Home About Atlas of Light PhotoExploration AstroEgypto Products Services Client Area Version française
About Atlas of Light PhotoExploration AstroEgypto Products Services Client Area Legal Informations Version française

About Culture Diff' ...

About Culture Diff' ...

The Culture Diff' company was created in 2000 with the aim of spreading scientific culture and promoting the results of fundamental research - in the field of Egyptian archaeoastronomy, in particular. At that time, I was preparing a doctoral thesis on this theme located at the interface between exact sciences (Astronomy / Photometry) and human sciences (Archaeology / Egyptology) at the University of Toulouse III, France. The objective was to identify, among the stars that fill our sky, those whose hieroglyphic names adorn the walls of sarcophagi as well as the ceilings of temples and tombs of Egyptian antiquity. In other words, to reconstitute the sky map of ancient Egypt. A childhood dream that became a professional project and then the guiding principle of an entire life dedicated, on the one hand, to capturing, by means of appropriate devices, the light coming from the Universe, and on the other hand, to reconstituting, by means of dedicated algorithms, the light bathing every part of our Earth. This light which sets in motion our atmosphere, draws the contours of the surrounding relief, brings life, guides our steps, directs our glance, fills our spirit, nourishes our imaginary, ...

Capturing the light is one thing, recording it on a durable support in order to restore, with a relative accuracy, the information it contains is an other thing. Thus visual memory, coupled with oral language, constituted for a long time the only support, the living memory, of the past events to which our ancestors had attended. Then, stone was used as a medium for recording and disseminating information: some blocks were covered with rudimentary inscriptions showing the variations of the positions of sunrise and sunset over time; others - the megaliths - were oriented towards the position of sunrise or sunset at specific times of the year, such as the summer solstice. Ancient Egyptian monuments lie in the continuity of the great megalithic complexes of the Neolithic period: all point - or rather pointed, at the time of their construction, towards the position of appearance or disappearance of the Sun or a given star on the surface of the local horizon.

By attributing to their edifices a particular astronomical orientation,
by decorating the ceiling of their monuments with celestial representations,
by covering their inner walls with texts refering to the surrounding Nature,
the ancient Egyptians have delivered their vision of the world and the beyond.
Assisted by suitable softwares, let's try to decipher their legacy to humanity ...


Deciphering the meaning of the hieroglyphic inscriptions that cover the walls of the sarcophagi as well as the ceilings of the Egyptian temples and tombs, determining the astronomical orientation of these stone monuments erected on both sides of the Nile Valley, require several resources (scientific publications, unpublished archaeoastronomy softwares, video animations) which have been made available to you within the AstroEgypto section.

After being engraved in stone, astronomical events were recorded in manuscripts and books, combining texts and images. Then came the time to write with light: from the year 1838, astronomers succeeded in making daguerreotypes - of the Moon, the Sun, then of bright stars such as Vega (alpha Lyrae). Astronomical photography was born, which would soon make it possible to take ever more detailed shots of portions of the Sky from the Earth, then from Space. These shots testified for some of a distant past (explosion of a star in supernova, formation of the first galaxies), for others of forthcoming events (passage of a comet, space weather). Initially, these photographs were acquired in the visible range only by means of plates coated with photosensitive emulsions which had to be exposed for a certain time in order to obtain detailed shots. From the 1980s, astronomical photography became digital. Gradually, electronics invaded our field of exploration, extending our observations to the invisible - to the radio, infrared, ultraviolet, X, gamma domains. At the end of the 20th century, our Universe was revealed in a new light...

Curiosity leads to exploration ...
Observation raises many questions ...
Since both the inert and the living leave traces of their past and present existence.
It is to observe a fraction of Sky, a portion of Earth, that the Exploration section invites you.
The Land of Oc' will be the starting point of this trip towards other spaces, in other times ...


A hundred photographs acquired within the Occitanie region, southern France, make up a wall of images accessible from the PhotoExploration section. Click on one of these photographs and dive, through various texts and poems, into the heart of an exotic, surprising, unexpected universe, rich in information about human beings and their environment, in different historical, geological and even astronomical eras! Some of these shots were used to print postcards, others were exhibited in various sites of the Occitanie region (castles, medieval villages or classified as historical heritage). Likewise, associated photographisms - graphics resulting from the application, to landscape photographs, of image processing algorithms. Each photographism offers a graphic reinterpretation of the real world, a renewed vision of the surrounding Nature. On the contrary, 3D simulations offer a visual reconstruction - in the form of screenshots and animations - of past, present or upcoming reality.

Whether it is direct or reflected, emitted by a point or an extended source,
light guides the steps of the photographer, directs the gaze of the astronomer.
It is to simulate then to observe the effects of this natural or artificial light,
of its diurnal, seasonal or secular variations on our environment,
on our way of thinking, that the Atlas of Light invites you ...


Digital simulations form the core of the Atlas of Light section. They enable us to accurately reconstruct the movements of the Sun, the Earth and the other planets of our Solar System - in other words, to display a map of our Sky in real time, to visualize the succession of the year's seasons as well as the days and nights on our Earth's surface, to model the effects of anthropogenic light pollution on the visibility of celestial objects located close to the Earth's horizon, and so on. By combining celestial mechanics and photometry algorithms with elevation and imagery data acquired by satellites orbiting the Earth, it becomes possible to reconstruct the appearance of the celestial vault over the Earth's relief - in other words, to simulate any local-scale celestial phenomenon that has occurred in the past or is likely to occur in the future. The creation of this five-dimensional Sky/Earth interface (three dimensions to describe the Earth's surface, one dimension to position celestial objects on the surface of an earth-centered sphere and one dimension for time) is the highpoint of my research work, which began some thirty years ago ...

by Karine GADRE,
Culture Diff' company-header and founder,
Ph.D in Astronomy of the University of Toulouse, France.
Member of the Astronomers for Planet Earth Group,
Signatory of The Fossil Fuel Non-Proliferation Treaty,
Support of the actions of the WWF France foundation for Nature.