NO leap second will be introduced at the end of December 2015

On Monday, July 13, 2015 at 3:33:12 PM UTC-6, Quadibloc wrote:
(Or is UT1 rather simply 'mean solar time'

Indeed it is:

https://en.wikipedia.org/wiki/Universal_Time

And since Liberia only adopted Standard Time in 1972, now I know the political
reason why the _Atlas Jeune Afrique_ did not include lines of latitude and
longitude on its maps, which I had found bizarre.

John Savard

On Monday, July 13, 2015 at 3:41:32 PM UTC-6, Quadibloc wrote:
On Monday, July 13, 2015 at 3:33:12 PM UTC-6, Quadibloc wrote:
(Or is UT1 rather simply 'mean solar time'

Indeed it is:

https://en.wikipedia.org/wiki/Universal_Time

And from there I also learned that Terrestrial Dynamical Time is now just
called Terrestrial Time - it's basically International Atomic Time, but without
the 32.184 second offset from Ephemeris Time. So it's useful for satellites and
space probes, because that way they don't have to convert all the old
information on the elements of the orbits of the planets and suchlike.

John Savard

On Mon, 13 Jul 2015 14:33:10 -0700 (PDT), Quadibloc
wrote:
So UT1 still exists? Then we can run the Internet on that and not
have computer
software having problems with leap seconds.

Running the ?nternet on UT1 would be worse: instead of dealing with
leap seconds now and then you'd have to introduce corrections of a
fraction of a second every few week or so. That's because UT1 cannot
be predicted, it must be determined by observing the Earth's rotation
with high precision.

I thought it was dead.

It's UT2 which is dead. UT2 is UT1 with corrections applied for
seasonal variations in the Earth's rotation.

(Or is UT1 rather simply 'mean solar time' as opposed to
the old pre-atomic system where the length of the second was varied
by an
integral number of milliseconds for part of the year... and thus
not something
defined in a usable manner for a time standard?)

UT0 is mean solar time for the Greenwich meridian. UT1 is UT0 with
corrections applied for pole wandering - the difference is of the
order of magnitude of milliseconds. The difference between UT1 and
UT2 is larger, a few tens of milliseconds.

Do you still want to run the ?nternet on UT1??

On Tuesday, July 14, 2015 at 7:27:50 AM UTC-6, Paul Schlyter wrote:

Do you still want to run the ?nternet on UT1??

No; what I would have wanted to run the Internet on would be a time standard
similar to what existed prior to 1978 or thereabouts, when UTC was introduced.

So there would be no leap seconds, but occasionally the *clocks* would be
adjusted to add 100 milliseconds, and there would be a frequency offset each
year.

So the clocks would be adjusted, but the next lower level, the software, would
never be touched because there would be no leap seconds ever. Seconds would
just change in length.

John Savard

On Tue, 14 Jul 2015 06:40:39 -0700 (PDT), Quadibloc
wrote:
On Tuesday, July 14, 2015 at 7:27:50 AM UTC-6, Paul Schlyter wrote:

Do you still want to run the ?nternet on UT1??

No; what I would have wanted to run the Internet on would be a time
standard
similar to what existed prior to 1978 or thereabouts, when UTC was
introduced.

UTC was introduced in 1972. Before then we had UT, defined by the
Earth's rotation, Ephemeris Time, defined by the orbital motions of
the planet, and atomic time, which at first was frequently adjusted
by fractions of seconds to correspond close to UT.

So there would be no leap seconds, but occasionally the *clocks*
would be
adjusted to add 100 milliseconds, and there would be a frequency
offset each
year.

So the clocks would be adjusted, but the next lower level, the
software, would
never be touched because there would be no leap seconds ever.
Seconds would
just change in length.

John Savard

That means you want to imtroduce a new time sale, and you also want
to redefine the length of the second, one of the fundamental SI
units. Do you realize what can of worms you want to open?

Regarding today's computers, they already implement leap seconds as
clock adjustments. Hardly any computer system is able to deal with
leap seconds as one minute which actually has 61 seconds. The Unix
time() function, which is supposed to give the number of seconds
since 1 Jan 1970, never includes leap seconds in its count. And the
same holds for other time counts in other computer environments.

So basically you want to make the current leap seconds problem ten
times more frequent. I'd prefer the opposite approach: let UTC and
UT1 drift apart, and when the difference approaches one hour,
introduce a leap hour instead. That would be necessary once a
millennium or so, and it can be predicted many decades in advance,
giving computer technicians plenty of time to adapt. And we're
already used to leap hours twice a year when we start and end DST.
This extra leap hour could be implemented by ending DST **without**
turning back the clock, which would decrease rather than increase the
number of clock changes for that year.

The human mind becomes trapped inside an ideology which attempts to tie the Earth's rotation in isolation directly to the 24 hour day and into the subdivisions of hours,minutes and seconds.

There is nothing difficult about the founding principles where timekeeping and the motions of the Earth come into close proximity and easily understood by the day and rotation of February 29th. The original external reference is an astronomical event where a star,emerging from behind the glare of the central Sun, skips an appearance by one day after 4 annual cycles of 365 days and rotation.

http://www.gautschy.ch/~rita/archast...liacsirius.JPG


Attempting to wipe out the historical and technical components which correlate the cyclical references supplied by the Earth's motions with human timekeeping is an act of thuggery every bit if not more catastrophic than all other attempts to wipe out ancient traditions.

There has to be more than a few observers willing to accept the core principles by which rotations are referenced off the orbital period of the Earth and from there into the equalizing of natural noon cycles to a 24 hour average and continuing on to the Lat/long system where this 'average' is converted into constant rotation at a rate of 4 minutes for each degree of rotation.

On Tuesday, July 14, 2015 at 3:25:50 PM UTC+1, Paul Schlyter wrote:
introduced.

UTC was introduced in 1972. Before then we had UT, defined by the
Earth's rotation, Ephemeris Time, defined by the orbital motions of
the planet, and atomic time, which at first was frequently adjusted
by fractions of seconds to correspond close to UT.


The introduction of the Earth's motions and an accurate structure to the solar system by the original heliocentric astronomers borrowed on the earlier work of the geocentric astronomers who used specific arguments based on the motions of celestial objects through the background field of stars and constellations. The later homocentric empiricists turned these arguments on their head by appealing to circumpolar motion of the stars from horizon to horizon thereby obscuring the methods by which the arguments for the Earth's motions were presented.

" The 10th argument,taken from the periodic times, is as follows; the apparent movement of the Sun has 365 days which is the mean measure between Venus' period of 225 days and Mars' period of 687 days.Therefore does not the nature of things shout out loud that the circuits in which those 365 days are taken up has a mean position between the circuits of Mars and Venus around the Sun and thus this is not the circuit of the Sun around the Earth -for none of the primary planets has its orbit arranged around the Earth,but the circuit of the Earth around the resting Sun,just as the other planets, namely Mars and Venus,complete their own periods by running around the Sun." Johannes Kepler

If people took pride in their ability to reason they would begin to see a wonderful and complex narrative emerge which untangles the flaws and limitations which constitute the thorny issue where timekeeping and planetary dynamics merge and separate. It is absolutely crucial to drop the motion of the Sun through the constellations and adopt the line-of-sight observation which causes the stars to drift behind the Sun in sequence and gives us the leap correction and its dynamical meaning.

Again, a person who takes pride in the ability to reason and is not afraid of the challenges can engage with some the the biggest modifications astronomy has seen since the emergence of the heliocentric structure of the solar system. In relation to the subject of this thread, the modifications are comprehensively detailed such as the less productive and ultimately flawed perspective of Huygens -

"Here take notice, that the Sun or the Earth passes the 12. Signs,
or makes an entire revolution in the Ecliptic in 365 days, 5 hours 49
min. or there about, and that those days, reckon'd from noon to noon,
are of different lengths; as is known to all that are versed in
Astronomy." Huygens

On Tuesday, July 14, 2015 at 8:25:50 AM UTC-6, Paul Schlyter wrote:

That means you want to imtroduce a new time sale,

Yes.

and you also want
to redefine the length of the second, one of the fundamental SI
units.

No.

Do you realize what can of worms you want to open?

I would not redefine the length of the second. Just as was true before 1972,
the second of civil time would happen to be longer than the second used to
determine the frequencies of radio stations, to define the ohm and the farad
and the henry, and so on and so forth.

So the "real" second would still be the SI second, but we'd set our watches to be a teensy bit slow to keep down with the Earth's rotation. Just sneak the leap second in where our computers won't notice it.

John Savard

On Wed, 15 Jul 2015 19:23:13 -0700 (PDT), Quadibloc
wrote:
On Tuesday, July 14, 2015 at 8:25:50 AM UTC-6, Paul Schlyter wrote:

That means you want to imtroduce a new time sale,

Yes.

and you also want
to redefine the length of the second, one of the fundamental SI
units.

No.

Do you realize what can of worms you want to open?

I would not redefine the length of the second. Just as was true
before 1972,
the second of civil time would happen to be longer than the second
used to
determine the frequencies of radio stations, to define the ohm and
the farad
and the henry, and so on and so forth.

So the "real" second would still be the SI second, but we'd set our
watches to be a teensy bit slow to keep down with the Earth's
rotation. Just sneak the leap second in where our computers won't
notice it.

John Savard

Then we'd have to start manufacturing watches where you could adjust
the speed. This is rarely possible on today's watches.

On Thursday, July 16, 2015 at 2:54:19 AM UTC-6, Paul Schlyter wrote:

Then we'd have to start manufacturing watches where you could adjust
the speed. This is rarely possible on today's watches.

I'm not aware that today's watches, even with quartz crystals, are so accurate
that they need to be reset to take leap seconds into account anyways. I was
speaking metaphorically...

John Savard