Through the Doppler effect is more energy emittet in the direction of movement as in the opposite direction. This should have a braking effect on moving and radiating objects.
Thesis The Deceleration of moved Energy emitting Objects by the Dop...
Hans-G H.> This should have a braking effect on moving and radiating objects.
No!
It is interesting homework to figure out in detail why this is not so (it would be against the relativity principles of Galileo and Einstein); hence I disagree with the down-vote of this question.
The Doppler-Fizeau 1842 effect is the change in frequency which distinguishes the emission from the reception and which then makes it possible to estimate the speed of a mobile or not.
Doppler does restrain movement, but not by much in most cases until very high speed is attempted.
Hans-G H.> This should have a braking effect on moving and radiating objects.
No!
It is interesting homework to figure out in detail why this is not so (it would be against the relativity principles of Galileo and Einstein); hence I disagree with the down-vote of this question.
I found this interesting approach to answer the question. Briefly, no, it says, because the photon was emitted by an atom, and energy and momentum was conserved, between the atom that emitted the photon, and the photon.
http://www.newtonphysics.on.ca/einstein/chapter8.html
Let us use the moving frame of the particle from which the photon is emitted. To be detected in the rest frame, the photon must be emitted backward (-x axis) from the moving atom, in the direction of the rest frame where the observer is located. When the photon is emitted, the atom gets a recoil in the forward (+x axis) direction giving it an increase of velocity deltaV.
I suppose a more opaque way of answering the question might be to say that conservation of energy and momentum is valid only within a given frame of reference.
Kåre, you are undoubtful a profound expert in theory.
But is the radiation pressure a fantasy?
The picture below shows the the radiation of energy in the direction of motion and in opposite direction. Between increase and decrease is an increasing difference. It would mean that the moving object (star) at higher speed more energy radiates as at lower speed. There are two possibilities: The star cools off at high speed or it produces more energy. Both possibilities are impossible.
You should consider that theories are only theories. The reality (respectively the whole world or the universe) is not the result of theories. Exactly the contrary: The theories should be the depiction of reality. A sustainable physics should perceive at first it internal contradictions.
“I am the first who explained the Gravitational redshift”
Adrian Ferent
I discovered the equation for photon – graviton interaction:
E = h × f + a × f - a × ν
All the physicists, mathematicians, engineers…where not capable to explain the gravitational redshift.
Time dilation in Special theory of relativity is caused by positive energy.
“Gravitational time dilatation is caused by negative energy”
Adrian Ferent
Only my Gravitation theory explains the gravitational redshift.
https://www.researchgate.net/publication/310952956_Gravitational_redshift_explained
Article Gravitational redshift explained
The errors are due to taking quantities that depend on the reference frame as independent thereof. This is a homework problem in undergraduate physics, whose solution is known, so there's no point in going into all the wrong ways of treating it, when the correct way of treating it is known.
Once more, history is being mixed up with physics.
The Doppler effect doesn't have anything to do with radiation pressure.
Hans-G.> ... profound expert in theory.
Between lines you make established knowledge sound suspect.
Hans-G.> But is the radiation pressure a fantasy?
No, what makes you think so?
Hans-G.> The picture below shows... Both possibilities are impossible.
Nothing wrong with the picture. But your analysis is incorrect, and so is your conclusion.
Hans-G.> The theories should be the depiction of reality. A sustainable physics should perceive at first it internal contradictions.
Absolutely! But wrongly claimed contradictions, as perceived by those who fail to apply or accept a theory, do not count against that theory.
I used to give essentially this problem as the very first homework in an undergraduate course I taught, attached.
In actuality the present formulation of the Doppler effect is in concordance with Einstein's Postulate of Relativity but it is in disagreement with the Galileo's Principle of Relativity.
Dear Hans,
the Relativistic Doppler effect whose relation has been confirmed experimentally, is meant to occur between Inertial Reference Frames as a consequence, by definition, no deceleration whatsoever should occur.
In the case of the Double Doppler effect, or the MOving Mirror there is a work done by the mirror on the radiation when a mirror approaches. It has been pointed out by Cooper http://scitation.aip.org/content/aapt/journal/ajp/80/8/10.1119/1.4730599
In other words there is a net delta energy and momentum of the radiation in the IRF of the source.
Since RDE consists in a radiation exchange between two bodies for sure the relevant radiation exerts a pressure .
There is a net radiation force as also described by Censor in the IRF of the emitter for a moving mirror.
https://www.researchgate.net/publication/260815208_Energy_Balance_and_Radiation_Forces_for_Arbitrary_Moving_Objects
The RDE consists in a approximation to what in real situations can occurr between emitters and absorbers of radiation, since bodies exchanging radiation may not be considered inertial.
If the breaking due to radiation occurs on a moving mirror going against a souce, it means that the Mirror is not anymore attached to an IRF and the Doppler radar relations cannot be applied anymore. https://en.wikipedia.org/wiki/Doppler_radar
Article Energy Balance and Radiation Forces for Arbitrary Moving Objects
Dear Stefano!
Thanks for your detailed answer. I don't have much time in the moment but I shall return to this matter.
What is with the equivalence: actio = reactioin this case?
Hans
Once more, the confusion results from assuming that energy is independent of the reference frame-it does depend on it, since it transforms as the time-like component of the energy-momentum 4-vector of the particles used and individual components of 4-vectors transform under Lorentz transformations.
The claims made in the papers linked to are, at least, confusing in this sense.
whose confusion are you talking about? since I specified that energy and momentum of the photons or the wave have to be "measured" in the same Inertial reference frame of the emitter. In such case there is not need of any four vectors to describe energy and momentum.
Let me try to be clear about what happens: in the system's rest frame, the radiating system loses energy, but neither gains nor loses momentum.
Energy is the timelike component of the 4-momentum, so when one goes to a moving reference frame, the momentum balance is affected by the energy imbalance present in the rest frame, since the separation between momentum conservation and energy conservation is frmae-dependent.
So the ``star'' does indeed lose momentum. Of course, it does not lose speed, since that would lead to a contradiction with Lorentz invariance, which is the foundation of the whole edifice. The point is that it loses mass, according to the well-known relation E=mc2, and thus, at fixed speed, also loses momentum.
Concerning internal contradictions: to avoid them, one should systematically use a well-defined mathematical theory, such as Special Relativity, and derive everything preferably from scratch from a few basic ideas. This is much safer, from a logical viewpoint, than combining a hodgepodge of formulae, the detailed significance of which are poorly understood. As pointed out by Kare, in this case, one needs to consider the effect of aberration (so that one takes into account the modification of the intensity distribution when viewed from the moving frame) together with the Doppler effect.
It doesn't matter how one does the calculation, only the result. And the statement that matters is that it isn't true that the Doppler effect results in any ``braking'' or ``restraining'' on anything, by itself.
It is very interesting to observe discussion finally gives the right importance to reference frames. It is what I have always thought and the result has been the Theory of Reference Frames. The invariance regards only laws of physics for inertial reference frames. The Principle of Relativity says only this and all the rest is arbitrary.
Special relativity is limited to inertial frames-general relativity isn't. And, just like any wave defines effective Lorentz transformations, non-inertial motion can be described in terms of an effective curved metric.
The ``discrepancies between measurements'' of non-invariant quantities don't make any sense, that's all. They represent choices of coordinates.
Daniele> The Principle of Relativity says only this and all the rest is arbitrary.
It is not arbitrary in physics. The transformation rules under general coordinate transformations, for the various types of fields and objects used in physics, has been known for a long time. Such transformations can be performed through a deductive and unambiguous (though often cumbersome) process.
(I interpret a reference frame to mean a coordinate system covering a local region of space-time, with its associated tangent, cotangent and similar spaces. And I don't consider the principle of relativity as the current unique basis of physics.)
Outside the framework of relativity, the Doppler effect can't be described at all.
And relativity, once more, certainly does not imply that the photoelectric effect depends on the frame-that's, simply, wrong. Certain aspects of it are frame dependent, others are not. It's the quantities that are independent of the frame that are significant, the others are not. In particular the statement that photons are massless is a Lorentz invariant statement.
Similarly, the statements that the 4-current of emitted electrons does or doesn't vanish are Lorentz invariant statements: they hold in all frames. They express the meaning of the photoelectric effect. That's why it's the 4-current that matters, not the density and the 3-current separately. And, of course, the signature of the 4-current is another Lorentz invariant.
For geometries which have a timelike Killing or conformal Killing vector, there is an invariant connected to each null-geodesic; this makes it possible to deduce red- and blue-shift effects. Which is a good thing for the interpretation of cosmological observations.
The Principle of Relativity says laws of physics are invariant with respect to inertial reference frames and aren't invariant with respect to other reference frames. In Special Relativity in order to guarantee the respect of the Principle of Relativity it needs to add to the Principle of Relativity the Postulate of the Constancy of the Speed of Light. Like this you obtain another theory, that has nothing in common with relativity, that was called Special Relativity. The Principle of Relativity says a simplest thing: let you consider any physical law and write it with respect to two inertial reference frames S[O,x,y,z,t] and S'[O',x',y',z',t']. For expediency you consider for instance S at rest and S' in relative motion with constant speed v. The Principle of Relativity says only you can write similarly the law in the two reference frames. The Postulate of the Constancy of the Speed of Light is outside relativity and it represents just a postulate that has no meaning in physics. GR then intends to study the behaviour of physical events with respect to non-inertial reference frames. Like this you obtain a Theory of non-Relativity. And anyway I agree that relativity isn't the unique basis of physics.
This discussion would have to turn on some consequences of the Doppler effect. Because the Doppler effect has numerous formulations according to the theory of reference, it is normal that there are confusions. For instance I agree that physical space is discrete, but I think also it is infinite and infinitesimal. Similarly also you would have to understand this definition of space. You affirm then time is not physical, but this statement doesn't consider time is a physical quantity that we measure with greatest accuracy. It would be therefore suitable to clarify what you intend for physics. Time doesn't have only a relational connection as you write, time is a physical quantity, naturally different from space.
In order to complete my preceding comment, I would want to add in electronics we make use of time like independent main variable.
Sorry, you don't know electronics. In electronics there isn't space, there is only time. You have a personal concept of physics, physics is the science of observable and measurable quantities. In order to measure a length you need a rod as tool, for measuring a time you need a clock as tool. Our accuracy in measuring time is also greater than the accuracy for measuring a length. I am considering a physical time and you are considering a metaphysical time, therefore you conclude time isn't physical. I think nevertheless we are talking here about physics and not metaphysics. Clocks are tools for measuring time, like for every physical quantity there is a measurement instrument. For you only space is physical, all the rest is a concept. Clocks are instruments for measuring physical time, period is just an unity of measurement and when the period is one second we have the measurement unity of the International System. Also length is cyclic and all measurement unities are cyclic. A length of 10 m is obtained through the cyclic application of the measurement unity for ten times.
It is not possible to continue this discussion. I apologize to Hildebrandt for making use of his space. Greetings and regards to all.
"Nor is it true that a moving source of electromagnetic radiation can enhance sunburn, for example, if it's moving towards a human body, due to any blueshift, simply due to its relative velocity (assuming flat spacetime, where relative velocity makes sense, of course). "
So you would sustain that if one body approaches at non negligible speed to an emitter of radiation the increased frequency that the detector will experience does not correspond to an actually higher EM energy and momentum absorbed, always in the RF of the emitter?
"It doesn't matter how one does the calculation, only the result."
Yes like renormalisation...it does not matter if you substitute a series that diverges with a finite number, what matters is that eventually it gives accurate results.
It has been for sure a genious who found such methods, to shed a light on something so unknown... but after 50 years I see that nobody worries to find what is behind these kind of "tricks". Instead of checking if there is something really important that has not been understood or some huge mistake in the theory so far, they just swollow it.
My greatest congratulations to those mathematical/physicists who resigned in front of a better understanding of the reality.
On second thought: the Doppler effect is an effect of relative-not absolute-motion, so it must have some measurable consequences. But it does require a bit more analysis to compute the invariant quantities.
As usual, the confusion is due to using ambiguous words-and to making statements that must refer to invariant quantities, by using frame-dependent quantities. While such shortcuts may hold in the non-relativistic case, one should be aware that the relativistic case does not have the same invariant quantities.
It's not useful to throw irrelevant terms in the discussion. Renormalization doesn't have anything to do with the subject and the statements made about it, incidentally, are meaningless. Nobody's resigned-they studied the subject, instead of wasting time in discussing nonsense. The ``tricks'' are understood-it's just that they're explained in textbooks, not popular magazines and books. That's why nobody is particularly ``worried''. Especially about the Doppler effect.
Though it does require some independent effort-many presentations, unfortunately, stress the calculation of non-invariant, coordinate-dependent quantities, rather than invariants. That does make understanding harder and leads to misunderstandings.
It's nothing more complicated than the other so-called ``paradoxes'' of special relativity, that are resolved by computing the invariant quantities. That's why 4-vectors matter: statements about 4-vectors can be seen more easily to be (or not) invariant than statements about individual coordinates.
@Kåre: Yor conclusions are limited on theories. The reality is only a disruptive factor. I would define this as thoretical dogmatism. On this way the sun will soon again rotate about the earth.
A presumption of validity does not apply for theories. Einsteins theories showing parallels to reality but they are not the reality. By the way he was less convinced from his own theories as his followers. In some points his theories have to apply always as falsified.
- To declare the increase in mass you have not to fall back on relativity theory. The increase in mass is caused by the accumulation of energy and is to calculate with an integral.
- The gravitational red shift of the solar radiation would be so significant that experimenters before Einstein would have notice it. Pound/Rebka and others take into account in their experiments only the desired effects which are visible within the backround noise of events (I say indulgent in German: positive Erwartungshaltung). Energy respectively radiation have only a mass equivalence and can never have the same properties as mass. See also the Pioneer anomaly.
- The mass attraction between macroscopic objects (par example between Earth and Newtons apple) gave rise to the simple conclusion of equivalence of gravitational mass and inert mass. The gravitational effect of mass has other causes as the inertia of mass. Furthermore is the „equivalence“ only or so proportionality. Look at the gravitational „constant“. If you are able to recognise connections in reality you will find a reason for the gravitational force. To draw theoretical conclusions within questionable theories is the wrong way to recognise the reality.
My paper is in good accordance with the reality resp. the observations about it. I have no reason to follow yor theoretical objections.
My Regards!
Hans
"Renormalization doesn't have anything to do with the subject and the statements made about it, incidentally, are meaningless."
for sure it does not, it is even not the case to mention it regarding the RDE. It was address to a "generic" sentence of yours.
That's why nobody is particularly ``worried''. Especially about the Doppler effect.
RDE is quite simple, if understood....
"Nobody's resigned-they studied the subject, instead of wasting time in discussing nonsense. The ``tricks'' are understood-it's just that they're explained in textbooks, not popular magazines and books."
I don't see any physical attempt at finding a justification to the substution in a diverging Riemann Zeta function with a finite value.
@ HGH: you claim absolute precedence of experiment over theory. So do we all. However, your question is surely not experimental: you have not built a radiating system and measured a braking effect due to the Doppler effect of the radiation.
Rather, what you do is the following: you isolate a few formulae (photon energy and Doppler effect) from their whole context, combine them in a way which neglects essential effects and important corrections, and obtain a result that contradicts basic theory, in particular Lorentz invariance.
Now Lorentz invariance has been experimentally tested to truly amazing accuracy (much more than merely astronomical). So denying that on the basis of your very simplified views on the Doppler effect, is indeed theoretical dogmatism of the very worst kind.
As for the issue of mass variation, one observes in accelerators particles whose mass have increased by a factor of a million or more from their rest mass. It is surely not ``theoretical dogmatism'' to accept a theory that explains, to high accuracy, this velocity dependence of the mass (In fact, I should speak of ``relativistic momentum'', and not use the incorrect expressions concerning mass, but these old-fashioned concepts can in any case be understood correctly with some effort).
Your question rests on theory, and theory alone. What Kare and myself have tried to explain is what other elements of relativity exist and are relevant to the problem you state, and yet have not been taken into account by you.
If you wish to avoid a charge of dogmatism yourself, you should, at the very least, attempt to listen.
Stam> But it does require a bit more analysis to compute the invariant quantities.
The invariant decider for being sunburnt or not is the parameter (k ub), where ub is the 4-velocity of the sunbather being exposed. The invariant k-distribution of photons from the burning sun is 1/[exp(a(k us)) -1], where us is the 4-velocity of that sun, and a=ħ/kBT. But, for the sunbather the possible directions of k is determined by the direction to the sun, modulo some scattering in the atmosphere.
The question raised by Hans G. Hildebrandt underlines the so-called Pioneer anomaly that consists in an unexplanable behaviour with respect to the Doppler effect predicet by the theory of Special Relativity. Many corrections and explanations ad hoc have been proposed: the presence of dark matter in the extreme zone of the Sun System, the Modified Theory of Newtonian Gravitation with the introduction of a new acceleration ad hoc, the effect reactive of engine, thermal effects due to reflected heat from antennae of sondes. H.G.H. has proposed a further explanation based on the fact that radiant energy emitted by sondes produces a braking effect on sondes. I observe reports of the anomaly aren't concordant and a few reports talk about an anomalous acceleration while others about an anomalous deceleration. Consequently the question isn't solved at all and before giving solutions and explanations it needs to clarify if the anomaly consists in an acceleration or in a decelaration. Therefore the discussion would have to start in case from this clarification.
The paper that you have linked is very interesting and I observe this paper talks about an anomalous acceleration and it is in concordance with the report of the first team of scientists who pointed out the phenomenon (JPL of Pasadena, California, 1998). This experimental fact was detected studying the Doppler effect of radio waves between Pioneer sondes and the Earth. The measurement of the Doppler effect in frequency pointed out an anomalous acceleration with respect to the expected value of speed of sondes. Up to now I have understood it about this phenomenon and I hope to have interpreted well the thing.
Daniele> it needs to clarify if the anomaly consists in an acceleration or in a decelaration.
The anomalous acceleration is negative (about 9x10-10 m/s2, directed towards the Sun), which may be why some have referred to it as a deceleration. Cf. the figure on slide 21 of the presentation Ales linked to. There has never been any uncertainty about the direction. It has been pointed out that the numerical value is very close to Hc, where H is the Hubble constant. But the favoured explanation is much less exciting...
``I don't see any physical attempt at finding a justification to the substitution in a diverging Riemann Zeta function with a finite value.''
That is presumably correct, but there is in fact a large body of work involved with attempts to understand renormalisation, and to make it rigorous. I am not familiar with it, as it is very technical, but the picture you draw of physicists ``resigned'' to not understanding renormalisation is quite misleading. As far as I am aware of, considerable progress has been made on this subject, see the corresponding Wikipedia article for a very summary intro.
https://en.wikipedia.org/wiki/Renormalization
Thanks Kare for your clarification. If I have understood well slide 21, acceleration of spacecraft is negative towards the Sun; it means acceleration is positive into reverse. It means still spacecraft moves away from the Sun with greater speed than that expected. Is it right this conclusion?
Dear Hans-G,
Very nice question! It suggests that the condition of a constant velocity in SRT will in practice result in a continious need of push force, in order to maintain this required constant velocity.
This point of view will hold in the case of a medium in which particles and light move, and which may cause a spontaneous decrease of velocity. Hence Maxwell science.
When such a moving object is emitting light at both sides of its line of motion, a doppler effect will however occur *in* the medium, and only be extroverting (not being the cause of) the velocity decrease of the object (if it has no push-correction).
@ Daniele: actually no, Pioneer's speed is decreasing at a faster rate than expected.
The explanation which so far seems more likely is somewhat related to this thread: it is believed that the thermal radiation emitted by the spacecraft is not isotropic (the intensity of radiation emitted in a given direction depends on the material). This then leads to a change in momentum of the spacecraft, since the total momentum of the emitted radiation is in the direction in which most radiation is emitted and this momentum must be lost to the spacecraft.
It is a fairly involved calculation to estimate accurately whether this effect is sufficient to account for the Pioneer acceleration, and whether the structure of the space craft does indeed lead to radiation being preferentially emitted away from the Sun in the appropriate quantities. However, presently, a consensus that this is in fact the case has been reached.
The only thing that it is possible to say certainly at present regarding the Pioneer anomaly is this: experimental values and expected values calculated as per known theories are out of tune. The solution of the problem doesn't consist in searching for solutions and corrections ad hoc that are always inappropriate, like the history of physics teachs. The solution of the problem consists instead in searching for new physico-mathematical models that go toghether better with new exigences and outcomes of theoretical and experimental contemporary physics.
Daniele> It means still spacecraft moves away from the Sun with greater speed than that expected.
No, as Francois already explained.
The original publication is https://arxiv.org/pdf/gr-qc/9808081v2.pdf. The terminology used is not expected/unexpected, but modelled/un-modelled. An in-depth presentation, as of 2010, is http://relativity.livingreviews.org/Articles/lrr-2010-4/download/lrr-2010-4Color.pdf
The mass of the Pioneer 10 is a little more that 200 kg; hence an acceleration of 9*10-10 m/s2 means a force of 2*10-7 N, corresponding to 60 W of photons constantly being radiated in (exactly) the forward direction. The energy production inside Pioneer 10 during the time period of interest was about 80 W, which is in the ballpark. However, it seems unrealistic that (i) the radiated heat should be so well directed towards a single direction, and (ii) that this direction should happen to be so well aligned with the direction of motion. I vaguely seems to remember that this was also the conclusion of the original publication. Hence, I am surprised that this can be the conclusion of the later, very detailed analysis. How can one, by accident, build a spacecraft with such extraordinary radiative properties?
Daniele> The solution of the problem doesn't consist in searching for solutions and corrections ad hoc
I don't think that is a fair description of the works done on this topic. Despite the scepticism expressed above.
Kare,
"However, it seems unrealistic that (i) the radiated heat should be so well directed towards a single direction, and (ii) that this direction should happen to be so well aligned with the direction of motion. I vaguely seems to remember that this was also the conclusion of the original publication. Hence, I am surprised that this can be the conclusion of the later, very detailed analysis."
I don't know anything about the Pioneer's anomaly but according to what you say it is quite unrealistic the explanation given. I will ask Victor Toth if he can join us.
While the Pioneer anomaly doesn't have anything to do with the Doppler effect, as such, (beyond using it for measurement) this might be useful: https://arxiv.org/pdf/1204.2507v1.pdf
As is often the case, one needs to have a good understanding of the background, to appreciate whether there's a signal. So while there might be a signal of some new effect, the Pioneer satellite can't be used to describe it.
The question of the Pioneer anomaly clarifies in order to reconcile experimental data with known theories it is necessary to introduce an unmodelled acceleration. Numerous hypotheses were done in order to explain the anomaly and the unmodelled acceleration: planetary perturbations, radiation pressure, thermal radiation, dark matter, etc... . All these causes would have to explain the small anomalous constant negative acceleration that would be necessary for explaining results of models of calculation deduced from the Doppler effect of known theories. All those hypotheses would derive from the certainty that the model of calculation is exact and the anomaly is due to a mysterious cause that would change experimental values with respect to expected values. Versus those explanations ad hoc I suggest a more substantial hypothesis and i.e. that the anomaly is due just to the inappropriate model that is used for the Doppler effect that is the heart of the process of measurement and of calculation: experimental data disagree with theoretical data. A different formulation of the Doppler effect, that is not based on the contingent necessity due to the Pioneer anomaly, but on the theoretical convinction that the present formulation isn't unsatisfactory, could eliminate the problem at the root. Naturally this solution involves a significant dose of courage and critical mind but sometimes those qualities are necessary for solving problems.
@Daniel, you don't know the Theory of Reference Frames. There are numerous papers in which I have described a new formulation of the Doppler effect and I formulated it before knowing the existence of the Pioneer anomaly. I am only applying now that theory to the question of the Pioneer anomaly. Therefore your right consideration isn't applicable in this case.
@Daniel, I don' t understand your words. I wrote in a preceding comment that you don't know electronics and I have good reasons for thinking it. But you have to understand it isn't an offence. There are billions of things that I don't know and if you say I am ignorant about biology, for instance, I don't take offence because it is the truth. With regard to the Theory of Reference Frames I am the author of that theory and therefore if you inform me that you know it I am very glad.
@ Daniele: the Pioneer anomaly consists in an excess deceleration over and above what can be modelled. The crucial point, then, is that one must take all possible contributions to acceleration. Since the acceleration is exceedingly small, we must take into account all possible acceleration sources which have the appropriate magnitude. Nothing ad hoc about that: you must first subtract all known effects of the relevant magnitude before you claim a new discovery.
Now thermal radiation from the space craft is certainly emitted. The claim is that, if you do a careful analysis of the emitted intensity and its orientational distribution, based on detailed construction data of Pioneer, you get results of the order of the Pioneer anomaly (80-120%). The details are quite technical: if you wish to consult them:
New Journal of Physics 11 (2009) 113032
as well as, in yet greater detail
arXiv 1104.3985
New Journal of Physics is Open Access, so you can look it up.
Francois> New Journal of Physics 11 (2009) 113032
I am confused. The original paper refers to a starting value of 160 W, decaying to 80 W at the actual times. The above paper says 2580 W, decaying with a half-life of 88 years. The latter values makes a net amount of 60 W directed radiation quite believable. But what is the origin of the large discrepancy?
Dear Kare,
I surely do not know the answer. I gave the link as a hint of where the results can be obtained and what they say. I also noticed the discrepancy with your claim. Of course, unless we want to redo the whole computations, we are at the mercy of the good faith of the people who do these calculations. However, in that particular paper, they make extensive references to the specific makeup of Pioneer. I would be inclined to trust them. As to the other paper, I would somehow assume they meant something subtly different, because that kind of a difference is not readily attributable to a difference in opinion.
Note added in Proof: I just looked at the original paper: it says:
``At launch the RTGs delivered 160 W of electric power''
160 W of electric power: is that not compatible with 2500 W waste heat? Katz in a comment says yes:
PRL 83 1892 (1999)
@Daniel very well, you raised very accurate questions about TR and I have to answer your questions. You have quoted the fundamental principle of the Theory of Reference Frames: the "Principle of the Preferred Reference". It claims a simplest thing: in every physical situation among all reference frames there is only one preferred reference frame in concordance with the physical situation that we are considering. This principle is outside classic physics that instead postulated an unique absolute reference frame in all physical situations: the so-called ether. Besides this principle is outside modern physics that instead postulated the total equivalence of all reference frames (you cite this definition in your comment). The "Principle of the Preferred Reference" is the outcome of a critical consideration with respect to both viewpoints. I would want to do two examples in order to clarify that principle.
1. Let us consider a body that falls on the Moon and let us consider two observers: the first observer is placed on the Moon and the second observer is placed on the Earth. We can be sure that the first observer will see the body fall in concordance with the general law of gravitation, i.e. along the perpendicular direction. We don't know what the second observer sees, but certainly he not will see the body falls along a perpendicular direction, i.e. with respect to the second reference frame (on the Earth) fall happens in different way with respect to the general law of gravitation. The "Principle of Preferred Reference" claims in this physical situation the reference frame on the Moon is a preferred reference frame and the observer on the Moon is a preferred observer. If we change the physical situation and we consider body falls on the Earth, also the preferred reference frame and the preferred observer change and the situation is inverted. In two different and inverted physical situations the two observers see the same thing in concordance with the general law of gravitation, but with respect to the same fall at the same time they see two different things.
2. Let us consider a body that falls into a train that moves with constant speed and let us consider two observers: the first inside the train and the second outside along tracks. The first observer sees body falls along the perpendicular direction in concordance with the general law of gravitation, the second sees body falls along an oblique direction because his observation is affected by motion of the train. It is manifest that the first observer is a preferred observer and his reference frame is a preferred reference.
Claim: If a theory is in conflict with the reality than is never the reality wrong.
Francois> ``At launch the RTGs delivered 160 W of electric power''
The 160 W has just been a misinterpretation on my part all along. With 2580 W total radiation an imbalance of 60 W is perfectly plausible.
Daniele> An error of 60W on 2580W represents an error of 2.33%.
Where does the notion of error come from here? It is a question of how 2560 W of radiation are directionally emitted from a spacecraft. Is it an error by Pioneer 10 that it is not emitted perfectly symmetrically (as viewed from its rest frame)?
@Kare, you wrote "with 2580W total radiation an imbalance of 60W is perfectly plausible". Because the Pioneer anomaly is based on an error of the experimental value with respect to the expected and calculated value, and because your claim wants to explain that discrepancy it means those 60W represent just an error that would have to justify that discrepance. Otherwise you have to make use of another term with respect to the imbalance.
The issue of symmetrical emission is not relevant: cf. https://arxiv.org/pdf/1204.2507v1.pdf It just highlights, once more, how futile it is for people outside an experimental collaboration to speculate about issues, specific to the apparatus.
Once more, from the analysis it is concluded that the systematic uncertainties of the satellite itself can account for the putative anomaly and, therefore, that it's not possible to attribute it to any other factor on the basis of the Pioneer data alone.
I read in introduction of the last paper that has been linked:
"The discrepancy can be eliminated by incorporating a constant sunward acceleration of unknown origin with magnitude of a=(8.74+1.33)10-10m/s2 into the orbital model".
Continuing reading of paper the unknown acceleration is explained then with "a recoil force associated with an anisotropic emission of thermal radiation off the vehicles". The paper ends with the following claim: "we conclude that once the thermal recoil force is properly accounted for, no anomalous acceleration remains". In actuality there is no experimental proof of that anomalous acceleration but its prediction becomes necessary in order to explain in affected manner the anomaly of the experimental result with respect to the expected result that is calculated by known theories. Naturally the doubt that the known theory can give a wrong value is considered in no way.
Daniele> Because the Pioneer anomaly is based on an error of the experimental value with respect to the expected and calculated value
As I read the papers linked to by Francois and Stam, thermal analyses by (at least) two independent groups reduces the difference between observed and modelled values by about a factor 5 relative to the original 1998 reported anomaly. This makes any difference statistically insignificant, because it is within the uncertainties of observations and modelling.
The paper by Turishev, Tooth et. al. "conclude that once the thermal recoil force is properly accounted for, no anomalous acceleration remains."
Daniele> there was never
any exciting new physics to explain. Yes, apparently not :-(
Fooled again!!
The ``exciting'' physics lies in the explanation, not the novelty. And it becomes the background for discoveries.
@Daniel L. Burnstein,
You insist in error. Milions of people saw the fall of body on the Moon that was photographed by a telecamera that represented the viewpoint of the observer on the Moon. Also if you put a telecamera into the train the observer on tracks sees the same thing that the observer inside train sees. But the mathematical representation of the two trajectories is different for the two observers and it represents also the real different viewpoint of the two observers. Anyway I not will answer to further questions.
DS: 1. Let us consider a body that falls on the Moon and let us consider two observers: the first observer is placed on the Moon and the second observer is placed on the Earth. We can be sure that the first observer will see the body fall in concordance with the general law of gravitation, i.e. along the perpendicular direction. We don't know what the second observer sees, but certainly he not will see the body falls along a perpendicular direction, i.e. with respect to the second reference frame (on the Earth) fall happens in different way with respect to the general law of gravitation.
For any law of gravitation to be "general", it must give a consistent prediction for every well-constructed frame, whether based on the Earth or the Moon in your example.
DLB: The observer on the train knows that the train is moving. Being smart, ...
You are being misled by the common anthropomorphism implied in the word "observer". Moving relates to speed and speed is dx/dt where x is a distance measured by a ruler and t is a time measured by a clock. "The observer on the train" means a ruler bolted to the train and a set of synchronised clocks, each at a fixed location as measured by that ruler. Obviously, using that ruler, the train cannot be moving according to "the observer on the train", by definition.
In fact GD, the law of gravitation is general and it is valid always similarly (i.e. perpendicular fall) with respect to the reference frame in which body falls (preferred reference frame). In the considered example, i.e. fall of body on the Moon, the general law of gravitation is valid similarly (i.e. perpendicular fall) for the observer on the Moon but for the observer on the Earth the fall law of the same body must be conflated with motion of the Moon with respect to the Earth and consequently the observer on the Earth sees and describes a different trajectory from the perpendicular.
Daniel, you subscribe the importance of reference frames, but your subsequent reasoning contradicts your starting point. We know in the physical reality reference frames don't exist, but observers exist and different observers can be in a relative state of motion. The reference frame has just the purpose to allow every observer to describe the physical event that he observes. With respect to nature every physical event is unique, but with respect to different observers the description of the physical event can be and generally is different. This is the background that leads to the Principle of Relativity.
With regard to the simulataneity it is possible to prove it can be violated also by two observers who are in a state of asymmetric reciprocal resting state and therefore the violation of simultaneity isn't an exclusive right of states of relative motion.
Dear Daniel L. B: what you describe in your train example is correct, but this is not the SRT interpretation. That is the Newtonian interpretation.
In SRT, one cannot define which reference frame is *really* moving, which results in the conclusion of each of the observers that the other observer is getting a dilatation of time. Hence, when calculating the line of time events, both observers will become older than the other observer, and causality is broken.
This kind of resonning also appears in the wrong belief that, in order to be "relativistic", a theory should comply to Lorentz invariance (Lorentz symmetry).
I think the subsequent clarification, before still considering relativistic aspects, regards the concept of "description of motion". It isn't the same thing if for "description of motion" we intend the dynamic physical law that describes motion or the physical relation that describes more properly the trajectory of motion.
Dear Daniel L. B., you pointed out another problem od SRT than I did, so, that makes two reasons to dismiss SRT.The issue that I described is extremely incriminating to it.
Since SRT is not physically substantiated, lets start with another approach. The velocity of electrons can only be defined wrt a steady electric field, because it will generate a magnetic field of which the amplitude can perfectly be measured, and matched with the E-M theory.
In Newtonian theory, velocity is (in practice) related to the masses of the objects, and in fact also the gravity fields of these objects, because of the (static) equivalence of inertial and gravitational mass.
Hence, it would be very physical to assign velocity to the gravitational fields that are present.
So, SRT must be extended to that situation, including the right definition of velocities, in order to have a chance to become valid. The speed of light can then be considered as having a possible dependence from the gravity fields as well.
``Using rigid rods fixed to the train as a reference frame, you will find that the train is moving at a certain speed, thus will have a component vector in direction of the motion.''
I cannot discern a comprehensible meaning. If a rod is ``fixed to the train'', in any sense of the word ``fixed'' of which I am aware, it should measure that the remainder of the train is ``at rest'' and cannot find that ``the train is moving at a certain speed''. It can, of course, conceivably be found that the trees on the embankment have a given speed, but that is something else.
It is begun again the lottery of downvotes and the discussion has no serious meaning when a few hide their opinion behind the anonymity.
I know at least one pathological relativistic down voter, who is following this thread and who permanently believes it's Halloween...
DLB: We can determine the speed of the train relative to the embankment,
Only with rulers and clocks fixed to the embankment.
DLB: which is equivalent to the speed of the embankment relative to the train.
Rulers fixed to the train measure this. To infer the speed of the train however then assumes some coordinate transform. It is then no longer a measurement but a prediction (of what might be measured in the other frame).
Dear George!
I therefore ask you to respect the rules of courtesy. Every user at RG has a (first) name. I don't like to talk with a pumpkin.
Dear Colleagues!
I go evan further as in my question above. The Doppler effect is showing respectively pointing at a real cause of the anisotropy of space like Einstein did deign to describe in his theories. To identify the rest or movement of any object we have to examine its energetical output respectively its inert energetical conditions.
My Regards! Hans
@Daniel L. B: "if an axiom of a theory comes into question, then one's work must start work from the axiom set".
Yes, but that is not how scientific progress has been made in the past. In the first place, we need to observe, make experiments, like many great scientists did in past centuries: Newton, Faraday, Coulomb, Volta, Ampère, etc.
Then only, rudimentary equations can be made, and based upon hypotheses, these equations can further be integrated into a real theory, like Maxwell and Heaviside did. Then only, one can get further and attempt to make predictions.
This is what I have been doing, and I have applied equations of gravity, which were initiated by Heaviside and developed by Jefimenko.
These applications have shown in an extremely precisely way that gravitomagnetism, as the transcription of Maxwellian electromagnetism into gravity, is relativistically valid and solved many issues.
Therefore, the definition of velocity as I gave it, w.r.t. the gravity fields, is valid for gravity, just as velocity w.r.t. electric fields is valid for electromagnetism.
Indeed, now it can be worked out axiomatically, and I am convinced that you would do that very professionally indeed.
@ Thierry: I fully agree with your views on history of science. First comes experiment, then theory. That, in fact, is how SRT was developed.
Gravitoelectromagnetism arises very nicely as a formal mathematical analogy between Maxwell's equations and a putative theory of gravity. However, the calculations to check GEM with experiment are tedious, but straightforward, and unfortunately it fails a large number of tests by orders of magnitude.
Pathologically yours,
Francois
@ Leyvraz, why don't you give your alleged large numbers of tests where it would fail with orders of magnitude? Why can't you falsify any calculations of my book "Gravitomagnetism"?
Easy: the Hulse-Taylor pulsar, the Mercury precession, the Venus, Earth etc... precessions (those are important due to the claim sometimes adduced that the rotation within the Galaxy might be responsible: such an effect would affect essentially all planets alike, and would thus be refuted, since the outer planets show essentially no precession.) The bending of light, for which it gives the Newtonian value (which is only half the observed value, but a factor 10^5 outside the error bars).
I do not have your book, nor intend to buy it. However, none of the articles you have posted, and which I have looked at, contain anything I would call a calculation. Formulae are just strung along without much rhyme or reason, and thus do not easily lend themselves to criticism. However, it is not hard to see how the calculations could be done, and while I have not performed the computations in full detail, from what I know the results ought to come out quite differently from GRT, which in the above examples is confirmed by experiment.
That, I guess, is enough for now.
You forget that GEM is a mainstream theory, well substantiated (provided that Heaviside's gravitomagnetism is used); GEM is linked to Thirring-Lense and the perturbation theory, and well tested with the G-probe B and flyby-issues.
You forget that the Hulse-Taylor pulsar was a "best curve-fit" by Post Post Newton parametrized equations with free parameters, by using physical properties of the masses, spins, and orbits giving the best fit within assumed errors, and by assuming Keplerian elliptic orbits.
How do you come to the idea that gravitomagnetism is unable to do that?
You forget that there is no reliable measurements of the precessions of other planets, neither of the distant ones, as well explained in the Vankov's annexed paper "General Relativity Mercury’s Anomaly Prediction: What and How to Test?".
You forget that the answers to the question in RG: "How sure can we be that the bending of light grazing the Sun, as well as the Shapiro delay is free of any refractional bending?" is conclusive: the bending of light due to splasma and atmosphere is calculated by mainstream by sustracting the alleged gravitational double light bending (compared with Newton's).
Hence, there is no evidence at all that there is a gravitational double light bending, since the mix with the bending due to splasma and atmosphere has not been separated by observation in a gravitational bending part and a non-gravitational bending part.
It is all just unscientific fantasy, presented as if everything were well substantiated.
Moreover, from gravitomagnetism it can be found that, depending from the physical properties attributed to light, the calculus of the bending is either Newton's (material particle at speed c), either 5/4 th of Newtons (rotational material particle at speed c), either 8/4th of Newtons (material wave at speed c and LT-symmetry), or 9/8th of Newton's (rotational material wave at speed c and LT-symmetry). Gravitomagnetism indeed will help finding out the true nature of light.
Your attempt of populistic intoxication is unscientific, and just again, air. My book is annexed. I can help you bit by bit to understand the calculus that is too hard for you.
What is concerning your alleged need for rhyme and reason, it is clear that your own thoughts are much more dizzy: you believe that null results have value when the physical context is even not well known, like the MMX. You think that such a null result is valid to dismiss a centuries-lasting certitude about the transmission of waves through a medium (a rope, water, air, solids,...), of which the physical properties define de propagation speed.
You also think that there is no problem with SRT, spites the fact that all observers (even mutually) in SRT see all other observers having a speed and thus becoming younger. Hence, observers become mutually younger than themselves.
Not understanding such physical impossibilities does rise questions regarding your competence wrt physics, indeed...
http://gsjournal.net/books/De-Mees-Gravitomagnetism-and-Coriolis-Gravity-2011-A4.pdf
https://www.researchgate.net/post/How_sure_can_we_be_that_the_bending_of_light_grazing_the_Sun_as_well_as_the_Shapiro_delay_is_free_of_any_refractional_bending#view=584d7a91615e272829657352
Just to show up *one* of your remarks as nonsense:
``there is no reliable measurements of the precessions of other planets,''
Of course! But that is due to the fact that these are unmeasurably small. We are in fact quite certain that planets other than Mercury have very small precessions. A galactic effect would be essentially the same for all, which is completely at variance with observation.
``How sure can we be that the bending of light grazing the Sun, as well as the Shapiro delay is free of any refractional bending?''
Because some of the experiments (involving radio waves) involve rays that come no closer than 1/2 AU, where any kind of refraction is absent. There are plenty of experiments where the rays are not ``grazing'' in any reasonable sense of the word.
And so on...
@F. Leyvraz: >>First comes experiment, then theory. That, in fact, is how SRT was developed.
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