pioneer 10 gravitational analomy

Everyone

Are there any ideas as to Pioneer 10 gravitational analomy as presented in:

http://xxx.lanl.gov/abs/gr-qc/0409117

I did a quick calculation based on rough Pioneer dimensions and mass m:

m a = A rho c^2

Pioneer mass m= 257,640 gram
Pioneer diameter = 274 centimeter
Pioneer crossection A= 58,965 cm^2
Pioneer acceleration a= 8.74E-08 cm/sec^2

Calculated Space Density rho is then:
space density rho = 8.52E-28 g/cm^3

this value for space density is near what is presented for dark matter.

My question is why Pioneer velocity does not come into this calculation.
Could such space probes with tuned A/m ratios be used to quantify dark
matter/energy?

More questions than answers

Richard

[Mod. note: HTML removed. Please post in plain text only -- mjh]

Richard Saam wrote:
Everyone

Are there any ideas as to Pioneer 10 gravitational analomy as
presented in:

http://xxx.lanl.gov/abs/gr-qc/0409117

I did a quick calculation based on rough Pioneer dimensions and mass
m:

m a = A rho c^2

Pioneer mass m= 257,640 gram
Pioneer diameter = 274 centimeter
Pioneer crossection A= 58,965 cm^2
Pioneer acceleration a= 8.74E-08 cm/sec^2

Calculated Space Density rho is then:
space density rho = 8.52E-28 g/cm^3

this value for space density is near what is presented for dark
matter.

My question is why Pioneer velocity does not come into this
calculation.

The formula you give is wrong. Replace c by v to get the drag on a
body
with drag coefficient of unity. This makes the required density 600
million times larger than your value. I think the acceleration is due
to anisotropic radiation of waste heat from the RTGs, but Anderson
disagrees.

The radiator design was symmetric, but the symmetry was never tested
and can't
be checked now. After decades of completely one-sided exposure to the
Sun I imagine the black paint on the radiators could have faded on one
side. A 3% asymmetry would provide the needed thrust.

See http://www.astro.ucla.edu/~wright/PioneerAA.html

Could such space probes with tuned A/m ratios be used to quantify
dark
matter/energy?

More questions than answers

Richard

--Edward L. (Ned) Wright, UCLA Professor of Physics and Astronomy
See http:www.astro.ucla.edu/~wright/cosmolog.htm

Originally Posted by

Richard Saam wrote:
Everyone

Are there any ideas as to Pioneer 10 gravitational analomy as
presented in:

http://xxx.lanl.gov/abs/gr-qc/0409117

I did a quick calculation based on rough Pioneer dimensions and mass
m:

m a = A rho c^2

Pioneer mass m= 257,640 gram
Pioneer diameter = 274 centimeter
Pioneer crossection A= 58,965 cm^2
Pioneer acceleration a= 8.74E-08 cm/sec^2

Calculated Space Density rho is then:
space density rho = 8.52E-28 g/cm^3

this value for space density is near what is presented for dark
matter.

My question is why Pioneer velocity does not come into this
calculation.

The formula you give is wrong. Replace c by v to get the drag on a
body
with drag coefficient of unity. This makes the required density 600
million times larger than your value. I think the acceleration is due
to anisotropic radiation of waste heat from the RTGs, but Anderson
disagrees.

The radiator design was symmetric, but the symmetry was never tested
and can't
be checked now. After decades of completely one-sided exposure to the
Sun I imagine the black paint on the radiators could have faded on one
side. A 3% asymmetry would provide the needed thrust.

See http://www.astro.ucla.edu/~wright/PioneerAA.html

Could such space probes with tuned A/m ratios be used to quantify
dark
matter/energy?

More questions than answers

Richard

--Edward L. (Ned) Wright, UCLA Professor of Physics and Astronomy
See http:www.astro.ucla.edu/~wright/cosmolog.htm

******
My intent was to keep velocity as "c" and not "v" so that perhaps the unique nature of dark energy/matter could be probed and possibly be the source of the Pioneer acceleration anomaly. This assumes that all of the dark matter energy "mc^2" is released to the spacecraft on "impact".

Possibly anisotropic waste heat radiation would be a factor. Only well designed multiple spacecraft will find the answer.

Richard Saam

Wrote:
The formula you give is wrong. Replace c by v to get the drag on a
body
with drag coefficient of unity. This makes the required density 600
million times larger than your value. I think the acceleration is due
to anisotropic radiation of waste heat from the RTGs, but Anderson
disagrees.

The radiator design was symmetric, but the symmetry was never tested
and can't
be checked now. After decades of completely one-sided exposure to the
Sun I imagine the black paint on the radiators could have faded on one
side. A 3% asymmetry would provide the needed thrust.

See http://www.astro.ucla.edu/~wright/PioneerAA.html

My intent was to keep velocity as "c" and not "v" so that perhaps the
unique nature of dark energy/matter could be probed and possibly be the
source of the Pioneer acceleration anomaly. This assumes that all of
the dark matter energy "mc^2" is released to the spacecraft on
"impact".

Possibly anisotropic waste heat radiation would be a factor. Only well
designed multiple spacecraft will find the answer.

Richard Saam


[Mod. note: quoted text re-organized -- mjh]

--
Richard Saam

The "anisotropic radiation" argument doesn't work, this is why Anderson
disagrees. Please take the time to look at the actual results and note
the constant acceleration. Any thermodynamic effects, such as a photon
rocket from the RTG, would result in a decay in the rate of
acceleration over time (proportional to the RTG isotope). This is not
apparent from the observations, so Anderson drawns the correct
conclusion by ruling it out.

Alastair @ Nodem wrote:
The "anisotropic radiation" argument doesn't work, this is why
Anderson
disagrees. Please take the time to look at the actual results and
note
the constant acceleration. Any thermodynamic effects, such as a
photon
rocket from the RTG, would result in a decay in the rate of
acceleration over time (proportional to the RTG isotope). This is not
apparent from the observations, so Anderson drawns the correct
conclusion by ruling it out.

The mean life time of Pu-238 is 127 years, so in the 11 year run
analyzed by Anderson etal there would be a 9% change in the waste
heat, or a 2.5% RMS variation. Given the covariance between the
uncertainty in the 1/r^2 radiation pressure term and this decay term,
there is probably insufficent sensitivity to detect the decay.

In any case the hypothesis that prolonged anisotropic exposure to
space generates the anisotropy in the radiation naturally leads to an
increasing coefficient times a decaying total heat. So Anderson etal
cannot rule this out. This is just a hard problem, and given that the
effect is not present for the planets I think it is best to work on
other problems where progress can be made.

[Mod. note: reformatted -- mjh]

wrote:
The mean life time of Pu-238 is 127 years, so in the 11 year run
analyzed by Anderson etal there would be a 9% change in the waste
heat, or a 2.5% RMS variation. Given the covariance between the
uncertainty in the 1/r^2 radiation pressure term and this decay term,
there is probably insufficient sensitivity to detect the decay.

Correct, the efficiency of the RTGs was lower than I had expected. At
launch they supplied 160W, which dropped to 70-75W by the end of the 11
year run. This is more than a 50% decrease over the entire life time of
the space craft; however the waste heat at launch would have been
around 2,420W, dropping to around 2,000W over the same period (a 17%
decrease over 17 years).

In any case the hypothesis that prolonged anisotropic exposure to
space generates the anisotropy in the radiation naturally leads to an
increasing coefficient times a decaying total heat. So Anderson etal
cannot rule this out.

Yes, this would (conveniently) act against any decrease in thermal
output of the RTGs.

This is just a hard problem, and given that the effect is not present
for the planets...

True, I can't see any conceivable reason why this would be a real
acceleration, hence no effect on planetary orbits would be seen...

..I think it is best to work on other problems where progress can be
made.

....however what is being measured here is not an acceleration. The
Doppler ranging measurements made to these space probes (and others,
including Cassini) show the relative change of in the scale of the
universe. Einstein covers the issue of redshift succinctly in the
appendix of the second edition of "The Meaning of Relativity" (1945).
His analysis is ultimately based on the assumption that, "certain
atomistic forms are not related by 'similarity' but by 'congruence'".
But what if they *were* related by similarity and there are no absolute
physical properties in the universe what so ever? Doesn't bear
thinking about does it... best to work on other problems!

Study of the Pioneer Anomaly: A Problem Set
Slava G. Turyshev, Michael Martin Nieto, and John D. Anderson
(Dated: February 24, 2005)
http://xxx.lanl.gov/abs/physics/0502123

Gentlemen

I have updated (April, 2005) my paper:

http://arxiv.org/abs/physics/9905007

to incorporate the "Problem Set" parameters
and in its particular
Pioneer spacecraft translational and rotational parameters.
It is concluded (page 19-22)
that one space mass density (6.38E-30 g/cm^3)
based on elastic space lattice
and close to observed dark matter density
and in congruence with CMBR
predicts the observed Pioneer spacecraft translational
and rotational deceleration
assuming this space mass density is available
to the spacecraft as momentum transfer (mc/area).

Note: that translational and rotational velocities
are three (3) orders of magnitude of each other
which makes the above observed and calculated
deceleration results rather remarkable.

Further,
1. No deceleration effects will be noticed on planets
because of their large mass to area ratios.

2. The nanoTesla magnetic field in the vicinity of
Earth orbit around the sun, although small,
is large enough to destroy the elastic space lattice
(superconductor critical field analogy)
and hence no observable deceleration on
objects close to the sun. The effect
only "kicks in" far from the sun 10 AU
and extending into deep space.

Richard Saam

Study of the Pioneer Anomaly: A Problem Set
Slava G. Turyshev, Michael Martin Nieto, and John D. Anderson
(Dated: February 24, 2005)
http://xxx.lanl.gov/abs/physics/0502123

Gentlemen

I have updated (April, 2005) my paper:

http://arxiv.org/abs/physics/9905007

to incorporate the "Problem Set" parameters
and in its particular
Pioneer spacecraft translational and rotational parameters.
It is concluded (page 19-22)
that one space mass density (6.38E-30 g/cm^3)
based on elastic space lattice
and close to observed dark matter density
and in congruence with CMBR
predicts the observed Pioneer spacecraft translational
and rotational deceleration
assuming this space mass density is available
to the spacecraft as momentum transfer (mc/area).

Note: that translational and rotational velocities
are three (3) orders of magnitude of each other
which makes the above observed and calculated
deceleration results rather remarkable.

Further,
1. No deceleration effects will be noticed on planets
because of their large mass to area ratios.

2. The nanoTesla magnetic field in the vicinity of
Earth orbit around the sun, although small,
is large enough to destroy the elastic space lattice
(superconductor critical field analogy)
and hence no observable deceleration on
objects close to the sun. The effect
only "kicks in" far from the sun 10 AU
and extending into deep space.

Richard Saam


--
Richard Saam