The answer is yes, but mainly the esoteric and academic applications to
precision pendulum clocks (although Allan Variance came out of quartz
oscillator analysis).
Electronic measuring and recording methods are necessary. In my case I made and
used an electronic stopwatch method, with radio tim
On 2/22/2017 6:01 AM, sundial-requ...@uni-koeln.de wrote:
Do horologists worry about Allan Variance? I do
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Many thanks to those who have answered my questions.
Geoffrey Thurston’s summary is clear and accords with the rudimentary, but
effective, instrumental approach advocated by Lancelot Hogben in his epic book,
Science for the Citizen.
Mike Shaw has added succinct advice, and the reason for choos
Frank King wrote:
>
> I have often pondered an even more primitive question: I am dumped on a
> desert island and I want to count the days since I arrived. What
> discipline should I follow?
>
> I could, of course, cut a notch in a stick every morning when I first
> wake up but what happens when o
Dear Doug,
The answers to your first question about
noting seasonal drift 1000 years ago have
all missed something crucial...
The astronomical comments have been very
sound but what is missing is any account
of just how you would maintain your
records?
These days you could buy a desk-top diary
a
and if your clock is only accurate to about 1 second per day you
measure at day 0 then at day 100, not consecutive nights.
Mike Shaw---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Doug,
I didn’t answer your second question:
"Assuming that in 1850s I had access to a good transit telescope, and a
reasonable clock (daily errors about 1 second a day), how would I refine the
quarter of a day into several decimal places?”
The formula is:
Year = (1 day – transit time differenc
Doug,
If you lived 1000 years ago, in temperate latitudes, you would see the
sunrise and sunset azimuths move closer together as the winter solstice
approached.
They would then stop and move apart again.
Knowing nothing about why this happened, you would worry in case one
year they kept goin
Doug,
1. You could do what the Egyptians and the Greeks did 1500 years
earlier. Use a mural quadrant in the meridian to establish the greatest and
least altitude of the noon sun ( from this you could calculate the orbital
inclination and your latitude) and mark the mid altitude. You t
Yes – the drift, and how would I notice it. What reference points in the sky
(stars) would I look for to define the ‘orbital’ year?
> On 18 Feb 2017, at 18:16, Steve Lelievre
> wrote:
>
> On 2017-02-18 10:07 AM, Douglas Bateman wrote:
>> Given that this group has experts on the calendar and t
On 2017-02-18 10:07 AM, Douglas Bateman wrote:
Given that this group has experts on the calendar and the earth’s
orbit, I have a couple of questions.
1. Assuming that I was living a 1000 years ago, and had unlimited time
watching the sun and stars (and *without prior knowledge*) how would I
n
Given that this group has experts on the calendar and the earth’s orbit, I have
a couple of questions.
1. Assuming that I was living a 1000 years ago, and had unlimited time watching
the sun and stars (and without prior knowledge) how would I notice that each
year was growing by about a quarter
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