goffik
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Re: Silbury Upwards Sun Roll.
May 08, 2011, 13:54
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Undoubtably! :)
Sorry - I thought there was the suggestion it might have been a deliberate thing on the builder's part... Which, of course, is as possible as - if not moreso than - a lot of theories! :)
G x
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Resonox
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Re: Silbury Upwards Sun Roll.
May 08, 2011, 14:00
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Thanks Tiompan...yes it was Maes Howe....don't know where I got the idea it was long dismantled.....and yes I agree it might not have been a deliberate design...just sheer good luck...noticed only on one certain day from one certain position and significance attached from that day onwards...which was why I wondered if anyone had filmed evidence of the "roll" sunrise/set on other days from different viewpoints(at Silbury) as they have at other places...like MH. To be deliberate would surely take a long observation period...made longer depending on weather conditions. So ANY construct could have the same effect on any day depending on where you were standing...which got me to my original question about a vewing point/marker being erected at the same time as the hill was built to indicate the siting and rolls were less than coincidence....it seems as though such a marker was only a later addition then.....cleared up..Cheers.
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tiompan
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Re: Silbury Upwards Sun Roll.
May 08, 2011, 14:15
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Resonox wrote: Thanks Tiompan...yes it was Maes Howe....don't know where I got the idea it was long dismantled.....and yes I agree it might not have been a deliberate design...just sheer good luck...noticed only on one certain day from one certain position and significance attached from that day onwards...which was why I wondered if anyone had filmed evidence of the "roll" sunrise/set on other days from different viewpoints(at Silbury) as they have at other places...like MH. To be deliberate would surely take a long observation period...made longer depending on weather conditions. So ANY construct could have the same effect on any day depending on where you were standing...which got me to my original question about a vewing point/marker being erected at the same time as the hill was built to indicate the siting and rolls were less than coincidence....it seems as though such a marker was only a later addition then.....cleared up..Cheers.
The sun doesn't "roll" at Maes Howe though .No ,not ANY structure you have to find one that has the same angle of rise or set as the sun on the day , the sun must be in a place in the sky where it does set or rise and the horizon must be clear clear with sufficient length of slope to make it worthwhile .
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Resonox
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Re: Silbury Upwards Sun Roll.
May 08, 2011, 16:55
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Yes but it clears up what I was thinking. So it makes a bit more sense in my mind(if no place else)...cheers.
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cerrig
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Re: Win Hill sun roll
May 08, 2011, 18:35
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George, is there somewhere I could look up regarding this rise/set angle throughout the year. I'm not looking for sun rolls as such, although that would make a good photo, but more a way of getting an idea where the sun would appear/disappear over local horizons. This would be using nothing more than a compass and clinometer(suunto)
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tiompan
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Re: Win Hill sun roll
May 08, 2011, 18:55
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cerrig wrote: George, is there somewhere I could look up regarding this rise/set angle throughout the year. I'm not looking for sun rolls as such, although that would make a good photo, but more a way of getting an idea where the sun would appear/disappear over local horizons. This would be using nothing more than a compass and clinometer(suunto)
Andrew , am I right in thinking that what your'e looking for is not the angle of rise /set but where the sun sets/rises ?
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cerrig
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Re: Win Hill sun roll
May 08, 2011, 20:02
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Both really.
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tiompan
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Re: Win Hill sun roll
May 08, 2011, 21:28
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The angle of rise and set of the sun at the latitude of South Wales varies by about 10 degrees all year i.e. 30-39 degrees for rise and set at the equator it's can be straight up -90 degrees .
I think it's the point where the sun rises and sets that is more important for you this is more problematical as it depends on the horizon .There are programs and formulae but as they don't know what the horizon is likely to be they will not not much help in prediciting . With a compass , clinometer and calculator you can work out the declination of a point on the horizon from an observers viewpoint and calculate whether or when the sun will rise or set at a particualr point on the horizon . You could also have a rough idea of the setting point before setting out and do a rough calc when you asses the horizon using the clinometer . You can also do a lot remotely if the information is accurate i.e observer and horizon heights ,distance between the two, azimuth and latitude is all you need . A specific case might be useful . Hope that helps or have I misunderstood ?
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cerrig
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Re: Win Hill sun roll
May 08, 2011, 22:11
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Thats great thanks George.
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tiompan
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Re: Win Hill sun roll
May 08, 2011, 22:21
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e-mail me if there is anything that is not clear .
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