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

Saturday, September 10, 2016

Ales Stenar and the Moon

The Ales Stenar, known in English as the Ale’s Stones, is an ancient megalithic monument of Sweden. The stones are outlining a ship. The paper
"Astronomical Alignments of Ales Stenar Along Sunset and Moonset Directions"
shows alignments of the stones along the northern possible moonset on major and minor lunar standstills. These astronomical alignments are shown using the Photographer’s Ephemeris. It is possible that this megalithic monument was used for observing the cycles of the moon.

In this image, we can see the left side of the Ales Stenar and the direction of the northern moonset (blue line) on a major lunar standstill, represented by the blue line. Note the alignment of the stones along this direction.

Here, we can see the right side of the Ales Stenar and the direction of the northern moonset (blue line) on a minor lunar standstill, represented by the blue line. Note the alignment of the stones along this direction.

The images are snapshots of the results of Photographer's Ephemeris. In the images, the yellow and orange lines are giving the directions of sunrise and sunset on the days of lunar standstills.

On the summer solstice, we have the main axis of Ales Stenar oriented along the sunset. In the following image, this direction is given by the orange line. 




Wednesday, September 7, 2016

A skyscraper as a huge diffraction grating

The Intesa Sanpaolo Tower in Torino behaves like a huge "diffraction grating". The facade is a doudle-skin one, the outer skin being mabde by a steel frame an orientable transparent panels. This outer skin  becomes a huge optical device.
The south side has only the central part covered by the doudle-skin. The rest is covered by photovoltaic panels. In the proper incident sunlight,  we can see the central part dispersing the white light in colored beams. Here two images of the phenomenon.



The sequence lasts 10 minutes. 

For more details, read please this article
A skyscraper as a huge diffraction grating