The incredible precision with which the two spheres mentioned in the article have been manufactured sure is mind-boggling. But I think the article itself is a g

The incredible precision with which the two spheres mentioned in the article have been manufactured sure is mind-boggling. But I think the article itself is a good example for what I find pretty annoying in popular presentation of quantitative results in science. - "off by anything larger than one one-hundred-billionth of a degree" - [normal gyroscopes] "are over ten-million times less accurate" ...and to a lesser extent, because people in mechanical engineering or metal-working are actually used to measure in micrometers: - "three ten-millionths of an inch away" - "only 25 nanometers away from being perfectly round" The precision is presented as a very impressive sounding, but to the typical reader pretty meaningless number, because in our normal lives we don't have any reference for hundred-billionths of anything, and frankly many people have difficulties writing up 100-billionths correctly, anyway. I'd really like to see the general notion of "order of magnitude" be used for these kinds of achievements, which can be presented as a "number of digits" figure easily: - To measure the relativistic frame-dragging, Gravity Probe B had to measure the degrees of rotation of its gyroscopes with a precision of 11 digits after the decimal point whereas (military gyroscopes) only are accurate up to 7 digits. - three ten-millionth of a inch -> Diameter (in inch, let's assume it's 3 inches) specified with 8 digits of accuracy, similarly for the "25 nanometers away from being round)