Hi: I have a some what related question.
I'm just curious how far back in time do the current time scales extend ?
(Ie. When was the first "second hack / synchronization" that can be related
to our current time.)
Thanks in advance for any answers.
Mark Spencer
All -- thanks much for all the great references! I am giving the preso this
afternoon (to a bunch of university space science students) so this will be a
big help. And it looks like there's a lot of great reading for when I have
time to breathe.
Thanks again.
John
On Mar 25, 2019, 10:03 PM,
It all depends on how far back you want to go. With mechanical
timepieces, even before the pendulum there was Jost Burgi¹s astronomical
clock which achieved a precision of a second, and is reported to have been
accurate to that level based on astronomical measurements. Tycho Brahe
tried to
I have been pondering something somewhat related to all of this.
We know that the smallest unit of a substance is a molecule. The smallest unit
of charge is maybe an electron. So what could one imagine the smallest unit of
time to be? Is time digital in the nanoscale, or is it always an
Hi John:
One of the papers from 1968 mentioned "continental drift" could be detected if two stations were at the same latitude,
i.e. looking at the same set of stars.
That was also the case for the Latitude Observatories which were all at 39:08. While they were setup with Zenith
Telescopes
I recently picked up a NAVICOM RCGD-M GPSDO off of Ebay. Does anybody have any
info on these?
One version seems to have a Furuno GT08031, another seller show Lady Heather
monitoring a Motorola 8 channel GPS,
___
time-nuts mailing list --
The Danjon impersonal astrolabe is perhaps better suited to accurate
measurements:
https://www.nzmuseums.co.nz/collections/3267/objects/3380/astrolabe
Bruce
> On 27 March 2019 at 15:48 Tom Van Baak wrote:
>
>
> BobH wrote:
> >> This would be an excellent project for time-nuts to verify.
On Wed 2019-03-27T16:26:09+1300 Bruce Griffiths hath writ:
> The Danjon impersonal astrolabe is perhaps better suited to accurate
> measurements:
> https://www.nzmuseums.co.nz/collections/3267/objects/3380/astrolabe
Danjon became director of Observatoire de Paris (and thus also the
BIH) in 1945.
These light curves for a star being occulted by the moon should give some idea
of the effects of diffraction:
http://tdc-www.harvard.edu/occultations/moon/vb141occa.html
Bruce
> On 27 March 2019 at 15:48 Tom Van Baak wrote:
>
>
> BobH wrote:
> >> This would be an excellent project for
It must be a sign of the dedication that Harrison applied to his work.
It is not as simple as the description first appears, this is England,
and the method presupposes that there are no clouds. It might be a week
or two before two nights occurred, when an unclouded night was followed
by another
BobH wrote:
>> This would be an excellent project for time-nuts to verify. First, a
>> better explanation of John Harrison’s method is in order. A vertical
>> window edge is not sufficient - a second vertical reference at a
>> distance is required - Harrison used a chimney on a neighbor's house.
Greetings time-nuts,
Harrison's method depends on the star having the same true azimuth at 1
Sidereal day intervals (23 hours 56 minutes 04 seconds). It does not depend on
a visible horizon since the altitude (which changes with the season) is not
relevant except that one must be able to see
On 3/26/19 3:48 PM, Bob Holmstrom wrote:
Ben Bradley stated > "Perhaps closer to your question: I recall in my
readings about clockmaker John Harrison (likely either in "The Quest
for Longitude” or Dava Sobel's "Longitude") that he would look from
the edge of his window at a particular star each
On 3/26/19 4:27 PM, Neville Michie wrote:
It must be a sign of the dedication that Harrison applied to his work.
It is not as simple as the description first appears, this is England,
and the method presupposes that there are no clouds. It might be a week
or two before two nights occurred, when
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