Jonathan E. Hardis said:
> Time zones with the width of an hour are generally
> acceptable, which indicates that the public might accept DUT1 as large
> as 1800, or so.
The reason I haven't been involved in this thread up to now is that I spent
the last week in a place where apparent solar tim
On Nov 2, 2010, at 7:06 AM, Clive D.W. Feather wrote:
> The reason I haven't been involved in this thread up to now is that I spent
> the last week in a place where apparent solar time and official clock time
> were about 7800 seconds apart. It was quite curious being near the tropics
> and yet
A long flight was time to really read Ken Seidelmann's book and part of
Woolard and Clemence, Spherical Astronomy. Subsequent exchanges with
Ken give me a new understanding. (Probably an old understanding for the
rest of you.)
When we solve equations approximating physical processes, we are real
On Tue 2010-11-02T13:30:42 -0400, Finkleman, Dave hath writ:
> We must correlate time as perceived in our analyses
> with the temporal relationships among objects in the universe.
For the sake of operational systems I would phrase this as the
requirement that all precision intercomparisons of time
In message <3b33e89c51d2de44be2f0c757c656c88099aa...@mail02.stk.com>, "Finklema
n, Dave" writes:
>It is a hierarchy each level of which is sufficient for a range of
>applications. Every time we solve dynamical equations, we are defining
>a unique time scale and time interval based on things such
My colleague, Sal Alfano, included in distribution observes with
relevance that the state of Indiana in the U.S., legislated that Pi=3
for convenience. Eliminating leap seconds for convenience is similar.
In the former case, it meant that no circle would ever close, lacking
(pi/3-1) fraction of th
Finkleman, Dave said:
> My colleague, Sal Alfano, included in distribution observes with
> relevance that the state of Indiana in the U.S., legislated that Pi=3
No, they didn't.
--
Clive D.W. Feather | If you lie to the compiler,
Email: cl...@davros.org | it will get its revenge.
We
On Tue 2010-11-02T18:27:13 +, Clive D.W. Feather hath writ:
> Finkleman, Dave said:
> > My colleague, Sal Alfano, included in distribution observes with
> > relevance that the state of Indiana in the U.S., legislated that Pi=3
>
> No, they didn't.
but they have messed with civil time more than
In message <3b33e89c51d2de44be2f0c757c656c88099aa...@mail02.stk.com>, "Finklema
n, Dave" writes:
>My colleague, Sal Alfano, included in distribution observes with
>relevance that the state of Indiana in the U.S., legislated that Pi=3
>for convenience. Eliminating leap seconds for convenience is s
On Tue 2010-11-02T18:37:11 +, Poul-Henning Kamp hath writ:
> I am pretty sure that if you told a random sample of people that
> "some scientists belive that some days should be one second long
> or shorter than usual", they would compare that to the Pi=3 idea,
> not the other way around.
The t
On Tue, 2 Nov 2010, Poul-Henning Kamp wrote:
>
> Finagle Subject to
> FactorUnit/Resolution politics since
>
> Leap days 86400 sec. 2000 bc.
> Timezones 36
On Nov 2, 2010, at 11:27 AM, Clive D.W. Feather wrote:
> Finkleman, Dave said:
>
>> the state of Indiana in the U.S., legislated that Pi=3
>
> No, they didn't.
Indiana may not have "legislated" this, but it was proposed - scroll to the
bottom of:
http://www.snopes.com/religion/pi.asp
In message , Tony Fi
nch writes:
>On Tue, 2 Nov 2010, Poul-Henning Kamp wrote:
>>
>> Finagle Subject to
>> Factor Unit/Resolution politics since
>>
>> Leap days86400 sec.
On Nov 2, 2010, at 11:34 AM, Steve Allen wrote:
> but they have messed with civil time more than most places
>
> http://en.wikipedia.org/wiki/Time_in_Indiana
>
> and Palm Springs decided to enact Daylight Time in the winter
> due to the shadow Mt. San Jacinto looming to its west.
> http://books.
In message <20101102184333.gy21...@ucolick.org>, Steve Allen writes:
>On Tue 2010-11-02T18:37:11 +, Poul-Henning Kamp hath writ:
>The existing international agreement for the meaning
>of "day" is "mean solar day".
You mean "one of the existing..." ?
The astronomical meaning of the word day
On Tue, 2 Nov 2010, Poul-Henning Kamp wrote:
>
> I may be misremembering, I thought the longitude conference was in 1884 ?
Yes, but by that time there had already been 40 years of railway time in
the UK. We officially switched to a single time zone in 1880, but local
mean solar time had already be
In message , Tony Fi
nch writes:
>On Tue, 2 Nov 2010, Poul-Henning Kamp wrote:
>>
>> I may be misremembering, I thought the longitude conference was in 1884 ?
>
>Yes, but by that time there had already been 40 years of railway time in
>the UK. We officially switched to a single time zone in 1880, b
Poul-Henning Kamp wrote:
> I'm not sure I see that any one country fixes their national time as
> relevant, as the fact that the international community, such as it were,
> argreed to do so.
Except that your suggestion is that we can ignore the whole thing because the
wisdom of local governanc
On Tue 2010-11-02T18:55:17 +, Poul-Henning Kamp hath writ:
> >The existing international agreement for the meaning
> >of "day" is "mean solar day".
>
> You mean "one of the existing..." ?
>
> The astronomical meaning of the word day may indeed be what you say,
> but the equally internationally
In message <211ee304-6f59-40a1-837f-3f8359f68...@noao.edu>, Rob Seaman writes:
>Poul-Henning Kamp wrote:
>Except that your suggestion is that we can ignore the whole thing
>because the wisdom of local governance will sort it all out with
>kaleidoscopically shifting timezone policies.
Which was ex
On 11/02/2010 12:26, Finkleman, Dave wrote:
My colleague, Sal Alfano, included in distribution observes with
relevance that the state of Indiana in the U.S., legislated that Pi=3
for convenience. Eliminating leap seconds for convenience is similar.
In the former case, it meant that no circle wo
In message <20101102194805.gb21...@ucolick.org>, Steve Allen writes:
>On Tue 2010-11-02T18:55:17 +, Poul-Henning Kamp hath writ:
>The POSIX standard admits that its "seconds" are not all of the same
>length, and for practical purposes that makes them "mean solar
>seconds", not "SI seconds" nor
On Tue 2010-11-02T20:22:29 +, Poul-Henning Kamp hath writ:
> It admits no such thing, and for all I know, and despite your
> complaints about the lack of an "essen" unit, that there is more
> than one definition of a second in use at present ?
Section A.4.15
http://www.opengroup.org/onlinepubs
On 11/02/2010 12:44, Tony Finch wrote:
Leap days are also an instructive example, since it took about 300 years
for Europe to deploy a revision to the previous standard which had been in
place for about 1600 years...
One not completely adopted either: to compute many religious holidays,
many ea
In message <20101102202753.gc21...@ucolick.org>, Steve Allen writes:
>On Tue 2010-11-02T20:22:29 +, Poul-Henning Kamp hath writ:
>> It admits no such thing, and for all I know, and despite your
>> complaints about the lack of an "essen" unit, that there is more
>> than one definition of a secon
On 11/02/2010 13:48, Steve Allen wrote:
On Tue 2010-11-02T18:55:17 +, Poul-Henning Kamp hath writ:
The existing international agreement for the meaning
of "day" is "mean solar day".
You mean "one of the existing..." ?
The astronomical meaning of the word day may indeed be what you say,
bu
On 11/02/2010 14:27, Steve Allen wrote:
On Tue 2010-11-02T20:22:29 +, Poul-Henning Kamp hath writ:
It admits no such thing, and for all I know, and despite your
complaints about the lack of an "essen" unit, that there is more
than one definition of a second in use at present ?
Section A.4.
Warner Losh wrote:
> There's nothing magical about leap seconds. They are not an inherent
> property of time. They are a means to the end of relating the number of SI
> seconds that have elapsed to the angular orientation of the earth.
Indeed. Here are some other non-magical facts:
1) Ther
On 2010-11-02 18:55, Poul-Henning Kamp wrote, first quoting
Steve Allen:
> The existing international agreement for the meaning
> of "day" is "mean solar day".
You mean "one of the existing..." ?
The astronomical meaning of the word day may indeed be what you say,
but the equally
On 11/02/2010 14:38, Poul-Henning Kamp wrote:
In message<20101102202753.gc21...@ucolick.org>, Steve Allen writes:
On Tue 2010-11-02T20:22:29 +, Poul-Henning Kamp hath writ:
It admits no such thing, and for all I know, and despite your
complaints about the lack of an "essen" unit, that ther
> 5) Every time we have one of these entertaining discussions, the one obvious
> fact is that nobody associated with pushing the issue through the ITU-R is
> choosing to participate in our forum.
Is anybody surprised?
The ITU is an official body, sanctioned by the UN and indirectly by most
nat
In message , Rob Seaman writes:
>1) There is no pressing need to act now rather than 20 or 50 or
> 500 years from now.
There very much is: With each passing day, the probability that the next
leap second will kill somebody because of sloppy engineering increases
by a possibly non-trivial amount.
In message <4cd07cd9.7080...@yahoo.com>, Michael Deckers writes:
>Isn't a day always exactly 86400 s, in whatever time scale you
>are considering?
No, because the second is defined using quantum mechanical properties
of Cs133, not as being 1/86400 of whatever day you look at.
--
Poul-H
In message <4cd07cb5.5090...@bsdimp.com>, Warner Losh writes:
>A standards compliant system could also be off by 12us. The
>application programmer has no way of knowing that error and shouldn't
>rely on it being smaller than any specific amount.
Well, POSIX doesn't tell you a bound, any contem
Poul-Henning Kamp wrote:
> In message , Rob Seaman writes:
>
>> 1) There is no pressing need to act now rather than 20 or 50 or
>> 500 years from now.
>
> There very much is: With each passing day, the probability that the next
> leap second will kill somebody because of sloppy engineering incre
On Nov 2, 2010, at 11:05 AM, Rob Seaman wrote:
On Nov 2, 2010, at 7:06 AM, Clive D.W. Feather wrote:
The reason I haven't been involved in this thread up to now is that
I spent the last week in a place where apparent solar time and
official clock time were about 7800 seconds apart. It was
leapsecs-boun...@leapsecond.com wrote on 11/02/2010 04:27:53 PM:
> From:
>
> Steve Allen
>
> To:
>
> Leap Second Discussion List
>
> Date:
>
> 11/02/2010 04:28 PM
>
> Subject:
>
> Re: [LEAPSECS] An example
>
> Sent by:
>
> leapsecs-boun...@leapsecond.com
>
> On Tue 2010-11-02T20:22:29
Op 02-11-10 23:56, Poul-Henning Kamp schreef:
> There very much is: With each passing day, the probability that the next
> leap second will kill somebody because of sloppy engineering increases
> by a possibly non-trivial amount.
Then why aren't you demanding proper engineering instead? Giving in
In message <96ccc117-8e0b-4cd1-917d-96fd995c7...@noao.edu>, Rob Seaman writes:
>Proponents of this change don't appear to believe risks exist. If
>not, shouldn't it be straightforward to demonstrate this?
Such belief would probably be harder to muster, if just a single
credible case could be doc
In message <536635d43949d1db19f5fa0ce101632e.squir...@mx.pipe.nl>, "Nero Imhard
" writes:
>Op 02-11-10 23:56, Poul-Henning Kamp schreef:
>
>> There very much is: With each passing day, the probability that the next
>> leap second will kill somebody because of sloppy engineering increases
>> by a po
Rob ... you're absolutely right. Eliminating leap seconds WOULD
introduce a secular trend ... IF (and here's the part I haven't convinced
you about yet) no other means for compensating for it is implemented,
FOREVER AND EVER.
The Pisa architects are in a meeting:
"Let us not worry ab
Leap seconds carry no discernible benefit to non-astronomers so
even if they were trivial to code correctly, they would not be
worth it.
What about benefits that we are unable to yet discern?
-paul
___
LEAPSECS mailing list
LEAPSECS@leapsecond.
In message <20101103001404.22295.qm...@protonet.co.za>, p...@2038bug.com writes:
>> Leap seconds carry no discernible benefit to non-astronomers so
>> even if they were trivial to code correctly, they would not be
>> worth it.
>
>What about benefits that we are unable to yet discern?
Like ?
Is
But "somehow" is not what is on the table. The astronomers in this forum have not been
unwilling to consider alternate "somehows". It is the ITU-R which is unwilling to debate
the issues.
Please don't confuse Poul-Henning and myself for ITU-R apologists.
We've presented a wide range of rem
In message <4cd0aeda.1010...@bsdimp.com>, Warner Losh writes:
>I don't have any connection to the ITU-R.
And I'm even more disconnected from ITU-R: My country is not
even likely to vote once it comes in front of the general assembly...
Poul-Henning
--
Poul-Henning Kamp | UNIX since Zilo
On Wed 2010/11/03 00:03:16 -, "Poul-Henning Kamp" wrote
in a message to: Leap Second Discussion List
>Leap seconds carry no discernible benefit to non-astronomers so
>even if they were trivial to code correctly, they would not be
>worth it.
No discernible benefit? And the future be damned!
In message , Mark Calabretta writes:
>
>On Wed 2010/11/03 00:03:16 -, "Poul-Henning Kamp" wrote
>in a message to: Leap Second Discussion List
>
>>Leap seconds carry no discernible benefit to non-astronomers so
>>even if they were trivial to code correctly, they would not be
>>worth it.
>
>No d
On Wed 2010-11-03T12:14:11 +1100, Mark Calabretta hath writ:
> No discernible benefit? And the future be damned!
Compromise?
Difficulties encountered by users of their recommendations?
Guidance regarding means of implementing their recommendations?
Social difficulties with their recommendations?
On Wed 2010-11-03T01:30:15 +, Poul-Henning Kamp hath writ:
> What is the benefit of leap-seconds to non-astronomers ?
http://www.google.com/images?q=dennis+di+cicco+analemma&hl=en&client=safari&rls=en&prmd=iv&source=lnms&tbs=isch:1&ei=qbvQTMXYNoOosQOUmZzVCw&sa=X&oi=mode_link&ct=mode&ved=0CAcQ_
> Like ?
Just because we can't immediately see a reason, does not mean that there is
none. A lot will change in 100 years that even the venerable PHK cannot foresee.
But more importantly: no one should RUSH to scrap leap seconds if we cannot
undo it.
You seem to be in a irrational RUSH to scr
On Wed 2010/11/03 01:30:15 -, "Poul-Henning Kamp" wrote
in a message to: Leap Second Discussion List
>>>Leap seconds carry no discernible benefit to non-astronomers so
>>>even if they were trivial to code correctly, they would not be
>>>worth it.
>>
>>No discernible benefit? And the future
In message <20101103013706.ga9...@ucolick.org>, Steve Allen writes:
>On Wed 2010-11-03T01:30:15 +, Poul-Henning Kamp hath writ:
>> What is the benefit of leap-seconds to non-astronomers ?
>
>http://www.google.com/images?q=dennis+di+cicco+analemma&hl=en&client=safari&rls=en&prmd=iv&source=lnms&t
In message <777400951-1288749388-cardhu_decombobulator_blackberry.rim.net-33140
75...@bda950.bisx.prod.on.blackberry>, p...@2038bug.com writes:
>Just because we can't immediately see a reason, does not mean that there is
> none. A lot will change in 100 years that even the venerable PHK cannot
>f
In message , Mark Calabretta writes:
>Do I understand correctly from your answer that you also don't
>discern any benefit from leap days?
Being non-religious: No, I don't really care. Being born in January
I wouldn't mind seeing a different season on my birthday.
But the comparison is not valid
On Wed 2010/11/03 02:57:06 -, "Poul-Henning Kamp" wrote
in a message to: Leap Second Discussion List
>Being non-religious: No, I don't really care. Being born in January
>I wouldn't mind seeing a different season on my birthday.
I believe that other non-religious people do care, and not on
Poul-Henning ponders:
> What is the benefit of leap-seconds to non-astronomers ?
Leap-seconds are the means to an end.
Civil timekeeping - likely on this or any other planet - has a fundamental
cadence synchronized to the mean synodic day.
It has been hypothesized that our Moon plays a signifi
Poul-Henning Kamp wrote:
> I really think ATC systems are more important than some photographers
> quest...
Wrong! Ground all planes immediately! Outlaw air travel! Go back to
stone age! Oh, and have PHK stoned to death for heresy while at it...
MS
__
On 11/02/2010 22:46, Michael Sokolov wrote:
Poul-Henning Kamp wrote:
I really think ATC systems are more important than some photographers
quest...
Wrong! Ground all planes immediately! Outlaw air travel! Go back to
stone age! Oh, and have PHK stoned to death for heresy while at it...
2
I was working on a synthesizer project recently. Some of you
know about dual-modulus frequency dividers. Anyway, here's
an idea that came out of that.
(1)
We know the astronomical community depends on UT1 for
terrestrial telescope applications. They use UTC instead of
UT0 or UT1 because UTC is ava
On Nov 2, 2010, at 10:15 PM, Tom Van Baak wrote:
> What would happen if instead of getting rid of leap seconds
> we had *more* of them? So many more that all software just
> had to implement them. And so often that products would
> have a plenty of chances to be "leap second qualified" before
> re
60 matches
Mail list logo
