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Author Topic: What do each of these sun-dials do?  (Read 3368 times)

Offline dentstudent

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What do each of these sun-dials do?
« on: 12/01/2009 08:37:16 »
Whilst out walking yesterday, I came across a cube sun-dial that had the traditional dial in the top, but also had four further dials on each of the side faces:


Eastern side


Southern side


Western side


Northern side


So what do each of these dials do?


 

Offline DoctorBeaver

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What do each of these sun-dials do?
« Reply #1 on: 12/01/2009 13:38:34 »
Perhaps they were put there merely to confuse arborealists.

The East & West faces look like mirror images. Could they be something to do with sunrise & sunset?
The North face apparently shows a time that is variable as there are a plus & a minus sign with what appears to be a graph.
The South side is a conventional sundial but for the benefit of short people who cannot see the top  :D

P.S. What the hell were doing out walking in weather like that? That poor child!
« Last Edit: 12/01/2009 13:40:35 by DoctorBeaver »
 

Offline dentstudent

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What do each of these sun-dials do?
« Reply #2 on: 12/01/2009 14:21:45 »
But what's the point of having a sundial on the northern side? It's not as if it'll actually ever get much sun.....

Weather? Ha! It was only -12C! And since when have you ever taken pity on sprogs children?

And for information, the photos were taken at 13:40, CET.
« Last Edit: 12/01/2009 14:29:30 by dentstudent »
 

Offline DoctorBeaver

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What do each of these sun-dials do?
« Reply #3 on: 12/01/2009 15:16:25 »
-12oC? Sod that! Anything less than 25oC has me running for an overcoat.

I do sometimes take pity on brats. The other day, for instance, I felt sorry enough for brat junior that I only nailed 1 of his ears to the door.

But what's the point of having a sundial on the northern side? It's not as if it'll actually ever get much sun.....

I notice there are only a few numbers on that side. Perhaps the chap who made it suddenly realised he'd got the plans the wrong way round.
« Last Edit: 12/01/2009 15:19:44 by DoctorBeaver »
 

Offline dentstudent

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What do each of these sun-dials do?
« Reply #4 on: 12/01/2009 15:27:42 »
I wonder if the Roman numerals on the northern face that run from 8 down to 6 on the left, and 4 down to 6 on the right are months, since 6 would be June, and therefore contain the highest elevation of the sun. Perhaps the sun only shines on this face from April to August, though I don't see a link between where the shadow ouwld fall, and the "wave" that shows the addition or reduction of some time measure.
 

Offline DoctorBeaver

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What do each of these sun-dials do?
« Reply #5 on: 12/01/2009 15:34:07 »
I wondered what the numerals on the right were. I couldn't see due to the relection.

Why would XI be on both sides?
 

Offline dentstudent

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What do each of these sun-dials do?
« Reply #6 on: 12/01/2009 15:35:52 »
The southern side dial has "Tagesdauer" which means day-length, so when the sun is at its highest, the shadow is at its longest on the dial, and therefore shows a longer day length. As you move around the dial's "face", the numbers on the left increase (therefore June, July, August...) whilst the numbers on the right decrease (June, May, April, March...), with both converging om XII (December) at the bottom. Perhaps it can only be used at 12:00 midday.....
 

Offline dentstudent

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What do each of these sun-dials do?
« Reply #7 on: 12/01/2009 15:38:32 »
I wondered what the numerals on the right were. I couldn't see due to the relection.

Why would XI be on both sides?

IDK, but "Zeit Ausgleich" is "time reconciliation".
 

Offline dentstudent

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What do each of these sun-dials do?
« Reply #8 on: 12/01/2009 15:52:44 »
The eastern side one only shows time from 4 in the morning (left of the dial) to midday, far right of the dial. The western dial shows time from midday (left of the dial) to 8 in the evening (right of the dial).
 

Offline DoctorBeaver

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What do each of these sun-dials do?
« Reply #9 on: 12/01/2009 16:53:04 »
Dumme Sache
 

Offline Soul Surfer

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What do each of these sun-dials do?
« Reply #10 on: 12/01/2009 23:45:15 »
All the faces are in effect sundials that work when the sun shines so that the block on the face casts a shadow  a north facing vertical surface gets the sun early morning and late evening in sulmmer. 

the "time reconciliation" curve on the north face shows the equation of time which is the time error from mean time shown by a sundial through the year.  This error is due to the ellipticity of the orbit of the earth.
 

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What do each of these sun-dials do?
« Reply #10 on: 12/01/2009 23:45:15 »

 

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