Well, I can't match Tom's poetry but I note that the deregulation of
power-line-time makes the WWV-series even more critical. So far, though, I
haven't seen super-large changes in the timing of the 60 Hz signals coming into
the USNO. Seems like there was a net 30 second drop in June.
I was surprised to find phrases in the Lick web pages: "CCIR ignored the
advice that astronomers " and "squelched astronomers who insisted that leap
seconds would cause trouble".
I realize their author is not the only person with a strong emotional bias, but
even so I question the tone of
>From the table in the reference provided by Paul Hirose's post
>(http://astro.ukho.gov.uk/nao/lvm/) , the uncertainty in delta-T is 0.4 hours.
> At a latitude of 31 degrees, I compute a (1-sigma) distance of 500 km, which
>the internet tells me is about as far away as Alexandria. Judging
The quote below (from biblegateway.com) may imply a meteor shower also took a
toll on their adversaries.Perhaps someone should scan the area for
meteorites suitably below ground?
... having marched all night from Gilgal. 10 So the Lord routed them before
Israel, killed them with a great
I'm surprised nobody reacted to some of the things in Steve's email. It's
probably because 8 years is a long time (7 now).
With regards to the last paragraph, the support for Steve's inference seems
rather weak. I feel an obligation to point out that as far as I have seen my
employer, the
Look for a TV show on National Geographic or PBS called "Genius by Stephen
Hawking". Episode 1: Can We Time Travel?
It is at 9 PM in Washington DC
___
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LEAPSECS@leapsecond.com
https://pairlist6.pair.net/mailman/listinfo/leapsecs
Dr. Gernot Winkler passed on April 30. To this list he is well-known as the
person who, along with Dr. Essen of NPL. initiated the current system of leap
seconds in UTC. To us in the U.S. Naval Observatory's Time Service Department,
Gernot was an inspiring leader in every way. A strong and
...@leapsecond.com] On Behalf Of Greg
Hennessy
Sent: Wednesday, January 28, 2015 4:50 PM
To: Leap Second Discussion List
Subject: Re: [LEAPSECS] The leap second, deep space and how we keep time -Brooks
On 01/28/2015 01:42 PM, Matsakis, Demetrios wrote:
To Steve mostly,
It would be misleading
The marketplace.org article quotes Bob Tjoelker as saying his team, and
deep-space missions in general, can handle leap seconds. I've known Bob
Tjoelker for years. He's a super-scientist designing super-clocks. Since
some of those clocks are space-qualified, he is literally a rocket
Tom,
I don't have any special predictive insights, but when I look at the data
things appear to be fairly flat.Although the length of day (LOD) has
dropped below 86400 in the recent summers, it didn't last year. As my
viewgraphs indicate, the best predictor for this kind of variation is
With regards to Gerard's question (below), I think the answer is that his
timescale is one of a large class of possible timescales that could be given
any name desired as soon as anybody had a use for it. It would be trivial to
compute the calendar dates he talks about of course, but it's
; Matsakis, Demetrios
Subject: Re: [LEAPSECS] Earth speeding up?
In message e517a9af6a49aa479d731ec5f891c0bbfe81d...@echo.usno.navy.mil, Mats
akis, Demetrios writes:
The best hand-waiving arguments I've heard for these recent decadal
fluctuations is that the oblateness of the Earth is changing
http://www.timeanddate.com/news/time/paris-meridian-gmt-obsolete.html
-Original Message-
From: leapsecs-boun...@leapsecond.com [mailto:leapsecs-boun...@leapsecond.com]
On Behalf Of leapsecs-requ...@leapsecond.com
Sent: Thursday, April 03, 2014 12:01 PM
To: leapsecs@leapsecond.com
Sometimes it doesn't matter how much notice is given. This morning I got an
email from someone asking why his clock just jumped to daylight time.I've
had many emails from people whose clocks incorporate a change late, which could
be due to radio reception problems among other things.
Not my issue, but the last day of the 20th century is technically December 31,
2000.I wish it weren't. When this controversy passed in 1701, Isaac
Newton is quoted has having rejoiced that the issue was finally behind us.
Also, I would add November 18, 1858 as the first day in the
Rumors that the USNO tried to insert a leap decade as an experiment are not
exactly correct. See the message in http://tycho.usno.navy.mil/ntp.html. One
of the 50-odd emails we got indicated that it would take working all night to
undo the damage. A few responded that it was a good lesson
Rumors that the USNO tried to insert a leap decade as an experiment are not
exactly correct. See the message in http://tycho.usno.navy.mil/ntp.html. One
of the 50-odd emails we got indicated that it would take working all night to
undo the damage. A few responded that it was a good lesson
Although I believe I included amateur astronomer concerns uncritically
in my URSI report on the leap seconds, I have always wondered how many
astronomers who are at the level of needing to correct for UT1 would not
be competent to do so. I would guess that most would consider doing so
part of
I can't help with the flying cars, but UTC does deliver a frequency
that is the most precisely and accurately measured quantity known to
humans. Time is the integral of that frequency, and over one
leapsecond-less day a frequency error of 1.E-12 corresponds to a time
error of 86400*1.E-12 = 86
It wouldn't surprise me if you have your kids build one of those for a science
fair project!
From: Tom Van Baak
Sent: Tue 10/26/2010 2:14 AM
To: Leap Second Discussion List
Subject: Re: [LEAPSECS] Saint Crispin's Day
...
And no, my lab isn't near as good as NIST; but I do keep
an eye out
I have now heard from two sources that the revised ITU-R draft
recommendation TF.460-6 passed a major hurdle in Geneva last week. It
will be sent by SG7 to the January 2012 Radiocommunication Assembly
meeting. At the Radiocommunication Assembly only countries that belong
to the ITU-R can vote
I asked an unquestioned expert on celestial navigation about its UT
requirements. This was his response:
For observed stars that are near the celestial equator or at low
declinations, the error can be up to 0.25 nm per uncorrected second.
This
is a systematic error, i.e., all lines of position
The concept of whether TAI is a product in itself, or just a step to generate
UTC, has led to some disagreements over time.
However, there is only one UTC, which has many realizations. The true UTC is
determined not from the realizations, but from the clocks behind those
realizations.
Discussion List
Subject: Re: [LEAPSECS] UTC is derived from TAI
On Sun 2010-03-14T21:11:58 -0400, Matsakis, Demetrios hath writ:
However, there is only one UTC, which has many realizations. The
true UTC is determined not from the realizations, but from the clocks
behind those realizations
Microsoft's NTP package gives no notice of a pending leap second, even
when acting as a server. Here are some pastes from Microsoft's web
site:
The Windows Time service does not indicate the value of the Leap
Indicator when the Windows Time service receives a packet that includes
a leap second.
I agree with Tom about GPS. Over the past decade both GPS's delivered
prediction of UTC(USNO) and GPS time have been getting closer and closer to
UTC(USNO), modulo 1 second and as measured by the RMS. That is mostly due to
improved GPS clocks, but tighter steering was implemented about ten
There is a mistake in the viewgraphs, which the authors will correct in
any other reports they generate. This is the reference to URSI.
I was the person who chaired the URSI Commission J working group, and
later chaired the URSI-wide working group on the matter. Every report
noted that no
...@echoex.timenet.usno.navy.mil,
Matsakis, Demetrios writes:
On the basis of six years of non-expression of interest from their
constituency, the URSI secretariat made a unanimous decision to not
respond to the ITU-R's Special Rapporteur Group's letter, and my
working group was disbanded.
Does that non-response
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