>Thanks - What is the gravity probe's job.
This was covered in a thread a few months ago.
The Special Theory of Relativity (from 1905) and the General Theory of Relativity (from 1915), and calculations based on those, make some very specific predictions, most of which have been confirmed by experiment.
Gravity Probe B is a 700-million-dollar project, to confirm or refute one of these predictions, that was not yet confirmed by experiment. Specifically, the rotation of objects with mass is supposed to cause additional distortions (i.e., in addition to the non-rotating mass) in the space-time fabric. The Gravity Probe B sattelite is supposed to detect this. For this purpose, it has four gyroscopes, which are the most perfect spheres made yet - the discrepancy from a perfect sphere is no more than 10 atoms of diameter. The purpose in this case is to eliminate other effects which it would otherwise have.
The Web-site, at the end of the weekly updates, gives some more details.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
