Re: [LEAPSECS] independence day

From: Rob Seaman <seaman_at_noao.edu>
Date: Wed, 5 Jul 2006 12:05:45 -0700

John Cowan wrote:

> I regret to state that this remark appears to me no more than
> scaremongering.

Merely hyperbole intended to make a point about the art of crafting
fundamental standards. Obviously I failed to make that point :-)

Why precisely, however, do you regret your inference? If my
arguments were to be deemed specious, surely that would strengthen
opposing arguments (or at least remove competing options).

> If the U.S. tied its legal time to the ITU, it could untie
> it in future if that seems like a good idea.

and later in reply to Markus Kuhn:

> "Reader, suppose you were an idiot, and suppose you were a member
> of Congress; but I repeat myself." --Mark Twain (1882)

You can't have it both ways. Either a prudent decision making
process is being followed, or it ain't.

What would be prudent? How about taking the consensus at the Torino
meeting at face value? A civil timescale without leap seconds should
prudently be called something other than "UTC". Heck - define it
right now and let the market decide. If that consensus is deemed
unacceptable, what might be a prudent response? How about holding
another - well advertised - conference to discuss the issues some
more? Hold it in Washington so members of Congress can attend -
assuming they're capable enough to locate the venue :-) What else
might be prudent? How about taking our time characterizing the
problem fully before proposing solutions? The current standard is
good for several hundred years. What precisely is the hurry?

> In any case, changing the legal definition of U.S. time from GMT
> to UTC merely regularizes the de facto position, since GMT no
> longer has a specific international definition.

That was my point, if only my épée hadn't rattled ineffectually
aside. GMT has a physical definition that trumps any international
definition (although I'm a bit perplexed at why you assert the latter
to have gone completely missing). Let me pose my argument again in
the hopes of snagging my point d'arret in your knickers:

1) Notionally, the first leap hour would occur 600 years hence should
the Absurd Leap Hour Proposal (ALHP) be rammed through by the
mumbling minions with fingers in their ears.

2) Six centuries ago, the New World was Terra Incognito - the Sistine
chapel was yet to be built, let alone painted - the Ptolemaic cosmos
and the Julian calendar were unchallenged - the Medici were in full
flower, although Machiavelli was but a potentiality inherent in his
grandparents - the Canterbury tales were written, but their publisher
was equally unborn - Shakespeare lay in the distant future, of
course, but his Prince Henry was still hanging about with Falstaff in
taverns, not the French at Agincourt - and the great Chinese eunuch
admiral Zheng He had set sail with 27000 men on 300 ships, with the
protectionist retreat of the later Ming dynasty still a century in
the future.

3) During all the time since, flavors of solar time have provided the
fundamental standard for timekeeping in Asia and in Europe and in the
Americas - and across civilizations on all the continents, and on
islands scattered across the world's seas and oceans, and on vessels
traversing those oceans and later the skies above them.

4) Who knows what changes the next six centuries will bring? Rather
than being an argument for the timekeepers having the freedom to
follow whatever policy making whims seem expedient - this question is
instead a demand for prudence beyond bureaucracy and deliberation
beyond misconstrued self-interest.

5) A time standard rooted in solar time can be recovered at remote
times and in diverse places. Patrick O'Brian's pugnacious ill-
educated Napoleonic era characters perform this feat daily from the
rolling quarterdeck of a Frigate with sightings taken to establish
local noon. Their chronometers are synchronized to the observatory
at Greenwich, not to some random clock in a basement in Paris (not
coincidentally, that would have been under the control of their
enemies).

6) A time standard rooted in an ensemble of clocks, on the other
hand, is subject to the vagaries of happenstance and history (like,
say, another Napoleon). What price to ensure 24/7/365/600
reliability? (I look forward to your riposte pointing out that the
metric system emerged from the Reign of Terror :-)

7) The calendar, and its constituent subdivisions by the clock, is
the mother of all international standards. It deserves the respect
we show our own mothers, not the derision reserved for avoirdupois or
cubits.

>> What in practice would stop these individuals
>> from leaping the clock forward or backward at will, or from changing
>> the rate of UTC, or for that matter from making the clocks run
>> backwards?
>
> The fact of being rendered irrelevant, not to say a laughingstock.
> What is to prevent the IERS from issuing bogus leap second
> announcements?

Precisely the constraint that DUT1 < 0.9s. Precisely the fact that
UTC is currently tied to an underlying physical phenomena common to all.

Over 600 years of cultural evolution yet to come, the likeliest
correction to an emasculated UTC would be some awkward jump of an odd
number of minutes and seconds to restore the timescale to its
original concept when the magnitude of the original sin is inevitably
realized.

Lord knows that no technological laughingstocks have appeared on the
world stage over the last 60 decades :-)

Rob
NOAO
Received on Wed Jul 05 2006 - 12:06:35 PDT