Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV),
Tom
Impressive. Nice job.
How would one go about to prove beyond a doubt in that experiment that 18ns
of phase shift in 24 hrs was truly caused by freq offset due to Relativity
and not by some other combination of environment and handling issues that
effected phase &/or freq once the identical clocks where separated and
operating at different temperatures, pressures, elevations, vibration, tilt
angles, power supply voltages, airflow, cosmic rays, ozone, or some other
unmeasured things that may be effecting the results?
To increase gravity a lot more than a 7,000 ft altitude change, and
without changing the environment variables, could one set of the CS clocks
be put on a centrifuge, such as a fast spinning merry-go-round at a local
park?
Anyone know what the 2G turn over effect, TC, etc, is of portable CS
standards? Ideally they should all be zero, but probable aren't.
ws
Hi
If you noticed, when they played at the back of the car, Tom seemed to have a few “spare”
5071’s along….. Just out driving around with a half dozen 5071’s in the middle of Arizona ….
nothing at all odd about that ….
Any time you see a TV show that does something like this, you can be pretty sure that there
are things going on to make it “flow” for the average viewer. I think they did a terrific job in
that respect, without turning it into mush.
Bob
On May 21, 2016, at 11:37 AM, ws at Yahoo via time-nuts time-nuts@febo.com wrote:
Tom
Impressive. Nice job.
How would one go about to prove beyond a doubt in that experiment that 18ns
of phase shift in 24 hrs was truly caused by freq offset due to Relativity
and not by some other combination of environment and handling issues that
effected phase &/or freq once the identical clocks where separated and
operating at different temperatures, pressures, elevations, vibration, tilt
angles, power supply voltages, airflow, cosmic rays, ozone, or some other
unmeasured things that may be effecting the results?
To increase gravity a lot more than a 7,000 ft altitude change, and
without changing the environment variables, could one set of the CS clocks
be put on a centrifuge, such as a fast spinning merry-go-round at a local
park?
Anyone know what the 2G turn over effect, TC, etc, is of portable CS
standards? Ideally they should all be zero, but probable aren't.
ws
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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On 5/21/2016 8:37 AM, ws at Yahoo via time-nuts wrote:
How would one go about to prove beyond a doubt in that experiment that 18ns
of phase shift in 24 hrs was truly caused by freq offset due to Relativity
and not by some other combination of environment and handling issues that
effected phase &/or freq once the identical clocks where separated and
operating at different temperatures, pressures, elevations, vibration, tilt
angles, power supply voltages, airflow, cosmic rays, ozone, or some other
unmeasured things that may be effecting the results?
To increase gravity a lot more than a 7,000 ft altitude change, and
without changing the environment variables, could one set of the CS clocks
be put on a centrifuge, such as a fast spinning merry-go-round at a local
park?
Anyone know what the 2G turn over effect, TC, etc, is of portable CS
standards? Ideally they should all be zero, but probable aren't.
ws
I was on the 5071A design team 25 years ago. I designed most of the RF
sections. We analyzed all known environmental effects (they were
known from experience with the 5061) and, using newer digital
technology, the individual effects where budgeted to better than
10^-14 each, and in most cases much better. Len Cutler insisted!
It was refreshing to have a manager who didn't believe in "good enough".
This budgeting was to address ABSOLUTE accuracy. We feel we proved
that absolute accuracy was mainly limited to end to end phase shift
in the Cs cavity. Proprietary techniques were used to reduce this to
values equivalent to a mechanical asymmetry of a small fraction of a
"mil" (1/1000 inch).
Tom's experiment only requires STABILITY. As you can see from Tom's
measurements vs an H maser, the Allan deviation is pure white noise
down to where the curves end at 10^-14. Thus for sufficiently long
averaging time, the stability can be measured to this accuracy.
Even at this level, AD still has not "flickered out" meaning the
it would level off, and would not improve with additional time
averaging.
Various environmental tests were done with extremely long averaging
in an attempt to put a number on parameters such as tempco, humidity,
pressure, magnetic field, etc. These tests took place over the
better part of a year. The results were that none of these parameters
could be measured, because no effects were observed. We could only
say that there was an upper bound in the area of 10^-15 on these
effects.
2G turnover is a special case. Because the beam is a physical stream
of particles, it is possible that acceleration could affect the
beam. Len Cutler discovered that previous HP cesium beam tubes
had a design flaw that made them have transient errors when used
in submarines (IOW they could get "seasick" :-). I don't remember
exactly the details, but it was something like using dual beams,
that seemed like a good idea at the time, but had some sort of
physics fallacy. Simply mounting the standard upside down vs
right side up does not create any error as it does in a crystal
oscillator. I believe that the perfected design was also immune
to the act of flipping it over, carrying it around, or driving
around in a car with it. I don't know about a centrifuge. At
some point, the internal OCXO error will not be correctable
by the slow feedback loop. Let's be reasonable here.
In any event, event the original 5060A flying clock trips made
by Cutler himself survived baggage handlers (who I am sure were
on their best behavior under Len's watchful eye.) The 5071A is
light years ahead of that design, with virtually everything
under closed loop control.
We felt that we did as well as was possible for a non-reversible
cavity of that size, without optical pumping. Not to mention
that it runs on an internal lead acid battery (this was before Li Ion)
and can be lifted by one (strong) person.
It was great to see that this clock is still relevant as it nears
its 25th birthday.
Rick Karlquist N6RK
I too enjoyed the show as well as Tom's part in it. However call me "doubting Thomas" or in this case Mike, I have the same concerns as expressed by "ws". Also, an initial comparison of the two used, at low altitude, to show an unmeasurable difference would have been helpful. All that aside it was great, and, I am not smart enough to understand it all anyway. Regards - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of ws at Yahoo via time-nuts
Sent: Saturday, May 21, 2016 11:37 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV),
Tom
Impressive. Nice job.
How would one go about to prove beyond a doubt in that experiment that 18ns of phase shift in 24 hrs was truly caused by freq offset due to Relativity and not by some other combination of environment and handling issues that effected phase &/or freq once the identical clocks where separated and operating at different temperatures, pressures, elevations, vibration, tilt angles, power supply voltages, airflow, cosmic rays, ozone, or some other unmeasured things that may be effecting the results?
To increase gravity a lot more than a 7,000 ft altitude change, and without changing the environment variables, could one set of the CS clocks be put on a centrifuge, such as a fast spinning merry-go-round at a local park?
Anyone know what the 2G turn over effect, TC, etc, is of portable CS standards? Ideally they should all be zero, but probable aren't.
ws
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hoi Rick
On Sat, 21 May 2016 10:02:50 -0700
"Richard (Rick) Karlquist" richard@karlquist.com wrote:
I was on the 5071A design team 25 years ago. I designed most of the RF
sections. We analyzed all known environmental effects (they were
known from experience with the 5061) and, using newer digital
technology, the individual effects where budgeted to better than
10^-14 each, and in most cases much better. Len Cutler insisted!
It was refreshing to have a manager who didn't believe in "good enough".
I'd give a lot to read the design documents of the 5071.
There must be a lot of knowhow and techniques in them.
This budgeting was to address ABSOLUTE accuracy. We feel we proved
that absolute accuracy was mainly limited to end to end phase shift
in the Cs cavity. Proprietary techniques were used to reduce this to
values equivalent to a mechanical asymmetry of a small fraction of a
"mil" (1/1000 inch).
What reference did you use to measure its absolute accuracy?
Did you have access to the NIST standards?
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
On Sat, 21 May 2016 08:37:25 -0700
ws at Yahoo via time-nuts time-nuts@febo.com wrote:
To increase gravity a lot more than a 7,000 ft altitude change, and
without changing the environment variables, could one set of the CS clocks
be put on a centrifuge, such as a fast spinning merry-go-round at a local
park?
A centrifuge does not increase gravity. It only applies an ever changing
accelerating force onto the object. As such, it does not change how
time progresses.
The only two things that have this effect are (true) gravity and speed.
The book "Modern Physics" by Tipler and Llewellyn has a very nice and
easy to understand introduction into special and general relativity
and is worth a read.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
Hi Bob,
That's right. The Hawking/PBS show wanted to show time dilation. My goal was to make absolutely sure that the experiment worked. Given that the UK producers flew a group of ten to Tucson for the filming I did not want to be the one to screw up. So that's one reason my car had so much gear. It's wasn't "spare" like an unused spare tire; all the gear was running.
A full set of 3 + 3 clocks, counters, dist amps, power supplies, laptops, a triple redundant 12/12/120 VAC power system, 750 pounds of batteries, etc. All clocks were compared for a week before the trip and during the 2 day trip down to Arizona, as well as comparison amongst the 3 hotel/car clocks and the 3 summit clocks. Again, I did not want to be the one to screw up the film, or make relativity look bad. Oh, it was also a one-shot experiment; the schedule did not permit any "re-takes". So let's say I felt some pressure to make sure it all worked. I even signed up for AAA when I realized that the car itself was a single point of failure.
I brought the SR620 along because I like its bold camera-friendly display. For the final scene we used it along with just two 5071A, to keep things simple. The focus was time dilation, not clock ensembles or multi-channel phase comparison techniques. But, yes, behind the scenes, all 6 clocks and 53132A counters were used in the experiment. This arrangement allowed me a seamless backup if one (or even two) of the clocks died, or lost power, or was dropped. As it turns out nothing went wrong, so my reward is more data than necessary; for additional self-checking or a sqrt(n) boost.
/tvb
----- Original Message -----
From: "Bob Camp" kb8tq@n1k.org
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Saturday, May 21, 2016 9:15 AM
Subject: Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV),
Hi
If you noticed, when they played at the back of the car, Tom seemed to have a few “spare”
5071’s along….. Just out driving around with a half dozen 5071’s in the middle of Arizona ….
nothing at all odd about that ….
Any time you see a TV show that does something like this, you can be pretty sure that there
are things going on to make it “flow” for the average viewer. I think they did a terrific job in
that respect, without turning it into mush.
Bob
Mike,
For the episode itself it was probably unnecessary to show that zeroing or syncing step. But of course it's important to me, the original doubting Thomas, and is covered in all the data analysis.
For you, or others who want to read more about the experiment, scroll down to the time dilation plots:
http://leapsecond.com/great2016a/photos.htm
/tvb
----- Original Message -----
From: "Mike Feher" mfeher@eozinc.com
To: warrensjmail-one@yahoo.com; "'Discussion of precise time and frequency measurement'" time-nuts@febo.com
Sent: Saturday, May 21, 2016 11:03 AM
Subject: Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV),
I too enjoyed the show as well as Tom's part in it. However call me "doubting Thomas" or in this case Mike, I have the same concerns as expressed by "ws". Also, an initial comparison of the two used, at low altitude, to show an unmeasurable difference would have been helpful. All that aside it was great, and, I am not smart enough to understand it all anyway. Regards - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of ws at Yahoo via time-nuts
Sent: Saturday, May 21, 2016 11:37 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV),
Tom
Impressive. Nice job.
How would one go about to prove beyond a doubt in that experiment that 18ns of phase shift in 24 hrs was truly caused by freq offset due to Relativity and not by some other combination of environment and handling issues that effected phase &/or freq once the identical clocks where separated and operating at different temperatures, pressures, elevations, vibration, tilt angles, power supply voltages, airflow, cosmic rays, ozone, or some other unmeasured things that may be effecting the results?
To increase gravity a lot more than a 7,000 ft altitude change, and without changing the environment variables, could one set of the CS clocks be put on a centrifuge, such as a fast spinning merry-go-round at a local park?
Anyone know what the 2G turn over effect, TC, etc, is of portable CS standards? Ideally they should all be zero, but probable aren't.
ws
On Sat, 21 May 2016 20:30:16 +0200
Attila Kinali attila@kinali.ch wrote:
The only two things that have this effect are (true) gravity and speed.
TvB and ws both pointed out that I am wrong here.
A homogenous gravity field and linear acceleration are indisdinguishable.
The rest of the mail still holds, as a centrifuge does not apply a
linear acceleration, but a rotating vector who's average is zero.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
On 5/21/2016 11:25 AM, Attila Kinali wrote:
I'd give a lot to read the design documents of the 5071.
There must be a lot of knowhow and techniques in them.
Read papers by me and my colleagues at the 1992 Frequency
Control Symposium. There is nothing else in the public
domain.
What reference did you use to measure its absolute accuracy?
Did you have access to the NIST standards?
Attila Kinali
At that time, HP had an ensemble of 5061B's that they
compared to LORAN and it was somehow traceable to NIST.
It was claimed to be the most accurate clock on the
west coast at the time.
Also, one of the first pilot production units was
actually taken to Boulder and compared directly with
NIST's frequency reference. I remember that it was
off by a few parts in 10^13, after correcting for
the gravitation effect of Boulder at 5000 ft vs
Santa Clara at sea level.
Over time, customers like NIST and the Naval Observatory
accumulated data on 5071A's to establish their accuracy.
At one time, 85% of the weight of the TAI (International
Atomic Timescale) consisted of 5071A's. Jack Kusters said
that, as a group, the 5071A's were accurate to around
10^-14, because there were no significant systematic errors.
Hard to argue with that.
Rick