Sundials

[Anonymous]

In the past I have not had much time for sundials and woudn't have one in my garden if you paid me.

However we have just come back from holidays and we visited the Tropic of Capricorn and i had a good look at the sundial there and i was amazed at how accurate it was only about 1 minute slow. Is this because it was right on the tropic and the calculations could be made more accurately?

Another thing was that it ran backwards ie anticlockwise, why is this ? does anyone know? Is it because I was at the Tropic of Capricorn and that is in the Southern hemisphere? do sundials work the other way in the Northern Hemisphere?


If so why do clocks run clockwise?

Any one have and views or any real knowlege?


Regards

ian

[Anonymous]

Iandor, Maybe it's the same reason or so I heard that when you flush a toilet in the southern hemisphere the water goes down in I believe a counterclockwise fashion where as in the northern hemisphere it goes down clockwise. Gravitational pull? I have no real Idea. This may keep me awake tonight![:p]

[Anonymous]

QUOTE: Originally posted by carpenter matt

Iandor, Maybe it's the same reason or so I heard that when you flush a toilet in the southern hemisphere the water goes down in I believe a counterclockwise fashion where as in the northern hemisphere it goes down clockwise. Gravitational pull? I have no real Idea. This may keep me awake tonight![:p]

I've always wondered if this effect worked upon the blood. Ian, when you visit the Northern Hemisphere do you feel any ill effects?

As for sundials, I don't have much love for them either...but I have always wanted to pretend I was zooming forward through time like Rod Taylor in the George Pal "The Time Machine" movie from the 1960s. He has such a sundial in his garden.

[Anonymous]

much time for sundials

Ian, good one. If it's a minute slow going backwards would it be a minute fast going the right way? This is a strange one Ian, the whole planet, obviously, rotates to the east and there we find dawn and the first rays of the sun will hit a vertical post on a sundial the same way, irrespective of the hemisphere. Because one is in winter and the other in summer I would think that sun dials would have to be set for 'local time' at noon. I have just edited this bit because I forgot the northern hemisphere sun swings south & the southern hemisphere sun swings north, which will make it appear to be going backwards. Have you also considered that using that sundial would mean you left before you arrived!!
Cheers,
Kim
[tup][#offtopic] I think this should say 'OFF TROPIC'

[BillBrakeman]

I hope the following succesfully befogs everyone.
The sun dial was first used in the Northern Hemisphere. With the dial located north of the sun's path its shadow will track from left to right (west to east) across the top (northern) side of the sundial in a "clockwise" direction. When mechanical clocks were first invented they were designed to have the hand(s) imitate the movement of the sun dial's shadow by moving from left to right. Thus was adopted the world standard clock face and clockwise movement of clock hands.
If a sun dial is located in the Southern Hemisphere with the sun's path north of it the shadow's movement will be from right to left on the dial in a counter-clockwise direction.
I have no clue as to the accuracy of sun dials except to think that it is dependent on its correct orientation to the sun. I, personally, never look at the one my wife has is the garden.

Bill

[Anonymous]

sleep at last[zzz]

[Anonymous]

Bill I loved your reasoning but you didn't seem to finalise it do sundials work clockwise in the northern hemisphere or not ?

I have had no trouble with my blood in the northern hemisphere nor do we walk around on our hands here in the antipodese. But I do have trouble with my brian due to jet lag and going into the northern hemisphere, more from east to west than the other way around. For instance i am ok travelling to the USA but I suffer a lot from short term memory loss in Europe.

As far as the toilets discharging anticlockwise, we do not have that trouble in Australia they go straight down but its the wash basins we have trouble with.

I knew a guy who visited a country in cental Africa and it was right on the equator and he had a guide that would actually demonstrate the phenonema to you. But in the end added with a laugh that it was all a joke.

So now has anyone actually seen a sundial working clockwise in the northern hemisphere or not?


Ian

[BillBrakeman]

QUOTE: Originally posted by iandor

Bill I loved your reasoning but you didn't seem to finalise it do sundials work clockwise in the northern hemisphere or not ?

So now has anyone actually seen a sundial working clockwise in the northern hemisphere or not?


Ian

Yes, Ian. In the Northern Hemishpere a sun dial's shadow duplicates the movement of the hands of an analog clock . The shadow cast by a sundial in the morning points to the west (swest, west, or nwest depending on the time of year). The shadow resembles a clock hand pointing to the left side of a clock dial. During the day the sun will move from east to west staying south of the dial and the shadow will stay oppposite the sun's position. This causes the shadow to move from west to east (left to right or clockwise) across the top (northern) side of the dial. Ergo something

Golly now I' m beffogged
Bill

[Anonymous]

Well gentlemen and Rene that just about ends that subject

Thanks ian