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Thanks Geoffrey for (re-)introducing me.

Yes, I did confuse you with George Huxtable with whom I indeed corresponded in 
the past and also had the pleasure of meeting at the 2006 NMM conference.

However, although I am interested in celestial navigation and other things 
maritime, I am (alas) not an active sailor.

I am looking forward in joining some of the discussions on this list.

Rob van Gent

http://www.staff.science.uu.nl/~gent0113/


-----Original Message-----
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Geoffrey Kolbe
Sent: 17 September 2012 10:36
To: Gent, R.H. van (Rob)
Subject: [NavList] Re: Zodiacal coordinates

Hello Rob

I remember you well, welcome back.

By way of (re)introduction for newer members, Rob is an acknowledged expert on 
delta-T and the intricacies of UTC, UT1, leap seconds and all that goes with 
it. When the subject of leap seconds comes around again, as I am sure it 
will, I look forward to Rob giving us the benefit of his profound knowledge 
on the subject.

Rob is also active historian of astronomy in general, and an active sailor too, as I recall.

I well remember Rob's talk on the tobacco boxes of Pieter Holm, given to the 
National Maritime Museum symposium on navigational instruments back in 2006.

George Huxtable (with whom I think you have confused me Rob,) is unfortunately is no longer with us.

Geoffrey Kolbe

At 08:51 17/09/2012, you wrote:
>Hi George,
>
>I agree - my claim that it was an astrological website was perhaps too 
>hasty. I got this impression from the astrology adverts appearing in 
>the bottom-right corner.
>
>It is indeed better described as a website useful to both astronomers 
>AND astrologers.
>
>I note that the adopted delta-T value for now (71.7 secs) is slightly 
>too high - a value near 67 secs would be more accurate, though this 
>difference would only affect the moon's longitude by a few arcseconds.
>
>To the older list members I should perhaps explain that I am not really 
>'new' to this list. Many years ago I also contributed to this list but 
>when I stopped receiving postings I assumed that the list had been 
>suspended.
>
>I only recently discovered that the list still exists (and is also very 
>much alive).
>
>Rob van Gent
>
>-----Original Message-----
>From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Geoffrey 
>Kolbe
>Sent: 15 September 2012 10:24
>To: Gent, R.H. van (Rob)
>Subject: [NavList] Re: Zodiacal coordinates
>
>At 15:16 14/09/2012, you wrote:
> >Hi,
> >
> >I am new to this list but perhaps I can help.
> >
> >The site you have visited is an astrological website and the 
> >celestial positions are given according to astrological conventions.
> >
> >The first number is indeed the degree, followed by the zodiacal sign 
> >(Aries starts at 0, Taurus at 30, Gemini at 60, etc.) and then the 
> >number of arcminutes and arcseconds. The positions are ecliptical and 
> >appear to be tropical.
> >
> >The R found at the end of some longitudes indicates that the planet's 
> >motion is retrograde (astrologers find this very important).
> >
> >I hope that this helps.
> >
> >Rob van Gent
>
>Well Rob, this is an ephemeris which is obviously meant to be used for 
>historical research as the validity period is 1600 to 2100.
>Astronomers at the start of that era would certainly recognize this 
>format for ecliptic longitudes, which is still used by astrologers 
>today, as you correctly say. And today, astrologers do not have much 
>use for ecliptic latitudes (they never did) and most astrologers would 
>probably not know a Right Ascension if it hit them between the eyes. 
>Right Ascension today is (I think) only used by astronomers. I would 
>conclude that this is actually an astronomical almanac, formatted to be 
>useful for historical research.
>
>As for it being as astrological website, I struggle to actually find 
>the word "astrology" anywhere on the website!
>
>Geoffrey
>
>
>
>
>
>: http://fer3.com/arc/m2.aspx?i=120607





: http://fer3.com/arc/m2.aspx?i=120629

   

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