Atlas of Light
Atlas of Light
Every earthly species migrate for their survival.
The human being has the particularity to move also by desire.
The need to explore new territories, to discover other cultures.
For this reason, since the highest antiquity, we have developed cartography.
Satellite imagery and 3D display are among the most recent tools.
Introduction
The idea of a Sky/Earth interface that would reproduce the appearance of the celestial vault over any terrestrial environment (flat or uneven) in any epoch, past, present or future, was born in the 2000s, when I was completing the preparation of my doctoral thesis on the topic of Egyptian archaeoastronomy. In my opinion, such an interface would make it possible to immerse oneself in a past context which no more exists - by way of example,
- to observe the heliacal rising of the star Sirius from the site of Denderah in Middle Egypt, at the time when the Temple of Isis was being built (around 1250 BC),
- to explore the Old Kingdom pyramid field under a starry sky, some 2500 years BC,
- to determine the stars towards which various elements of the Nabta Playa megalithic complex in Upper Egypt were pointing circa 4500 BC, etc.
In other words, such an interface would make it possible to combine utility with pleasure: to marvel at a given environment while determining the astronomical source of orientation of various monuments - temples and tombs erected on both sides of the Nile Valley, in this case.
3D reconstruction of sunset on the Giza plateau in 2500 BC using the 5D Sky/Earth interface.
Fifteen years of experimentation ...
Fifteen years of diverse experimentation followed:
- the photographic exploration of the Occitanie Pyrénées/Méditerranée region, southern France, i.e. the search for the appropriate light for each site visited, using terrestrial maps and celestial planispheres. For a photographer, having such a Sky/Earth interface would make it possible to anticipate the light at a given location, and therefore to program the day and time of the on-site visit. This photograph of the Pic de Bugarach surmounted by the Milky Way was taken on a summer's night: for the shot to evoke a starburst, the gas and dust clouds of the Milky Way had to be visible at the top of the rocky peak, which presupposed a dark, moonless, cloudless sky, restricting observation possibilities to just a few summer nights. Many other shots in the PhotoExploration section required this kind of preparatory work.
- numerous tests of graphical interfaces developed by space agencies, private companies and groups of individuals. Some correctly represent the Earth's 3D surface, but surmount it with a timeless, immutable or even imaginary celestial vault. While others depict the contemporary celestial vault in motion above a three-dimensional fragment of the Earth, with varying degrees of spatial resolution, etc.
Eruption of stars on top of the Pic de Bugarach
Recent advances in graphics display, coupled with the availability of satellite data and images with ever-higher spatial resolutions from space agencies (NASA, ESA, JAXA), have made it possible to create this five-dimensional Sky/Earth interface: three dimensions represent the Earth's surface, one dimension is associated with the celestial vault, and the fifth dimension represents the time scale. Thanks to this graphical interface, it is now possible to walk on the surface of the Earth under a sunny, twilight or starry sky, in any era (historical, contemporary or futuristic).
An original and innovative Sky/Earth 5D interface
Early 2024 : the Sky/Earth 5D interface is nearing completion. Take a look at the first video sequences resulting from the use of this interface :
- in an archaeoastronomical context: the determination of the astronomical source of orientation of the pyramids of Giza in Egypt, whose construction dates back more than 4500 years.
- in a contemporary context (below): a sunset on La Reunion Island, observed from the ground and from Earth orbit.