Dear Dialists,
On this link
https://news.artnet.com/style/artist-daniel-arsham-hublots-new-brand-ambassador-just-installed-a-massive-crystal-sundial-high-in-the-swiss-alps-2267460
your see a ’sundial’ made in Switzerland. It’s looks beautful, but it is not
really a dial. I would call it a
Dear John,
I know this object as “Horizontoscope".
http://www.horizontoscop.com/eng/index_eng.html
I bought one recently after reading about it in one of Helmut Sonderegger’s
articles, where he gives the math of it.
Dear Steven,
The relation of solar declination delta(t) to ecliptic longitude lambda(t)
delta(t) = ArcSin[Sin[23.44]*Sin[lambda[t]]
You are interested in the relation of solar declination to time since the
equinox.
Your formula delta(t) = 23.44*Sin(t), with t being the time (in degrees)
dial/mainpage.htm
There are some pictures and details given on this page. What I like
particularly is that when looking from the edge of the equatiorial disc to the
style it projects the Analemma curve onto the sky.
There is a photo under the tab ‘Analemma’.
best regards
Werner Riegler
On 9 Sep
a steel cable that you
tention at the two extremities. Like this you don't have to worry about
the stability of the thin piece. A steel cable of 2mm diameter is
already extremely strong, so this will be a very good approximation to
the 'zero' radius.
Best regards Werner Riegler
From
body that is tangential to this surface.
This is described in the presentation 24.9.2004 link on the page.
Best regards Werner
Riegler
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
Hello Jos,
As you know the equation of time (EOT), which you measure, is a unique
function of three parameters:
1) The tilt of the earth's axis towards the ecliptic
2) The distance (or time) between the perihelion passage of the
earth (around Jan. 4th) and the spring equinox
)/sqrt(1-sin^2(dec)) I find exactly your
formula ! So I guess this is proof that you haven't goofed.
Best Wishes
Werner Riegler
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf
This sounds very interesting. However -- the formula quoted below is
completely wrong in this context and has nothing to do with relativity.
Does it say that it has to do with relativity ? To me it looks more like
a formula for the effect of Abberation. Could you send me the picture of
the dial
PROTECTED]
Sent: Tuesday, May 31, 2005 4:31 PM
To: Werner Riegler; sundial@rrz.uni-koeln.de
Subject: Re: Relativistic sundial
What do you mean by Aberration, Werner?
The formula looks close to right for the time dilation effect, as if
quoted from memory.
I think it was supposed to be delta Tau
[mailto:[EMAIL PROTECTED]
Sent: Tuesday, May 31, 2005 6:21 PM
To: Dave Bell; Werner Riegler; sundial@rrz.uni-koeln.de
Subject: RE: Relativistic sundial
A small picture of the formula is attached. I hope it gets through the
size filter.
Roger
-
without it. Taking the sundial with him would mean to pack the
earth and the sun in his suitcase and bring it on the trip ...
Werner Riegler
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of anselmo
Sent: Monday, May 30, 2005 10:02 AM
12 matches
Mail list logo
