Gravity Probe B press conf. 4 May (any surprises? comment?)

[marcus]

Apparently NASA announced final results of GP-B today, with a bit of fanfare:
http://science.nasa.gov/science-news/science-at-nasa/2011/04may_epic/

Has anyone seen a final report? All I saw that's new is the press release.

Here is a nice pedagogical background piece from 2008
http://einstein.stanford.edu/SPACETIME/spacetime4.html

My impression from today's announcement is that GR was precisely confirmed. Maybe someone knows more.

 

[Matterwave]

It certainly reads that way to me!

 

[Misericorde]

What I've read since just confirms your supposition: after a lot of hard work this is another confirmation of GR to within .2% . From eclipses to to the smoothest spheres we've ever made, GR just keeps on keeping on.

 

[Daverz]

What I've read since just confirms your supposition: after a lot of hard work this is another confirmation of GR to within .2% . From eclipses to to the smoothest spheres we've ever made, GR just keeps on keeping on.

The press release gives 0.039 plus or minus 0.007 arcseconds for the "residual" precession. This is more like 20% than .2%. Am I missing something?

 

[Misericorde]

The press release gives 0.039 plus or minus 0.007 arcseconds for the "residual" precession. This is more like 20% than .2%. Am I missing something?

The Geodetic Effect was measured to within .2%, and frame dragging to 19%, so, I was imprecise.

 

[TrickyDicky]

So then I guess GR was precisely confirmed for the geodetic precession and imprecisely confirmed for frame dragging: a plus or minus 20% imprecision- almost half the total value after more than five years of fine tuning the data is basically useless as far as precise confirmations of GR go.
But the real issue (wrt frame dragging) is to analyze exactly how the raw data has been handled to reach that result. When NASA cut funds in 2008 it also warned that after all the manipulation the data had been subjected to, skepticism wrt the frame dragging result was justified, so I guess it is important to see their final analysis and their methods.

 

[Daverz]

So then I guess GR was precisely confirmed for the geodetic precession and imprecisely confirmed for frame dragging: a plus or minus 20% imprecision- almost half the total value

Calling .007 "almost half" of 0.039 is quite creative.

 

[TrickyDicky]

Calling .007 "almost half" of 0.039 is quite creative.

I meant the total margin of error is plus/minus 0.007, so when added it approaches 40%.