NASA Baffled by Unexplained Force Acting on Space Probes

[ToSeek]

NASA Baffled by Unexplained Force Acting on Space Probes

Mysteriously, five spacecraft that flew past the Earth have each displayed unexpected anomalies in their motions.

These newfound enigmas join the so-called "Pioneer anomaly" as hints that unexplained forces may appear to act on spacecraft.

A decade ago, after rigorous analyses, anomalies were seen with the identical Pioneer 10 and 11 spacecraft as they hurtled out of the solar system. Both seemed to experience a tiny but unexplained constant acceleration toward the sun.

A host of explanations have been bandied about for the Pioneer anomaly. At times these are rooted in conventional science — perhaps leaks from the spacecraft have affected their trajectories. At times these are rooted in more speculative physics — maybe the law of gravity itself needs to be modified.

Now Jet Propulsion Laboratory astronomer John Anderson and his colleagues — who originally helped uncover the Pioneer anomaly — have discovered that five spacecraft each raced either a tiny bit faster or slower than expected when they flew past the Earth en route to other parts of the solar system.

[BigDon]

Yay! Of all the mysteries of space, I thought the Pioneer anomaly, (no need for quotes) was going to be significant because its so close to home. And now the flybys are showing it. I'd really like to see a good solution to this. I wonder if it has anything to do with gravity and space topograghy ala the rubber sheet theory.


Thank you Toseek!

[spacestart.eu]

It is certainly something if it happens to five different spaceprobes, I am very curious what this could be.

[Noclevername]

We've got a lot of unmapped and undetected mass, dust, and gas out there. No surprise that not everything goes as smoothly as equations and simulations predict.

[Trocisp]

If each of them had a similar or the exact same effect (all faster or all slower) I wouldn't be at all hesitant to say that it was an unknown force, possibly.

And while it still might be an unknown force, it seems far more likely that noclevername has the idea down, small anomalies a new theory for gravity do not make.

[Cougar]

NASA Baffled by Unexplained Force Acting on Space Probes

For instance, the NEAR mission approached Earth at about latitude 20 south and receded from the planet at about latitude 72 south. The spacecraft then seemed to fly 13 millimeters per second faster than expected. While this is just one-millionth of that probe's total velocity, the precision of the velocity measurements was 0.1 millimeters per second, carried out as they were using radio waves bounced off the craft. This suggests the anomaly seen is real — and one needing an explanation.

The fact this effect seems most evident with flybys most asymmetrical with respect to Earth's equator "suggests that the anomaly is related to Earth's rotation," Anderson said.

Hmm. Lot of variables there. Not a very big anomaly.

[John Mendenhall]

There was a recent article/post that I read, and I wish I could remember where, that attributed the anomalies to GR induced electromagnetic radiation. The effect had been overlooked in the calculations. It sounded plausible.

Richard?

[BigDon]

Hmm. Lot of variables there. Not a very big anomaly.

Mr. Cougar,

I know you are a person who takes his physics seriously, but isn't it said that most great discoveries aren't discovered with "Eureka!" but with, "Hmmm, that's funny."

[Jay200MPH]

I don't really buy that the close-Earth-approach data is anomalous. From a geodesy standpoint, the "calculated" orbits of GPS satellites have to be constantly tweaked or they'll drift so far from reality to become useless in a matter of days. Our best gravity maps of the Earth just aren't that precise. With spacecraft - as opposed to satellites - you get one pass to figure out how well your a priori orbit matches reality. I'd expect a little more error to pop up than what they are assuming.

- J

[RGClark]

There was a recent article/post that I read, and I wish I could remember where, that attributed the anomalies to GR induced electromagnetic radiation. The effect had been overlooked in the calculations. It sounded plausible.

Richard?

Perhaps you are thinking of this:

NASA's astonishing evidence that c is not constant: The pioneer anomaly.
http://arxiv.org/abs/physics/0701130

Or this:

January 20th, 2008
A Possible Answer to Flyby Anomalies.
Written by Ian O'Neill
"Strange things are happening to our robotic space explorers. Also
known as the "Pioneer effect" (the unexpected and sudden alterations
to Pioneer 10 and Pioneer 11 trajectories measured as they continue
their journey into the outer solar system), similar anomalies are
being seen in flybys by modern space probes. Earth flybys by Galileo,
Rosetta, NEAR and Cassini have all experienced a sudden boost in
speed. After cancelling out all possible explanations, including
leakage of fuel and velocity measurement error, a new study suggests
the answer may lie in a bizarre characteristic of universal physics..."
http://www.universetoday.com/2008/01...yby-anomolies/



Bob Clark

[Noclevername]

If it was really a single unexplained force, there would be some consistency. Instead some are too fast, some are too slow, and all are moving in different directions.

[BigDon]

Clev,

The post above your's says all were faster. As if all were "uphill" upon returning from beyond Earth's orbit. The slow one I heard of elsewhere was coming from "downhill"

[Ken G]

What I'd like to know is, how do they know the theoretical uncertainties? When everything comes out an "anomaly", it looks to me like there are simply more variables than they are tracking-- no new physics.

[tracer]

A decade ago, after rigorous analyses, anomalies were seen with the identical Pioneer 10 and 11 spacecraft as they hurtled out of the solar system. Both seemed to experience a tiny but unexplained constant acceleration toward the sun.

"What could be causing a tiny but constant acceleration toward the sun?" NASA's scientists asked themselves.

Finally, after much brilliant research, they hit upon a novel idea:

Maybe the sun exerts gravity!



<ducking and running>

[Noclevername]

Clev,

The post above your's says all were faster. As if all were "uphill" upon returning from beyond Earth's orbit. The slow one I heard of elsewhere was coming from "downhill"

That post wasn't above mine when I posted my post!

[KaiYeves]

If I was living in a movie, it would start with me reading this thread, and the creepy music would start playing...

[Swift]

If I was living in a movie, it would start with me reading this thread, and the creepy music would start playing...

You, you mean you can't hear the MUSIC!
dun dun dun

[publius]

There was a recent article/post that I read, and I wish I could remember where, that attributed the anomalies to GR induced electromagnetic radiation. The effect had been overlooked in the calculations. It sounded plausible.

Richard?

I wasn't aware of that until I saw RGClark's posts. Thanks RGC.

The first paper, in physics-general, about a variable speed of light depending on the total energy density of space, including the gravitational energy density(which idea is not very well defined in GR), is well, not too serious. It's an idea, but one that doesn't fit too well with known physics.

The second one, and this is probably the effect you were thinking about is *Unruh* radiation. This is heavy duty QFT stuff and is related to Hawking radiation -- heck they are the same thing, which brings up this vexxing question I have about coordinate vs real radiation. My gut says that only real curvature should produce "real" Hawking-Unruh, and the rest is some sort of coordinate effect.

Anyway, an accelerating observer should see himself in a "bath" of thermal radiation (very small). This is a coordinate effect that shifts the quantum vacuum as seen by the non-inertial observer in some complex way I don't begin to understand. The upshot is the "vacuum" is a frame dependent thing. There's something there to do with Killing vectors and preserving the metric. Classes of observers with the same metric see the same vacuum. Different metrics see different vacuua. That is, all that quantum field crap operators that tell what the various field values will be resolve differently in different metrics.

So Inertial observers in flat space-time with a Minkowski metric see the vacuum in it's zero state, say. No radiation. However, go to the curved coordinates of the accelerating observer, and that vacuum looks filled with excited states. You can see that as Hawking radiation coming from the Rindler horizon, actually!

All this is well beyond me, mind you, so don't take my ramblings here as gospel, just my vague attempts to paint a picture.

The idea that the Unruh effect would be large enough to cause the Pioneer anomaly is sort of hard for me to believe. I figured it would be so vanishly small for anything short of millions and billions of g's worth of acceleration.

-Richard

[Maksutov]

Could it be that the probes were doing what they were expected to be doing and something affected the radio waves that provided evidence of the velocity deltas?

Meanwhile I'm surprised there hasn't been a somewhat reluctant cosmological post in this thread.

[RGClark]

I wasn't aware of that until I saw RGClark's posts. Thanks RGC.

The first paper, in physics-general, about a variable speed of light depending on the total energy density of space, including the gravitational energy density(which idea is not very well defined in GR), is well, not too serious. It's an idea, but one that doesn't fit too well with known physics.

The second one, and this is probably the effect you were thinking about is *Unruh* radiation. This is heavy duty QFT stuff and is related to Hawking radiation -- heck they are the same thing, which brings up this vexxing question I have about coordinate vs real radiation. My gut says that only real curvature should produce "real" Hawking-Unruh, and the rest is some sort of coordinate effect.

Anyway, an accelerating observer should see himself in a "bath" of thermal radiation (very small). This is a coordinate effect that shifts the quantum vacuum as seen by the non-inertial observer in some complex way I don't begin to understand. The upshot is the "vacuum" is a frame dependent thing. There's something there to do with Killing vectors and preserving the metric. Classes of observers with the same metric see the same vacuum. Different metrics see different vacuua. That is, all that quantum field crap operators that tell what the various field values will be resolve differently in different metrics.

So Inertial observers in flat space-time with a Minkowski metric see the vacuum in it's zero state, say. No radiation. However, go to the curved coordinates of the accelerating observer, and that vacuum looks filled with excited states. You can see that as Hawking radiation coming from the Rindler horizon, actually!

All this is well beyond me, mind you, so don't take my ramblings here as gospel, just my vague attempts to paint a picture.

The idea that the Unruh effect would be large enough to cause the Pioneer anomaly is sort of hard for me to believe. I figured it would be so vanishly small for anything short of millions and billions of g's worth of acceleration.

-Richard

This report suggests the thermal radiation in the vacuum can effect the timing of atomic clocks:

Aug 11, 2006
Atomic clocks feel the heat.
"Temperature is not something that most people take into account when trying to find out what time it is -- unless your watch has frozen or melted that is. But in the ultra-precise world of atomic timekeeping, which governs navigation technology such as the global positioning system, the temperature is vital."
http://physicsworld.com/cws/article/news/25595

If this is so, then we might expect as well some effect based on the energy content of the quantum vacuum. Some years ago I speculated something like this "Pioneer effect" might be observed on close Earth flybys, but I thought the satellite motions would undergo turbulence (aside from the atmospheric effects) because of the effects of the quantum vacuum:

Newsgroups: sci.astro, sci.physics, sci.physics.relativity
From: "Robert Clark" <rcl>
Date: 1997/09/28
Subject: A test for 'Sakharov gravity'?
http://groups.google.com/group/sci.p...ea19e65168e22/

I called it "Sakharov gravity" because Sakharov speculated the effects
of gravity might be due to the "quantum vacuum". If you're *really*
interested you can read about it in the general relativity textbook
"Gravitation", by Wheeler, Misner, and Thorne. (You have to be really
interested because the book is such a massive tome.)
To get a better idea on this would be to look at very low flybys
conducted close to the Moon with very accurate radar rangers placed on
the Moon's surface to look for deviations in the velocities.
I was also intrigued to see that one of the scientists involved in these latest satellite observations suggested the cause might be related to the Earth's rotation. I also speculated such an effect might seen be due to rotation in a discussion of variable speed of light theories:

Newsgroups: sci.physics.research, sci.physics.relativity
From: rgregorycl...@yahoo.com (Robert Clark)
Date: 4 Sep 2003 00:27:45 -0400
Local: Thurs, Sep 4 2003 12:27 am
Subject: Re: VSL (Variable Speed of Light) Relativity

Hello Marc. I'm a fan of your work with NASA's "Breakthrough Physics"
program. Nice to see you as a contributor to this group, though I
might suggest putting some type of spam blocker to your address if
this is a usable email address for you.
I remember reading that Kip Thorne first worked out the mathematics
of wormholes at the request of Carl Sagan as background for Sagan's
book "Contact". Since Thorne also suggested that the material medium
description is equivalent to the warped space-time description of GR
in his book "Black Holes and Time Warps: Einstein's Outrageous
Legacy", he would probably be a good source to find out if black holes
can be described this way.
However, since the book was about black holes I can't imagine he would
say the two descriptions were equivalent if he was not also including
the possibility of black holes.
Also I recall seeing recently there is some work on creating "lab
versions" of black holes. I think it was by using the material medium
analogy to GR.
If the material medium description is equivalent to the space-time
description of GR then we should also expect phenomena that occur in
fluid dynamics to occur in GR.
One that I'm interested in is the Magnus effect:

The Magnus Effect.
http://www.geocities.com/k_achutarao/MAGNUS/magnus.html

This is an effect that produces a transverse force on a rotating body
in a fluid.
There is an effect in GR known as "frame dragging". But in the
descriptions I've seen, only the precession of the orbit of a
satellite is described. However, from the mathematical similarity of
the equations of general relativity to those of motion through a
material medium we might also expect there to be a force produced that
drags the satellite in toward the parent body.
Detecting this inward force in addition to the normal GR
gravitational effect (without rotation) would be one test of this
effect. Another possible test would come from the origins of the
Magnus effect: it's due to the fluid being dragged along with the
rotating body. This results in the speed of propagation of a wave in
that fluid being increased or decreased, depending on direction. Then
light speed should be increased or decreased near a massive rotating
body depending on direction in GR as well.
I found another interesting comparison to the Magnus effect after a
Google search:

================================================== =========================
From: paul vose (paral...@bluesky.net.au)
Subject: Lorentz Force and Magnus Effect compared (and a gif) -
the_same.gif (0/1)
Newsgroups: sci.physics
Date: 1996/12/29

Has anyone ever noticed the similarities between the Lorentz Force and
the Magnus Effect ?

For those who have never heard of either term, a simple definition of
each follows.

---> The Lorentz Force is the centripetal force experienced by a
MOVING CHARGED particle as it travels through a magnetic field. Only
that component of the particle velocity at right angles to the field
is involved. The field does not add any energy to the particle
velocity. The field, the velocity, and the force are always at right
angles to each other, so as the direction of travel of the particle
changes the force also rotates accordingly. The particle ends up
travelling in a circle or a spiral path, depending on the angle at
which it enters the magnetic field. Loss of kinetic energy should also
be taken into consideration. For those who prefer an equation, here it
is..
F = Bq (V sinq), where B is the field strength, q is charge, V is
velocity, and q is the angle between the (total) velocity and the
field. If all of the particle velocity is at right angles to the
field, then sin90 = 1, means maximum force experienced by the
particle.

---> The Magnus Effect is the centripetal force experienced by a
MOVING SPINNING object as it travels through a fluid medium. (The
proviso is that the object be capable of dragging some of the
surrounding fluid around it's 'equator' as it spins - i.e. it needs to
have a rough surface...like a golf ball or a tennis ball). Only that
component of the object velocity at right angles to the spin axis is
involved. The rate of spin does not add any energy to the object
velocity. The spin axis, the velocity, and the force are always at
right angles to each other, so as the direction of travel of the
object changes the force also rotates accordingly. The object would
end up travelling a full circle if gravity and fluid fluctuations did
not act upon it. Golfers and tennis players use the Magnus Effect all
the time, when they use backspin or sidespin to good effect for their
game. Assuming a spinning golf ball travels through the air and drags
some of that air around its equator, it creates a slight vacuum on one
side (at the surface of the ball) where the air is hauled away from
the oncoming wind. On the opposite side, the fluid is thrown into the
oncoming wind and the pressure is increased. The net force on the ball
causes it to change direction continuously. The equation describing
the Magnus Effect is a little complicated for me to describe here.

These two phenomena are extraordinarily similar I think, and it aint
just a coincidence !
================================================== ===================

Then perhaps there is an actual physical interpretation of the
electrons spin as a rotation. There were some attempts to do this
mathematically early on but it was found to require rotation speeds
greater than the speed of light. However, if light speed is no longer
an absolute maximum or if it is allowed to vary this is no longer an
legitimate objection.

Bob Clark

Marc Millis <marc.g.mil...@nasa.gov> wrote in message

<news:20030828160834243-0400@newsread.grc.nasa.gov>...
> In <bibsgg$...@netnews.proxy.lucent.com> Tom Roberts wrote:
> -snip-
> > And also, I suspect, because such an Euclidean interpretation cannot
> > possibly hold in a region with strong gravitation....

> This would be an interesting analysis, but I suspect one would have to
> be careful with starting assumptions in trying to figure out how to
> appropriately apply this optical model in cases such as black holes.
> That, by itself, would be a challenging task.

> I am definitely under the impression that wormholes or warp drives are
> not describable from this perspective, but this is just an impression,
> not a reliable conclusion on my part.

> For example, to consider the back hole case, here is just one detail
> that muddies up the works: Time. One would have to be careful on how
> one defines the propagation of time. For clocks that are based on an EM
> phenomena (remember that c varies with respect to the gravitational
> potential in the optical model), one has to be careful on which clocks
> to use as a reference. So long as it is all applied consistently, any
> selection should suffice (uh, maybe). Perhaps a master clock at
> infinity (far from sources of gravitational potential), but there are
> multiple ways to treat this too.

> BTW, one of the optical analogy papers I cited earlier describes the
> phenomenon of gravitational red-shift using the optical analogy.

> I have not seen a reference that attempts this or that uses such an
> attempt to refute such optical perspectives. If anyone knows of such a
> reference, I would greatly appreciate having it pointed out to me.

> Thanks,

> Marc

[RGClark]

Also found these references after a Google groups search:

Sakharov's induced gravity: a modern perspective.
"Sakharov's 1967 notion of 'induced gravity' is currently enjoying a significant resurgence. The basic idea, originally presented in a very brief 3-page paper with a total of 4 formulas, is that gravity is not ``fundamental'' in the sense of particle physics. Instead it was argued that gravity (general relativity) emerges from quantum field theory in roughly the same sense that hydrodynamics or continuum elasticity theory emerges from molecular physics. In this article I will translate the key ideas into modern language, and explain the various versions of Sakharov's idea currently on the market."
http://arxiv.org/abs/gr-qc/0204062

Towards a new test of general relativity?
23 March 2006
"Scientists funded by the European Space Agency believe they may have measured the gravitational equivalent of a magnetic field for the first time in a laboratory. Under certain special conditions the effect is much larger than expected from general relativity and could help physicists to make a significant step towards the long-sought-after quantum theory of gravity."
http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html


Bob Clark

[ASEI]

Well, as far as conventional explainations go - the Earth's gravity field isn't perfectly regular. There are concentrations of mass here and there that distort it into something a little more lumpy than a perfect spherical well.

There is light pressure from the sun, reflected every which way by the surfaces. There are rarified gasses that could produce drag. There is a particle flux from the sun.

There are other large bodies in the solar system (Jupiter, ect).

All sorts of things to produce divergence from simple astrodynamics calculations.

[Jerry]

"I am feeling both humble and perplexed by this," said Anderson, who is now working as a retiree. "There is something very strange going on with spacecraft motions. We have no convincing explanation for either the Pioneer anomaly or the flyby anomaly."

In the one probe the researchers did not confirm a noticeable anomaly with, MESSENGER, the spacecraft approached the Earth at about latitude 31 degrees north and receded from the Earth at about latitude 32 degrees south. "This near-perfect symmetry about the equator seemed to result in a very small velocity change, in contrast to the five other flybys," Anderson explained — so small no anomaly could be confirmed.

This is a very good clue: a symetrical approach and departure would not be effected by such forces as a greater frame dragging than predicted; or a miscalculation in the mass distribution of of the earth due to non Newtonian gravity.

The calculations used in gravitational assists are not trivial, they account for all known variables (solar wind, GR, other planets); and the variation in the Earth's gravity at gravitational assist differences are trivial-if Newton is correct. I can't remind you too many times that the calculated models of the landings on Mars, Titan and the plunge of the Galileo Jupiter Probe have all required exception wind conditions.

Continually writing off observations as either poor engineer, poor calibration and exceptional atmospheric conditions is a Ptolemeic approach. We need to include, (in future space probes) fundamental testing of models that are not so myoptic.

[Ara Pacis]

I assume they have already discarded or calculated effects from magnetic fields and Casimir effect from structural materials on the probes.

[KaiYeves]

You, you mean you can't hear the MUSIC!
dun dun dun

That's Jaws, isn't it? I was thinking maybe of something with a theremin.

[trinitree88]

This is a very good clue: a symetrical approach and departure would not be effected by such forces as a greater frame dragging than predicted; or a miscalculation in the mass distribution of of the earth due to non Newtonian gravity.

The calculations used in gravitational assists are not trivial, they account for all known variables (solar wind, GR, other planets); and the variation in the Earth's gravity at gravitational assist differences are trivial-if Newton is correct. I can't remind you too many times that the calculated models of the landings on Mars, Titan and the plunge of the Galileo Jupiter Probe have all required exception wind conditions.

Continually writing off observations as either poor engineer, poor calibration and exceptional atmospheric conditions is a Ptolemeic approach. We need to include, (in future space probes) fundamental testing of models that are not so myoptic.

Jerry. A good clue indeed. I'll suggest a thought from some of your "stuff".... cosmic rays interacting with the probes instead of the heliopause. The solar system cosmic ray flux is pretty isotropic, but does respond to solar mass ejections, which in the following article cause a net reduction. Usually diurnal fluctuations amount to less than 1%, so the sun can generally be ignored.
However, upon approaching the Earth environs, the rays being largely charged protons, heavier nuclei, and electrons, feel the Earth's field and the isotropy is modified with a net flow towards the poles. This should produce a slight acceleration for probes taking an asymmetrical path through the Earth's magnetosphere. The data shows that the most symmetrical path produced the probe with the least acceleration, and I'll lay a hot fudge sundae that the probe with the largest acceleration had the most asymmetrical path, and will call it the Hess/Peterson Effect in honor of Victor who discovered them, and my dad.
There ought to be a way to test this. The Bates Linear Accelerator did a study on the parity effect in electromagnetic interactions using a polarized gas target of Helium 3...circa 1991-2. The electrons in the gas are dynamically polarized using microwaves, and as they pass near the nuclei the electromagnetic momentum of the electrons slowly spin flip the nuclei. (the two protons anti-align canceling statistics...and the interaction with the polarized neutron could be determined). A population inversion of sorts exists, (I believe it was ~ 3%...and the target was subjected to energetic electron scattering.)
So, if you placed a polarized target in a satellite and did an asymmetrical-flyby/gravitational-assist....you ought to get an even more dynamic boost from the additional asymmetry in the electromagnetic interaction of the polarized target with the near-Earth cosmic ray flux. The measured asymmetry in that interaction is about 4%, and it would be diluted over the ratio of the mass of the polarized nuclei to the total number of isotropic nuclei in the craft...(~ it's mass ). Here we use the ambient cosmic ray flux as phi and multiply it by sigma, the known cross-section to get the interaction rate.
Flying two side by side satellites, one with polarized target, one not, would provide a definitive result. Not cheap. Interesting though. pete

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Title Tests of a high density polarized sup 3 He target for electron scattering
Creator/Author Chupp, T.E. ; Loveman, R.A. (Harvard University Physics Laboratories, Cambridge, Massachusetts 02138 (United States)) ; Thompson, A.K. ; Bernstein, A.M. ; Tieger, D.R. (Physics Department, Laboratory for Nuclear Science, and Bates Linear Accelerator Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States))
Publication Date 1992 Mar 01
OSTI Identifier OSTI ID: 7235483
DOE Contract Number AC02-76ER03069
Other Number(s) ISSN0556-2813; CODEN: PRVCA
Resource Type Journal Article
Resource Relation Physical Review, C (Nuclear Physics) ; Vol/Issue: 45:3; DOE Project
Subject 661220 -- Particle Beam Production & Handling; Targets-- (1992-) ;663420 -- Lepton-Induced Reactions & Scattering-- (1992-) ;663510 -- Nuclear Mass Ranges-- A=1-5-- (1992-); CEBAF ACCELERATOR-- TARGET CHAMBERS;HELIUM 3 TARGET-- ELECTRON REACTIONS;HELIUM 3 TARGET-- POLARIZED TARGETS;STANFORD LINEAR ACCELERATOR CENTER-- TARGET CHAMBERS; DESIGN;ELASTIC SCATTERING;EXPERIMENTAL DATA;MEV RANGE 100-1000;PERFORMANCE TESTING;POLARIZED BEAMS
Related Subject ACCELERATOR FACILITIES;ACCELERATORS;BEAMS;CHARGED-PARTICLE REACTIONS;DATA;ENERGY RANGE;INFORMATION;LEPTON REACTIONS;LINEAR ACCELERATORS;MEV RANGE;NATIONAL ORGANIZATIONS;NUCLEAR REACTIONS;NUMERICAL DATA;SCATTERING;TARGETS;TESTING;US DOE;US ERDA;US ORGANIZATIONS
Description/Abstract We have developed a polarized {sup 3}He target for polarized electron scattering measurements.^The target has a {sup 3}He density of 1.1{times}10{sup 20} nuclei cm{sup {minus}3}, a total length of 7.5 cm and thin glass windows of 120--180 {mu}m thickness. {sup 3}He polarization as large as 40% was produced, limited only by the available laser power.^The {sup 3}He polarization was maintained during bombardment with up to 22 {mu}A of 578 MeV electrons.^A measurement of elastic scattering of polarized electrons from polarized {sup 3}He confirmed that the nuclei in the electron beam had the expected polarization.^The polarization is produced by spin exchange with laser optically pumped Rb vapor, and the target design incorporates two separated volumes, one for optical pumping and the other for the electron bombardment.^Extensions of this design are practical for fixed target electron scattering from polarized {sup 3}He planned for SLAC and CEBAF.
Country of Publication United States
Language English
Format Pages: 915-930
System Entry Date 2001 May 13
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edit: this link shows a laser induced spin-exchange polarization....the original MIT target was microwave dynamicaally polarized and to a lesser degree...(personal tour of the Bates Linear Accelerator's detector facility for the winter class of 91-92 by Wade Sapp, then director of the Bates Accelerator). pete

[Jerry]

These gravitational assists have been well outside any 'focused' cosmic ray corridors.

When I hypothesized that gravitational assists should net different yields than expected using Newtonian mechanics, I did not include gravitational assists from the Earth - only other planets.

If the mechanism IS the same for the earth, it means the Newtonian prediction of the mass of the Earth is wrong, too. It also means there should be measurable degeneracies in gravitational maps of the earth taken from satellites in elliptical orbits - including the moon. While these degeneracies DO EXIST in the gravitational maps of Mars, I am not aware of any papers that indicate similar degeneracies exist in satellite maps of the earth. They may occur, but may also be masked by tidal effects.

The ATM concept I have developed works better if the mass of the earth is greater than Newtonian physics predicts; but it also means that the love numbers are off - the core is heavier. This would mean that the density measured in deeply drilled holes slumps of at lower rates than expected...is that true? (I just went looking...and)

http://www.ias.ac.in/currsci/jun10/articles26.htm

The basement depth determination by a previous USGS study in the Pahute Mesa region appears to be inconclusive. The basement thickness was predicted to be 7000 ft, whereas the drill hole UE 20f in the central region up to a depth of 13,686 ft did not encounter the basement rocks.

Isn't this fun?

Edited to add:

http://paranormal.about.com/gi/dynam...5%2Finner1.htm

How much faith can be put in the theories concerning the composition and density of rocks at different depths? The only place where the accuracy of scientific models can be tested directly is in the uppermost few kilometres of the crust. Although oil companies have drilled as deep as 8 km on land, they drill in sedimentary basins. The igneous and metamorphic basement, which averages 40 km thick and makes up most of the continental crust, has rarely been sampled deeper than 2 or 3 km.

The deepest borehole drilled for scientific purposes is located on the Kola Peninsula near Murmansk, Russia, in the northwestern part of the Baltic Shield. The drilling of the main borehole began in 1970, and a final depth of 12,262 metres was reached in 1994. The drilling of this and other deep and superdeep wells has produced one surprise after another, and the findings have been extremely embarrassing for earth scientists [1]. One scientist commented: 'Every time we drill a hole we find the unexpected. That's exciting, but disturbing.' And a science reporter remarked: 'Kola revealed how far from truth scientific theory can roam.'

At the Kola hole, scientists expected to find 4.7 km of metamorphosed sedimentary and volcanic rock, then a granitic layer to a depth of 7 km (the 'Conrad discontinuity'), with a basaltic layer below it. The granite, however, appeared at 6.8 km and extends to more than 12 km; no basaltic layer was ever found!

[trinitree88]

Jerry. I'm hunting. I'll be back. pete

see:http://www.springerlink.com/content/n12251u3v9736m74/

see:http://arxiv.org/abs/astro-ph/0009336

see:http://www.journals.uchicago.edu/doi/abs/10.1086/319467

[Jerry]

Jerry. I'm hunting. I'll be back. pete

Let me help you out:

http://xxx.lanl.gov/PS_cache/arxiv/p...802.2312v1.pdf

Page 24

The problem is that if you look at the count rates, even with these high energy particles, there is not enough energy potential in any direction to deflect a furrball.

[ToSeek]

Earth's rotation may account for wayward spacecraft

A mysterious phenomenon causing small, unexpected deviations in robotic spacecraft trajectories near Earth may be a step closer to an explanation. Scientists have come up with a mathematical formula that successfully reproduces all the known occurrences of the effect, and they suspect the Earth's rotation may somehow be to blame.