Benvenuti in queste pagine dedicate a scienza ed arte. Amelia Carolina Sparavigna

Wednesday, December 30, 2015

The orientation of the King's Knot of Stirling Castle

Using SunCalc.net we can see the orientation of the King's Knot of the Stirling Castle with respect to sunset and sunrise on solstices. Note the alignment to Midsummer sunset.
More details in my paper published in PHILICA at:

Wednesday, January 14, 2015

Tianluokeng Tulou cluster

Tianluokeng tulou cluster  is one of the better known groups of Fujian Tulou. It is located in Fujianprovince, Zhangzhou City, Nanjing CountyShuyang Township, Tian Luo Keng Village (literally "Snail Pit" Village) in southern China. The cluster consists of a square earth building at the center of a quincunx, surrounded by four round earth buildings (or more exactly, 3 round earth buildings and one oval shape earth building).

Friday, January 9, 2015

Castlerigg stone circle

The stone circle at Castleriggis situated near Keswick in Cumbria. One of around 1,300 stone circles in the British Isles and Brittany, it was constructed as a part of a megalithic tradition that lasted from 3,300 to 900 BCE, during the Late Neolithic and Early Bronze Ages. (Wikipedia). It is in a location northern of the Hardknott Roman Fort.To have a detailed discussion of the alignment of the stones at Castlerigg, please visit this site

In the following images, using SunCalc, we cans ee how the sun is moving above this stone circle.

Summer solstice

Winter solstice

Here the map showing position of the stone circle and of the roman fort.

SunCalc at the Hardknott Roman Fort

As told by its owner (Vladimir Agafonkin), SunCalc is an app that shows sun movement and sunlight phases during the given day at the given location, where we can see sun positions at sunrise, specified time and sunset. A thin orange curve is the current sun trajectory, and the yellow area around is the variation of sun trajectories during the year. The closer a point is to the center, the higher is the sun above the horizon.

Here an example: SunCalc at the hardkontt Roman Fort

Summer solstice

Winter solstice

More at:

Suncalc and ancient Sun

In a recent paper, entitled "Was Lepenski Vir an ancient Sun or Pleiades observatory?", the authors Vladan Pankovic, Milan Mrdjen and Miodrag Krmar, have discussed the hypotesis of the mesolithic village Lepenski Vir (9500 -- 5500 BC) as an ancient (one of the oldest) Sun observatory. The authors had been so kind to follow a method I suggested of using "freely available software" for the local Sun radiation direction simulation. I used sollumis.com , they used the suncalc.net software.
Here an example of suncalc software.