[LEAPSECS] Cheating means more planning, not less

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Dec 29 03:01:59 EST 2008


In message <67C8553C-1504-495B-AC99-6E006E0CC01B at noao.edu>, Rob Seaman writes:


>Just one comment. The requirements for "timing applications" (of

>whatever precision) are distinct from the requirements for civil clock

>applications.


You seem to think "civil clock applications" is little old ladies
walking to church once a week.

A modern passengerplane moves approximately 300 meters per second.
Are you willing to to accept a +/- 300 meter tolerance on the radar
track during final approach in Cat3 conditions, if you are on the
plane ?

How much havoc do you think a one second difference makes in a
modern robotic car-production facility ? Have you ever wondered
why the car industry is so interested in IEEE-1588 ?

Having to classify applications into "timing" and "civil" in the
first place is what brought us here.

A lot of people didn't know that their applications were "timing"
so they didn't add code for the leap-second-polka.


>The key issue is the stability of the civil timescale, not its

>precision. However, degrading the precision by 5 orders of magnitude

>in one gulp seems rather...excessive.


Rob, we could take you a whole lot more serious if you didn't spew
bull-shit like this.

The earth is not going to jump 15 degrees of rotation on jan 2nd
2018, so any talk about "degrading precision by 5 orders of magnitude"
is disinginuous and deliberately misleading.

As has been well documented, it will take several hundred years
before the difference approaches an hour.

Second, the ITU proposal decentralizes the time-of-day vs. solar
position tolerance to national issue.

I think is very proper, considering the very different policies
adopted with respect to timezones (EU vs China for instance)
and different durations of sunrise/sunset (Van Mayen vs. Congo for
instance).


> Rather, the nine years spent ankle-biting at the ponderous

> machinations of the ITU could have been better spent actually

> discovering a full set of requirements for civil timekeeping.


So Rob, why didn't you ?

Ankle-biting is the best description for your disinformation
campaign I have seen yet.

Poul-Henning

--
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.


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