Related papers: The sunrise amplitude equation applied to an Egypt…

It is shown how repeated observations of the sunset from various points up a tall building can be used to determine the Earth's radius. The same observations can also be used, at some latitudes, to deduce an approximate value for the amount…

In this paper we discuss the orientation of the Egyptian pyramids at Giza with respect to sunrises and sunsets, using SunCalc.net software. We can see that Khufu and Khafre pyramids had been positioned in a manner that, from each pyramid,…

The issue of the orientation of Greek Temples has been the subject of several debates since the end of the 19 century. In fact, although a general tendency to orientation within the arc of the rising sun is undeniable, specific patterns and…

A sunset over the sea surface offers the possibility to chronometrate a solar transit across the horizon. The vertical solar diameter is proportional to the duration of the sunset, the cosine of the azimuth and the cosine of the latitude of…

The great Vishnu temple at Angkor Wat in north-central Kampuchea (Cambodia) is known to have been built according to an astronomical plan. In this note we show that the little-understood solar formula of the temple is identical to the one…

In the planning of some Chinese towns we can see an evident orientation with the cardinal north-south direction. However, other features reveal a possible orientation with the sunrise/sunset azimuth on solstices too, as in the case of…

The chain of late Roman fortified settlements built in the Kharga Oasis, in Egypt Western Desert, represents an interesting case study to analyse how the ancient Roman town planners interacted with the landscape. A peculiar feature of the…

It seems that the ancient Roman towns were oriented with the sunrise. Here I propose a discussion on the orientation of Torino, the Julia Augusta Taurinorum, which has the ancient Roman structure perfectly preserved. According to this…

Derivation of the following formulae for solar position as seen from orbiting planet based on a simplified model: sunrise direction formula, solar declination formula, sunrise equation, daylight duration formula, solar altitude formula,…

A major focus of the archaeoastronomical research conducted around the world focuses on understanding how ancient cultures observed sunrise and sunset points along the horizon, particularly at the solstices and equinoxes. Scholars argue…

Here the orientation of the Gothic cathedrals in France is discussed and investigated using the satellite maps. Except a few of them, these buildings have the apse facing the rising sun, according to a practice adopted during the middle…

We express the position of the Sun in the sky as a function of time and the observer's geographic coordinates. Our method is based on applying rotation matrices to vectors describing points on the celestial sphere. We also derive direct…

This paper presents textual evidence for an astronomical basis of the dimensions of the axis and perimeter in the plan of the Indian temple.

Reports from the 2nd and 3rd Century AD attribute the first measurement of the angular size of the Sun to Thales of Miletus, in the 6th Century BC. Cleomedes, also in the 2nd Century AD, described a method to perform the measurement, based…

Solar astrometry deals with the accurate measumerent of the solar diameter, and in general with the measurement of the shape of the Sun. During the last decades several techniques have been developed to monitor the radius and the irradiance…

In this paper the practical approach to evaluate the incoming solar radiation on buildings based on atmospheric composition and cloud cover is presented. The effects of absorption and scattering due to atmospheric composition is taken into…

The pyramids of ancient Egypt are said to have shone brilliantly in the sun. Surfaces of polished limestone would not only have reflected diffusely in all directions, but would also likely have produced specular reflections in particular…

The Peaks of Eternal Light (PELs), that are largely unshaded regions mostly at the lunar south pole, have been suggested as a source of solar power for mining the water and other volatiles in the nearby permanently dark regions. As mining…

In these notes, we do the computation of the formula giving the expression of solar energy received by an horizontal section of 1 square meter, relatively to the latitude, obliquity and current day (the quantity is also proportional to the…

Among the magnificent temple complexes built during the Khmer empire, two single out both for their distance from the Angkor heartland as well as for their anomalous, not cardinal, orientation: Koh Ker and Preah Khan of Kompong Svay. Their…