atomic clocks

[dave]

On 06/27/2014 09:15 AM, Jeff Liebermann wrote:

On Fri, 27 Jun 2014 08:02:28 -0700 (PDT), Tim R <timothy42b@aol.com
s-is-wrong/19387

The 16 seconds might not seem like much, but consider that it started
at zero 34 years ago. Left unchecked, we run the risk of repeating
the mess created by the harmonization of the Julian and Gregorian
calendars, which maintained an 11 day difference until 1752. There
were allegedly rioting in the streets demanding the return of the 11
lost days. Hopefully, that won't happen when UTC and GPS time are
eventually harmonized.

I hope this helps, but if you want a better explanation from the
experts, try the time nuts mailing list and archive:
http://www.febo.com/pipermail/time-nuts/

UTC and GPS used to be synchronized but you really can't skip GPS time
because it determines so many other processes. Much easier to get a GPS
clock with a programmable delay and tell the celestial navigators to
update their kit.

 

[Leif Neland]

Tim R har bragt dette til verden:

On Tuesday, June 24, 2014 2:02:04 PM UTC-4, Jeff Liebermann wrote:

Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for

astronomers, which is where the leap second originates.



Is this always true? So GPS is precise to the nanosecond, but inaccurate by
a quarter minute?

The GPS is precise. The earth is inaccurate.

Leif

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[Ian Field]

"dave" <ricketzz@earthlink.net> wrote in message
news:uPadnVSH6cQ5GSTOnZ2dnUVZ_radnZ2d@earthlink.com...

On 06/27/2014 08:02 AM, Tim R wrote:
On Tuesday, June 24, 2014 2:02:04 PM UTC-4, Jeff Liebermann wrote:

Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for

astronomers, which is where the leap second originates.



Is this always true? So GPS is precise to the nanosecond, but inaccurate
by a quarter minute?


The earth is slowing down its RPM.

Stop the world - I wanna get off.

 

[Jeff Liebermann]

On Sun, 06 Jul 2014 10:17:24 -0700, dave <ricketzz@earthlink.net>
wrote:

On 06/27/2014 08:02 AM, Tim R wrote:

On Tuesday, June 24, 2014 2:02:04 PM UTC-4, Jeff Liebermann wrote:
Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for
astronomers, which is where the leap second originates.

Is this always true? So GPS is precise to the nanosecond, but inaccurate by a quarter minute?

The earth is slowing down its RPM.

Too much friction. When that happens, you should lubricate the
bushings on your globe. If that's insufficient, replace them with air
bearings, which should help decrease the rate of slowing.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Tim R]

On Sunday, July 6, 2014 3:54:07 PM UTC-4, Jeff Liebermann wrote:

On Sun, 06 Jul 2014 10:17:24 -0700, dave <ricketzz@earthlink.net

wrote:



On 06/27/2014 08:02 AM, Tim R wrote:



On Tuesday, June 24, 2014 2:02:04 PM UTC-4, Jeff Liebermann wrote:

Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for

astronomers, which is where the leap second originates.



Is this always true? So GPS is precise to the nanosecond, but inaccurate by a quarter minute?



The earth is slowing down its RPM.



Too much friction. When that happens, you should lubricate the

bushings on your globe. If that's insufficient, replace them with air

bearings, which should help decrease the rate of slowing.

A magnetic bearing would be great, but that would require the earth have a magnetic field.

Oh wait..............

 

[Jeff Liebermann]

On Mon, 7 Jul 2014 08:20:52 -0700 (PDT), Tim R <timothy42b@aol.com>
wrote:

On Sunday, July 6, 2014 3:54:07 PM UTC-4, Jeff Liebermann wrote:
On Sun, 06 Jul 2014 10:17:24 -0700, dave <ricketzz@earthlink.net
The earth is slowing down its RPM.

Too much friction. When that happens, you should lubricate the
bushings on your globe. If that's insufficient, replace them with air
bearings, which should help decrease the rate of slowing.

A magnetic bearing would be great, but that would require the earth have a magnetic field.
Oh wait..............

No waiting required. Magnetic levity is commonly available:
<https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Tim R]

On Monday, July 7, 2014 2:14:11 PM UTC-4, William Sommerwerck wrote:

"Jeff Liebermann" wrote in message

news:kdhlr91fqtqrglknfu4h1nkebvi4qdeigk@4ax.com...



No waiting required. Magnetic levity is commonly available:

https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch



What's funny about magnetism?

I'm shocked you don't get it.

 

[jfeng@my-deja.com]

On Monday, July 7, 2014 9:18:15 AM UTC-7, Jeff Liebermann wrote:

No waiting required. Magnetic levity is commonly available:

https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch

That's nothing. Andre Geim, winner of the 2010 Nobel Prize in physics for graphene, also won the 2000 Ig Nobel Prize for levitating frogs and mice with magnetic fields.

 

[William Sommerwerck]

"Jeff Liebermann" wrote in message
news:kdhlr91fqtqrglknfu4h1nkebvi4qdeigk@4ax.com...

No waiting required. Magnetic levity is commonly available:
https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch

What's funny about magnetism?

 

[Michael A. Terrell]

Jeff Liebermann wrote:

On Sun, 22 Jun 2014 02:10:36 +0100, "Arfa Daily"
arfa.daily@ntlworld.com> wrote:

I have another atomic clock with an external antenna. I'll set it up so
it's vertical, and see what happens over the next day or two.

Surely 'atomic clock' is the wrong term for these devices ? As I understand
it, an atomic clock is a laboratory time-standard instrument based on the
decay rate of some atomic isotope, usually caesium ? The devices to which
you are referring are radio-synchronised clocks (also referred to, again
wrongly in my opinion, as "radio controlled clocks" ), deriving their
synchronisation from data broadcast from a number of low frequency
transmitters around the world. Otherwise, in between the synchronisation
times, these clocks are just free-running, much like any other clock.

http://en.wikipedia.org/wiki/Atomic_clock

Well, at the end of the WWVB chain, there is a cesium standard
oscillator feeding the station.

Yep. Even the NIST doesn't like the term.
WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers
and Consumers (2009 edition)
http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903649
See 9.B. Use of "Atomic Clock" Nomenclature Pg 34.
... we contend that use of the term "atomic
clock" is technically incorrect and misleading to
consumers, and its usage should be avoided. Unless
there is actually an atomic oscillator inside the
RCC (such as a cesium or rubidium oscillator), we
recommend that the term "radio controlled clock"
be used to correctly describe the product. Labeling
products or documentation with the term "atomic timekeeping"
is also considered acceptable.

Good luck stuffing this genie back into the bottle.

Incidentally, the easiest way to check your signal strength is to just
cram an oscilloscope into the clock module and look at the decoded
data. This should offer some clues as to what to look for:
http://www.leapsecond.com/pages/sony-wwvb/
(Note that the loopstick is horizontally mounted.)
According to the NIST, to obtain reliable updates, the decoded SNR
should be 20 dB or better. That should be easily visible on a scope
and what I'll try tonite.

http://www.tmchistory.org/tmc_manuals/tmc_commercial_manual_page.htm has
the manuals for the TMC transmitters used by all the WWV services. They
were designed for the US Navy.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

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