Gravity probe B?

[argosy]

Are there any news about this mision? Results? Conslusions?<br />Haven't heard anything about it for a long time, strange for such a important experiment...

 

[yevaud]

I believe they will begin to release the conclusions later this year. However, from what I have alread heard, they did indeed confirm Frame-Dragging and all of the tiny Relativistic effects exactly as predicted.<br /><br />One hell of a milestone. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[yevaud]

Thank you. I'd been going direct to the Gravity-B website, and the best it says (as of the last time I went there, a few months ago) is "we're working on it." <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[qso1]

Interesting results so far. I'm always hoping some hole in relativity will allow FTL travel but the experimental results pretty much always verify what Einstein predicted. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[serak_the_preparer]

Progress report:<br /><br />Gravity Probe B by Phil Schewe and Ben Stein (Physics News Update)<br /><br />April 18, 2007<br /><br /><i>Gravity Probe B the orbiting observatory devoted to testing the general theory of relativity, has measured the geodetic effect-the warping of spacetime in the vicinity of and caused by Earth-with a precision of 1%. The basic approach to studying this subtle effect is to monitor the precession of gyroscopes onboard the craft in a polar orbit around the Earth. The observed precession rate, 6.6 arc-seconds per year, is close to that predicted by general relativity. <br /><br />The geodetic effect can be measured in several ways, including the use of clocks, the deflection of light, and the perturbative influence of massive bodies on nearby gyroscopes. GP-B is of the latter type, and its current precision is as good as or better than previous measurements. And once certain unanticipated torques on the gyroscopes are better understood, GP-B scientists expect the precision of their geodetic measurement to improve to a level of 0.01%. These first GP-B results were reported at the APS meeting by Francis Everitt (Stanford)....</i><br /><br />Also, see Scientists Provide First Public Peek At Gravity Probe B Results by Bob Kahn at <i>Space Daily</i>. Anticipated final result this December.

 

[serak_the_preparer]

<i>I'm always hoping some hole in relativity will allow FTL travel but the experimental results pretty much always verify what Einstein predicted.</i><br /><br />A thoughtful review by Megan Donahue, posted yesterday to <i>New Scientist</i>'s space blog:<br /><br />Will Gravity Probe B fulfill its promise?<br /><br />Regarding a real test of one of Einstein's predictions - frame-dragging - a portion of the article is excerpted below:<br /><br /><i>. . . As mission leader Francis Everitt says on NPR's All Things Considered, the measurements are now 1000 times less precise than they expected. Careful modelling may regain a factor of 100 by December.<br /><br />If that projection is correct, at least some measurement of frame-dragging might be possible. Reconciling Dr. Everitt's statement on NPR with Stanford's press release (a PDF of which is here), it appears as if the team is optimistic about detecting frame-dragging, but perhaps not measuring it accurately enough to truly challenge the theory of general relativity....</i><br /><br />Problems interfering with the precision of the gyroscope data threaten the core of the mission. We may have to wait another 40 years for greater insight into FTL travel... : (