The eccentric English physicist Boys made quartz fibres by attaching one
end to a crossbow bolt, heating the middle and then firing the bolt, at
what I have been unable to determine. He used this to measure the
gravitational constant by suspending iron spheres from the resultant fibre,
which of
There is a good writeup of the Dicke switch in Horowitz Hill The Art of
Electronics, since Horiwitz is a radioastronomer of note. I've just bought
my daughter a copy for Xmas, poor girl, she wants to be an engineer...
Tom Harris celephi...@gmail.com
On 11 December 2013 13:02, Don Latham
:Hi Tom:
I can't find anything in the Table of Contents or in the index.
Can you tell me the page or title of the writeup?
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
Tom Harris wrote:
There is a good writeup of the Dicke switch in Horowitz
On 12/12/13 4:28 PM, Tom Harris wrote:
The eccentric English physicist Boys made quartz fibres by attaching one
end to a crossbow bolt, heating the middle and then firing the bolt, at
what I have been unable to determine. He used this to measure the
gravitational constant by suspending iron
It's in the section on lock in amplifiers I think. The switch has a clever
3 way action I think but I can't quire remember how it works. I do remember
thinking how ingenious it was at the time, since I was designing lock in
amplifiers for detecting optical absorbance over 10cm path lengths using
Jim Lux
The very one...
Don
Was that the same Boys who invented the Boys camera used to take
lightning photographs? It's a sort of rotating drum streak camera.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
-boun...@febo.com] On Behalf Of johncr...@aol.com
Sent: Tuesday, December 10, 2013 19:57
To: time-nuts@febo.com
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
(Brooke Clarke)
It is not surprising that one can find little about Alfred
Loomis. He was notoriously publicity shy
In message d82c3cbd5688ab036d49d2d32515a859.squir...@webmail.montana.com, Do
n Latham writes:
I think if I were to start designing, I'd use a quartz rod instead,
I'd go for SiC, like they did for the optics bench in the GAIA satellite
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
In message 82901.1386754...@critter.freebsd.dk, Poul-Henning Kamp writes:
In message d82c3cbd5688ab036d49d2d32515a859.squir...@webmail.montana.com, Do
n Latham writes:
I think if I were to start designing, I'd use a quartz rod instead,
I'd go for SiC, like they did for the optics bench in the
19:57
To: time-nuts@febo.com
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
(Brooke Clarke)
It is not surprising that one can find little about Alfred
Loomis. He was notoriously publicity shy and never gave
interviews. Before his death he had much of research material
Here's a well-written introduction to time frequency article. Both a good
overview for any newcomer to the group and some addition photos and recent
information for the rest of us:
Time - the SI Base Unit Second, by Andreas Bauch (PTB, 2012)
time and frequency measurement
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
Hi Tom:
The way I read the comment about detecting the influence of the Moon was
that it was discovered in 1984, but I was under the impression that
Loomis found it long before.
I looked on other Wiki pages
]
Sent: Tuesday, December 10, 2013 9:54 AM
To: 'Discussion of precise time and frequency measurement'
Subject: RE: [time-nuts] Shortt Clock Recent Measurements
Here's a specific reference from 1931:
http://adsabs.harvard.edu/full/1931MNRAS..91..575B
Bill Hawkins
-Original Message-
From
'; 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
Sorry, I should have read the article. It was found by asking for
Loomis moon pendulum
The article is fascinating to Shortt clock fans, but does not mention
the moon.
Use their page back
...@leapsecond.com
Date: Mon, 9 Dec 2013 18:39:26 -0800
To: time-nuts@febo.com
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
Brooke,
Not sure what you find in error; please explain.
I have all the Shortt info you need. Not all of it is for Wikipedia; contact
me off-line.
Just got
The Wiki page for the Shortt pendulum clock has a Recent Measurements
(1984) paragraph that's in error.
http://en.wikipedia.org/wiki/Shortt-Synchronome_clock#Recent_accuracy_measurement
While it's probably true that the clock is stable to 200 uS per day (i.e.
2E-9) I believe Alfred
One could try claiming that Loomis was the first to make detailed
measurements of a Shortt, but it would take some digging to prove
he was first and not just one of the first.
Just FYI:
During my reading of BSTJ I noticed a reference to a paper by
Loomis and Marrington at bottom of p4:
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
The Wiki page for the Shortt pendulum clock has a Recent Measurements
(1984) paragraph that's in error.
http://en.wikipedia.org/wiki/Shortt-Synchronome_clock#Recent_accuracy_
Baak
Sent: Tuesday, December 10, 2013 5:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
The Wiki page for the Shortt pendulum clock has a Recent
Measurements
(1984) paragraph that's in error.
http://en.wikipedia.org
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak
Sent: Tuesday, December 10, 2013 5:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
Hi Tom:
Here's a web page that has an annotated list of some patents applicable to
pendulums:
http://www.prc68.com/I/Pendulums.shtml
Many of the early gravity meters were just pendulums, then came the falling
corner reflectors.
There are a couple of patents by Dicke and this one:
3036465
Sent: Tuesday, December 10, 2013 5:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Shortt Clock Recent Measurements
The Wiki page for the Shortt pendulum clock has a Recent
Measurements
(1984) paragraph that's in error.
http://en.wikipedia.org
Brooke Clarke
PS When I was working in microwave electronics we talked about the Dicke
radiometer, but I haven't found any definitive
web page about that.
Gotta look at Radio Astronomy pages and history. Actually, Dicke was
using that radiometer to look for the microwave cosmic background,
It is not surprising that one can find little about Alfred Loomis. He was
notoriously publicity shy and never gave interviews. Before his death he had
much of research material disposed of. However the private lab he created at
Tuxedo Park NY. was a gathering place for all of the key scientists
On 12/10/13 5:57 PM, Don Latham wrote:
I always thought invar was the magic metal. Quartz rod? You can get
those
at some reasonable cost?
12 mm dia fused qtz, about $10 per ft, so under $40 to get going,
assuming 4 or 5 to learn how to do it right. It does break...
12.7 mm dia Invar 1 m long
Hi:
The Wiki page for the Shortt pendulum clock has a Recent Measurements (1984)
paragraph that's in error.
http://en.wikipedia.org/wiki/Shortt-Synchronome_clock#Recent_accuracy_measurement
While it's probably true that the clock is stable to 200 uS per day (i.e. 2E-9) I believe Alfred Loomis
I thought I needed to throw this in the mix.
http://www.allanstime.com/Research/Pendulum/index.html
Enjoy.
Thomas Knox
Date: Mon, 9 Dec 2013 17:02:22 -0800
From: bro...@pacific.net
To: time-nuts@febo.com
Subject: [time-nuts] Shortt Clock Recent Measurements
Hi:
The Wiki page
Brooke,
Not sure what you find in error; please explain.
I have all the Shortt info you need. Not all of it is for Wikipedia; contact me
off-line.
Just got back from the CalTech
Time Symposium:
http://leapsecond.com/nawcc2013/
The conjecture about tides is explained in great detail here:
Hi Tom:
The way I read the comment about detecting the influence of the Moon was that it was discovered in 1984, but I was under
the impression that Loomis found it long before.
I looked on other Wiki pages and did not see on any of the them information about Loomis and the effect of the Moon
29 matches
Mail list logo
