[LEAPSECS] alternative to smearing

[Preben Nørager]

On Wed, 2017-01-04 at 15:25 +0100, John Sauter wrote:


"Preben, You and I disagree on this issue.  For me this is fundamentally a
moral
concern.  I believe that each generation should handle its problems as
best it can, leaving to the next generation only unforeseen problems.
The tension between the need of civil society and science for a time
scale that simultaneously matches the Earth and atomic time is met by
the Gregorian Calendar and UTC.
The reform that brought the calendar back into synchronization with the
seasons was proposed several times but got no traction until 1582.
That generation bit the bullet and suffered the dislocation of dropping
10 days from the calendar rather than continue to defer the problem.
It took centuries for everyone to get on-board, but today almost
everyone uses the Gregorian calendar.
UTC, as it is defined today with leap seconds, is a similar challenge.
We can fix the buggy software or we can cause a problem for the next
generation.  I feel that it would be immoral to remove an adequate
solution just because we are too lazy to write code correctly."


--


Dear John,

The existing leap-second-system will not last forever. Because of future
deceleration of earth rotation, the need for leap seconds will sometime
become so immense, that future generations will have to have another system
anyway. And as I said international atomic time, with national official
time zones, seems the best way forward. I agree with you that the gregorian
reform was a good thing, but there were actually two different aspects of
that reform. The first was the new rule for leap years. That new rule
brought the calendar back into synchronization with the seasons and hurra
for that. The other aspect was the dropping of ten days. I don't know
exactly why the march equinox shall occur allways around march 21. Would
allways around march 11 not have been just as good? Anyway, meeting the
need for synchronization with the seasons is not the same as meeting the
need for synchronization with solar noon. The gregorian calendar can meet
the need of the one, and atomic time with time-zones can meet the need of
the other. I think honestly your moral concern is not future generations,
but something else.

Preben

2017-01-04 16:22 GMT+01:00 Steve Summit <scs+ls at eskimo.com>:

> John Sauter wrote:
> > On Tue, 2017-01-03 at 13:28 -0500, Michael Rothwell wrote:
> > > Why are you in such favor of leap seconds?
> >
> > I regard leap seconds as a reasonable compromise between the needs of
> > civil time and of science.  Civil time needs a clock that tracks the
> > days and the seasons.  Science requires a clock that measures time in
> > precise intervals.  UTC provides both, using leap seconds to keep
> > atomic time synchronized with the rotation of the Earth.
>
> 100% agree with John.  For thousands of years we've been doing a
> better and better job of more perfectly aligning our chronometry
> with the natural world.  If we abandon leap seconds, we're taking
> a step (however small) backwards.
>
> Another reason: I'm a C programmer.  The C standard says that
> tm_sec has the range [0, 60].  But Posix won't let me see that 60.
> I want to fix that.
>
> Another reason: I'm a programmer at all.  One way of looking
> at the present situation is that it's the physicists and the
> astronomers who have done a better and better job of aligning our
> chronometry with the natural world, but if we take this step
> backwards, it's because it's too hard for the *programmers* to
> properly implement the solution.  So there's definitely some
> professional pride at stake here.
>
> In fact -- for me, not talking about anyone else -- probably
> the real reason I'm still tilting at this windmill is almost
> perfectly summed up in that classic old screed about engineers:
>
>         Ego
>
>         The fastest way to get an engineer to solve a problem is
>         to declare that the problem is unsolvable.  No engineer
>         can walk away from an unsolvable problem until it's solved.
>         No illness or distraction is sufficient to get the
>         engineer off the case.  These types of challenges quickly
>         become personal -- a battle between the engineer and the
>         laws of nature.
>
> But don't get me wrong; I do understand (the more so having
> grappled with them up close and personal) that the obstacles to
> "proper" handling of leap seconds are formidable.  I mentioned
> being a programmer, but the other kind I am is a Unix programmer,
> and it was Unix that gave rise to Richard Gabriel's essay about
> the "New Jersey approach", which holds that simplicity of
> implementation is sometimes even more important than strict
> correctness.  And it only recently occurred to me that there's
> no better example of this tradeoff than deciding that
> monotonic-seconds-since-1970 is "good enough", is practically
> better even though it's also "worse" in not having any good way
> of encoding leap seconds.
>
> Steve Summit
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