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

In summary, NASA announced final results of GP-B today, with a bit of fanfare. Apparently 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.
  • #1
marcus
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  • #2
It certainly reads that way to me!
 
  • #3
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.
 
  • #4
Misericorde said:
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?
 
  • #5
Daverz said:
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.
 
  • #6
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.
 
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  • #7
TrickyDicky said:
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.
 
  • #8
Daverz said:
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%.
 

1. What is the purpose of the Gravity Probe B press conference on May 4th?

The Gravity Probe B press conference on May 4th is being held to announce any new findings or surprises from the mission. It is also an opportunity for scientists to share their insights and analysis of the data collected from the Gravity Probe B spacecraft.

2. Were there any unexpected results from the Gravity Probe B mission?

Yes, there were several unexpected results from the Gravity Probe B mission. One of the most surprising findings was the confirmation of the geodetic effect, which is the warping of spacetime caused by the mass of the Earth. This confirmed a key prediction of Einstein's theory of general relativity.

3. Did the Gravity Probe B mission provide any new insights into the nature of gravity?

Yes, the Gravity Probe B mission provided new insights into the nature of gravity. The spacecraft's measurements of the geodetic effect and frame-dragging effect helped to further validate Einstein's theory of general relativity and provided a more precise understanding of how gravity works.

4. How long did the Gravity Probe B mission last and what were its main objectives?

The Gravity Probe B mission lasted for 16 years, from 2004 to 2020. Its main objectives were to test Einstein's theory of general relativity, specifically the geodetic and frame-dragging effects, and to measure the shape of the Earth's gravitational field.

5. What impact do the results from the Gravity Probe B mission have on our understanding of the universe?

The results from the Gravity Probe B mission have had a significant impact on our understanding of the universe. By confirming Einstein's theory of general relativity, the mission has provided further evidence for the validity of this fundamental theory and has helped to refine our understanding of gravity and the nature of spacetime.

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