Hi Frank,
  Thank you for the photos of the Jesus Green Analemmatic Sundial.  Too bad 
there wasn't any sunshine for the unveiling, as I see no hint whatsoever of a 
shadow.

>> I see that the GNU license states that
>> the author of the work must nevertheless
>> be attributed...
> 
> I don't actually see that stated.  The
> wording is:
> 
>  Attribution - You must attribute the work
>  in the manner specified by the author or
>  licensor...
> 
> I do not see any specification by the author.
> Can you point me to this?
> 
> While I would certainly cite Douglas Hunt
> myself, I see no formal requirement to do
> this.

  The Human Sundial image is licensed under the Creative Commons Attribution 
ShareAlike 3.0 License, which is defined at 
creativecommons.org/licenses/by-sa/3.0 and whose attribution rules state that 
"You must give appropriate credit, provide a link to the license, and indicate 
if changes were made. You may do so in any reasonable manner, but not in any 
way that suggests the licensor endorses you or your use.".

  Douglas Hunt has since gotten back to me about the Human Sundial image which 
has been posted to Wikimedia Commons, and he has made it quite clear that he 
has never submitted anything to them even though the image is correctly 
attributed the image to him.  This brings up a whole new discussion point on 
what is to stop random people from making images available to the public 
domain, and what can be done to rectify this when that happens.

>> In regards to the "Bill Gottesman stance",
>> it's an interesting concept, but it seems
>> to me that the narrow triangle of light
>> formed in this manner would be so short
>> as to preclude any kind of precision in the
>> reading of the time.  Is this not correct?
> 
> The triangle is certainly short but so is a
> compass needle and yet you can use such a
> needle to navigate a large boat.
> 
> The triangle also has a pointed tip, again
> as a compass needle.  Moreover, you also pay
> more attention to where your feet are.  With
> practice, you can get good results using the
> Bill Gottesman stance.

  I get your example about the compass needle being short and yet can still be 
used to navigate a boat, but to do this you simply need to point the boat in a 
general direction to get somewhere, until such a time as to use landmarks in 
the end for accurate navigation.  It still seems to me that the short shadow 
given by the Bill Gottesman stance may be quite accurate, but it would still be 
difficult to extrapolate such a short shadow to an accurate reading of the more 
distant hour markers of the Human Sundial.  Everybody seems to like the stance 
however, and I guess that in practice it's easier to extrapolate the shadow 
that I imagine it is, so I think I'll just have to try it out for myself...

Thank you,
Paul Ratto
SunClocks North America
438-792-4823
www.sunclocks.net

On May 11, 2014, at 14:52, Frank King <[email protected]> wrote:

> Dear Paul,
> 
> You ask:
> 
>> ...would you have any actual images
>> of the sundial that was unveiled at
>> unveiled on Cambridge's Jesus Green?
> 
> You can see four here:
> 
> https://www.flickr.com/photos/60409645@N05/sets/72157644179797609
> 
> These were taken before and after the
> crowds were around!  I haven't seen
> the press photographs yet.  As you can
> tell, the two rings look very much like
> those in the Douglas Hunt drawing that
> you use as your logo.  They are square
> rather than round and have Roman numerals
> rather than Arabic but the two ranges
> seem to be the same, eg 7am to 6pm for
> the winter times.
> 
>> I see that the GNU license states that
>> the author of the work must nevertheless
>> be attributed...
> 
> I don't actually see that stated.  The
> wording is:
> 
>  Attribution - You must attribute the work
>  in the manner specified by the author or
>  licensor...
> 
> I do not see any specification by the author.
> Can you point me to this?
> 
> While I would certainly cite Douglas Hunt
> myself, I see no formal requirement to do
> this.
> 
>> In regards to the "Bill Gottesman stance",
>> it's an interesting concept, but it seems
>> to me that the narrow triangle of light
>> formed in this manner would be so short
>> as to preclude any kind of precision in the
>> reading of the time.  Is this not correct?
> 
> The triangle is certainly short but so is a
> compass needle and yet you can use such a
> needle to navigate a large boat.
> 
> The triangle also has a pointed tip, again
> as a compass needle.  Moreover, you also pay
> more attention to where your feet are.  With
> practice, you can get good results using the
> Bill Gottesman stance.
> 
> Take a look at:
> 
>  https://www.flickr.com/photos/60409645@N05/8901352415
> 
> I wasn't quite ready for the photograph to
> be taken but the narrow triangle actually
> points more precisely to the required
> hour point than is suggested by the shadow
> of my head.
> 
> There is no substitute for a long stick
> held vertically in the correct place but
> you don't always have one to hand!
> 
> Frank King
> Cambridge, U.K.
> 

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