> -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Mark Sims > Sent: Wednesday, August 19, 2009 8:56 AM > To: time-nuts@febo.com > Subject: [time-nuts] Accurate 1 pps signals > > Know where the heck you are down to a gnats ass and get that location > into the unit with full accuracy. Errors in the saved antenna > position from its true position have a definite effect on the quality > of the output. Ideally have the antenna location surveyed in WGS84 > coordinates. >
OK.. just what is a gnat's ass in actual SI units? It's small.. Is it a standardized unit drawn from physiology (like the yard or foot, relative to King John's physical dimensions, or the cubit) Is it a traditional term for some other standard unit (e.g. a "barn" being 1E-24 cm^2 or a shake being 1E-8, both being from early nuclear weapons development, and essentially a rounded value for some useful size: cross-section for a nuclear reaction, and generation time for fission, respectively) (I understand from some casual googling that the gnat's ass is used by machinists to refer to a tenthousandth of an inch/tenth of a mil, although none of the machininsts I know use the term. They talk in tenths when being quantitative, and have somewhat earthier terms when talking qualitative) What I did find with google was interesting.. I didn't know that gnat's ass as a term for very small dated at least back to Aristophanes, although the lines 160-164 in Clouds are still qualitative, not quantitative (narrow, thin/subtle: stenos, leptos) Next up, we need to decide which species of gnat is being referred to.. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
