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#3120 by dustinthewind on 12 Jun, 2016 21:23
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...the purpose of the polymer insert in NASA's experiments is not one of a dielectric based on the electric permittivity (as in Shawyer's experiments with an inorganic dielectric with relative permittivity ~38), since NASA used polymers with relative permittivity ~2 closer to the one of air or vacuum ~1. The purpose of NASA's polymer insert may be due instead to electrostriction effects and on its polymer chain orientation anisotropy.
On that note,
...
https://en.wikipedia.org/wiki/Electrostriction
"Although all dielectrics exhibit some electrostriction, certain engineered ceramics, known as relaxor ferroelectrics, have extraordinarily high electrostrictive constants. The most commonly used are
lead magnesium niobate (PMN)
lead magnesium niobate-lead titanate (PMN-PT)
lead lanthanum zirconate titanate (PLZT)"
also
https://en.wikipedia.org/wiki/Magnetostriction
might be another route.
My thoughts on this are, this seems it might further stretch out the wavelength at the narrow end. That is if the index is minimal, the slowing of light is minimal, while the light shares a fair portion of its energy with the material, so is there a chance that the interaction via electrostriction gives the light some increased mass with minimal change in velocity, some how paralleling to an increased wavelength at the narrow end? That is, the material amplifies the lengthened wavelength at the narrow end, that is present even without the dielectric.
I also keep seeing that electrostriction is a non-linear effect, which may be important.
could the phenomena mentioned in this book be an important effect related to electrostriction? Quantum Electronics: A Treatise
edited by Herbert Rabin
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#3121 by FattyLumpkin on 12 Jun, 2016 23:26
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Dr. Rodal, I only capitalized those few words for emphasis (no ill intent whatsoever!) My apologies if it came off as being terse.
If memory serves Sonny suggested that changes in geometry and frequency would be part of their continued testing (I believe what is now in peer review). X_Ray was chiding me with his "touché" is this regard. This brings up an important point though: Is Cannae a legitimate part of this thread? Or?
With Dave gone, perhaps you might let me know if there has been a consensus on this.
As with many things here at NSF the devil is often in the details. I only wanted to know what the geometry of the Cannae drive was/is (if known at all).Certainly as with the frustum inaccurate geometry and poor fabrication of these devices will result in poor or no performance. no?
Attached is a drawing of the 2014 Cannae RC (without cavity slots)...RF would be injected from middle left. Please disregard the straight vertical lines (they represent where the two separate plates are fitted together after milling). K
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#3122 by Rodal on 13 Jun, 2016 00:17
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Dr. Rodal, I only capitalized those few words for emphasis (no ill intent whatsoever!) My apologies if it came off as being terse.
If memory serves Sonny suggested that changes in geometry and frequency would be part of their continued testing (I believe what is now in peer review). X_Ray was chiding me with his "touché" is this regard. This brings up an important point though: Is Cannae a legitimate part of this thread? Or?
With Dave gone, perhaps you might let me know if there has been a consensus on this.
As with many things here at NSF the devil is often in the details. I only wanted to know what the geometry of the Cannae drive was/is (if known at all).Certainly as with the frustum inaccurate geometry and poor fabrication of these devices will result in poor or no performance. no?
Attached is a drawing of the 2014 Cannae RC (without cavity slots)...RF would be injected from middle left. Please disregard the straight vertical lines (they represent where the two separate plates are fitted together after milling). K
No need to apologize. I should have used a nicer tone in my previous message, as well.
Concerning whether the Cannae drive is on-topic or not, I have no idea what the consensus is, my personal opinion is that it seems to me that discussions about the geometry of the Cannae drive is much more on topic, (since it is after all a resonant cavity in the RF frequency range displaying an anomalous force, and intended for SpaceFlight applicaitons) than several things that were being previously brought up, like rants about other forums. Also, the Cannae drive is contained in the same Wikipedia article that used to be called EM Drive, and where google takes you if you type Wikipedia EM Drive.
I think that nobody can go wrong about being on-topic if we ask ourselves whether the subject at hand is related to
EM Drive Developments - related to space flight applications: that's after all the title of this thread.
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#3123 by FattyLumpkin on 13 Jun, 2016 00:57
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Indeed, I did forgot the Cannae was included in Experimental Results. hmmm
After some search I did find this video which shows Cannae in action in a Cubesat. (wonder where the audio is?)
Click: "Watch on Vimeo" to play the vid!
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#3124 by Mulletron on 13 Jun, 2016 06:44
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For EmDrive theories which require massive photons, further evidence of non-zero photon mass:
http://www.sciencealert.com/heavy-light-could-explain-dark-energyQuoteExperiments have already proven that light can’t be more massive than about 10-62 kilograms. That’s a zero, a decimal point, 61 more zeros, and then a one, which is a really small number. But it’s not zero, as Kouwn and his team point out.
https://arxiv.org/abs/1512.00541
They showed that if the photon’s mass is 10 million times smaller than that limit, the way that photons interact with the different fields and forces in the Universe leads to a repulsive effect that looks an awful lot like what we’ve been calling dark energy. In other words, massive photons could cause dark energy.QuoteA detailed numerical analysis shows that the nonvanishing photon mass of the order of ~10−34 eV is consistent with the current observations. This magnitude is far less than the most stringent limit on the photon mass available so far, which is of the order of m≤10−27eV.
http://journals.aps.org/prd/abstract/10.1103/PhysRevD.93.083012QuoteHowever, the consideration of non-vanishing photon mass [9] has a long history, and theoretically, it is well known that Maxwell theory with abelian gauge symmetry can be extended to a gauge invariant massive theory by means of the Stueckelberg mechanism [10]1.
Similar to the Higgs mechanism the paper mentions the Stueckelberg mechanism, a way to have a massive photon and maintain gauge invariance.
1.The photon can also become massive through spontaneous symmetry breaking via Higgs mechanism
It introduces a scalar field which compensates the gauge transformation of the vector field. Such massive theory preserves the unitarity and renormalizability of the massless theory. Moreover, the possible conflict between the massive QED and standard model could be avoided [12]. In a particular gauge where the scalar field is set to zero, the massive theory reduces to the Proca theory which describes electrodynamics of massive vector field [13]. The question of a photon mass in QED should then be tested experimentally. If there is any deviation from zero, it must be very small, because Maxwell theory has been verifed to an extreme accuracy. On the other hand, the experimental constraints on the photon mass has considerably
increased over the past several decades, putting upper bounds on its mass. So far, the most stringent upper limit is given by m≤10−27eV [14]. In all these researches, the photon is described by massive Proca theory, which does not include the Stueckelberg field.
https://en.wikipedia.org/wiki/Stueckelberg_action
https://en.wikipedia.org/wiki/Higgs_mechanism#Affine_Higgs_mechanism
http://physics.stackexchange.com/questions/70302/what-are-the-similarities-and-differences-between-stueckelberg-mechanism-and-hig
Remember seeing someone else raising the possibility of a new scalar field in video 7.3b @ ~10:30
http://forum.nasaspaceflight.com/index.php?topic=39772.msg1534683#msg1534683
Part of the allure of studying the EMdrive is the continuous pursuit and gain of knowledge that it provides. -
#3125 by OttO on 13 Jun, 2016 09:17
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My thoughts on this are, this seems it might further stretch out the wavelength at the narrow end. That is if the index is minimal, the slowing of light is minimal, while the light shares a fair portion of its energy with the material, so is there a chance that the interaction gives the light some increased mass with minimal change in velocity, some how paralleling to an increased wavelength at the narrow end? That is, the material amplifies the lengthened wavelength at the narrow end, that is present even without the dielectric.
I previously shared the paper below, perhaps it could seed your ideas even if it is about optical light...
In http://arxiv.org/abs/1603.07224 Photon mass drag and the momentum of light in a medium
the energy and momentum of light propagating in a medium are carried by quasiparticles, coupled states of field and matter, which have a finite rest mass and the Minkowski form of momentum. The total momentum of the quasiparticle, the Minkowski momentum, is the only directly measurable momentum of light in a medium since, due to the coupling, the momenta of the field and the matter cannot be separately measured. The finite rest mass of the quasiparticle directly leads to a photon mass drag ef fect optomechanically displacing the medium along the photon flow. After photon transmission, part of the initial photon energy is dissipated to heat when the mass distribution of the medium returns to equilibrium. This energy is however negligible, of the relative order of 10-27 depending on the material. -
#3126 by Monomorphic on 13 Jun, 2016 18:37
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An image I pulled from one of Cannae's images on their website. Looks to me that Cannae no longer uses the "frisbee" geometry Fatty is posting. The green cavity is probably a 3D printed prototype.
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#3127 by FattyLumpkin on 13 Jun, 2016 19:50
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Monomorphic, how/where did you find this image? (certainly reinforces the argument re the RCs of some LINACS) FL
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#3128 by Monomorphic on 13 Jun, 2016 20:03
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Monomorphic, how/where did you find this image? (certainly reinforces the argument re the RCs of some LINACS) FL
It is in the background of the image here: http://cannae.com/new-superconducting-demo-scheduled/ -
#3129 by keithpickering on 13 Jun, 2016 20:45
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Also, again, the purpose of the polymer insert in NASA's experiments is not one of a dielectric based on the electric permittivity (as in Shawyer's experiments with an inorganic dielectric with relative permittivity ~38), since NASA used polymers with relative permittivity ~2 closer to the one of air or vacuum ~1. The purpose of NASA's polymer insert may be due instead to electrostriction effects and on its polymer chain orientation anisotropy.
Again: electrostriction instead of dielectric effects.
That may well have been the purpose, but its effect (assuming there is one, and that it is at least somewhat related to the presence of the material) might be due to its dielectric properties.
Given an infinite budget, I would try a full wave of boron nitride (permittivity~=4) at the small end, capped with a 1/4 wave anti-reflection layer of PTFE. If there really is an effect from dielectric slowdown of the photons, that should demonstrate it fairly well.
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#3130 by dustinthewind on 13 Jun, 2016 21:17
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My thoughts on this are, this seems it might further stretch out the wavelength at the narrow end. That is if the index is minimal, the slowing of light is minimal, while the light shares a fair portion of its energy with the material, so is there a chance that the interaction gives the light some increased mass with minimal change in velocity, some how paralleling to an increased wavelength at the narrow end? That is, the material amplifies the lengthened wavelength at the narrow end, that is present even without the dielectric.
I previously shared the paper below, perhaps it could seed your ideas even if it is about optical light...
In http://arxiv.org/abs/1603.07224 Photon mass drag and the momentum of light in a medium
the energy and momentum of light propagating in a medium are carried by quasiparticles, coupled states of field and matter, which have a finite rest mass and the Minkowski form of momentum. The total momentum of the quasiparticle, the Minkowski momentum, is the only directly measurable momentum of light in a medium since, due to the coupling, the momenta of the field and the matter cannot be separately measured. The finite rest mass of the quasiparticle directly leads to a photon mass drag ef fect optomechanically displacing the medium along the photon flow. After photon transmission, part of the initial photon energy is dissipated to heat when the mass distribution of the medium returns to equilibrium. This energy is however negligible, of the relative order of 10-27 depending on the material.
It appears they propose the photon itself is without mass and with it is a polariton which consists of mass. Minkowski forumula p=n(h_bar)(k_not) and Abraham momentum is p=(h_bar)(k_not)/n. I think they propose the Minkowski is the momentum of the polariton and the Abraham is the momentum of the massless photon which doesn't seem to be measurable? So it appears only the Minkowski momentum is correct for measurements.
quotes from paper mentioned in link above:
"The experiment irrefutably shows that the total momentum of a photon or, more precisely, the momentum of a polariton is proportional to the refractive index and is given by the Minkowski formula..." p=nhk
"... it is natural to consider a possibility that the light wave is actually a coupled state of field and matter with a small but finite rest mass.
"
..."We show that the Minkowski form of the polariton momentum can be derived directly from the Maxwell’s equations and the related Lorentz force law. The calculations also show that the Abraham momentum is the momentum that can be associated to the electromagnetic field part
of the coupled polariton state. In this sense, the traditional Einstein’s box thought experiment captured only this part of the total polariton state. Due to the coupling, the Abraham momentum is, however, not directly measurable as the only measurable momentum is the total momentum of the polariton."
Now I would like to point out a few things that caught my attention. First that their measurements of momentum don't appear to conserve momentum. It actually increases with the index of refraction as p=nhk. That is unless I am miss-understanding some fundamental point, such as the increase in velocity of the medium possibly.
The other point is that this appears to uncover the quantum nature of light in such a way that an EM wave is coupled to a particle such that we have both a particle and a wave.
A third point is that we know in empty space photons still have measurable momentum (solar sails for example) so the polariton I would assume is present, if as they suggest, we can't measure the momentum of the photon and only the polariton? This to me suggest that the polariton exists in the vacuum as an interaction with something similar to a polarizable vacuum, or the seething QV?
If such a polariton exists in the cavity and it is increasing in mass at the narrow end does this suggest the pressure of light is measureably greater at the narrow end or more able to transfer energy effectively. Still this seems it depends on dielectric constants and I don't know how it relates to electrostriction and the sharing of energy in that sense as well as the differences in the velocity of light. A lot to chew on here.
I'm still caught on the stretching of the wavelength at the narrow end that I observed in some of the simulations way back. I wouldn't have thought that would happen. -
#3131 by Rodal on 13 Jun, 2016 21:29
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No on the contrary please look at the effect shown by the experimental results with dielectrics by NASA and by Shawyer.
Also, again, the purpose of the polymer insert in NASA's experiments is not one of a dielectric based on the electric permittivity (as in Shawyer's experiments with an inorganic dielectric with relative permittivity ~38), since NASA used polymers with relative permittivity ~2 closer to the one of air or vacuum ~1. The purpose of NASA's polymer insert may be due instead to electrostriction effects and on its polymer chain orientation anisotropy.
Again: electrostriction instead of dielectric effects.
That may well have been the purpose, but its effect (assuming there is one, and that it is at least somewhat related to the presence of the material) might be due to its dielectric properties.
Given an infinite budget, I would try a full wave of boron nitride (permittivity~=4) at the small end, capped with a 1/4 wave anti-reflection layer of PTFE. If there really is an effect from dielectric slowdown of the photons, that should demonstrate it fairly well.
All the experimental information shows the complete opposite of what you are proposing that "might be due to its dielectric properties" (meaning the value of the relative electric permittivity). On the contrary, when NASA and Shawyer, both, used dielectric materials with high relative electric permittivity inserted asymmetrically in the cavity, the anomalous force was significantly smaller.
Best results by NASA were obtained with polymer materials like PTFE and HDPE having low values of relative permittivity, much closer to the relative permittivity of vacuum than to the relative permittivity of the dielectrics used by Shawyer.
----
Also, how can "dielectric slowdown of the photons" result in self-acceleration ? -
#3132 by keithpickering on 14 Jun, 2016 04:54
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No on the contrary please look at the effect shown by the experimental results with dielectrics by NASA and by Shawyer.
Also, again, the purpose of the polymer insert in NASA's experiments is not one of a dielectric based on the electric permittivity (as in Shawyer's experiments with an inorganic dielectric with relative permittivity ~38), since NASA used polymers with relative permittivity ~2 closer to the one of air or vacuum ~1. The purpose of NASA's polymer insert may be due instead to electrostriction effects and on its polymer chain orientation anisotropy.
Again: electrostriction instead of dielectric effects.
That may well have been the purpose, but its effect (assuming there is one, and that it is at least somewhat related to the presence of the material) might be due to its dielectric properties.
Given an infinite budget, I would try a full wave of boron nitride (permittivity~=4) at the small end, capped with a 1/4 wave anti-reflection layer of PTFE. If there really is an effect from dielectric slowdown of the photons, that should demonstrate it fairly well.
All the experimental information shows the complete opposite of what you are proposing that "might be due to its dielectric properties" (meaning the value of the relative electric permittivity). On the contrary, when NASA and Shawyer, both, used dielectric materials with high relative electric permittivity inserted asymmetrically in the cavity, the anomalous force was significantly smaller.
Best results by NASA were obtained with polymer materials like PTFE and HDPE having low values of relative permittivity, much closer to the relative permittivity of vacuum than to the relative permittivity of the dielectrics used by Shawyer.
Which might have been due to reflection off of the dielectric surface (a) degrading resonance and (b) providing an effectively larger small end, making the cavity appear more nearly cylindrical. Hence the advantage of using an anti-reflective layer. The ideal anti-reflective layer will have n=√n' where n' is the refractive index of the primary refractor and n is the refractive index of the layer. Thus BN and PTFE are well matched.Also, how can "dielectric slowdown of the photons" result in self-acceleration ?
You have already shown convincingly that self-acceleration cannot occur without different physics than is currently accepted. That should put an end to Shawyer's theory and put McCullough's into prime consideration. In that theory, self-acceleration is required by conservation of momentum as the intertial mass of photons increases while in the large end, and decreases while in the small end, due to restrictions on the creation of Unruh radiation.
But if McCullough's theory is correct, there may be another mechanism that causes photons' intertial mass to change, and that is relativistic mass change which might occur as photons slow down when entering a dielectric. -
#3133 by keithpickering on 14 Jun, 2016 05:13
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Stabilizing magnetron frequency
I just picked up from my local library a copy of "Microwave Magnetrons" edited by George Collins (McGraw-Hill 1948) and it's a winner: 800 pages of theory and practice from the days when radar was just being declassified.
It includes a chapter on frequency stabilization, and it occurs to me that it's quite likely that magnetrons used in ovens don't bother with any of that, because there's simply no reason to in an oven. But that also would mean that there is untapped potential available to DIYers that might improve performance significantly.
Schematically a resonant cavity is a capacitor in parallel with an inductor. A magnetron is one type of a resonator. The basic idea of frequency stabilization is to connect a secondary resonant cavity in parallel with the magnetron. The stabilizer is designed (or tunable) to resonate at the desired frequency. In practice, a shunt resistor is also hooked in series to suppress resonant modes other than the primary mode.
The secondary resonator increases the effective Q of the system such that a stabilization factor S is observed:
S = (Q1 + Q3) / Q1
... where subscript 1 is for the magnetron and subscript 3 is for the stabilizer. (Subscript 2 would be for the transmission line between them.) In the ideal case S = 3, implying that the stabilizer should be designed to have twice the Q of the magnetron itself. Of course, finding the magnetron's Q may not be straightforward.
I have no idea if any of the DIYers out there would be interested in going down this path, but it seems to me that it might have definite advantages. -
#3134 by Gilbertdrive on 14 Jun, 2016 15:26
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Also, how can "dielectric slowdown of the photons" result in self-acceleration ?
You have already shown convincingly that self-acceleration cannot occur without different physics than is currently accepted. That should put an end to Shawyer's theory and put McCullough's into prime consideration. In that theory, self-acceleration is required by conservation of momentum as the intertial mass of photons increases while in the large end, and decreases while in the small end, due to restrictions on the creation of Unruh radiation.
But if McCullough's theory is correct, there may be another mechanism that causes photons' intertial mass to change, and that is relativistic mass change which might occur as photons slow down when entering a dielectric.
By the way, does somebody have a formula that gives the change of inertial mass, or the redshift of a photon accelerating, in the MiHsc Theory ? I did not remember having seen one, but there were so many thing in these threads... -
#3135 by keithpickering on 14 Jun, 2016 15:44
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Also, how can "dielectric slowdown of the photons" result in self-acceleration ?
You have already shown convincingly that self-acceleration cannot occur without different physics than is currently accepted. That should put an end to Shawyer's theory and put McCullough's into prime consideration. In that theory, self-acceleration is required by conservation of momentum as the intertial mass of photons increases while in the large end, and decreases while in the small end, due to restrictions on the creation of Unruh radiation.
But if McCullough's theory is correct, there may be another mechanism that causes photons' intertial mass to change, and that is relativistic mass change which might occur as photons slow down when entering a dielectric.
By the way, does somebody have a formula that gives the change of inertial mass, or the redshift of a photon accelerating, in the MiHsc Theory ? I did not remember having seen one, but there were so many thing in these threads...
Try Mike's blog post here:
http://physicsfromtheedge.blogspot.com/2016/05/we-learn-by-doing-mihsc-emdrive.html
... which is very easy to follow. Note that photons don't accelerate because of MiHsC, they just change inertial mass. However photons can accelerate under standard physics when entering medium of lower refractive index. -
#3136 by Gilbertdrive on 14 Jun, 2016 15:55
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Also, how can "dielectric slowdown of the photons" result in self-acceleration ?
You have already shown convincingly that self-acceleration cannot occur without different physics than is currently accepted. That should put an end to Shawyer's theory and put McCullough's into prime consideration. In that theory, self-acceleration is required by conservation of momentum as the intertial mass of photons increases while in the large end, and decreases while in the small end, due to restrictions on the creation of Unruh radiation.
But if McCullough's theory is correct, there may be another mechanism that causes photons' intertial mass to change, and that is relativistic mass change which might occur as photons slow down when entering a dielectric.
By the way, does somebody have a formula that gives the change of inertial mass, or the redshift of a photon accelerating, in the MiHsc Theory ? I did not remember having seen one, but there were so many thing in these threads...
Try Mike's blog post here:
http://physicsfromtheedge.blogspot.com/2016/05/we-learn-by-doing-mihsc-emdrive.html
... which is very easy to follow. Note that photons don't accelerate because of MiHsC, they just change inertial mass. However photons can accelerate under standard physics when entering medium of lower refractive index.
Thanks very much. I had already seen this page in the past, I shall read it more carefully now.
I thought that the photon was also accelerating when it was bouncing on something, and that, because of that acceleration, the MiHSC Theory was giving a modification of it's inertial mass. have I misunderstood ? -
#3137 by keithpickering on 14 Jun, 2016 16:29
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Thanks very much. I had already seen this page in the past, I shall read it more carefully now.
I thought that the photon was also accelerating when it was bouncing on something, and that, because of that acceleration, the MiHSC Theory was giving a modification of it's inertial mass. have I misunderstood ?
That is a misunderstanding. In MiHsC, inertia is caused by the emission of Unruh radiation, and it is the restrictions on the creation of Unruh radiation that causes inertial mass to change. -
#3138 by Gilbertdrive on 14 Jun, 2016 17:11
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Thanks very much. I had already seen this page in the past, I shall read it more carefully now.
I thought that the photon was also accelerating when it was bouncing on something, and that, because of that acceleration, the MiHSC Theory was giving a modification of it's inertial mass. have I misunderstood ?
That is a misunderstanding. In MiHsC, inertia is caused by the emission of Unruh radiation, and it is the restrictions on the creation of Unruh radiation that causes inertial mass to change.
It remains that the changes of Unruh Radiation make inertial mass to increase when the item is accelerating, and so that a massive item is slow down, and get a final speed lower than the speed calculated only taking into account it's imposed acceleration. That is why a massive item coming into our solar system, and accelerating because of the gravity of the sun and it's planets, should have, when it reach the sun, a speed lower than the speed that would have been calculated using only the Gravity formulas in General Relativity.
And, at the opposite, an item, as the Pioneer Probe, that is decelerating in our referential, because of the sun gravity, is decelerating less that calculated in General Relativity.
Have I correctly understood the prediction of the MiHsC theory on these points ? -
#3139 by keithpickering on 14 Jun, 2016 17:27
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It remains that the changes of Unruh Radiation make inertial mass to increase when the item is accelerating, and so that a massive item is slow down, and get a final speed lower than the speed calculated only taking into account it's imposed acceleration. That is why a massive item coming into our solar system, and accelerating because of the gravity of the sun and it's planets, should have, when it reach the sun, a speed lower than the speed that would have been calculated using only the Gravity formulas in General Relativity.
No, not really. Classical physics correctly predicts most motions and accelerations even though (according to MiHsC) the cause of inertia is misunderstood. Further, for objects moving in space the restrictions on Unruh radiation are quite small, and only noticeable under special circumstances.And, at the opposite, an item, as the Pioneer Probe, that is decelerating in our referential, because of the sun gravity, is decelerating less that calculated in General Relativity.
The Pioneer anomaly is one of those special cases. Although it is true that objects moving in space have few restrictions on Unruh radiation, there is one final restriction, and that is the Hubble Scale of the universe, beyond which information cannot be obtained. This ultimate restriction means that there is a longest-possible Unruh wavelength (the Hubble scale), which also means that there is a smallest-possible acceleration for an object moving in space. Pioneer is encroaching against that limit, which is the cause of the acceleration anomaly.
If memory serves Sonny suggested that changes in geometry and frequency would be part of their continued testing (I believe what is now in peer review). X_Ray was chiding me with his "touché" is this regard. This brings up an important point though: Is Cannae a legitimate part of this thread? Or? 
