Re: Monsters from the id

2006-01-17 Thread Mark Calabretta
On Mon 2006/01/16 00:40:28 CDT, John Cowan wrote
in a message to: LEAPSECS@ROM.USNO.NAVY.MIL

I realize the ALHP has severe problems with this, but I don't approve
of the ALHP anyhow (save perhaps tactically, as explained).

Agreement!

But does anyone think that the leap hour proposal is anything other than
a political device?  If so, please describe in detail how it could/would
work.

Mark Calabretta
ATNF


Re: Monsters from the id

2006-01-17 Thread Neal McBurnett
On Sat, Jan 14, 2006 at 02:09:20AM -0700, Rob Seaman wrote:
On Jan 13, 2006, at 12:46 AM, John Cowan wrote:
  In the end, it will be impossible to maintain the notion that a solar
  day is 24h of 60m of 60s each: we wind up, IIRC, with the solar day
  and lunar month both at about 47 current solar days.

There's a lot of difference between what happens over a billion years
and a million years.  Length of day increases only about 20s per million
years.  Should we be here to care in a million years, only a 1/4 of 1/10
of
one percent tweak to the length of the civil second would suffice to
allow
our Babylonian clock paradigm to continue in use.

Of course, since there is a future time of equilibrium (though a long
time off...), the quadratic nature of the accumulation of leap
seconds will also stop at some point, and eventually we won't need
them any more.  I hope the 47 day calculation takes the solar tidal
influences into effect, and that the moon has to overcome that.

It makes me wonder when the maximum rate of change in length of day
will come?  Not that we need to plan for events that far in the future
- just some fun astronomy

Neal McBurnett http://bcn.boulder.co.us/~neal/
Signed and/or sealed mail encouraged.  GPG/PGP Keyid: 2C9EBA60


Re: Monsters from the id

2006-01-15 Thread Mark Calabretta
On Fri 2006/01/13 18:39:01 CDT, John Cowan wrote
in a message to: LEAPSECS@ROM.USNO.NAVY.MIL

 The situation with the proposed leap hour is quite different.  Given
 that AEST is defined as UTC+1000, and AEDT as UTC+1100, would someone
 care to speculate, in terms similar to the above, what will happen when
 a leap hour is inserted?

Perhaps the two scales will be labeled O.S. and N.S., as our anglophone
antecessors did when switching from Julian to Gregorian.

If you go through the exercise trying to tie leap hours to DST, as I
challenged, you will discover that it raises many questions that are not
addressed by the leap hour proposal.

If you make some plausible assumptions as to how it would operate, with
DST starting and ending at the usual times of year and leap hours
occurring on new year's eve, I believe you will find it far from simple
to do in a rigorous fashion, and that at least one of the timescales is
genuinely discontinuous.

Mark Calabretta
ATNF


Re: Monsters from the id

2006-01-15 Thread John Cowan
Mark Calabretta scripsit:

 If you go through the exercise trying to tie leap hours to DST, as I
 challenged, you will discover that it raises many questions that are not
 addressed by the leap hour proposal.

I realize the ALHP has severe problems with this, but I don't approve
of the ALHP anyhow (save perhaps tactically, as explained).

 If you make some plausible assumptions as to how it would operate, with
 DST starting and ending at the usual times of year and leap hours
 occurring on new year's eve, I believe you will find it far from simple
 to do in a rigorous fashion, and that at least one of the timescales is
 genuinely discontinuous.

Indeed.  But the sensible approach would be for each State government to
fail to omit the hour of the normal spring transition in the year 2700,
say.  In that way, AEDT would become TI+1000 and a normal-looking autumn
transition would cause AEST to become TI+0900.  Countries without DST
transitions would have to actually repeat an hour, of course, just
as Algeria had to do in 1940, 1956, 1977, and 1981 (the country has
repeatedly flipflopped between UTC+ and UTC+0100).

By the way, I re-counted all the secular time zone transitions worldwide.
According to the Olson timezone database, there have been 516 of them
since the beginning of standard time (when that is, of course, varies
with the country or subdivision thereof).

--
John Cowan  http://www.ccil.org/~cowan  [EMAIL PROTECTED]
Be yourself.  Especially do not feign a working knowledge of RDF where
no such knowledge exists.  Neither be cynical about RELAX NG; for in
the face of all aridity and disenchantment in the world of markup,
James Clark is as perennial as the grass.  --DeXiderata, Sean McGrath


Re: Monsters from the id

2006-01-14 Thread Rob Seaman
On Jan 13, 2006, at 12:46 AM, John Cowan wrote: In the end, it will be impossible to maintain the notion that a solarday is 24h of 60m of 60s each: we wind up, IIRC, with the solar dayand lunar month both at about 47 current solar days. There's a lot of difference between what happens over a billion yearsand a million years.  Length of day increases only about 20s per millionyears.  Should we be here to care in a million years, only a 1/4 of 1/10 ofone percent tweak to the length of the "civil second" would suffice to allowour Babylonian clock paradigm to continue in use.  Alternately, we mightdecide to add one second to just one minute out of each hour.I won't claim one of these would be the choice.  There are manifoldoptions for representing time.  But I do assert that our descendants - foras long as they may be regarded as human - will desire to have somecommon way to represent fractions of a day.  And no matter whatrepresentation they choose, they will still face the quadraticaccumulation of leap seconds or their equivalent.Far from being a motivating factor for deprecating leap seconds, thequadratic clock lag resulting from the roughly linear tidal slowing ofthe Earth is precisely the strongest argument for preserving meansolar time as our common basis for timekeeping now and forever.Besides, it is simply a charming fact of life in the solar system thatour Moon is receding while the Earth spins down.  Apollo era laserretro-reflectors show that for each second our day lengthens, theMoon's orbital radius grows by a mile or so.Time is a fundamental element of all that we do.  Surely publicpolicy should not be governed by a drab and dystopian vision ofa fragmented planet scrabbling randomly to keep our disjointclocks aligned.The simplest - nay, the only - way to keep our clocks synchronizedone to the other is to keep them all tied to Mother Earth. "You think the Earth people think we're strange you think."Rob SeamanNOAO

Re: Monsters from the id

2006-01-13 Thread Tom Van Baak
 It should be clear that the gaps and repeats are fictitious, especially
 if you think of AEST and AEDT as existing beyond the times when they are
 in legal use.  Putting it in practical terms, suppose I have a traffic
 accident at 0230 on 2006/04/02, what time will the police officer write
 in his report?  For most times of the year he can omit the timezone spec
 because there is no legal ambiguity, but to do so for this specific hour
 would be insufficient, he must specify AEDT or AEST.

There are two instances of 0230 but only one
0230 EST and one 0230 EDT. So that could take
care of the ambiguity, if the officer were clever.

Or he could use UTC/GMT/Zulu, if the office had a
military background.

Or, how about this for a laugh... Suppose DST were
implemented with +/- leap hours. Consider if the DST
switch were made around midnight instead of 2 AM.

Then the Spring DST change would jump from 22:59 to
00:00 skipping the 60 minutes labeled 23:00 to 23:59.
The Fall DST would be implemented after 23:59 where
and extra 60 minutes labeled 24:00 to 24:59 would be
added. That takes care of your EST/EDT ambiguity...

/tvb
http://www.LeapHour.com


Re: Monsters from the id

2006-01-12 Thread Michael Deckers
   John Cowan wrote:

   [If TAI - 33 s were taken as the new basis for civil timescales, then]

  It is UTC that would be eliminated as the basis for local time.  It could
  be maintained for such other purposes as anyone might have.

   Yes, the IERS could maintain it as the timescale for a timezone
   whose local time approximates UT1 up to a second.

   Michael Deckers


Re: Monsters from the id

2006-01-12 Thread Mark Calabretta
On Thu 2006/01/12 02:36:44 CDT, John Cowan wrote
in a message to: LEAPSECS@ROM.USNO.NAVY.MIL

We already have that repeated time sequence and gap in much of the world,
and live with it.  These repetitions would be no better and no worse;
when a gap is present, the local sovereignty can omit the gap, but this
is not a necessary feature of the proposal.

At the start of daylight saving where I live the clocks are set forward
from 2am to 3am.  Naively it looks like there is a gap.  Likewise at the
end of daylight saving the hour from 2am to 3am appears to be repeated.

The apparent gaps and repeats are simply an artifact of what happens to
a clock display when you change it to read a different timescale.

Standard time Summer timeLegal time
     --
  2005/10/30 00:01:58 AEST (:   ):
  2005/10/30 00:01:59 AEST (2005/10/30 00:02:59 AEDT)   AEST
  2005/10/30 00:02:00 AEST  -  2005/10/30 00:03:00 AEDT  AEST/AEDT
 (2005/10/30 00:02:01 AEST) 2005/10/30 00:03:01 AEDTAEDT
 (:   ) 2005/10/30 00:03:02 AEDTAEDT
 (:   ) ::
 (:   ) ::
 (:   ) 2006/04/02 00:02:58 AEDTAEDT
 (2006/04/02 00:01:59 AEST) 2006/04/02 00:02:59 AEDTAEDT
  2006/04/02 00:02:00 AEST  -  2006/04/02 00:03:00 AEDT  AEST/AEDT
  2006/04/02 00:02:01 AEST (2006/04/02 00:03:01 AEDT)   AEST
  2006/04/02 00:02:02 AEST (:   ):
  :(:   ):

It should be clear that the gaps and repeats are fictitious, especially
if you think of AEST and AEDT as existing beyond the times when they are
in legal use.  Putting it in practical terms, suppose I have a traffic
accident at 0230 on 2006/04/02, what time will the police officer write
in his report?  For most times of the year he can omit the timezone spec
because there is no legal ambiguity, but to do so for this specific hour
would be insufficient, he must specify AEDT or AEST.

The situation with the proposed leap hour is quite different.  Given
that AEST is defined as UTC+1000, and AEDT as UTC+1100, would someone
care to speculate, in terms similar to the above, what will happen when
a leap hour is inserted?

Mark Calabretta
ATNF


Re: Monsters from the id

2006-01-12 Thread Rob Seaman
On Jan 12, 2006, at 12:36 AM, John Cowan wrote:No one, at least not on this list, is arguing for an alignment of theabsurd leap hour proposal (henceforth ALHP) with DST changes.I went rummaging through the ITU proposal and back as far as Torino.  Found this comment from a LEAPSECS thread on 28 July 2003: At Torino the proponents of omitting leap seconds supposed that the governments of the world might handle this situation using leap hours introduced into civil time by occasionally omitting the annual ``spring forward'' change to jump to summer/daylight time.This particular quote originated with Steve Allen's excellent page:  http://www.ucolick.org/~sla/leapsecs/dutc.htmlI couldn't find any explicit mention of this in the discussions at Torino, but Steve must have gotten it somewhere - and as you say, not from the list.  It may be an opportune time for folks to reread the presentations from Torino: http://www.ien.it/luc/cesio/itu/ITU.shtmlFor example, I found this interesting tidbit from the Russians: "This is to inform you that to our opinion it is necessary to preserve the status-quo of the UTC time scale."Considering GLONASS is always trotted out as the only explicit example of a system that fails to handle leap seconds, this seems significant somehow.More-or-less the entire text of the proposed change to ITU-R TF.460-6 is expressed here:Operational rules(after  UTC 21 December of the transition year)1   ToleranceThe difference of UT1 from UTC should not exceed ±1h.2   Adjustments to UTC2.1Adjustments to the UTC time-scale should be made as determined by the IERS to ensure that the time-scale remains within the specified tolerances.2.2The IERS should announce the introduction of an adjustment to the UTC time-scale at least five years in advance. At the time of the announcement the IERS should provide directions regarding the details of the implementation of the adjustment.2.3All operational rules and nomenclature prior to  UTC 21 December of the transition year given above no longer apply.NOTE 1 – The broadcast of DUT1 will be discontinued.NOTE 2 – Predictions of the Earth’s rotation currently indicate that such an adjustment would not be required for thousands of years.Note the inaccurate and self-serving "thousands of years" that is corrected to 500 years in the draft.  There isn't the slightest specification (or analysis) of how a leap hour might be implemented - just an assumption that the IERS will persist indefinitely.  We're certainly aware that "all operational rules" are to be changed - but what about the nomenclature?  Imagine changing an ISO or SI standard - preserving a trail of coherent nomenclature would be half the document.  And then, of course, the amazing fact that the document simultaneously increases the importance of DUT1 by orders of magnitude, while discontinuing its issuance.  This "proposal" is not only ill considered, it is simply - well - lazy and arrogant.We already have that repeated time sequence and gap in much of the world,and live with it.  These repetitions would be no better and no worse;when a gap is present, the local sovereignty can omit the gap, but thisis not a necessary feature of the proposal.The point I was trying to make is that you can't simultaneously omit the overlaps/gaps and preserve anything even vaguely resembling the familiar relationship between our clocks and the solar day.  It doesn't matter whether we continue an international civil time system or abandon it for local anarchy - people everywhere in the world would  have to deal with the repercussions.  That the situation will degrade slowly over a few hundred years before collapsing catastrophically doesn't really seem to recommend the plan.It may not sound like it, but I am willing to be convinced otherwise - but you'll have to do a lot better than rivaling the scant length of the ITU proposal.  How about a detailed scenario of exactly how you see this working for a couple of neighboring but distinct local timezones?  What is the precise mechanism that might be used?The subtext of both your position and the "absurd leap hour proposal" is that civil timekeeping is so trivial that everybody from barbers to burghermeisters should be encouraged to make public policy - after all, these aren't "important" scientific and technical issues.  Rather, civilian users deserve as good or better a timescale as the technical users (who ultimately can take care of themselves). Historians already deal with the discontinuity between Julian andGregorian calendars, which was similarly conducted in a decentralizedfashion between 1582 and 1924.That there was a global mess several hundred years in the past is not a particularly good reason to generate another global mess several hundred years in the future.Aliens?  Us?  Is this one of your Earth jokes?Rob SeamanNOAO

Re: Monsters from the id

2006-01-12 Thread John Cowan
Rob Seaman scripsit:

 I went rummaging through the ITU proposal and back as far as Torino.
 Found this comment from a LEAPSECS thread on 28 July 2003:

  At Torino the proponents of omitting leap seconds supposed that the
  governments of the world might handle this situation using leap hours
  introduced into civil time by occasionally omitting the annual ``spring
  forward'' change to jump to summer/daylight time.

This is definitely the PHK/JWC proposal rather than the ALHP: civil time
refers to local legal/business time.

 The difference of UT1 from UTC should not exceed ±1h.

This, however, clearly is the ALHP.

 The point I was trying to make is that you can't simultaneously omit
 the overlaps/gaps and preserve anything even vaguely resembling the
 familiar relationship between our clocks and the solar day.

The relationship between our clocks (legal time clocks, the only kind
I am concerned with) and the solar day is very weak, as I have established
over and over.  If local  is the middle of the night, the practical
requirements of legal time are pretty much satisfied.

 people everywhere in the world
 would  have to deal with the repercussions.  That the situation will
 degrade slowly over a few hundred years before collapsing
 catastrophically doesn't really seem to recommend the plan.

There will be no catastrophic collapse, just a gradual local adjustment
as needed.

 It may not sound like it, but I am willing to be convinced otherwise
 - but you'll have to do a lot better than rivaling the scant length
 of the ITU proposal.  How about a detailed scenario of exactly how
 you see this working for a couple of neighboring but distinct local
 timezones?  What is the precise mechanism that might be used?

A sovereign country will notice that there is too much discrepancy
between solar time and legal time to be comfortable: perhaps kids are
waiting for school buses in the dark, as happened in the U.S. in 1974.
The country will then adjust its legal time, perhaps in coordination
with its neighbors, perhaps not.

 The subtext of both your position and the absurd leap hour proposal
 is that civil timekeeping is so trivial that everybody from barbers
 to burghermeisters should be encouraged to make public policy - after
 all, these aren't important scientific and technical issues.

Those who want UT1 or TAI know where to get it.

 Rather, civilian users deserve as good or better a timescale as the
 technical users (who ultimately can take care of themselves).

Good for what?  (This is not a rhetorical question.)

 Aliens?  Us?  Is this one of your Earth jokes?

No.

--
John Cowan  [EMAIL PROTECTED]  www.reutershealth.com  www.ccil.org/~cowan
The known is finite, the unknown infinite; intellectually we stand
on an islet in the midst of an illimitable ocean of inexplicability.
Our business in every generation is to reclaim a little more land,
to add something to the extent and the solidity of our possessions.
--Thomas Henry Huxley


Re: Monsters from the id

2006-01-12 Thread John Cowan
Rob Seaman scripsit:

 And the point I'm making is that you can't shift timezones at will to
 accomplish this without creating seams in legally realized time.

We already have seams in legally recognized time.

 Just making the dark stay put would result in ambiguous
 timekeeping.  Daylight saving time layered on solar locked standard
 time is a different thing from attempting to use an overtly similar
 mechanism to compensate for the misappropriate substitution of
 interval time for solar time.

Stripped of the adjectives, why is it different?

 What starts out as gradual (also known as ignored completely)
 will end in the same familiar quadratic rush.  Nothing about your
 notion mitigates this.

In the end, it will be impossible to maintain the notion that a solar
day is 24h of 60m of 60s each: we wind up, IIRC, with the solar day
and lunar month both at about 47 current solar days.

 1) provide a system for uniquely sequencing historical events

Haven't got that now.

 2) allow events in distant lands to be compared for simultaneity

We have that now, but it takes a computer to keep track of all the
details in the general case.

 3) avoid disputes over contractual obligations

That's done by specifying the legal time of a given place.  If I agree
to meet you under the Waverley at noon 13 March 2020, it's all
about what the U.S. Congress says legal time in New York City is
as of that date -- which is not predictable in advance.  (You will also
have a problem finding the Waverley, unless you are an old New Yorker.)

 4) minimize the potential for political disagreements

Good luck.

 5) satisfy religious requirements

Out of scope.

 6) keep it dark near 00:00 and light near 12:00

Agreed.

 7) support educational goals (Yes Virginia, the universe actually
 makes sense.)

No problem.

 8) allow coal miners to aspire to be amateur astronomers

Eh?  I am not recommending abolishing UT1, though it seems strange to
me to measure angles in hours, minutes, and seconds instead of in
radians like a proper SI-head.  (Fourteen inches to the pound, oh Bog!)

 9) permit the construction of sundials - public clocks with no moving
 parts

Sundials don't show legal time or even a good approximation of it much
of the time.

 10) tie an individual's first breathe on her first day to her last
 breathe on her last day

Where's the problem here?  Any timescale can do that, even the Mayan Long Count.

--
John Cowan  [EMAIL PROTECTED]  www.reutershealth.com  www.ccil.org/~cowan
The whole of Gaul is quartered into three halves.
-- Julius Caesar


Monsters from the id

2006-01-11 Thread Rob Seaman
What now, Dr. Moebius?                      Prepare your minds for a new scale...                    of physical scientific values, gentlemen.Mark Calabretta takes the lazy man's way out and appeals to facts: Here in a topology-free way is what the axis labels of my graph looklike during the said leap second insertion:            UTC axis                    TAI axis                 DTAI       2005/12/31 23:59:58         2006/01/01 00:00:30            32       2005/12/31 23:59:59         2006/01/01 00:00:31            32       2005/12/31 23:59:60         2006/01/01 00:00:32            32                        60.9                        32.9          32                        60.99                       32.99         32                        60.999...                   32.999...     32       2006/01/01 00:00:00         2006/01/01 00:00:33            33       2006/01/01 00:00:01         2006/01/01 00:00:34            33The seconds keep step and the graph has no gaps, jumps or kinks.Now let's look at a leap hour introduced as an extra "fall back" hour:  UTCTAI  2600-12-31T23:59:58   2601-01-01T00:00:31  33  2600-12-31T23:59:59 2601-01-01T00:00:32  33  2600-12-31T23:00:00 2601-01-01T00:00:33  33  2600-12-31T23:00:01 2601-01-01T00:00:34  33 (?)  ... ... 2600-12-31T23:59:58  2601-01-01T01:00:31 33 (?)  2600-12-31T23:59:59 2601-01-01T01:00:32  33 (?)  2601-01-01T00:00:00 2601-01-01T01:00:33  3633I chose to introduce the leap hour on December 31 - I don't believe the proposal indicates the date for doing so.  Folks have been tossing around the notion of aligning this with daylight saving time - but DST in what locality?  Does anyone really believe that a leap hour would be introduced on different calendar dates worldwide?  (It seems to me that the one time it is guaranteed NOT to occur is during a daylight saving transition.)Not satisfied with the ITU position that UTC should merely be emasculated to correspond to TAI - 33s - Nx3600s (which, of course, really has the effect of ensuring that TAI itself will remain a completely irrelevant mystery to the public), some would completely eliminate UTC from the equation (or is it that they would eliminate TAI?) Something like: GMT   TAI  2600-12-31T23:59:58   2601-01-01T00:00:31   2600-12-31T23:59:59  2601-01-01T00:00:32   2600-12-31T23:00:00  2601-01-01T00:00:33   2600-12-31T23:00:01  2601-01-01T00:00:34 ... ...  2600-12-31T23:59:58   2601-01-01T01:00:31   2600-12-31T23:59:59  2601-01-01T01:00:32   2601-01-01T00:00:00  2601-01-01T01:00:33  But we're to believe that this would be implemented as an omitted "spring forward" hour - ignoring the fact that many localities don't currently have this option because they don't use DST at all - can't omit what you don't have in the first place.  Well - fine, a "spring forward" event might look like: GMT   TAI  2600-12-31T23:59:58   2601-01-01T00:00:31   2600-12-31T23:59:59  2601-01-01T00:00:32   2601-01-01T01:00:002601-01-01T00:00:33   2601-01-01T01:00:01  2601-01-01T00:00:34   2601-01-01T01:00:02   2601-01-01T00:00:35 But under this interpretation we're to believe that the very notion of international civil time is anathema (except perhaps for TAI with some oddball persistent 33s offset and either a one hour gap or one hour repetition every few hundred years).  What this means is that *local* civil/business/legal time contains this gap or this repetition.  I suspect we can agree that the civilians/businesspersons/lawyers won't care whether the issue is local or not, all they are going to see is a repeated time sequence or a gap - and with no possibility of appeal to standard time, because standard time as we know it simply won't exist anymore.And historical time?  Well, historians will simply have to get with the program.  Suck it up.  Perhaps loudspeakers will announce the arrival of the leap hour (or leap timezone migration event) with the admonition to refrain from historically significant activity for the space of one hour.  (This announcement would be unnecessary in the Washington, D.C. city limits, of course.)And more to the point, since international time is a fiction, this gap/overlap in civil/business/legal/historical time would occur twice