Actually I haven't had any trouble with the triangles blocking the Sun in
winter months; the shadow is on the other half of the back of the disc from the
shadow cast by the side triangles. I will admit it was designed primarily for
summer and spring. In mid-winter the sun shines through the back
Brad,
Many thanks for your prompt response. Yes, as you found, my old shipmate
will now easily calculate the day on which the sun's upper limb was just
not visible in April 1911, taking into account refraction and
semi-diameter. Scott's Hut is at 77deg. 38'S, 166deg. 24'E. Scott's
party kept t
Greetings, fellow dialists,
An old shipmate asked me if the date of the start of winter at Scott's
Hut in Antarctica in 1911 could be found. I at once thought of those
wise people, the sundial group! He needs the sun's declination for any
single date close to 20 April 1911. He knows the latitud
Hi all,
Sara is spot on. If you are going to teach how a sundial works you have to 1st
start with the largest clock in the world, the Earth with a sundial at the
poles. The moment for this clock is the Earth spinning. Then move the sundial
to the Equator of the globe and show how the earth also
Hi all,
It was fun to reconstruct the state of the solar system on May 8, 1774.
Why that date?
On that day the moon, Mercurius, Venus, Mars and Jupiter would come
together in the sign of Aries. This led to panic, as the cosmos was by
many expected to collapse. An amateur astronomer, Eise Eis
This is very nice, but it appears that it will only work during the summer half
of the year between the equinoxes, because the side triangles will block the
sun from the underside of the disk during the winter half. I prefer teaching
sundials that are equatorial and can be compared to a globe
Tony,
I do not see why Brent has to offer its apologies to Martina.
As in a brainstorming session, without the nuisance of limitations, as creative
persons like Brent do, he gives suggestions.
He explained that his examples do not have to be interpreted too literally.
For someone like Martina, we
