On 6/4/19 3:21 PM, Poul-Henning Kamp wrote:
In message
, "William H. Fite" writes:
What I am asking is not the validity of the quest for better timing
but rather its tangible applications.
Tangible for who ?
For the average pedestrian there are no *current* tangible applications
On 6/4/19 3:05 PM, Hal Murray wrote:
Are we developing these incredible devices just to push boundaries? Or do
they have some practical purpose?
I don't know of any current projects that need a significantly better clock,
but that's the sort of thing that wouldn't get a lot of publicity -
Hi
G sensitivity in quartz crystals is a pretty well documented sort of thing. For
an AT cut numbers in the 1 to 2 ppb per G are
not uncommon. For SC’s the numbers may be a bit lower than that. It simply has
to do with the stress / strain properties of
the quartz and how they impact the
In answer to the question about radio astronomers, consider VLBI (Very Long
Baseline Interferometry).
VLBI is a mapping (imaging) process in which signals are *simultaneously*
received from
a small sky region of interest by a collection of radio telescopes
scattered about the world.
In order for
If I can stir the pot a bit.
What other standards are measured to the same degree of accuracy? i.e.
ppb or better.
The thing with TIME is that its measurement is a abstract concept. Most
other "standards" have a physical representation.
Cheers,
Will
On 5/06/19 10:21 AM, Poul-Henning Kamp
Can the shift be duplicated by an electromagnetic field?
If so this may be a was to fine tune an oscillator.
Glenn
On 6/3/2019 6:29 PM, Adrian Godwin wrote:
On Mon, Jun 3, 2019 at 11:01 PM Andy Backus wrote:
2. interesting observation: turning the unit 90 degrees onto its right
hand
The article cited below gives some examples of what Optical Lattice
Clocks (OLC) would be useful for:
https://ieeexplore.ieee.org/document/6905489
Rick N6RK
On 6/4/2019 9:43 AM, William H. Fite wrote:
What useful purpose, if any, is served by the continuing evolution of
clocks like NIST-F2
That's an excellent point, Bob. We have friends who have friends who are
involved with the long baseline interferometry (LIGO) lab in Louisiana. I
will inquire and, if they have any relevant information I will pass it
along to you.
Thanks for your reply.
On Tuesday, June 4, 2019, Bob kb8tq
I appreciate your point, one that I have emphasized to my graduate students
many times over 30 years of teaching. Of course you are entirely correct.
On Tuesday, June 4, 2019, Kevin Birth wrote:
> When a clock is represented as only losing a second in billions of years
> that is a statement
In message
, "William H. Fite" writes:
>What I am asking is not the validity of the quest for better timing
>but rather its tangible applications.
Tangible for who ?
For the average pedestrian there are no *current* tangible applications
where cesium level time-keeping isn't plenty.
In answer to your question, there are practical things that can be done
with an optical or electron microscope that cannot be done with unaided
vision. What I am asking is not the validity of the quest for better timing
but rather its tangible applications. Note that I did not say or even
suggest
You will have an answer if you can answer the question:
"Why is an optical microscope needed when unaided vision is good enough?"
My PhD is in high energy particle physics ca 1966.
This is not intended to be 'Dismissive and/or snarky'.
Your statement "Dismissive and/or snarky replies will be
Hi
One very basic thing that precision clocks allow you to dig deeper into is
gravity. A gravity wave passing between two clocks should show up as a time
ripple.
Bob
> On Jun 4, 2019, at 12:43 PM, William H. Fite wrote:
>
> Warning: Potentially heretical material below
>
> Let me begin by
Warning: Potentially heretical material below
Let me begin by saying I am neither an engineer nor a time expert. My PhD
is in statistics and my spouse's PhD is in theoretical computer science,
working on quantum computer algorithms. Neither of us claims any special
expertise when it comes to time
Attila Kinali wrote:
> Mike Cook wrote:
>
> > c. The first commercial cesium clocks were available in 1956, but the
> > second did not get redefined until 1967. There is no rush.
>
> Which caesium beam standards were available in 1956?
The Atomichron, I think:
Mike, Attila, Rick,
> Which caesium beam standards were available in 1956?
The Atomichron, made by the National Company. This was the first
commercial cesium standard; about 50 were made. Attila, you saw one at
my house when you visited last year. It's about 7 feet tall. The one I
have was
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