The disc of Nebra
The superposition of gold leaf inlays and the origin of the gold used to decorate the disk let us think that its creation required four stages:
At the origin, the disc contained 32 small golden discs set in a star pattern, a waxing moon crescent and a wide disc in gold representing the full moon or the sun. The fact that 32 solar years (of 365 days) correspond to 33 lunar years (of 29.5×12 = 354 days) leads us to deduce that the central disc represents both lunar and solar forms.
A single cluster of stars can be distinguished among the small golden discs. Composed of 7 discs located between the crescent and the full moon, it evokes the 7 stars of the Pleiades visible to the naked eye. In contrast to the current era, the Pleiades constituted, at the Bronze Age, a distinct constellation from the Taurus.
In accordance with the Gregorian calendar and commentaries of the archaeologist Harald Meller and astronomer Wolfhard Schlosser, the moon and the Pleiades appeared together in the sky of the northern hemisphere twice a year. The Pleiades set on March 10th, shortly after the new moon preceding the full moon of spring and rose on October 17th at full moon of fall (consult the site
Himmelsscheibe von Nebra in German). They probably marked the cycle of sowing and harvesting in many societies of that era. Consequently, the Pleiades were visible from October 17th to March 10th, which corresponded to a length of 145 days out of the 365 days of the year (=0.4).
Next, two lateral golden arcs were added. To do this, a small golden disc on the left side was moved towards the right and two small golden discs on the right side were covered. The small golden discs were reduced to the number of 30 henceforth.
The lines joining the opposing ends of both arcs make an angle of 82°. This value corresponds to the angle formed by the diagonals of the “solstitial rectangle” determined by the position of the sunrise and sunset at solstices. This angle depends on the astronomical data of the era and the latitude of the place of the discovery of the disc (φ = 51.3°) 1.
Let us note that the diagonals of the rectangle intersect inside the wide golden disc that, in this case, no longer acts as the moon, but the sun.
The following modification consisted in adding a golden arc turned towards the Pleiades in the lower part of the disc. Now, this arc is inscribed in a circle, internally tangent to the disc and going through its centre. Moreover, it is seen from the centre of this circle at an angle about 145° out of 360° of the circumference of the circle it is inscribed in.
If we compare the length of the golden arc inscribed in the circle with the length of the visibility of the Pleiades during the year, we note that they represent a proportion close to 0.4. It follows that the relative length of the golden arc corresponds to the relative length of the visibility of the Pleiades in the sky of the northern hemisphere.
In other words, the meaning of the golden arc is firstly astronomical and not symbolic. Attaching the image of the “solar Boat” crossing the world of darkness to it does nothing but complete the astronomical meaning. In fact, symbols often rely on a representation of cosmic order to suggest a reality of supra-cosmic order.
The last stage of the realization of the disc consists in piercing its circumference with 39 or 40 equidistant holes. In fact, the damaged part of the edge of the disc could have contained one or two holes according to various authors. As the spacing between holes is not completely regular, they are probably more the outcome of an empirical process than an exact calculation. Nevertheless, such a calculation gives an average value of 2.58 cm (hypothesis 39 holes) or 2.51 cm (hypothesis 40 holes). Knowing that the current inch measures 2.54 cm, these values suggest the use of a unit of measure corresponding to the inch of the region at the Bronze Age 2.
While putting his thumb on the edge of the disc after a hole to mark the following one, the person, empowered to work on the disc, introduced a new approach to the astronomical location. The man crowned the geometrical representation with a digital one based on the choice of a unit of measure 3.
We can deduct from all this that each of these stages added something important to this authentic astronomical instrument. Its symbolism will appear more clearly with the study of the site of Goseck.
The site of Goseck
Beyond the winter solstice
The site of Goseck was composed of a series of concentric circles: two outer circles edging a ditch and two inner ones made of wooden palisades. Three sets of openings or gates formed part of the circles.
The examination of the site by the astronomer Wolfhard Schlosser, from the astronomical institute of the Rhineland University of Bochum, indicates that the two sets of gates oriented south-east and south-west corresponded to the sunrise and sunset at the winter solstice. The third set was oriented according to the meridian of the place, that means towards north (see the site
Kreisgrabenanlage von Goseck in German). The site was certainly used as astronomical observatory, but it was not its only function.
Unlike the disc of Nebra, the site does not explicitly refer to both winter and summer solstices; it only stresses the winter solstice and the northern direction. To understand why, it is sufficient to consider both phases of the annual cycle of the sun in the northern hemisphere. The winter solstice corresponds to the start of the ascending phase of the sun towards the celestial north pole whereas the summer solstice is associated with the beginning of the descending phase of the sun towards the celestial south pole 4 (For more details, see the description of the celestial sphere). To privilege the winter solstice means referring to the "highest in the skies".
The celestial north pole, situated at the intersection of the pole Axis with the celestial sphere, symbolizes the highest fixed point of the pole Axis around which the astral bodies of the cosmic world are apparently turning. It depicts an image of the supra-cosmic Principle from which the astral bodies are radiating. The Principle contains in a potential state all possibilities of manifestation (and non-manifestation).
The knowledge of the Principle and its manifestation was nevertheless not accessible to everyone. In fact, the observer standing at the centre of the site, at winter solstice, could turn either:
- Towards south and see the sunrise and sunset in the row of the southeast and southwest gates. Moreover, when the sun attained its zenith and was located in the meridian of the place, the celestial pole Axis was projected alongside the south north terrestrial axis;
- Or towards north in line with the third set of gates. He could, while looking up at the night sky, see the celestial north pole or the closest star. Then, he would be looking at the image of the motionless Principle at the origin of the cosmic world. The projection of the celestial north pole alongside the Axis coincided with the structure centre.
These two types of events had to be associated with distinct rites:
- When the observer turned towards south at winter solstice, during the shortest day of the year, he performed solar rites related to the manifested world;
- When the observer turned towards north, during the longest night of the year, he performed polar rites linked to the Principle at the source of the manifested world.
The solar rites, related to the world in movement, could only take place at winter solstice. The polar rites, linked to the motionless Principle, could on the contrary be carried out, beyond the winter solstice, all year around. The manifestation is changing and fleeting, its Principle is immutable.
The three circles of people
The solar rites focused on the cosmic, manifested, visible world and took place at day light. A large number of people must have been present.
The polar rites were, on the contrary, concerned with the supra-cosmic, non manifested, invisible world, domain of night. They had to be intended for a small group of people, guardians of the knowledge of the Principle synonym of the Whole.
Nevertheless, some of the solar rites concerned the sunset at winter solstice. They took place at twilight and could precede the polar rites. They must have been reserved for people called to fulfil intermediary functions between those of the population and those of the guardians of the knowledge.
The rites were probably associated with three circles of people:
- The ordinary beings stationed in the outer space edged by the ditch, which marked its limit;
- The intermediary beings standing in the space delimited by both wooden palisades and in charge of the application of the principles defined by the most restricted group;
- This group was only composed of beings nourished by the knowledge of the supra-cosmic Principle at the source of all beings and things. The group gathered in the inner-most space and, more precisely, in its centre.
As everything in the universe is a part of the Principle, the latter could only be universal and reflected within any manifested being or thing. The essential goal of the solar and polar rites was certainly to awake and maintain the harmony between the beings and the universe.
It follows that the three spaces associated with the three circles of people also reflected the three terrestrial, intermediary or atmospheric and celestial worlds. The site of Goseck constituted a true representation of the cosmos.
The disc of Nebra and the site of Goseck were without any doubt destined to take down astronomical measures for agricultural purposes. Moreover, stressing the winter solstice marked the end of the period of the harvests and storage in order to face the harshness of the cold season. This moment also represented the beginning of the ascent of the sun towards the celestial heights. It was therefore suitable to gather people around various rites in order to keep alive the deep links which united the beings to the cosmos and beyond.
1 back At the solstitial sunrise and sunset, the angle formed by one of the diagonals of the solstitial rectangle with the south north direction can be determined by the following formula (see the position on the celestial sphere):
cos a = - sin (δ)/cos(φ)
Where δ represents the value of the ecliptic or the angle formed by the orbit of the annual movement of earth around the sun with the terrestrial equator. Nowadays, δ = ±23.5° at the solstices and
a = cos-1 [sin(23.5°)/cos(51.3°)] = 50.4°
It follows that both diagonals of the solstitial rectangle make an angle of 2×(90°-50.4°) = 79.2°.
The gap between the Bronze Age and current data can partly be explained by the variations of the angle δ through the Ages.
2 back Knowing that the radius r of the disc is approximately 16 cm, the average length p of the arc separating two holes is given by:
P = 2πr/39 = 2π×16/39 = 2.58 (hypothesis 39 holes).
p = 2πr/40 = 2π×16/40 = 2.51 (hypothesis 40 holes);
These values are very close of the unit of measure of the current inch (2.54 cm).
3 back Let us see, indeed, how the other dimensions of the disc are expressed in that unit of measure.
Let us start with the length C of the lateral golden arc seen under an angle α of 82°:
C = rα = 2πr×82/360;
C/p = 39×82/360 = 8.9 (hypothesis 39 holes).
C/p = 40×82/360 = 9.1 (hypothesis 40 holes);
In other words, the lateral golden arc measures approximately 9 inches.
Let us follow with the golden arc turned towards the Pleiades and of radius r/2:
U = πr×145/360
U/p = (145/360)×(39/2) = 7.9 (hypothesis 39 holes).
U/p = (145/360)×(40/2) = 8.1 (hypothesis 40 holes);
It means that the length of the golden arc turned towards the Pleiades is close to 8 inches.
4 back An analogous correspondence exists with the monthly cycle of the waxing and waning moon.