[LEAPSECS] Possible outcomes ?

[Rob Seaman]

On Aug 13, 2013, at 7:25 PM, Warner Losh <imp at bsdimp.com> wrote:


> You take Poul too literally. By "astronomer" he means anything that points a telescope, or other such-like device. Astronautical seems to fit that bill... 


Such-like devices as communications satellites, weather satellites, earth resources satellites, military and intelligence spacecraft - and yes, space telescopes and other science missions?  Both astronautical and ground-based platforms (including ground-based on Mars :-) need to navigate.  Such projects have naturally assumed that UTC would remain a type of Universal Time, and hence a close approximation to Greenwich Mean Time.

Navigation includes the operational workflow for the GPS satellites themselves:

	http://www.cacr.caltech.edu/futureofutc/2011/preprints/32_AAS_11-675_Malys.pdf

Not to mention shipping and aviation - the first "A" in NASA is "Aeronautics".  These are multi (x100) billion dollar industries that Poul is not taking literally.



> One could punt to the politicians, and then it becomes a once a century change to the timezones, which is in the noise as far as time zone changes go...


The fatal weaknesses of the kaleidoscopically shifting timezone scheme have been discussed here before, but "once a century" is a particularly naive notion.  Rather than some imagined lock-step shift negotiated with statesmanlike aplomb, different localities would be toggling back-and-forth relative to each other subverting any pretense of keeping track of the changes.  Not to mention that only a tiny fraction of the world's population lives in places whose politicians have any prior experience with DST changes.

And then there's the question of whether the local populations would go along with their politicians in the first place:

	http://articles.latimes.com/2009/mar/31/world/fg-china-timezone31

Noise indeed.



>> It is significant that even you are saying we have 200 years to sort this out.  Simple prudence suggests testing assertions from the several parties *before* making changes.

> 

> While that sounds good in theory, leap seconds were rushed into production originally. We've already debated how to fix leap seconds for much longer than the original debate to establish them...



I have never debated "fixing leap seconds" since I don't believe they are broken.  By all means let's continue debating various ways of improving civil timekeeping.  But improving timekeeping is the furthest thing from the proposal in front of the ITU-R, and its authors have never participated in the debate.

Rob