Subject: Re: [time-nuts] A different timenuts interest
Hi all,
I would like to thank everyone who responded to my post. This is a wonderful
group of talented and erudite people and it was a pleasure to read the posts
(and private emails) on the subject of the Foucault pendulum. Where else
could the
> Another perspective on time: http://www.longnow.org/clock/
> And some fascinating mechanical stuff.
The mechanical branch of time-nuts.
They have an office, show-room, museum, store, whatever in Fort Mason in San
Francisco. If you like neat mechanical stuff, it's well worth a trip. It's
art
Hi all,
I would like to thank everyone who responded to my post. This is a wonderful
group of talented and erudite people and it was a pleasure to read the posts
(and private emails) on the subject of the Foucault pendulum. Where else
could the discussion range over timekeeping, mechanical suspens
J. Forster wrote:
E A Foucalt Pendulum is not about time! It's about motion in
inertial space.
are they not the same, underneath it all?
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Another perspective on time: http://www.longnow.org/clock/
And some fascinating mechanical stuff.
-Demian
Message: 4
Date: Fri, 23 Jul 2010 02:11:04 +0200
From: Magnus Danielson
Subject: Re: [time-nuts] A different timenuts interest
To: Discussion of precise time and
E A Foucalt Pendulum is not about time! It's about motion in
inertial space.
-John
===
> Matthew,
>
> On 07/23/2010 02:15 AM, Matthew Kaufman wrote:
>> Magnus Danielson wrote:
>>> On 07/23/2010 01:54 AM, Oz-in-DFW wrote:
Hmmm. I thought time-nuts were nuts about time,
Matthew,
On 07/23/2010 02:15 AM, Matthew Kaufman wrote:
Magnus Danielson wrote:
On 07/23/2010 01:54 AM, Oz-in-DFW wrote:
Hmmm. I thought time-nuts were nuts about time, with branch interests
in accuracy, resolution, history...
History is nanoseconds ago.
Recent history is picoseconds ago.
Ju
Magnus Danielson wrote:
On 07/23/2010 01:54 AM, Oz-in-DFW wrote:
Hmmm. I thought time-nuts were nuts about time, with branch interests
in accuracy, resolution, history...
History is nanoseconds ago.
Recent history is picoseconds ago.
Just now is femtoseconds ago.
Fraction of mind ago is attos
-nanosecond to leap seconds, to leap years, to ...
John WA4WDL
--
From: "Jean-Louis Oneto"
Sent: Thursday, July 22, 2010 7:11 PM
To: "Discussion of precise time and frequency measurement"
Subject: Re: [time-nuts] A different timenuts int
John WA4WDL
>
> --
> From: "Jean-Louis Oneto"
> Sent: Thursday, July 22, 2010 7:11 PM
> To: "Discussion of precise time and frequency measurement"
>
> Subject: Re: [time-nuts] A different timenuts interest
>
>> I a
e and frequency measurement"
Subject: Re: [time-nuts] A different timenuts interest
I also think so,
but Time-nuts are nuts about attoseconds, not decades... ;-}
Jean-Louis Oneto
- Original Message -
From: "Bob Camp"
To: "'Discussion of precise time and frequen
f mike cook
Sent: Thursday, July 22, 2010 3:27 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] A different timenuts interest
As a number of examples have been referenced in the reply to the
original post, I will add a note on one of pendulums that Foucault
himself constructed.
Foucaults origin
time-n...@kasperkp.dk said:
> As a kid, I did a self sustaining pendulum with no moving parts and no
> magnets:
> The bob was suspended by two parallel wires, lacquered together, and
> shorted at the bob end. As the bob passed over the center, a one-shot sent
> a good-sized current pulse through
2010 3:27 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] A different timenuts interest
As a number of examples have been referenced in the reply to the
original post, I will add a note on one of pendulums that Foucault
himself constructed.
Foucaults original experiments used shortish c
I thought that might have caused some confusion ;) . The bob, of course.
I guess it can be replaced, but it is a shame that as a historical
instrument, it could not have been better cared for. All is not lost
though, as one of his smaller original pendulums is swinging in the
Panthéon it seems
> Unfortunately the cable reached its sell by date on the 18th May this year
> when it broke, dropping the ball on the marble floor , denting it. Most
> unfortunate.
Denting the bob or the marble floor? :)
___
time-nuts mailing list -- time-nuts@febo.c
As a number of examples have been referenced in the reply to the
original post, I will add a note on one of pendulums that Foucault
himself constructed.
Foucaults original experiments used shortish cables, but Napoleon
wanted a more prestigeous affaire. It was originally installed by
Foucaul
essage-
>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
>> Behalf Of Bob Camp
>> Sent: Thursday, July 22, 2010 11:53 AM
>> To: 'Discussion of precise time and frequency measurement'
>> Subject: Re: [time-nuts] A different timenut
Wouldn't that affect the path of the pendulum
by interacting with the Earth's magnetic field?
:)
J. Forster wrote:
How about putting a high voltage, high frequency on the bob and wire, so
any body part that gets within say 2 feet draws giant arcs? :<))
-John
_
Sent: Thursday, July 22, 2010 11:53 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] A different timenuts interest
Hi
At > $30K certainly not cheap. My guess is that the building modifications
and permits will set you back a pretty significant c
ime-nuts-boun...@febo.com] On
> Behalf Of Brooke Clarke
> Sent: Thursday, July 22, 2010 10:38 AM
> To: Discussion of precise time and frequency measurement
> Cc: Morris Odell
> Subject: Re: [time-nuts] A different timenuts interest
>
> Hi Morris:
>
> See:
> http://www.ca
a much better decision
than a one off.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Brooke Clarke
Sent: Thursday, July 22, 2010 10:38 AM
To: Discussion of precise time and frequency measurement
Cc: Morris Odell
Subject: Re:
ame coil to
>accelerate
>the pendulum and keep it swinging in infinity, or until the battery died,
>whichever came
>first.
>
>Have you looked for ideas on Bryan Mumford's website?
>
>-- FL
>
>
>
>--- Den ons 21/7/10 skrev Morris Odell :
>
>
>Fra
Eugen Leitl wrote:
On Wed, Jul 21, 2010 at 10:40:48PM -0400, Bob Bownes wrote:
Silly me, I just realized you need to compensate for the change in
length with temperature.
You could use an Invar wire.
Some insight from a friend (a proto-timenut) who was thinking about
building a 1ppm free pe
Hi Morris:
See:
http://www.calacademy.org/products/pendulum/pendulum_sales.html
http://www.calacademy.org/products/pendulum/pendspec.pdf
they are not cheap, but a proven design and probably lower in cost than
making just one of them.
One of these was working at Foothill College in Los Altos H
http://www.astro.louisville.edu/foucault/pendulum.pdf is one of the best
references I have in my bookmarks.
Matthew Kaufman
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On Wed, Jul 21, 2010 at 7:57 PM, J. Forster wrote:
> > I remember one someplace in London too.
>
> Science Museum in South Kensington, I'd expect, but I've not been there
> 20+ years.
>
>
Yes, they have one in one of their open multi-storey stairwells. If I
remember correctly, the energy input i
On Wed, Jul 21, 2010 at 10:40:48PM -0400, Bob Bownes wrote:
> Silly me, I just realized you need to compensate for the change in
> length with temperature.
You could use an Invar wire.
> This sounds like a great project!
>
>
> On Wed, Jul 21, 2010 at 10:26 PM, Bob Bownes wrote:
> > There is a
ed,
whichever came
first.
Have you looked for ideas on Bryan Mumford's website?
-- FL
--- Den ons 21/7/10 skrev Morris Odell :
Fra: Morris Odell
Emne: [time-nuts] A different timenuts interest
Til: time-nuts@febo.com
Dato: onsdag 21. juli 2010 17.13
Hi all,
I have been ask
On 07/22/2010 02:13 AM, Morris Odell wrote:
The pendulum requires a sustaining system to compensate for the inevitable
energy loss with each swing. The system is located in the building and
therefore rotates relative to the pendulum. It needs to provide an impulse
which does not affect the plane
J. Forster wrote:
The problem is straight forward, except for sensing the position of the
pendulum so the impulse is applied at the correct phase.
There must be a bunch of published designs, but if I were to try it, I'd
use something optical or capacitive.
For optical, I'd put a annular ring of
Morris Odell wrote:
Hi all,
I have been asked to help with the construction of a Foucault pendulum. This
is a long pendulum which oscillates in a slow stately fashion in a fixed
plane which appears to move as the earth rotates. In reality the surrounding
environment is really moving relative to
[snip]
> The bob on a Foucault pendulum is usually quite massive, so there's no
> reason
> why it can't be inexpensive lead-acid batteries that are recharged by
> solar cells.
IMO, there is no reason to put anything active on the bob.
> I'm sure you'd save money over mechanisms to move the pivot
> I remember one someplace in London too.
Science Museum in South Kensington, I'd expect, but I've not been there
20+ years.
-John
> Someone mentioned temperature compensation. What would you need to
> compensate for? Temp change in the wire wouldn't effect the rotation
> as far as I can tell. S
bow...@gmail.com said:
> Silly me, I just realized you need to compensate for the change in length
> with temperature.
It depends...
If your setup to replace the energy is PLLed to the pendulum position it
doesn't need to know the period. (at least not very accurately)
--
These are my opi
Silly me, I just realized you need to compensate for the change in
length with temperature.
This sounds like a great project!
On Wed, Jul 21, 2010 at 10:26 PM, Bob Bownes wrote:
> There is at least one in DC, at the Smithsonian iirc.
>
> RPI, where I went to college, had one in the 3 story stai
awkins (also on Jack's BA list)
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Morris Odell
Sent: Wednesday, July 21, 2010 7:13 PM
To: time-nuts@febo.com
Subject: [time-nuts] A different timenuts interest
Hi all,
I have been asked
There is at least one in DC, at the Smithsonian iirc.
RPI, where I went to college, had one in the 3 story stairwell in the
library. Don't know if it is still there.
I remember one someplace in London too.
Someone mentioned temperature compensation. What would you need to
compensate for? Temp ch
> The Museum of Science and Industry in Chicago had one when
> I lived there in the 1960's.
You lived at the Museum of Science and Industry? :)
Sorry, couldn't resist. But, you actually can live there for a month:
http://www.msichicago.org/matm/
Randy.
__
Hal Murray wrote:
Several years ago, I found a web site for a commercial place that made them
for museums. (I forget why I was looking for that sort of stuff.) You might
find interesting stuff/ideas via google but I didn't find a similar site with
a bit of searching.
The Museum of Scie
Griffith Park in LA operates a Foucault pendulum that's been going for at
least 70 years (don't ask how I know). They might have a writeup
somewhere. I think te pivot was a simple clamp holding the piano wire.
You'd think it would fail from stress, but the pendulum is very long, so
the angle of the
On 7/21/2010 7:13 PM, Morris Odell wrote:
Hi all,
I have been asked to help with the construction of a Foucault pendulum. This
is a long pendulum which oscillates in a slow stately fashion in a fixed
plane which appears to move as the earth rotates. In reality the surrounding
environment is real
> ... Foucault pendulum ...
> Has anyone here had any experience with such a system of have any
> suggestions regarding the sustaining system? This is an interesting and
> challenging project.
Several years ago, I found a web site for a commercial place that made them
for museums. (I forget w
Hi
If you use the mechanical system (raise and lower the pivot point): Can you use
the strain on the pivot to get the "location" information?
Bob
On Jul 21, 2010, at 8:53 PM, Mike S wrote:
> At 08:13 PM 7/21/2010, Morris Odell wrote...
>> Has anyone here had any experience with such a system
At 08:13 PM 7/21/2010, Morris Odell wrote...
Has anyone here had any experience with such a system of have any
suggestions regarding the sustaining system? This is an interesting
and
challenging project.
Scientific American, back in June 1958, covered many details of
Foucault pendulums, from
On 07/22/2010 02:13 AM, Morris Odell wrote:
Hi all,
I have been asked to help with the construction of a Foucault pendulum. This
is a long pendulum which oscillates in a slow stately fashion in a fixed
plane which appears to move as the earth rotates. In reality the surrounding
environment is re
The problem is straight forward, except for sensing the position of the
pendulum so the impulse is applied at the correct phase.
There must be a bunch of published designs, but if I were to try it, I'd
use something optical or capacitive.
For optical, I'd put a annular ring of IR LED/Phototransis
Hi all,
I have been asked to help with the construction of a Foucault pendulum. This
is a long pendulum which oscillates in a slow stately fashion in a fixed
plane which appears to move as the earth rotates. In reality the surrounding
environment is really moving relative to the plane of oscillati
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