On Mar 18, 2010, at 12:00 AM, Phillip Hallam-Baker wrote:
Well the US pint is 16 fluid oz which is 1 lb of water. The UK pint is
20 so a pint of water is a pound and a quarter. Go figure.
But since we are on the subject of time, why accept UTC as the basis
for Internet time? Leap seconds are unpredictable and lead to system
errors. The only group with a colorable benefit from leap seconds are
astronomers, the one group that might be expected to be able to fix
leap seconds retrospectively.
The ITU has been discussing plans to abandon leap seconds in
perpetuity, but the astronomers always seem to win in the end. If we
moved from UTC to Internet Time, we could abolish leap seconds.
This is backwards. Most astronomers I know regard UTC as a nuisance.
In their calculations, astronomers use TAI (or, if they need to know
the rotation of the Earth, UT1). Solar system ephemeris work uses
ephemeris time, for historical reasons (ET − TAI = 32.184 seconds).
GPS internally uses GPS time, which has the leap second adjustment
appropriate for the start of the series in 1980, supposedly because
the GPS program office didn't understand leap seconds (TAI - GPS = 19
seconds).
The push to create and maintain UTC came primarily from mariners &
various navies, who wanted to be able to do celestial navigation using
civil time (i.e., to treat UTC as an approximation of UT1, so that you
could do km level celestial navigation using time straight from NTP or
WWV). Now, with GPS/Glonass/Galileo, this seems largely moot.
Now, it is true that Ken Seidelmann is an astronomer, and he is
against the change, but that is mostly in a "if is isn't broke, don't
fix it" mode, and also because he is thinking of the long term (in 500
to 600 years the UT1-TAI offset should be order an hour, and people
can be expected to start complaining).
The biggest thing stopping any change is apathy (and the
aforementioned "if is isn't broke, don't fix it").
This site has a lot of information on this subject
http://www.ucolick.org/~sla/leapsecs/nc1985wp7a.html
I used to say that computer time should be TAI (closest to the actual
clocks, easy to calculate elapsed times), but that never seem to get
any traction.
Regards
Marshall
OK, I am not seriously proposing the IETF try to do this (well not
unless we get into a real fight with the ITU). But if you read some of
the idiotic arguments advanced in favor of introducing random,
unpredictable changes into the measurement of time, they are rather
interesting. There are astronomers who seem to think the earth
revolves around them. There are dire predictions that stopping
fiddling with the time system would be a 'major change'. Every
argument is thrown out, regardless of whether it makes any sense.
People who point out that leap seconds really do cost real money are
poo-pooed as having insignificant importance in such lofty debates.
Quite a few of the protagonists attempt to claim it is only the
ignorance and stupidity of the objectors to leap seconds that makes
them unable to see the reason that they are essential.
Over the course of a year, the length of a day varies by several hours
at this latitude. And the time at which noon occurs varies by several
minutes. And twice a year the state decides that we will all get up an
hour earlier or later. So what benefit are those leap seconds to me?
Absolutely none that I can see.
On Wed, Mar 17, 2010 at 12:18 PM, Iljitsch van Beijnum
<iljitsch@xxxxxxxxx> wrote:
On 17 mrt 2010, at 17:02, Michael Edward McNeil wrote:
(Although the exposure to non-standard ways of doing things may
make this harder for Americans.)
Since Americans habitually use month-day order anyway, why would
YYYY-MM-DD be especially difficult for them? It's Europeans and
others who typically use day-month order that would seem likely to
incur difficulties -- except that putting the year first is a
pretty glaring clue that the order shouldn't be regarded as it
usually is for them.
Absolutely. But Americans don't expect this kind of stuff to make
sense, because they're used to having a different way of measuring
everything, while in the rest of the world we're used to the metric
system so we assume things make sense. So an American wouldn't
necessarily consider yyyy-dd-mm inconceivable while people from
elsewhere probably would and just assume yyyy-mm-dd.
_______________________________________________
Ietf mailing list
Ietf@xxxxxxxx
https://www.ietf.org/mailman/listinfo/ietf
--
--
New Website: http://hallambaker.com/
View Quantum of Stupid podcasts, Tuesday and Thursday each week,
http://quantumofstupid.com/
_______________________________________________
Ietf mailing list
Ietf@xxxxxxxx
https://www.ietf.org/mailman/listinfo/ietf
_______________________________________________
Ietf mailing list
Ietf@xxxxxxxx
https://www.ietf.org/mailman/listinfo/ietf