Sorry, my reply was sent before your comment about speed up. Yes, in theory, if the earth were to speed up sufficiently we would need to subtract leap seconds. The old spinning top is unfortunately slowing down (with minor wobbles and variations such as the recent earthquake in Japan). "Minor" in terms of the effect on the earth, but of course not minor to those affected.
Rob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steve Rooke Sent: 14 July 2011 3:27 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Japan Quake May Have Shortened Earth Days, Moved Axis On 15 July 2011 02:08, Rob Kimberley <[email protected]> wrote: > However, atomic time and "earth time" effectively drift apart, and > that is why periodically we have leap seconds to bring the two closer > together again. So we still need the astronomical measurements. > > Think of it as atomic time being the "linear" reference, and earth > time a course saw tooth, which periodically comes into sync with the > addition (or > subtraction) of leap seconds. Thanks, I was aware of this but my comment was that instead of the usual need to add leap seconds, we perhaps may have a need to subtract in the future should the world speed up significantly compared to it's decaying rotation. The thought here is that event would be an interesting test for the GPS disciplined clocks around the world. Steve > Rob K > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > On Behalf Of J. Forster > Sent: 14 July 2011 2:41 PM > To: [email protected]; Discussion of precise time and frequency > measurement > Subject: Re: [time-nuts] Japan Quake May Have Shortened Earth Days, > Moved Axis > > So? > > That statement clearly imlies the Earth's period was shortened aganst > some standard. > > If the Earth was the standard, how could it be shortened with respect > to itself? > > It can't be. Time standards are atomic now. > > -John > > =================== > > >> "Calculations indicate that by changing the distribution of Earth's >> mass, the Japanese earthquake should have caused Earth to rotate a >> bit faster, shortening the length of the day by about 1.8 microseconds". >> >> http://www.nasa.gov/topics/earth/features/japanquake/earth20110314.ht >> m >> l >> >> Will >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
