Is atomic time changing wrt astronomical time?!

[Dunash]

This today from http://www.cyberspaceorbit.com/

"As Earth's rotational momentum begins to decrease, the law of the conservation of energy should cause core
temperatures and subsequent geologic stress to increase in an inversely proportional manner.
http://www.upi.com/view.cfm?StoryID=...2-101248-3039r

Over the next 6 months, take note if normally accurate time pieces increasingly gain time relative to the
"observed" rate of Earth's spin. As an experiment, you may wish to leave TWO precisely set, independently
ACCURATE time pieces unrecalibrated with any future time-checks to serve as benchmarks. Over the next 6
months, compare "official" time sources (Internet atomic clocks) against these benchmark time pieces to observe
and track if there is a steady increase in the amount of time they gain with each passing month."

Is atomic time changing wrt astronomical time?!

[Karl]

On 2002-04-02 14:44, Dunash wrote:
This today from http://www.cyberspaceorbit.com/

From just above that article:

Planet-X: Time Rolling Up?

Dunash,

Are you now endorsing Planet X hysteria?

[Hale_Bopp]

Let's see...a typical quartz watch is accurate to about 10 to 15 seconds per month. Don't think that is good enough for this experiment.

The atomic clock is synced to the standard by radio, so that's no good either.

Or is this effect supposed to be greather than 1.5 minutes (6 months * 15 seconds/month)?

Maybe I am missing some previous info on this one.

Rob

[Karl]

On 2002-04-02 15:58, Hale_Bopp wrote:

The atomic clock is synced to the standard by radio, so that's no good either.

Rubidium standards show up on eBay once in a while, but I've never been able to convince myself that I really need one. Yet. :-)

[aurorae]

On 2002-04-02 14:44, Dunash wrote:
"As Earth's rotational momentum begins to decrease, the law of the conservation of energy should cause core
temperatures and subsequent geologic stress to increase in an inversely proportional manner.
http://www.upi.com/view.cfm?StoryID=...2-101248-3039r

Umm, that is a story from UPI about some ground movement under the Three Sisters volcano complex in Oregon.

It's a volcano that hasn't done anything recently (in human terms, in geologic terms it is pretty young), but its a pretty big leap, don't you think, from observing that a single volcano has shifted a little to saying Earth's momentum is changing rapidly?

There are thousands of other volcanos on earth. At any one time some are active, many are not. Are you trying to draw a conclusion that all the volcanoes are going to erupt soon? Seems a pretty tall conclusion from the observation that something is happening under one of them.

And the text of your message was quoted entirely from that other web site. And that web site doesn't appear too concerned about accuracy or logic.

Oh, wait, maybe you could say it was due to the planetary conjuntion! And you could write a book. Oh, wait, that was done before.

<font size=-1>[ This Message was edited by: aurorae on 2002-04-02 17:04 ]</font>

[John Kierein]

The earth does seem to be slowing down slightly. We usually have to add a leap second every year or so to account for this. When working on Iridium, this was important to determining the time a satellite would be in view of a spot on the ground; as the earth rotation rate slowed, the time of arrival would be different. There is a service in France, the Earth Rotation Service, that makes the official time change addition of leap seconds. Some years there are no leap seconds and some years there can be 2. I don't think they've ever had to subtract time. For some reason, I think the leap second has to do with earth rotation, but the year is due to earth revolution around the sun. http://hpiers.obspm.fr/

<a name="20020403"> page 20020403 aka 20020403
On 2002-04-02 14:59, Karl wrote: To: 20020403

On 2002-04-02 14:44, Dunash wrote:
This today from http://www.cyberspaceorbit.com/

7:51 A.M. log on to D'bait this 386's time
drift um? maybe relative to the 486 just
to its right or maybe the computer that
hosts this message
I dont know

[GrapesOfWrath]

On 2002-04-03 07:47, John Kierein wrote:
Some years there are no leap seconds and some years there can be 2. I don't think they've ever had to subtract time. For some reason, I think the leap second has to do with earth rotation, but the year is due to earth revolution around the sun.

This old thread discussed leap seconds, and looked at this NIST page list of leap seconds. They've always been inserted on June 30 or December 31, and it says that there will not be one June 2002--which means that come December, it will have been four years that we have not had a leap second. In the thirty years that we've been inserting leap seconds, the next longest period between leap seconds was two and a half years in December of 1987.

[aurorae]

Careful, Grapes, you'll confuse the apocalypic types by using facts.

[img]/phpBB/images/smiles/icon_lol.gif[/img]

[DStahl]

Funny! I have always understood that Earth-Moon interaction was gradually slowing the rotation of the Earth, but I envisioned it doing so in a perfectly smooth manner--of course the effect of earthquakes and other terrestrial disturbances would make it a jumpy, uneven slowdown, of course they would.

I believe some German physicists recently finished construction of another ring laser facility capable of measuring tiny variations in the Earth's rotation, a sister to the Canterbury, New Zealand device. It's located in Wetzel (sp?), Germany, almost opposite the Canturbury installation on our Earthly sphere.

To calibrate the device the scientists are asking everyone on Earth to run at top speed to the west for 10 minutes, stop and stand still for 10 minutes, and then turn and run back to the east. The calibration date is to be announced soon. Refreshments will be provided.

Don "I just made that last part up" Stahl

<font size=-1>[ This Message was edited by: DStahl on 2002-04-03 12:14 ]</font>

[GrapesOfWrath]

On 2002-04-03 12:11, DStahl wrote:
Funny! I have always understood that Earth-Moon interaction was gradually slowing the rotation of the Earth, but I envisioned it doing so in a perfectly smooth manner--of course the effect of earthquakes and other terrestrial disturbances would make it a jumpy, uneven slowdown, of course they would.

Yes, it makes sense when you realize it. Still, and this is the exciting part, the variation is ten times what they can account for by all those things you list. They suppose that it is due to massive movements of dense material at the core of the Earth, but no one is sure. There has been some work with the Chandler wobble and meteorological excitation, but I haven't looked into it closely.

[John Kierein]

I think this is the most likely cause. Drag between the earth's core and surface.
http://www.ldeo.columbia.edu/press_r...s/song/pr.html

[GrapesOfWrath]

Do you mean the Earth's core and the mantle? That motion at that link is the differential rotation of the inner core, which doesn't touch the mantle.

<a name="20020407.6:16"> page 20020407.6:16 aka Time ticks
On 2002-04-03 15:29, GrapesOfWrath wrote: To: 6:16 A.M. PST
2002-04-03 09:01 = 7:51 A.M. +2h -50m
6:16-21 was? Posted: 2002-04-07 08:30
JUMP TO DATA {line after next line}
5:09 A.M. 2-4-09 From: 97209 Posted: 2002-04-07 08:30 5:10 A.M.
http://www.badastronomy.com/phpBB/vi...#20020410.3:02
TIME......DATE.........FROM...Extract...........? end of line time..5:11 A.M.Government corruption will always
5: Pacific Standard timebe reported in the past tense.
6: while my Zip 97209 has gon to "DAYLIGHT"
last line time 5:11 A.M.
<font size=-1>[ This Message was edited by: HUb' on 2002-04-08 03:54 ]</font>

<font size=-1>[ This Message was edited by: HUb' on 2002-04-09 07:21 ]</font>

<font size=-1>[ This Message was edited by: HUb' on 2002-04-13 08:28 ]</font>

[Donnie B.]

Hub,

Don't rely on the clock in your PC. They are not very accurate, and their drift isn't even predictable. My system at work can lose or gain minutes per day!

My home system is better, but still can gain or lose a few seconds a day.

My reference is NIST time. You can download an app that will access the NIST atomic-clock-based time and reset your PC clock to match; I do that here every few days.

The application I use is "About Time". There are lots of others. They all will set your PC clock to within a second of reference time, which is good enough for most uses but not for any scientific work.

If you're serious about doing absolute-time based studies, you can get WWV receivers that can output an accurate reference time on demand.

<a name="20020408.1:47"> page 20020408.1:47 aka 11:11, Donnie B Good
On 2002-04-07 11:11, Donnie B. wrote: To:
Hub, Listening to {in the `90's} the voice comming
out of a Mac computer .. at PSU i could recognize
Maryland Monrow instantly, when the two kids
who were running the equipment, and changed
the voice uttering those lines of text to W.C. Fields
it cracked up everone in that {un you know}[SOMBER]
computer lab. really kids were almost falling out of
their chairs with laughter and myrh.. Neadless to say
"THOSE COMPUTER's" did not last verey long,
"in an instiution of higher .edu" and by terms in
THEY were "OUT OF THERE" ahh the good old times..
__So sure if you can upload { or explain to me how }
TWO different "ABSOLUTE" time standards i'd try the test myself.. HUb'

[quote]
On 2002-04-08 04:05, HUb' wrote:
1: IT WOULD APPEAR
2: that when an entrys EDITED
3: that THAT entry retains the
4: ORIGIONAL post time
5: So theres no NEW time stamp to
6: compare to so my efforts
7: FEWtile {oh my}
8:
9:
anyway i'll not give up easily
and will endevor som way to do a cross check
--below may be a time test--and maybe not2
http://tycho.usno.navy.mil/
maybe that will link thru
and maybe it will NOT
now all i need's just one more time tick & [Can_Do]

[dapted]

I have been personaly responsible for keeping of atomic clocks in years past. The rubidium ones were not as reliable as the cesium ones. We used them to calibrate loran transmitters and worked in conjunction with other standards stations to keep up the National Bureau of Standards. Lots of fun things need to know what time it is down to 10^-16 seconds. But the rub came when we took multiple clocks on one aircraft flying around the earth east to west, while another cluster flew around west to east. Not a big time change, but enough difference to prove (sort of) the laws of causality and good old Einstein's Relativity.

The rub comes when we approach the speed of light even fractionally that time (for the moving object) slows down relative to us earthlings. The contrary must also be considered, if we find a way to get to zero speed, does time speed up or slow doem for us on earth? Can we make something age prematurely by putting it closer to zero speed. How do we measure zero speed? Against what? Since rotational speed around the center of the earth can cause time to be gained or lost, relative to sitting still, how can anybody claim that time is a constant? Won't it depend on which way your clocks are traveling and at what speed?

So the point of this? Is the earth rotational speed changing, or is the decay rate of cesium changing? Or is the clock used to measure it simply located someplace that doesn't move so fast around the axis of the earth? Say near a pole?

The more answers I get, the more questions I got.

Dan

[WHarris]

Here's another link, from USNO's Earth Orientation Dept.:
What is a Leap Second?

[GrapesOfWrath]

On 2002-04-11 01:23, dapted wrote:
Or is the clock used to measure it simply located someplace that doesn't move so fast around the axis of the earth? Say near a pole?

The more answers I get, the more questions I got.

And that is an interesting question. The Straight Dope answered the question "Do you age more quickly at the pole than than equator due to relativity?". Short answer? No.

[GrapesOfWrath]

On 2002-04-03 09:29, GrapesOfWrath wrote:
This old thread discussed leap seconds, and looked at this NIST page list of leap seconds. They've always been inserted on June 30 or December 31, and it says that there will not be one June 2002--which means that come December, it will have been four years that we have not had a leap second. In the thirty years that we've been inserting leap seconds, the next longest period between leap seconds was two and a half years in December of 1987.

Of course it now says that there will not be a leap second this month, so there probably won't have been one for four and a half years, come next June. It has taken us over a year to lose .2 second in UT1-UTC, but we are pretty much where we were four years ago just before the last leap second was inserted, so maybe we'll see a leap second in June.

<a name="2-12-10.clk"> page= 2-12-10.clk aka clocks
On 2002-12-09 11:54, GrapesOfWrath wrote:
1 of course? i hav my own words for clocks
and i use 5 clocks (C1,C2,C3,C4, &C5)
3 the comparison between D3=C3 where Earth Spin
and Earths orbit are the main topics
<a name="2-12-10.Lnk"> line= 2-12-10.Lnk
http://www.badastronomy.com/phpBB/vi...=3#20021105.TD aka 2003 TIME DRIFT
7 & D4=C2 where Electron Spin : orbit ratios matter
{call it atomic Clocks if you like} are all 5 changing {see follow up post}

<font size=-1>[ This Message was edited by: HUb' on 2002-12-10 10:46 ]</font>

<a name="2-12-10.5Ck"> page= 2-12-10.5Ck aka Five Clocks

C1/D5 ????????????? { o:s_?. } 2e??:1
theres not much know about this
C2/D4 Electron Orbit/spin ratios {o:s_El} 2:1
possibly spin locked(steady) orbits slowing (?red shift?)
C3/D3 Earth orbit/spin ratio { o:s_Ea } 1:365
currently spin slowing ? XfasterX Slower than orbit slowly Slowing dS/dO=1.?+
C4/D2 Sun orbit/spin ratio { o:s_Su } ?:24e7
split | outer stars slowing inner speading up?
C5/D1 Galaxy orbit/spin ratio ( o:s_Ga } 1:Big?
? What do Galaxies orbit? Each other ? Center of Uni ? {i donno}
Note If C1/D5 non existant then assume C6/D0 may? {beyound Uni}

<font size=-1>[ This Message was edited by: HUb' on 2002-12-11 19:14 ]</font>

[Mainframes]

Correct me if i'm wrong, but I always thought that the earth was slowing down (albeit at a very slow rate) due to interactions with the moon.

The underlying principle being the conservation of momentum and angular momentum, and the fact the moon is gradually gaining momentum from the earth causing the earth to slow down until it is tidally locked to the moon. Much like the moon is to earth already.

[Donnie B.]

Mainframes, you're correct. However, the rate of that slowdown is not constant. The Earth-Moon interactions are complex, with a lot of variables coming into play (such as the shape and position of the continents). So sometimes the deceleration is more pronounced than others. Hence the irregular application of leap seconds.

<a name="2-12-13.dD"> page= 2-12-13.dD aka dD
On 2002-12-11 09:48, Donnie B. wrote:
1 I tried2 access the lunar Distance data
never could understand the Laser numbers
3 My approach to the Distance question would be
different {IF I COULD} i would use
<a name="2-12-13.Lnk"> line= 2-12-13.Lnk
http://www.badastronomy.com/phpBB/vi...ic=311&forum=3
7 GeoSyncronus Satalite downLINKs
not the Graphics But THE RF carrier itself (see next post)

<font size=-1>[ This Message was edited by: HUb' on 2002-12-13 12:26 ]</font>

December 13, 2002 9:34 A.M.
<a name="2-12-13.rfD"> page= 2-12-13.rfD aka Radio Frequency Doppler
the THeory of Distance {based upon RF doppler}
1 Goes line this
Earth)=====0 Ge0syncrOnus satalite
a reciever/recorders set up on Earth
to recieve a downlink Radio Frequency signal
from a GeoSyncrnous satalite (no I don't know which 1)
anyone will do? {thats my guess}
anyway as the moon tugs the satalite away from
Earth as it passes over head at the Satalites Longitude
the RF carrier from the radio should shift
to a lower frequency ..thus there should be a STANDARD
shift up and down / phase locked to the Moon
of the RF doppler shift.. Once THERE IS A STANDARD plot
then veriation's from the standard should be found { as Sky lab passes benighth?} etc?

<a name="2-12-14.mh3"> page= 2-12-14.mh3 aka 5:59 A.M. Mh 3
On 2002-12-13 12:36, HUb' wrote: To? HUb'
1 yeah caluclate the doppler shift
differential on the approaching edge
3 and on the receeding edge of earth?

<a name="2-12-14.LkB"> line= 2-12-14.LkB
http://www.badastronomy.com/phpBB/vi...3187&forum=3&5
7
for a geostationary it would seam? at first
glance that /o there would be no shift
on eiithor side East or West
---------------------------
in terms of absolutes {reluctant Line of reason?}
it may be that the exact wave length WEST
would not exactly equal the wavelenght East?
========= I dont really know .. its of interest
and Iwill work on it {see how many years it takes}
for my 1st approximation to be posted {Math hours OVER}.

[GrapesOfWrath]

On 2002-12-14 09:01, HUb' wrote:
reluctant Line of reason?

You're dragging reason into this?

I have one question, what object are you asking about here: "as Sky lab passes benighth?"

[Tim Thompson]

Mainframes: ... I always thought that the earth was slowing down (albeit at a very slow rate) due to interactions with the moon.

Donnie B: Mainframes, you're correct. However, the rate of that slowdown is not constant.

Indeed not. I have written a FAQ file for the Talk.Origins archive which discusses the tidal interaction between Earth & the moon at some length: "The Recession of the Moon and the Age of the Earth-Moon System". Although written to counter creationist claims of a "young" Earth-moon system, the discussion is still much in line with the questions here.

At the moment, the rate of slowdown is about 0.0015 sec/day/century, meaning that every 100 years, the "24 hour day" gets 0.0015 seconds longer. It is an abnormally high rate of change, due to the fact that the size of Earth's ocean basin's is about the same as the wavelength of the lunar tidal wave, so they resonate and accelerate the slowdown. Once the continents drift around a bit, the slowdown rate will decrease rather noticably.

Some of the energy lost to Earth's spin is transferred to the moon, and it moves away from Earth as it gains energy. The rest of the energy is lost to thing like dissipation as heat in Earth's mantle. Today, most of the energy goes to the moon, but when the Earth was infantile, most of it went into dissipation.

As for the leapseconds, see the "What is a Leap Second?" page posted by WHarris. The leap second is not really related to Earth's slowdown, but rather to the fact that one UTC second and one TAI second are not the same, so there is a "beat frequency" between them. Out of an arbitrary desire to keep both clock's within 0.9 seconds of each other, the leap second is periodically added. So its sole function is to make two clocks, which run at differing rates, read the same time.

The Chandler wobble is probably due to exchange of angular momentum between the atmosphere, oceans, and solid Earth, though noone has proven this as far as I know. Friction at the core-mantle boundary is certainly responsible for the microsecond sized "jerks" in rotation speed, that happen essentially on a daily basis; see Excess to 86400s of the duration of the days, combined GPS solution, 1995-1997. The referenced diagram shows sharp, sub-millisecond sized "jerks" in the length of day, as well as a millisecond sized seasonal signature, which is certainly caused by an exchange of momentum between the atmosphere (mostly) and oceans and solid Earth.

But don't be too surprised if nothing "spectacular" happens in the next 6 months, as Dunash hints. The average heat energy coming up through the Earth's surface at the moment is about 0.0615 Watts/m^2, as compared to the top of atmosphere solar constant of about 1360 Watts/m^2. So if the Earth wants to compete with the sun for heat at the surface, the "jerk" might just knock you over.

And just to keep things astronomical, I will point out that the Chandler wobble was discovered by astronomers. Astronomers practicing precision astrometry discovered that their own station latitudes were not constant, which had been thought impossible. The International Latitude Service, established in 1899, was the response to the discovery that latitude could vary with time; see, for instance, "Historical Development of Earth Rotation Knowledge". So far as I know, the International Latitude Service no longer exists, its functions absorbed by the International Earth Rotation Service, represented in the U.S. by the Earth orientation Department of the U.S. Naval Observatory (it's still done by astronomers).

Cheers.