: Analemma origins.
Sent from my iPod
Begin forwarded message:
From: Fred Sawyer fwsaw...@gmail.com
Date: November 14, 2009 7:11:18 PM EST
To: John Carmichael jlcarmich...@comcast.net
Subject: Re: Analemma origins.
The next issue of the compendium will have an article by Kevin Karney
showing
Dear Jack,
You have prompted an interesting sequence of exchanges.
You now ponder...
... the coordinate system that generates the
figure 8 plot is virtually unique...
If you regard the equation of time as an angle [so
15 minutes of time is 3.75 degrees of angle] then
the coordinate system
...@chezaubert.net
Subject: Re: Analemma origins.
Jack
Your question puzzles me. I don't see anything strange or difficult
about the Analemma that would make it difficult to discover once the
equation of time is known. Ptolemy gives a table of values. Once
we have the idea of graphing tabular
Dear Fred,
You tempt me to digress...
Once we have the idea of graphing tabular values...
It seems that the idea of graphs and graphing is not
nearly as ancient as one might expect.
I commend a book:
Cosmic Imagery: Key Images in the History of Science
- John D. Barrow, W.W. Norton
wrote:
From: Frank King frank.k...@cl.cam.ac.uk
Subject: Re: Analemma origins.
To: Fred Sawyer fwsaw...@gmail.com
Cc: Sundial List sundial@uni-koeln.de
Date: Sunday, 15 November, 2009, 16:59
Dear Fred,
You tempt me to digress...
Once we have the idea of graphing tabular values...
It seems
Walking Shadow
From: Jack Aubert
Sent: Sunday, November 15, 2009 7:11 AM
To: 'Fred Sawyer' ; 'Sundial List'
Subject: RE: Analemma origins.
I think this was really a two part question.
The first question is the historical origins of the discrepancy between
apparent and mean solar time.
I
ng research on the clocks of
King Stanislaus August Poniatowski”.Photos: a b c d e f g h i j k l m n o p q r s
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On Behalf Of JOHN DAVISSent: Sunday, November 15, 2009 10:43 AMTo: Fred Sawyer; Frank KingCc: Sundial List
' ; 'Sundial List'
Subject: RE: Analemma origins.
I think this was really a two part question.
The first question is the historical origins of the discrepancy
between apparent and mean solar time.
I look forward to reading Kevin Karney’s discussion of Ptolemy’s
treatment of this which should
Hi Tony et all
Yes, I think you might be on the right track. The discoveor of the analemma
would need to have some sort of a clock that tells Mean Time (constant
time). Sand clocks, candle clocks and water clocks all keep Mean Time don't
they? Of these ancient clocks, I'm guessing that the
