View Full Version : Gravity Probe B Wraps Up Observations

2005-Oct-12, 02:20 PM
SUMMARY: After 17 months of productive data collection, NASA's Gravity Probe B satellite has gathered all the data it needs to pronounce Einstein right or wrong. The probe was launched in April 2004, with four spherical gyroscopes designed to test two of Einstein's predictions about General Relativity: how the Earth's gravity warps space, and how its rotation drags space around with it. Scientists will now spend about a year analyzing the data before presenting their conclusions.

View full article (http://www.universetoday.com/am/publish/gravity_probe_b_finished.html)
What do you think about this story? post your comments below.

2005-Oct-12, 02:34 PM
"After 17 months of productive data collection, NASA's Gravity Probe B satellite has gathered all the data it needs to pronounce Einstein right or wrong."

I think this statement pretty weird. I mean, who in hell think Einstein is wrong ? Those who not believe in Einstein will continue, no matter what proves came up. Certainly this is not the main objectivy of the mission but to give a better understanding of his theories. That would be of use to cience.

2005-Oct-12, 06:24 PM
No, Einstein could be wrong. There are a few of us who think he is likely wrong.

The formulation of General Relativity was an exercise in curve fitting and rejecting based upon observations, not the unqualified string of brilliant predictions contained in most historical accounts. Einstein revised his 'predictions' several times between 1905 and 1919, as observational constraints eliminated prior conjectures. (In 1911 Einstein was predicting a GR gravitational function of 1/r.) The final revision by Einstein, the removal of the cosmological constant, occurred much later.

After almost a century of trying, no one has successfully married GR with particle physics, no gravity waves have been detected, and virtually every cosmological boundry constrained by Einstein-deSitter mechanics has been breached.

A year ago, I fully expected the gravity probe B to fully confirm frame dragging. Today, I will be surprised if they can constrain the observed experimental variability enough to state with unambiguous confidence frame-dragging has been observed.

At this point in time, the best that can be said is that GR is a much better predictor than Newtonian mechanics of cosmic phenomenon. There are many loose ends.

2005-Oct-12, 07:54 PM
Einstein is not wrong. General Relativity, usually associated with the term "theory", has proven that it works precisely, and its predictions were proven to be right by the results of various experiments. So, GR cannot be estimated to be something merely "theoretical" any more. GR is a fact, and it describes the behaviour of the macroscopic world quite precisely.

Looking forward for future results,


2005-Oct-12, 08:47 PM
The Gravity Probe B frame-dragging experiment requires incredible precision, so much that some may be skeptical about the validity of any conclusions drawn from it. I don't know. In the late 1990's, some scientists apparently doubted that the human race was really capable of pulling this off at this stage of our development. Many felt that it was worth a try, though. Sort of like the princess and the pea (or maybe it was a grain of sand).

How will the magnitude of the result compare with the potential margin of error?