[time-nuts] Why 9,192,631,770 ??

Poul-Henning Kamp phk at phk.freebsd.dk
Wed May 9 05:43:51 UTC 2012


In message <F621A5241A5E4ACF82E70AA8CC48B714 at self6a5awnhg2m>, "Eric Lemmon" wri
tes:

>No, leap seconds have to do with the gradual slowing of the Earth's
>rotation, and nothing to do with Cesium.

Not quite true.

When they decided the 9,192,631,770 they did so with astronomical
observations which were half a century old.  If they had used a
more up to date astronomical result, we would have had a lower
rate of leap seconds, essentially getting rid of the "one leap
second every 18 months" average value.

In the long term it doesn't make a difference of course, there
earths slowing down will dominate.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.



More information about the time-nuts mailing list