Sun Stick Calender

[Pandabean]

Not sure where to put this, so here will do I guess.

I am reading through Mr Gooley's new book on Natural Navigation and there is a brief mention of using a stick in the ground and using it as a rough calender. However there is not a lot of detail about the method.

From what I can work out, the points where the sun is highest/lowest (Solstices) that forms the centre part of the curve created and the equinoxes form the ends.

Does anyone have any info on it or links to it on the web?

If your not sure what I am talking about, I guess most of you will have seen the film Castaway and in Tom Hanks' cave he has two curves on the wall marking dates. Im guessing this is a similar idea.

 

[Bravo4]

Declination of the sun and the equation of time.

http://www.wsanford.com/~wsanford/exo/sundials/shadows.html

http://www.scoutingresources.org.uk/codes/codes_direction_pointers.html

Stick viewed from the north (northern hemisphere), afternoon. Equinox shadows will fall between the solstice shadows, along the north/south line.

Looking west at the stick. Red line represents a shadow cast at Local Apparent (solar) noon on the Summer solstice, yellow the equinoxes, blue the winter solstice.

 

[Pandabean]

Your the man Bravo4. , Thanks. I wasnt quite sure what I was searching for on google.

Also im not sure if your missing a picture in your post or what the last part refrences.

ooking west at the stick. Red line represents a shadow cast at Local Apparent (solar) noon on the Summer solstice, yellow the equinoxes, blue the winter solstice.

 

[Bravo4]

Glad that helped. The last diagram must be missing if you don't see it, It comes up on my monitor but no matter. I'll have to check out that book when I get a chance.

If you scroll down to the bottom of this page,
http://www.rondexter.com/
...there is a selection of short articles under the heading, "Sun Position for Motion Picture Photography".

As a suggestion, make an equitorial sundial. Something as simple as this with a stick in the hole of the crosshairs.
If you already have a map protractor, even better. Hang a weighted string from the hole and use it also as a quadrant to determine altitude(use shadow method if "shooting" the sun).

Figure out how to "set it" down to the minute and you'll have solar nav 101 in the bag.