Strasbourg: Riddles of the "green ray" solved?

Light phenomenon at the equinox is based on room installation of the old master builders

Always exactly at the equinox, this figure of the Crucified is illuminated by a green ray of sunshine. © Wiessmann / Bares
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Medieval Mystery: In Strasbourg Cathedral, at the very beginning of spring and autumn, a "green ray" appears directly on a figure of Christ at the pulpit. So far, this lighting effect was considered mere coincidence. But now a symbolic scientist proves: the medieval master builders deliberately arranged the stained-glass windows, the pulpit and the figure of Christ so that the green glow would come on for the equinox. The same applies to a "white ray" at the winter solstice.

Soon it will be time again: As always at the beginning of spring and autumn, Strasbourg's Liebfrauenmünster on 23 September will have a special phenomenon of light: around noon, a bright green light will shoot across the wide nave. It illuminates the crucifixes in succession and a few accompaniment figures on the late-Gothic Münsterkanzel dating from 1485. The winter solstice on 21 December is repeated with a spectacle - but then with a white instead of a green ray of light.

Green light of Judas shoe

But what about this lighting effect? This question has long been hotly debated: "While some suspect it to be an astrological symbol from the Middle Ages, the others claim that this is a modern, purely random phenomenon, " explains the symbolist and Oliver Wießmann. He has extensively researched the historical, religious and architectural background of the light effect.

One thing is clear: the green beam comes from one of the side windows that face the pulpit. In the glass mosaic of this church window, King Judah points to one of his green shoes while turning his head up towards the sun. It is the green shoe glass that produces the light beam twice a year for around 20 minutes. But is this just one of many random lighting effects of the colorful windows or an illumination with a deeper message?

Way and times of the green and white ray in Stra burger M nster Wie mann

Calibration tool for church clock?

The Stra mitburg surveying engineer Maurice Rosart first recognized and made known the connection with the quinquets in the 1970s. At that time, Rosart suspected a medieval measuring tool in the light effect for example for one of the large clocks in the church building. But officially, the effect is still considered a mere coincidence. The green shoe of Judah was even temporarily glued over in the 19th century to block the beam. display

Wie mann has now gathered evidence that the church builders of the Middle Ages had indeed intended the green ray and adapted their construction accordingly which was not uncommon for the time. "Such artificially produced light rays are often found in sacral architecture. Well-known, for example, is the light beam that appears on June 21 in Notre-Dame Cathedral of Chartres, "says Wie mann.

Astronomical cycles and the theology of the huts

The constructors themselves provided a clue: "In the Middle Ages, the buildings represented their own closed caste and are sovereign, " he explains. "Within

Their circles had a special tradition. There they preserved and nurtured a knowledge that today is called Ancient Theology and can sometimes be called gnosis. "In this theology nature, astronomy and their cycles played an important role.

Astronomical references: The M nster could be aligned in honor of the divine Maria on the constellation Virgo. Wie mann

The marking of astronomical significant dates such as the equinox or the solstice, but also the use of astrological-astronomical symbolism in church construction was therefore quite normal for the master builders of the Middle Ages. Indications that this was also the case at the Stra burger M nster can be found, among other things, in the decorations of the main portal, as Wie mann explains. In an extant document of the original pulpit design, there are already references to the green ray of light.

Moved axis

Striking also: The main axis of the cathedral is not, as usual, usually aligned exactly in east-west direction. Instead, it deviates 30 degrees from this direction. One of the motives of the cathedral architects for this deviation might have been to align the church with the Virgo Virgo Stern constellation, which they attributed to the Blessed Virgin Mary.

At the same time, only by doing so can the sun fall through the church feast at the equinox and produce the ray. A second stream of white light falls on the pulpit on the 21st of December, just like the winter solstice, and likewise illuminates the figures depicted on it like a pointer.

Proof that the green beam - contrary to previous assumptions - already existed in the Middle Ages, found Wießmann in old sermons and writings of Johann Geiler von Kaysersberg. The theologian for whom the pulpit was built referred in some of his speeches to the green ray. According to the symbolic scientist, therefore, there is a lot to say that the green ray is by no means a coincidence, but an old, deliberate room installation.

(Salier Verlag, 13.09.2018 - NPO)