Mea culpa! I should have attended to the Royal Society motto: "nullius
in verba" (don't believe a word of it!) and not taken someone else's
word that the longest day of the year was in September. My grateful
thanks to those who pointed out that it is close to 22 December an
Subject: longest day
Greetings, fellow dialists,
I tried to astonish my grandson by telling him that this was the longest
day of the year. (I think this is correct; today is 24 hours and 22
seconds long.) He replied by asking if there was a name for this day. He
said he couldn't find anythi
rtest interval is 86,325 seconds."
>
> Ref. http://www.universetoday.com/14700/how-long-is-a-day-on-earth/
>
> Tom
>
>
>
> From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
> Behalf Of Tom Laidlaw
> Sent: Wednesday, September 14, 2011 2:25 PM
> To:
Frank,
I don't know a name for the longest day but it is not in september.
It is around Christmas.
Then a day is about 24 hours and 30 seconds.
Look in a table for the EoT to the difference from day to day.
Your value for mid-September is correct.
Best wishes, Fer
Fer J. de Vrie
ds."
Ref. http://www.universetoday.com/14700/how-long-is-a-day-on-earth/
Tom
_
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Tom Laidlaw
Sent: Wednesday, September 14, 2011 2:25 PM
To: 'Marcelo'; 'Frank Evans'
Cc: 'Sundi
...@uni-koeln.de] On
Behalf Of Marcelo
Sent: Wednesday, September 14, 2011 12:49 PM
To: Frank Evans
Cc: Sundial
Subject: Re: longest day
I used to think that the longest day was the summer solstice. Methinks that
you refer to some effect from the Equation of Time. And I don't know if
there is a
I used to think that the longest day was the summer solstice. Methinks that
you refer to some effect from the Equation of Time. And I don't know if
there is a name for it.
2011/9/14 Frank Evans
> Greetings, fellow dialists,
> I tried to astonish my grandson by telling him that t
Greetings, fellow dialists,
I tried to astonish my grandson by telling him that this was the longest
day of the year. (I think this is correct; today is 24 hours and 22
seconds long.) He replied by asking if there was a name for this day. He
said he couldn't find anything on the interwebs
Thanks to all for the formulas. For me, the format that's most convenient is
the one sent by Kevin Karney:
[acos(-tan{latitude} x tan{declination})] / 7.5
where declination = 23.5 at midsummer and -23.5 at midwinter.
If you flip the signs on the declination angles, so that midsummer = -23.5 an
On 2010 July 1, at 14:02, Willy Leenders wrote:
The formula of John Schilke is a good one when you divide the
result by 15
Exactly so; apologies! I forgot to copy that step.
John
John Schilke
jfs...@ipinc.net
---
https://lists.uni-koe
Using the formula of John Schilke I become 244,74 hours (above the horizon), for latitude 51° and declination 23,44°Using my formula (see picture) I become 16,32 hours.
Willy LEENDERSHasselt in Flanders (Belgium)Visit my website on the sundials in the province of Limburg in Flanders (Belgium) and o
[acos(-tan{latitude} x tan{declination})] / 7.5
Declination = 23.5 at midsummer , 0 at equinox -23.5 at midwinter
Kevin Karney
Freedom Cottage, Llandogo, Monmouth, NP25 4TP
Phone 01594 539 595. Mobile 07595 024 960
On 1 Jul 2010, at 18:12, John Goodman wrote:
> Hello all,
>
> I usually shu
The formula of John Schilke is a good one when you divide the result by 15
Willy LEENDERS
Hasselt in Flanders (Belgium)
Visit my website on the sundials in the province of Limburg in Flanders
(Belgium) and on worthwhile facts about sundials
www.wijzerweb.be
Op 1-jul-2010, om 22:58 heeft Will
Using the formula of John Schilke I become 244,74 hours (above the horizon), for latitude 51° and declination 23,44°Using my formula (see picture) I become 16,32 hours.
Willy LEENDERSHasselt in Flanders (Belgium)Visit my website on the sundials in the province of Limburg in Flanders (Belgium) and o
On 2010 July 1, at 10:12, John Goodman wrote:
I'm looking for a simple formula which calculates the number of
hours that the sun will be above the horizon on the summer solstice
for any given latitude. I don't need to worry about refraction, or
take into account the sun's diameter. I
Hello all,
I usually shudder when I see equations in messages posted to the list, but now
I have a problem than needs a mathematical solution.
I'm looking for a simple formula which calculates the number of hours that the
sun will be above the horizon on the summer solstice for any given latit
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