On Friday, June 16, 2017 at 11:54:33 PM UTC+10, Craig Markwardt wrote:
>> I note that you conveniently deleted and ignored this crucial discussion.
>> Anderson made simplifying assumptions that turned out to be incorrect or
>> too simple.
>
> I note no response. (see item #4 below)
>
>> I would still like to know how Turyshev arrived at 5% emissivity
>> reduction generated from solar radiation...
>
> If you had bothered to the check the footnote in Turyshev et al's
> text, you might have. (see item #2 below). It's also probably
> because the Anderson authors were exclusively navigation analysts,
> and did not have significant thermal experience.
>
>> Anderson's analysis in
>> section V111.C; "Differential emissivity of the RTG's" isn't
>> handwaving by any means. It's based on **very sound logic**.
>
> Really? Let's see what is argued in that section.
>
> Paragraph 1. Introduction.
>
> Paragraph 2. "Given our knowledge of the solar wind and the
> interplanetary dust (see Section XI A), we find that this amount
> of a radiant change would be difficult to explain, even if it
> were of the right sign." Note, no substantiation or quantitative
> reasoning is given for this statement. No sound logic.
A couple of sentences extracted from a paragraph is useless.
https://arxiv.org/pdf/gr-qc/0104064v5
Section V111.C. tells the story properly.
---
---
> Paragraph 6. Discussion of the temporal behavior of an RTG
> emissivity based effect. Anderson rules out a differential
> emissivity effect because the "anomaly" is constant. However,
> as found by Turyshev Toth Ellis & Markwardt (2010), there *is*
> evidence for a temporally varying acceleration. So the
> fundamental assumption of Anderson turned out to be incorrect.
> No sound logic.
FIG.6 in Anderson's paper shows a reducing anomaly with time.
> Therefore, while much of this discussion by Anderson et al was
> *plausible* at the time, it was still mostly unmotivated and
> lacking in quantitative basis. And, none of what Anderson
> discusses really pertains to solar UV damage which is the primary
> degradation mechanism identified in Turyshev et al (2012) and
> Broadway (1971). Therefore you are incorrect (see item #4 below)
>
> Furthermore, while Anderson et al were trying to discount the
> RTGs as the source of the *total* Pioneer "anomaly" magnitude,
> Turyshev et al (2012) only attempted to tally an uncertainty due
> to RTG coating degradations, which is a smaller fraction than the
> full anomaly. They didn't "need" to reach 100% anomaly level, as
> Anderson did to explain the anomaly.
Read his paper.
It's clear to me that Anderson set a "100% anomaly level" as
an example. He was well aware that there were other areas of
concern. He gave **an example** for a -1% relative fore/aft
emissivity on the RTG surfaces as well, which resulted in 10
watts of drive toward the sun. -10% emissivity fore/aft
difference would generate 100 watts, which would be enough to
counteract the entire anomaly. You yourself gave a 50 watt
sunward drive for -5% emissivity change on the sun facing
surface, so Anderson was obviously using exactly the same
math then as you are today.
>> So whether or not Turyshev had evidence that the emissivity of
>> similar surface coatings degrade by 5% in a solar environment is
>> irrelevant because **that's not what happened here**.
>
> I note you have absolutely zero evidence of this. Anderson et
> al 2002) never identifies whether or not a 5% degradation could
> occur due to solar UV damage. (see item #4 below)
>
>> And even if it was a possibility the error margin is increased
>> to only just barely encapsulate the anomaly.
>
> You are incorrect. Figure 4 of Turyshev et al (2012)
> demonstrates that there is very significant overlap between the
> 1-sigma thermal solution and the 1-sigma doppler solution. You
> could have read about this but did not (see item #2 below).
>
>> The odds on the RTG
>> surface coating being the one with the -5% emissivity would be
>> at most 1 in 20.
>
> The change of IR emissivity of about 5% was actually measured in
> several samples, after only a few hundred equivalent sun hours of
> exposure. This was not a rare change. And bear in mind that
> the cruise to Jupiter takes many *thousands* of hours.
Equivalent at what radius? Whatever the case the change in
emissivity is obviously not linear. I would expect that after a
few hundred hours of solar radiation the process will have slowed
considerably. If the process was linear, it wouldn't instantly
stop at 5% change, and the consequences would be easily noted as
a constantly increasing or decreasing anomaly, depending on the
sign. Increasingly -x% emissivity change on the RTG sun facing
surfaces, at the rate you have described, would give a very
obvious rising anomaly per time. Increasingly +x% would give an
equivalent falling anomaly.
According to FIG.3 from Turyshev's paper, and FIGs 6 and 7 from
Anderson's paper the anomalous acceleration reduces over time
(beyond 20 AU for Anderson). Which is evidence that the RTG
surface coating is of the +x% variety. That's only if the need
arises of course.
> So your claim
> of 1 in 20 is unsubstantiated.
>
>> How does that prove the Pioneer anomaly extinct
>> beyond any doubt?
>
> You have the wrong statistical standard. If the thermal and
> Doppler solutions overlap by about 50% at the 1-sigma confidence
> level, then they are essentially consistent with each other. The
> Pioneer data are consistent with "standard physics," so there is
> no statistical need to invoke an anomaly.
I'm aware that Turyshev required only -2.5% emissivity
differential, giving 25 watts of drive from the RTG's, which
adds enough to the total to explain the anomaly. If the error
bar was from 0% to -5% that gives a 50\50 chance that the anomaly
doesn't exist. But since the range of coatings extends to -5%
the confidence level becomes 100% . The problem here is that the
error bar is from +5% to -5% . So the confidence level goes back
50% again. You have clearly failed to meet the conditions set
out in your statistical standard.
This is another area where the thermal solution fails:
If the entire range of RTG surface coating possibilities were
tested, on a graph depicting solar induced emissivity changes
between +5% and -5% , how would they be distributed? Would the
distribution be uniform right up to the limits of the error bar,
or would the graph be more realistic and follow more of a
sinewave shape where the distribution around the limits is
sparse, with the vast majority falling around the central point
(0%) ? Of course it would.
Your 50\50 chance has diminished considerably.
> [ From your other message ]
>> But you've just shot yourself in the foot by acknowledging the
>> existence of an onset.
>
> I never claimed there was no "onset," but that those historical
> figures were presented by Anderson with little or no
> substantiation, and with no way to verify. As I pointed out,
> analysts at the time were working with more limited knowledge,
> and the setting of the solar constant K at 5 AU may have
> influenced the appearance of an "onset."
>
>> Analysts involved in describing the Pioneer anomaly set the zero
>> mark for the onset at around 5 AU, which gave a positive anomaly
>> for all radii beyond that point. If zero was set at i.e. 20 AU
>> the anomaly would be negative at lesser radii, and that would
>> throw your thermal solution out the window.
>
> You are correct that the choice of when/where to set the solar
> reflectivity constant K of the Pioneer will set the zero point of
> the anomaly. Anderson et al (2002) was not really aware of how
> much directional heat flux was present, which would have
> erroneously biased that selection. The presence of the thermal
> solution doesn't throw anything out the window.
The **thermal solution** is thrown out the window if the zero
mark for the onset is set at 20 AU because the anomaly would be
entirely negative and the anomalous acceleration **away** from
the sun would need to be explained. If the zero mark is set at
1 AU the anomaly would be substantially greater than it is, thus
creating a much greater problem for the thermal solution.
> The Turyshev
> authors were well aware that by estimating spacecraft properties
> using early or beginning-of-life data, could bias the solution.
> This is why they jointly re-solved the doppler and thermal
> equations and spacecraft parameters.
FIG.3 in Turyshev's paper sets the anomalous acceleration for
the beginning of the mission at around 1.43e-9 m/s^2. It falls to
8.74e-10 m/s^2 at around 10 AU, falling to less than 6e-10 m/s^2
just prior to 75 AU. Zero for the "solar reflectivity constant"
obviously has nothing to do with the zero used to counteract the
Pioneer anomaly.
>> The reason 5 AU was chosen as zero is because it gave the best
>> fit according to current theory.
>
> I note that you did not substantiate this claim. Anderson et al
> (2002) presented this selection as a fait accompli without
> explanation. (item #4 below)
>
> ...
>
> Let's summarize the issues you seem to be willfully ignoring.
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(snipping irrelevant diversionary tactic)
---
> So I ask again: if this is so important to you, why don't you
> stop ignoring important things? It's clear you have your own
> theory to hawk, and are willing to ignore anything that disagrees
> with it. So why should we listen to you?
Well if I had never come across the zero origin concept you
would probably never know that I existed. It's doubtful that our
paths would ever cross. Unfortunately there's a very sinister
message embedded in that theory and that's what drives me to
annoy you.
Incidentally, that theory generates a curve which is a perfect
match with the Pioneer anomaly as was described by those early
analysts who's contributions you deem unreliable because they
were too inexperienced. But I find it hard to believe that NASA
would launch a billion dollar mission while the analysts are
asking which button to push. They would have known **exactly**
what they were doing. That was proven when they reported the
anomaly. They weren't required to explain how or why it was
there, they only reported what they found.
According to my theory, in current theory, solar radiation
pressure is overestimated to overcome the discrepancy between
the two theories at a radius of 5 AU from the sun. At that radius
the increasing error per lesser radius can be concealed within
the environment local to the sun. But from 5 AU outward, no such
concealment mechanism exists and Pioneer begins an **apparent**
acceleration toward the sun.
The zero mark can be set anywhere by adopting the apparent
(according to current theory) solar radiation pressure at that
point as the standard. At around 12.6 AU the gforce difference
between the two theories is zero. I have suggested that this
should be the zero mark for current theory, but the true zero
line is the Pioneer anomaly as generated by my theory. It
traces a path back to the sun, which passes the 1 AU mark at
1.1e-6 m/sec^2. Setting a fixed zero mark at this point would
generate a relatively enormous anomaly.
There's no doubt at all that the Pioneer anomaly is very much
alive and well.
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Max Keon