And of course the time lines rotate in opposite directions north and
south of the equator, as the sun travels east, south, west in the
northern hemisphere and east, north, west in the southern hemisphere
(except seasonally in the tropics).
Frank, 55N 1W.
On 16/11/2015 10:49, rodwall1234 wrote:
Hi Phil,
The shadow forming edge of the Gnomon must be parallel the the axis of
the earth. To do that the shadow forming edge of the Gnomon is set to
be the same as your latitude. The only difference in the southern
hemisphere is the the tip of the Gnomon is facing South. While in the
Northern hemisphere it faces to the North. Doing this keeps the shadow
forming edge of the Gnomon parallel to the axis of the earth, whatever
the location.
Roderick Wall,
Melbourne
Australia.
On Nov 16, 2015 9:37 AM, Phil Dorman <p...@wattagan.com> wrote:
Hi Everyone,
I joined this list because I have a specific question which I
can't find a definitive answer to.
I want to install a sundial at Perth WA Australia which is pretty
close to 32deg South latitude.
From what I can determine that means the Gnomon should be 32deg
above horizontal.
Or is that just for the Northern Hemisphere ??
As I move North in Australia the Latitude number gets Smaller
Eg Latitude of Brisbane QLD (further North) is 27.46deg
So presumably the Latitude at the Equator would be Zero !
Which would mean a sundial Gnomon at the Equator would be
Horizontal ie Flat on the Ground
Which of course would not work.
And at the South Pole it would be Vertical 90deg from Horizontal
and also would not work since there would be no ground for the
shadow to fall on.
So. Am I correct to put it at 32deg from Horizontal for Perth WA
or not ?
Phil Dorman /:~)>
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