Gravity probe?

What happened to Gravity Probe B, the Stanford
experiment to test GR? They sent their detector
into orbit 3 years ago, but since then, no word.
Anybody here connected to that?

Could be prime grist for the conspiracy intellectuals -


--
Rich

On 2014-05-02, wrote:
What happened to Gravity Probe B, the Stanford
experiment to test GR? They sent their detector
into orbit 3 years ago, but since then, no word.
Anybody here connected to that?

Could be prime grist for the conspiracy intellectuals -

The final results were released in May 2011. The results were
published in Physical Review Letters.

A copy can be found at http://arxiv.org/abs/1105.3456

Interesting paper, but a little dry and inconclusive.
"Analysis of the data from all four gyroscopes results in a geodetic
drift rate of -6,601.8+/- 18.3 mas/yr and a frame-dragging drift rate
of -37.2 +/- 7.2 mas/yr, to be compared with the GR predictions of
-6,606.1 mas/yr and -39.2 mas/yr, respectively (`mas' is
milliarc-second; 1mas = 4.848 x 10-9 rad). "

So ... why the 4.3 mas/year discrepancy in geodetic frame drift rate
and 2.0 mas/year discrepancy in frame-dragging drift rate? Systematic
errors? Error bars? Flaws in GR?


Did you even read the paper, or just skim the abstract?

A mere
confirmation of GR to within the limits of confidence in the data
constrained by the engineering of the machine? In short, GP-B was a
failure?

Confirming a prediction of GR now counts as failure?

On Sat, 03 May 2014 00:03:53 +0100, John wrote:

On Fri, 2 May 2014 20:09:52 +0000 (UTC), Greg Hennessy
wrote:

On 2014-05-02, wrote:
What happened to Gravity Probe B, the Stanford
experiment to test GR? They sent their detector
into orbit 3 years ago, but since then, no word.
Anybody here connected to that?

Could be prime grist for the conspiracy intellectuals -

The final results were released in May 2011. The results were
published in Physical Review Letters.

A copy can be found at http://arxiv.org/abs/1105.3456

Cool, thank you for this. I managed to miss the results and I forgot
to look for them.
Interesting paper, but a little dry and inconclusive.
"Analysis of the data from all four gyroscopes results in a geodetic
drift rate of -6,601.8+/- 18.3 mas/yr and a frame-dragging drift rate
of -37.2 +/- 7.2 mas/yr, to be compared with the GR predictions of
-6,606.1 mas/yr and -39.2 mas/yr, respectively (`mas' is
milliarc-second; 1mas = 4.848 x 10-9 rad). "

So ... why the 4.3 mas/year discrepancy in geodetic frame drift rate
and 2.0 mas/year discrepancy in frame-dragging drift rate? Systematic
errors? Error bars? Flaws in GR?

The passage you quote shows the discrepancy is within the error bars.

On 02.05.14 22:09, Greg Hennessy wrote:
On 2014-05-02, wrote:
What happened to Gravity Probe B, the Stanford
experiment to test GR? They sent their detector
into orbit 3 years ago, but since then, no word.
Anybody here connected to that?

Could be prime grist for the conspiracy intellectuals -

The final results were released in May 2011. The results were
published in Physical Review Letters.

A copy can be found at http://arxiv.org/abs/1105.3456



Thanks! A nice set of results.

Did you even read the paper, or just skim the abstract?

Both, why?

Because several of your questions were answered in the paper.

Confirming a prediction of GR now counts as failure?

Yes, insofar as it advances the scientific base very little, gains us
no new physics, doesn't allow us a new technology like the WWWeb and
costs us a satellite and some man-years of highly educated scientists
and trying-to-get-educated PHD students.


Oh, the horror, those poor Ph. D. students who had to work on a FAILED
mission, one that gave the best verification of GR to date! They'll
never get jobs now with that stain on their resume.

On Friday, May 2, 2014 10:12:55 AM UTC-7, wrote:
What happened to Gravity Probe B, the Stanford

experiment to test GR? They sent their detector

into orbit 3 years ago, but since then, no word.

Anybody here connected to that?


Could be prime grist for the conspiracy intellectuals -

--

Rich

They ran out of public loot, and once again managed to not advance nor improve anything.

On Fri, 2 May 2014 20:09:52 +0000 (UTC), Greg Hennessy
wrote:

On 2014-05-02, wrote:
What happened to Gravity Probe B, the Stanford
experiment to test GR? They sent their detector
into orbit 3 years ago, but since then, no word.
Anybody here connected to that?

Could be prime grist for the conspiracy intellectuals -

The final results were released in May 2011. The results were
published in Physical Review Letters.

A copy can be found at http://arxiv.org/abs/1105.3456

Gravity probe B Is a disgraceful example of bad science passed off as
the real thing. The 4 gyroscopes were nothing but perfectly round
quartz spheres, which possess zero gyroscopic properties. Check your
Goldstein. This fundamental fact seems to have escaped the sponsors of
this experiment, also the 70 Phd's who earned their stripes trying to
straighten out the errors.
The balls did not have one point of support but floated in space. Any
sidewise pressure on the spin vector would simply add to the spin
vector without any resistance normally supplied by precession.
The gyroscopic property depends on the difference between moments of
inertia on the 3 axes. In this case they are all equal.
When supported by one point, such as a top, it will precess and resist
toppling, because I did my own testing. But when supported by 1 point
there is another set of equations that appliesbut of course not here.
John Polasek

On Monday, May 5, 2014 8:15:47 PM UTC-7, wrote:
On Fri, 2 May 2014 20:09:52 +0000 (UTC), Greg Hennessy

wrote:



On 2014-05-02, wrote:

What happened to Gravity Probe B, the Stanford

experiment to test GR? They sent their detector

into orbit 3 years ago, but since then, no word.

Anybody here connected to that?



Could be prime grist for the conspiracy intellectuals -



The final results were released in May 2011. The results were

published in Physical Review Letters.



A copy can be found at http://arxiv.org/abs/1105.3456



Gravity probe B Is a disgraceful example of bad science passed off as

the real thing. The 4 gyroscopes were nothing but perfectly round

quartz spheres, which possess zero gyroscopic properties. Check your

Goldstein. This fundamental fact seems to have escaped the sponsors of

this experiment, also the 70 Phd's who earned their stripes trying to

straighten out the errors.

The balls did not have one point of support but floated in space. Any

sidewise pressure on the spin vector would simply add to the spin

vector without any resistance normally supplied by precession.

The gyroscopic property depends on the difference between moments of

inertia on the 3 axes. In this case they are all equal.

When supported by one point, such as a top, it will precess and resist

toppling, because I did my own testing. But when supported by 1 point

there is another set of equations that appliesbut of course not here.

John Polasek

Computer science data extrapolated from that mission was revised in order to obtain anything meaningful, so there's no telling what was actually measured because Earth isn't round nor without mascon issues, not to mention what modulation our moon contributes. In other words, far too many variables taking place.

On Tue, 6 May 2014 08:45:44 -0700 (PDT), Brad Guth
wrote:

On Monday, May 5, 2014 8:15:47 PM UTC-7, wrote:
On Fri, 2 May 2014 20:09:52 +0000 (UTC), Greg Hennessy

wrote:



On 2014-05-02, wrote:

What happened to Gravity Probe B, the Stanford

experiment to test GR? They sent their detector

into orbit 3 years ago, but since then, no word.

Anybody here connected to that?



Could be prime grist for the conspiracy intellectuals -



The final results were released in May 2011. The results were

published in Physical Review Letters.



A copy can be found at http://arxiv.org/abs/1105.3456



Gravity probe B Is a disgraceful example of bad science passed off as

the real thing. The 4 gyroscopes were nothing but perfectly round

quartz spheres, which possess zero gyroscopic properties. Check your

Goldstein. This fundamental fact seems to have escaped the sponsors of

this experiment, also the 70 Phd's who earned their stripes trying to

straighten out the errors.

The balls did not have one point of support but floated in space. Any

sidewise pressure on the spin vector would simply add to the spin

vector without any resistance normally supplied by precession.

The gyroscopic property depends on the difference between moments of

inertia on the 3 axes. In this case they are all equal.

When supported by one point, such as a top, it will precess and resist

toppling, because I did my own testing. But when supported by 1 point

there is another set of equations that appliesbut of course not here.

John Polasek

Computer science data extrapolated from that mission was revised in order to obtain anything meaningful, so there's no telling what was actually measured because Earth isn't round nor without mascon issues, not to mention what modulation our moon contributes. In other words, far too many variables taking place.
You need to come to grips with this statement: a uniform sphere has no
gyroscopic properties. It is fatal.
There's also the problem that in setting up this experiment, it would
not have been possible to simulate it because it needs a gravity free
environment to float the Gyro Ball.
As I recall, the principal investigator enlightened us initiates by
boasting about the "extra inch". I take this to mean that instead of
going 25,000 miles around in orbit, the Einstein drag provided an
extra tilt that added 1.0" to what would otherwise have been
1,584,000,000 inches. Such precision is impossible, especially read at
the radius of 1 inch of the ball.
It looks to me like the experiment is fundamentally impossible.
John Polasek