraft anomalies, could be four or more.  Possibly enough to be statistically significant but this is not the point.

CORRECTION   I never mentioned anything about new ‘physics’ nor was it my intention so to do.  Throughout this debate, I have continuously referred to General Relativity gravitational time dilation as being the cause of the anomaly.  This is not new ‘physics’.  This idea was originally suggested, as it seemed the most obvious answer to the question.  If you have read the above then you will have seen that when analyzing the problem gravitational time dilation was ignored.  As I pointed out, it seems they choose to ignore General Relativity because they thought it irrelevant but they were wrong.

"They all have tons of math supporting their definitions"

As I have already mentioned maths supporting conflicting theories just shows how unreliable maths can be.

“And i still have to see how they can define a object moving away from the detector as blue shifted. There has to be an explanation to that idea, I've seen some id* mumbling about accelerating away as explaining it but that one is them mixing the idea of potential energy with red and blue shift.”

This was my original post and it contains the complete explanation.

“The Pioneer anomaly is due to time dilation that is caused by the gravity of the SolarSystem.  As pioneer leaves the solar System the rate of flow of time increases causing a doppler blue shift relative to our perspective.  This blue shift reduces the expected red shift so the red shift is not as far red shifted as expected.  The craft is where it is supposed to be, it just appears to be closer to us than it is.”


Another way of putting this is:-
The wavelength of photons emitted by the spacecraft are gravitationally red shifted as they enter the Solar System. 


What I said was:-
As pioneer leaves the solar System the rate of flow of time increases causing a
doppler blue shift relative to our perspective.


CORRECTION  I never said light was blue shifted only that it appears blue shifted from our perspective.  (Actually, thinking about it, yes it is blue shifted.  The blue shift reduces the expected red shift.  The red shift is not as far red shifted as expected.)


To not admit to what is true is one of the worst mistakes one can do. To generalize a propagation of light is well documented and follow laws of physics that allows us to give light a 'invariant speed', but I prefer to look at that as pure constant myself. And as I said, that lights speed is a 'invariant', a 'constant'. That was what Einstein built his theory on relativity on, not 'time pockets' and gravitational 'field' having their own 'time density'. Although I can see how you can think of it that way. 'motion' and 'distance' is relative in Einsteins universe, not light. Light has one same 'speed' in all frames, and as measured from any frame possible. That's actually what makes light unique. Well, there are more things too it, as always. Ask JP :) but that's what he built his theory of relativity on.”


To not admit to what is true is one of the worst mistakes one can do.
The implication being that I am knowingly refusing to admit to what is true.
There is nothing true that you or the scientific community have said that I have refuted.  On the other hand you have almost continually refuted, distorted and misquoted most of what I have said.  This is a fact documented by this thread
.[/color]

“And as I said, that lights speed is a 'invariant', a 'constant'. That was what Einstein built his theory on relativity on, not 'time pockets' and gravitational 'field' having their own 'time density'”.


I have never mentioned ‘Time Pockets’ or ‘time density’, they are your inventions. 
What I have mentioned and is consistent with General Relativity is gravitational time dilation.  If you accept gravitational time dilation as a very real, observable and quantifiable effect, which it has proved to be then you must accept that as the strength of gravity varies in the universe on a local scale so must the rate of flow of time.  In other words the speed of light is a constant because the rate of flow of time is a variable.  It is built into General Relativity.  It’s not my idea, I am not proposing anything new.


All the explanations above I have given before, I have to keep repeating the same facts.

I add this so there is no mistake on what I have proposed.  The Pioneer anomalies can and should have been explained by General Relativity.  No new physics are required


As I mentioned a few posts ago, I have e.mailed JPL with the above suggestion.  If and when I receive a reply I will post it here, assuming the thread to still be open of course.

Mike
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #45 on: 27/04/2011 10:54:42 »
I have just noticed this from my last post:-

"As I pointed out, it seems they choose to ignore General Relativity because they thought it irrelevant but they were wrong.

"They all have tons of math supporting their definitions"

As I have already mentioned maths supporting conflicting theories just shows how unreliable maths can be."

If I am correct in thinking that there is no anomaly, it is just an artifact of using the wrong math then it shows just how unreliable mathematics can be when applied by the Human mind.

Mike
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #46 on: 27/04/2011 11:58:23 »
Perhaps this will help to put things into context.

I have just done an online search, phrased in different ways, to find online gravity calculators.
There is an abundance of calculators for Newtonian gravity, likewise an abundance for relatavistic calculators as regards speed. 

I haven't found one that can calculate time dilation due to gravity.  It's obviously something that people just don't consider. 

That might make me the world expert! ;)

Mike
 

Offline imatfaal

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Have the Pioneer anomalies also affected other probes?
« Reply #47 on: 27/04/2011 12:20:57 »
Mike - you are starting to sound like a crackpot.  I can absolutely guarantee that time dilation due to both relative velocities and due to gravitational potentials are taken into account within the calculations for orbital positions of satellites. 

You seem to be failing to grasp how maths and science is inter-twined, and the power of falsification;  maths can support many ideas at the same time - but it can also rule out absolutely an idea that doesn't agree.  As a very simple example
- you are given an unknown function y=f(x)
- and told if x=2 then y=4
- the speculations abound ie y=2x or y=x^x or y=4 or y=x^2
- all are potentially valid
- but y=x^3 is not valid
- you are then given additional info if x=1 y=1; two of the above are ruled out and two remain
etc...

The maths behind the theory is an essential part of the physics - without engagement with the maths all we have is pipedreams
 

Offline MikeS

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Have the Pioneer anomalies also affected other probes?
« Reply #48 on: 27/04/2011 13:17:42 »
Mike - you are starting to sound like a crackpot.  I can absolutely guarantee that time dilation due to both relative velocities and due to gravitational potentials are taken into account within the calculations for orbital positions of satellites. 

You seem to be failing to grasp how maths and science is inter-twined, and the power of falsification;  maths can support many ideas at the same time - but it can also rule out absolutely an idea that doesn't agree.  As a very simple example
- you are given an unknown function y=f(x)
- and told if x=2 then y=4
- the speculations abound ie y=2x or y=x^x or y=4 or y=x^2
- all are potentially valid
- but y=x^3 is not valid
- you are then given additional info if x=1 y=1; two of the above are ruled out and two remain
etc...

The maths behind the theory is an essential part of the physics - without engagement with the maths all we have is pipedreams

Iv'e already said in an earlier post that general relativity is used in calculations relating to gps satelites.  So what we are not talking about satelites.  We are talking about craft exiting the solar system and the specific method used to analyse signals from them.  If you,ve read my earlier posts you will see that JPS have admitted that they did not use general relativity in their calculations.

You seem to be totally missing the point.  I am not proposing anything new.  The maths that should have been used to analyse the pioneer data was general relativity but it wasn't used.  If I am wrong then it is easy to prove do the math.

If I am right and had done the math and confirmed the 'anomaly' was due to JPL not using General relativity then I could have contacted them myself, end of story.  I thought the idea of a science forum was for debate.

The first of my last three consequtive posts was mainly in answer to clear up a load of miss quotes.  There is a lot of things in there that you could query or disagree with.  Stick to what I have said and if you disagree say why.  I really do not understand your attitude all I have ever said is that the Pioneer anomaly can be understood through the mathematics of General Relativity.  Jps have themselves admitted that they have not used General relativity in their calculations.  And your calling me a crackpot.  If there is anything appertaining to the pioneer anomaly that I have said that you disagree with then please tell me.

Mike
 

Offline JP

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Have the Pioneer anomalies also affected other probes?
« Reply #49 on: 27/04/2011 14:46:31 »
Stick to what I have said and if you disagree say why. 

Mike, what I disagree with is that this is a science Q&A forum and your response to the initial question is based entirely on an unscientific guess.  Your defense of your original answer isn't based on science either, it's based on your intuition.  Why post this on a science forum if you aren't willing to engage with other posters using the scientific method of offering quantitative and falsifiable results?
 

The Naked Scientists Forum

Have the Pioneer anomalies also affected other probes?
« Reply #49 on: 27/04/2011 14:46:31 »

 

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